Podcasts about rhinolophus

TWiV discusses a twice-yearly antiviral for prevention of AIDS, the WHO pandemic plan, West Nile resurgence in the US, the BANAL SARS-CoV-2 related viruses reproduce in human cells but do not transmit among animal hosts, and an amino acid change in dengue virus that enhances midgut replication in mosquitoes but reduces pathogenicity in humans. Hosts: Vincent Racaniello, Alan Dove, Rich Condit, and Kathy Spindler Subscribe (free): Apple Podcasts, Google Podcasts, RSS, email Become a patron of TWiV! Links for this episode MicrobeTV Discord Server PrEP with HIV-1 capsid inhibitor (NEJM) WHO pandemic plan (pdf) West Nile virus resurgence in US (NY Times) Properties of BANAL SARS-CoV-2 like viruses (Nat Micro) BANAL viruses on TWiV 809 Different effect of dengue virus amino acid change in humans and mosquitoes (Sci Transl Med) Eng Ong Ooi on TWiV 633 Letters read on TWiV 1137 Timestamps by Jolene. Thanks! Weekly Picks Kathy – Using big data to improve traffic light timing Rich – Dillo Dirt Alan – Dueling Banjos on banjo and kora Vincent – The world's most expensive dinosaur and more Listener Pick Mike – Science through a glass darkly Lisa – On A Mission“ Season Four Intro music is by Ronald Jenkees Send your virology questions and comments to twiv@microbe.tv Content in this podcast should not be construed as medical advice.

We have a special guest, Dr. Winnifred Frick, chief scientist of Bat Conservation International. The Hill's horseshoe bat, Rhinolophus hilli, had been feared extinct, as neither hair nor wing has been seen for forty years. But after a 5 year period of survey efforts, Bat Conservation International, and the Rwanda Wildlife Conservation Association, spotted a bat with an incredibly strange looking face...  Hill's Horseshoe bat rediscovery link: https://www.wildlifeacoustics.com/resources/blog/conservationists-announce-the-rediscovery-of-an-african-bat-species-lost-for-40-years See omnystudio.com/listener for privacy information.

Do you hear what I hear? Well that depends; are a human, a bat or a moth. In comparison, humans really suck as hearing.In our 30th episode, we finish up our five week journey into the five senses with hearing! And the two animals with the best hearing have been in competition with each other over who has the best hearing for the last 50 million years. The bats and moths! Bats need to eat and the most want to live another day! Who will win this great battle? Will we be around to watch it's end? Will there be an end? And what does hearing have to do with the great Bat/Moth War?As both animals of this episode not only have excellent hearing, it also allows them to be some of the best echolocators. By practically yelling so to capture their own echo and allowing their ears to process the vibrations, bats and moths can see the word though their own voices and the sounds of the world. And they are very good at it. Listen in to find out how.Scientific names:Rhinolophus ferrumequinum: Greater horseshoe bat Rhinolophus hipposideros: Lesser horseshoe bat Galleria mellonelila: Greater wax moth Achroia grisella: Lesser wax mothTo help bats further consider donating to Bat Conservation International!https://www.batcon.org/Or build a bat box!Instagram @wafpodcastTwitter @ExplicitWeirdYouTube: https://www.youtube.com/channel/UC8X57p2y-c7S8evAriKTn0wEmail: wafpodcastexplicit@gmail.com

If a bat eats a different species of bat for dinner, is that considered bat-cannibalism? Amber and Jennifer are divided on the answer in this week's episode on the horeshoe bat, so it's up to you to be to the tie-breaker!In current events, we call out Mike Pence and Trump for refusing to wear face masks during a global pandemic. Speaking of Covid-19, scientists have traced the origin to ... the horesehoe bat. However, just because the horeshoe bat is the original host, does NOT mean that bats caused the pandemic. While bats may not be the cause, we can help prevent the transfer of viruses by decreasing our interactions with wild animals. Never touch a wild animal! (Not sure why so many people need to be told that.) If you do, the animal might have to be killed to do a brain biopsy, what Jennifer called a brainopsy... True that, right Amber? Hashtag #ifitdriesitdies Listen as Jennifer and Amber lay down the facts of these adorable bats who epitomize evolution, at least in terms of navigation and bug hunting. They also explore the use of horsehoe bats in traditional medicine, including rubbing bat feces into one's eyes. Because someone ... thought that was good idea. The serial pig killer mentioned is Robert Pickton. Want to know why we bring him up, or want to know more about him? Then enjoy this week's episode of Better Than Human. Additional Link for this week's episode: A million tons of feces and an unbearable stench: life near industrial pig farms https://www.theguardian.com/us-news/2017/sep/20/north-carolina-hog-industry-pig-farmsFollow us on Twitter @betterthanhuma1on Facebook @betterthanhumanpodcaston Instagram @betterthanhumanpodcastEmail us at betterthanhumanpodcast@gmail.com or check out our website betterthanhumanpodcast.comWe look forward to hearing from you, and we look forward to you joining our cult of weirdness!#betterthanhuman #cultofweirdness #ifitdriesitdies

I Found The Source of the Coronavirus.Watch this video at- https://www.youtube.com/watch?v=bpQFCcSI0pU&feature=youtu.belaowhy86Hey Laowinners, After 2 weeks of painstaking searching, I refute the claim that the Coronavirus started outside of China. ◘ Support me on Patreon for early release, and much more! http://www.patreon.com/laowhy86 ◘ Donate and support this channel through Paypal http://paypal.me/cmilkrun ◘ OR Become a Sponsor on YouTube: https://www.youtube.com/channel/UChvi... Thanks to Snarky Guy for the footage - Check his China channel here - https://www.youtube.com/channel/UCaUl... ◘ My TV show: Conquering Northern China: https://vimeo.com/ondemand/conquering... ◘ Conquering Southern China https://vimeo.com/ondemand/conquering... ◘ Discount code for both shows: laowinning ◘ Join me every week for videos about China! Don't forget to subscribe! http://www.youtube.com/laowhy86 Be a Laowinner! Like comment subscribe! ◘ Facebook: http://www.facebook.com/laowhy86 ◘ Instagram: http://instagram.com/laowhy86 Music in this video - The Muse Maker https://soundcloud.com/themusemaker ◘ Music used most of the time - New World Hip Hop https://soundcloud.com/apollodrivenz https://www.youtube.com/channel/UCgir... Links for proof: http://www.whiov.cas.cn/105341/ http://www.whiov.cas.cn/105341/201911... http://www.whiov.cas.cn/105341/201912... http://159.226.126.127:8082/web/17190/20 http://159.226.126.127:8082/web/17190/46 http://gd.whiov.cas.cn/zxpy/yjsswgg/2... http://rfi.my/5OFG http://rfi.my/5OSZ http://gd.whiov.cas.cn/tzgg/201111/t2... http://www.whiov.ac.cn/tzgg_105342/20... http://blog.creaders.net/u/3027/20200... https://www.backchina.com/blog/261460... http://www.bjnews.com.cn/news/2020/02... https://bbs.pku.edu.cn/v2/post-read.p... Article Mentioned- https://www.nationalreview.com/2020/04/coronavirus-china-trail-leading-back-to-wuhan-labs/The Trail Leading Back to the Wuhan LabsBy Jim GeraghtyApril 3, 2020 1:20 PM  Medical workers in protective suits attend to a patient inside an isolated ward of the Wuhan Red Cross Hospital in Wuhan, the epicenter of the novel coronavirus outbreak, in Hubei Province, China, February 16, 2020. (China Daily via Reuters)There’s no proof the coronavirus accidentally escaped from a laboratory, but we can’t take the Chinese government’s denials at face value.It is understandable that many would be wary of the notion that the origin of the coronavirus could be discovered by some documentary filmmaker who used to live in China. Matthew Tye, who creates YouTube videos, contends he has identified the source of the coronavirus — and a great deal of the information that he presents, obtained from public records posted on the Internet, checks out. The Wuhan Institute of Virology in China indeed posted a job opening on November 18, 2019, “asking for scientists to come research the relationship between the coronavirus and bats.” The Google translation of the job posting is: “Taking bats as the research object, I will answer the molecular mechanism that can coexist with Ebola and SARS- associated coronavirus for a long time without disease, and its relationship with flight and longevity. Virology, immunology, cell biology, and multiple omics are used to compare the differences between humans and other mammals.” (“Omics” is a term for a subfield within biology, such as genomics or glycomics.) On December 24, 2019, the Wuhan Institute of Virology posted a second job posting. The translation of that posting includes the declaration, “long-term research on the pathogenic biology of bats carrying important viruses has confirmed the origin of bats of major new human and livestock infectious diseases such as SARS and SADS, and a large number of new bat and rodent new viruses have been discovered and identified.” Tye contends that that posting meant, “we’ve discovered a new and terrible virus, and would like to recruit people to come deal with it.” He also contends that “news didn’t come out about coronavirus until ages after that.” Doctors in Wuhan knew that they were dealing with a cluster of pneumonia cases as December progressed, but it is accurate to say that a very limited number of people knew about this particular strain of coronavirus and its severity at the time of that job posting. By December 31, about three weeks after doctors first noticed the cases, the Chinese government notified the World Health Organization and the first media reports about a “mystery pneumonia” appeared outside China. Scientific American verifies much of the information Tye mentions about Shi Zhengli, the Chinese virologist nicknamed “Bat Woman” for her work with that species. Shi — a virologist who is often called China’s “bat woman” by her colleagues because of her virus-hunting expeditions in bat caves over the past 16 years — walked out of the conference she was attending in Shanghai and hopped on the next train back to Wuhan. “I wondered if [the municipal health authority] got it wrong,” she says. “I had never expected this kind of thing to happen in Wuhan, in central China.” Her studies had shown that the southern, subtropical areas of Guangdong, Guangxi and Yunnan have the greatest risk of coronaviruses jumping to humans from animals — particularly bats, a known reservoir for many viruses. If coronaviruses were the culprit, she remembers thinking, “could they have come from our lab?” . . . By January 7 the Wuhan team determined that the new virus had indeed caused the disease those patients suffered — a conclusion based on results from polymerase chain reaction analysis, full genome sequencing, antibody tests of blood samples and the virus’s ability to infect human lung cells in a petri dish. The genomic sequence of the virus — now officially called SARS-CoV-2 because it is related to the SARS pathogen — was 96 percent identical to that of a coronavirus the researchers had identified in horseshoe bats in Yunnan, they reported in a paper published last month in Nature. “It’s crystal clear that bats, once again, are the natural reservoir,” says Daszak, who was not involved in the study. Some scientists aren’t convinced that the virus jumped straight from bats to human beings, but there are a few problems with the theory that some other animal was an intermediate transmitter of COVID-19 from bats to humans: Analyses of the SARS-CoV-2 genome indicate a single spillover event, meaning the virus jumped only once from an animal to a person, which makes it likely that the virus was circulating among people before December. Unless more information about the animals at the Wuhan market is released, the transmission chain may never be clear. There are, however, numerous possibilities. A bat hunter or a wildlife trafficker might have brought the virus to the market. Pangolins happen to carry a coronavirus, which they might have picked up from bats years ago, and which is, in one crucial part of its genome, virtually identical to SARS-CoV-2. But no one has yet found evidence that pangolins were at the Wuhan market, or even that venders there trafficked pangolins. On February 4 — one week before the World Health Organization decided to officially name this virus “COVID-19” — the journal Cell Research posted a notice written by scientists at the Wuhan Institute of Virology about the virus, concluding, “our findings reveal that remdesivir and chloroquine are highly effective in the control of 2019-nCoV infection in vitro. Since these compounds have been used in human patients with a safety track record and shown to be effective against various ailments, we suggest that they should be assessed in human patients suffering from the novel coronavirus disease.” One of the authors of that notice was the “bat woman,” Shi Zhengli. In his YouTube video, Tye focuses his attention on a researcher at the Wuhan Institute of Virology named Huang Yanling: “Most people believe her to be patient zero, and most people believe she is dead.” There was enough discussion of rumors about Huang Yanling online in China to spur an official denial. On February 16, the Wuhan Institute of Virology denied that patient zero was one of their employees, and interestingly named her specifically: “Recently there has been fake information about Huang Yanling, a graduate from our institute, claiming that she was patient zero in the novel coronavirus.” Press accounts quote the institute as saying, “Huang was a graduate student at the institute until 2015, when she left the province and had not returned since. Huang was in good health and had not been diagnosed with disease, it added.” None of her publicly available research papers are dated after 2015. The web page for the Wuhan Institute of Virology’s Lab of Diagnostic Microbiology does indeed still have “Huang Yanling” listed as a 2012 graduate student, and her picture and biography appear to have been recently removed — as have those of two other graduate students from 2013, Wang Mengyue and Wei Cuihua. Her name still has a hyperlink, but the linked page is blank. The pages for Wang Mengyue and Wei Cuihua are blank as well. (For what it is worth, the South China Morning Post — a newspaper seen as being generally pro-Beijing — reported on March 13 that “according to the government data seen by the Post, a 55 year-old from Hubei province could have been the first person to have contracted Covid-19 on November 17.”) On February 17, Zhen Shuji, a Hong Kong correspondent from the French public-radio service Radio France Internationale, reported: “when a reporter from the Beijing News of the Mainland asked the institute for rumors about patient zero, the institute first denied that there was a researcher Huang Yanling, but after learning that the name of the person on the Internet did exist, acknowledged that the person had worked at the firm but has now left the office and is unaccounted for.” Tye says, “everyone on the Chinese internet is searching for [Huang Yanling] but most believe that her body was quickly cremated and the people working at the crematorium were perhaps infected as they were not given any information about the virus.” (The U.S. Centers for Disease Control and Prevention says that handling the body of someone who has died of coronavirus is safe — including embalming and cremation — as long as the standard safety protocols for handing a decedent are used. It’s anyone’s guess as to whether those safety protocols were sufficiently used in China before the outbreak’s scope was known.) As Tye observes, a public appearance by Huang Yanling would dispel a lot of the public rumors, and is the sort of thing the Chinese government would quickly arrange in normal circumstances — presuming that Huang Yanling was still alive. Several officials at the Wuhan Institute of Virology issued public statements that Huang was in good health and that no one at the institute has been infected with COVID-19. In any case, the mystery around Huang Yanling may be moot, but it does point to the lab covering up something about her. China Global Television Network, a state-owned television broadcaster, illuminated another rumor while attempting to dispel it in a February 23 report entitled “Rumors Stop With the Wise”: On February 17, a Weibo user who claimed herself to be Chen Quanjiao, a researcher at the Wuhan Institute of Virology, reported to the public that the Director of the Institute was responsible for leaking the novel coronavirus. The Weibo post threw a bomb in the cyberspace and the public was shocked. Soon Chen herself stepped out and declared that she had never released any report information and expressed great indignation at such identity fraud on Weibo. It has been confirmed that that particular Weibo account had been shut down several times due to the spread of misinformation about COVID-19. That Radio France Internationale report on February 17 also mentioned the next key part of the Tye’s YouTube video. “Xiaobo Tao, a scholar from South China University of Technology, recently published a report that researchers at Wuhan Virus Laboratory were splashed with bat blood and urine, and then quarantined for 14 days.” HK01, another Hong Kong-based news site, reported the same claim. This doctor’s name is spelled in English as both “Xiaobo Tao” and “Botao Xiao.” From 2011 to 2013, Botao Xiao was a postdoctoral research fellow at Harvard Medical School and Boston Children’s Hospital, and his biography is still on the web site of the South China University of Technology. At some point in February, Botao Xiao posted a research paper onto ResearchGate.net, “The Possible Origins of 2019-nCoV coronavirus.” He is listed as one author, along with Lei Xiao from Tian You Hospital, which is affiliated with the Wuhan University of Science and Technology. The paper was removed a short time after it was posted, but archived images of its pages can be found here and here. The first conclusion of Botao Xiao’s paper is that the bats suspected of carrying the virus are extremely unlikely to be found naturally in the city, and despite the stories of “bat soup,” they conclude that bats were not sold at the market and were unlikely to be deliberately ingested. The bats carrying CoV ZC45 were originally found in Yunnan or Zhejiang province, both of which were more than 900 kilometers away from the seafood market. Bats were normally found to live in caves and trees. But the seafood market is in a densely-populated district of Wuhan, a metropolitan [area] of ~15 million people. The probability was very low for the bats to fly to the market. According to municipal reports and the testimonies of 31 residents and 28 visitors, the bat was never a food source in the city, and no bat was traded in the market. The U.S. Centers for Disease Control and Prevention and the World Health Organization could not confirm if bats were present at the market. Botao Xiao’s paper theorizes that the coronavirus originated from bats being used for research at either one of two research laboratories in Wuhan. We screened the area around the seafood market and identified two laboratories conducting research on bat coronavirus. Within ~ 280 meters from the market, there was the Wuhan Center for Disease Control & Prevention. WHCDC hosted animals in laboratories for research purpose, one of which was specialized in pathogens collection and identification. In one of their studies, 155 bats including Rhinolophus affinis were captured in Hubei province, and other 450 bats were captured in Zhejiang province. The expert in Collection was noted in the Author Contributions (JHT). Moreover, he was broadcasted for collecting viruses on nation-wide newspapers and websites in 2017 and 2019. He described that he was once by attacked by bats and the blood of a bat shot on his skin. He knew the extreme danger of the infection so he quarantined himself for 14 days. In another accident, he quarantined himself again because bats peed on him. Surgery was performed on the caged animals and the tissue samples were collected for DNA and RNA extraction and sequencing. The tissue samples and contaminated trashes were source of pathogens. They were only ~280 meters from the seafood market. The WHCDC was also adjacent to the Union Hospital (Figure 1, bottom) where the first group of doctors were infected during this epidemic. It is plausible that the virus leaked around and some of them contaminated the initial patients in this epidemic, though solid proofs are needed in future study. The second laboratory was ~12 kilometers from the seafood market and belonged to Wuhan Institute of Virology, Chinese Academy of Sciences . . . In summary, somebody was entangled with the evolution of 2019-nCoV coronavirus. In addition to origins of natural recombination and intermediate host, the killer coronavirus probably originated from a laboratory in Wuhan. Safety level may need to be reinforced in high risk biohazardous laboratories. Regulations may be taken to relocate these laboratories far away from city center and other densely populated places. However, Xiao has told the Wall Street Journal that he has withdrawn his paper. “The speculation about the possible origins in the post was based on published papers and media, and was not supported by direct proofs,” he said in a brief email on February 26. The bat researcher that Xiao’s report refers to is virologist Tian Junhua, who works at the Wuhan Centre for Disease Control. In 2004, the World Health Organization determined that an outbreak of the SARS virus had been caused by two separate leaks at the Chinese Institute of Virology in Beijing. The Chinese government said that the leaks were a result of “negligence” and the responsible officials had been punished. In 2017, the Chinese state-owned Shanghai Media Group made a seven-minute documentary about Tian Junhua, entitled “Youth in the Wild: Invisible Defender.” Videographers followed Tian Junhua as he traveled deep into caves to collect bats. “Among all known creatures, the bats are rich with various viruses inside,” he says in Chinese. “You can find most viruses responsible for human diseases, like rabies virus, SARS, and Ebola. Accordingly, the caves frequented by bats became our main battlefields.” He emphasizes, “bats usually live in caves humans can hardly reach. Only in these places can we find the most ideal virus vector samples.” One of his last statements on the video is: “In the past ten-plus years, we have visited every corner of Hubei Province. We explored dozens of undeveloped caves and studied more than 300 types of virus vectors. But I do hope these virus samples will only be preserved for scientific research and will never be used in real life. Because humans need not only the vaccines, but also the protection from the nature.” The description of Tian Junhua’s self-isolation came from a May 2017 report by Xinhua News Agency, repeated by the Chinese news site JQKNews.com: The environment for collecting bat samples is extremely bad. There is a stench in the bat cave. Bats carry a large number of viruses in their bodies. If they are not careful, they are at risk of infection. But Tian Junhua is not afraid to go to the mountain with his wife to catch Batman. Tian Junhua summed up the experience that the most bats can be caught by using the sky cannon and pulling the net. But in the process of operation, Tian Junhua forgot to take protective measures. Bat urine dripped on him like raindrops from the top. If he was infected, he could not find any medicine. It was written in the report. The wings of bats carry sharp claws. When the big bats are caught by bat tools, they can easily spray blood. Several times bat blood was sprayed directly on Tians skin, but he didn’t flinch at all. After returning home, Tian Junhua took the initiative to isolate for half a month. As long as the incubation period of 14 days does not occur, he will be lucky to escape, the report said. Bat urine and blood can carry viruses. How likely is it that bat urine or blood got onto a researcher at either Wuhan Center for Disease Control & Prevention or the Wuhan Institute of Virology? Alternatively, what are the odds that some sort of medical waste or other material from the bats was not properly disposed of, and that was the initial transmission vector to a human being? 14Virologists have been vehemently skeptical of the theory that COVID-19 was engineered or deliberately constructed in a laboratory; the director of the National Institutes of Health has written that recent genomic research “debunks such claims by providing scientific evidence that this novel coronavirus arose naturally.” And none of the above is definitive proof that COVID-19 originated from a bat at either the Wuhan Center for Disease Control & Prevention or the Wuhan Institute of Virology. Definitive proof would require much broader access to information about what happened in those facilities in the time period before the epidemic in the city. But it is a remarkable coincidence that the Wuhan Institute of Virology was researching Ebola and SARS-associated coronaviruses in bats before the pandemic outbreak, and that in the month when Wuhan doctors were treating the first patients of COVID-19, the institute announced in a hiring notice that “a large number of new bat and rodent new viruses have been discovered and identified.” And the fact that the Chinese government spent six weeks insisting that COVID-19 could not be spread from person to person means that its denials about Wuhan laboratories cannot be accepted without independent verification. JIM GERAGHTY is the senior political correspondent of National Review. @jimgeraghty

The un-encapsidated TWiV Humans discuss finding hepatitis D virus-related sequences in birds and snakes, and fatal swine acute diarrhoea syndrome caused by a coronavirus of bat origin. Hosts: Vincent Racaniello, Dickson Despommier, Alan Dove, Rich Condit, and Kathy Spindler Subscribe (free): iTunes, Google Podcasts, RSS, email Become a patron of TWiV! Links for this episode European Virus Archive ASV early bird registrationends 15 May FDA approves Dengvaxia Divergent hepatitis D-like agentin birds(Viruses) Novel deltavirus in snakes(mBio) SADS-coronavirusin piglets (Nature) Hosts and sources of endemic human coronaviruses(Adv Virus Res) Image credit Letters readon TWiV 546 Timestamps by Jolene. Thanks! This episode is sponsored by the 2019 Chem/Bio Defense Science and Technology Conference. Are you working on innovative research that can shape the future of chemical or biological defense? Submit your abstract and present your work to more than 1,500 leaders from government, academia and industry. Visit www.cbdstconference.com for more details. Weekly Science Picks Alan - Plots of Data visualization tool Rich - How to control the brain; Meet UF Physician Kelly Foote, MD Dickson- Oceanix Kathy- Iceproofing large structures Vincent - Neanderthal Man: In Search of Lost Genomes by Svante Paabo Listener Pick Johyne- NYTimes Mag Lab (sorry, no link) Sheena - History of Vaccines by NPR Intro music is by Ronald Jenkees. Send your virology questions and comments to twiv@microbe.tv

The un-encapsidated TWiV Humans discuss finding hepatitis D virus-related sequences in birds and snakes, and fatal swine acute diarrhoea syndrome caused by a coronavirus of bat origin. Hosts: Vincent Racaniello, Dickson Despommier, Alan Dove, Rich Condit, and Kathy Spindler Subscribe (free): iTunes, Google Podcasts, RSS, email Become a patron of TWiV! Links for this episode European Virus Archive ASV early bird registrationends 15 May FDA approves Dengvaxia Divergent hepatitis D-like agentin birds(Viruses) Novel deltavirus in snakes(mBio) SADS-coronavirusin piglets (Nature) Hosts and sources of endemic human coronaviruses(Adv Virus Res) Image credit Letters readon TWiV 546 Timestamps by Jolene. Thanks! This episode is sponsored by the 2019 Chem/Bio Defense Science and Technology Conference. Are you working on innovative research that can shape the future of chemical or biological defense? Submit your abstract and present your work to more than 1,500 leaders from government, academia and industry. Visit www.cbdstconference.com for more details. Weekly Science Picks Alan - Plots of Data visualization tool Rich - How to control the brain; Meet UF Physician Kelly Foote, MD Dickson- Oceanix Kathy- Iceproofing large structures Vincent - Neanderthal Man: In Search of Lost Genomes by Svante Paabo Listener Pick Johyne- NYTimes Mag Lab (sorry, no link) Sheena - History of Vaccines by NPR Intro music is by Ronald Jenkees. Send your virology questions and comments to twiv@microbe.tv

Watch Video | Listen to the AudioGWEN IFILL: Next: As we have seen with recent pandemics, emerging diseases like Zika and Ebola can cross continents and oceans with uncontrolled speed. Scientists are identifying areas where new infectious diseases are most likely to emerge, where there are high risks of animal viruses passing to humans. One of those areas is Southern China. Hari Sreenivasan brings us this report, which was produced in collaboration with Global Health Frontiers. DR. PETER DASZAK, President, EcoHealth Alliance: We’re in Guilin in Southern China, in one of the most beautiful parts of China with these amazing limestone hills and valleys and very scenic and picturesque. HARI SREENIVASAN: Peter Daszak is the president of EcoHealth Alliance, a nonprofit organization based in New York dedicated to protecting wildlife and public health from the emergence of disease. DR. PETER DASZAK: The reason we’re here is, we’re interested in the risk of new diseases emerging out of the wildlife trade in China, just like SARS did a few years ago and just like ultimately HIV did in Africa 40-odd years ago. If we can get to the source of where they come from and reduce the risk, we could solve a huge problem and save millions of lives, rather than waiting for them to emerge and try to mop it up afterwards. HARI SREENIVASAN: At markets across China, like this one, people come in daily to buy chickens and ducks. DR. PETER DASZAK: It increases the risk of a pathogen like avian flu from spreading, because you have got live chickens. If one of them is infected, it brings the virus in, and it spreads to this flock over a few hours, and then those animals are taken to all distant parts of the region. Now, you could see this activity anywhere in the world. This is just like what happens in rural America and rural parts of Europe. But the difference is, here, we’re in a hot zone for emerging diseases. This is a place where we have repeatedly seen outbreaks from poultry moving into people and spreading globally. HARI SREENIVASAN: Natural habitats can also contribute to the spread of viruses. DR. PETER DASZAK: We have got people fishing in the river. We have got people washing in the river. We know there is sewage coming directly from the houses into the river. There is not much wildlife here, but wild ducks will come down to this river as well and mix in and migrate with the viruses and spread them backwards and forwards into this mix. It’s a big mixing vessel for pathogens. HARI SREENIVASAN: At a goose farm, Daszak and his team are looking for signs of avian flu. DR. PETER DASZAK: The idea is that, if we can catch the viruses they carry here, we can prevent them going to market and potentially spreading the disease. OK, ready. We take swabs from the mouth, and we take cloacal swabs. We put them in viral transport medium and then ship them in liquid nitrogen to the lab for testing. Avian flu is a virus that’s common in many types of birds. But especially in poultry and waterfowl, it’s a real killer. And some of these strains can also jump directly into people. So that’s the problem. HARI SREENIVASAN: Viruses that can cross over and infect humans have led to previous pandemics, including the most devastating in recorded world history, the 1918 flu, which killed more people than the First World War, more than 500 million infected worldwide, and as many as 100 million deaths over a two-year period. DR. PETER DASZAK: We’re trying to say, where is the next avian flu going to come from? Can we see it before it becomes a pandemic problem and stop it? There you go. I look at this a little bit like earthquakes. We know earthquakes can be devastating. We know they’re pretty rare, and we know where they happen. So, this is the same for pandemics. We know that this is a hot spot for pandemics. We know why it happens, but what we’re not doing with pandemics that we are doing with earthquakes is reducing the damage initially. This has been going on for 5,000 years. HARI SREENIVASAN: Working with EcoHealth Alliance in this part of China is field operations manager Dr. Guangjian Zhu, a biologist trained in the ecology of bats, which are known to be the source of the SARS virus. DR. GUANGJIAN ZHU, Field Operations Manager: It’s really urgent to teach people how to deal with the virus and just change our normal behavior to decrease the risk of virus transfer. DR. PETER DASZAK: This is a big tourist cave. Shall we go? HARI SREENIVASAN: Daszak is concerned about a bat cave that is a popular tourist destination. DR. PETER DASZAK: You have got the Rhinolophus horseshoe bats right here in this cave with all these tourists going through. DR. GUANGJIAN ZHU: Yes. DR. PETER DASZAK: Yes. The bats here in this cave are the same bats that carry SARS virus. Bats live in the cave all day long, because they’re nocturnal. And when they’re up there, they urinate and defecate, right on top of the tourists that are walking through. And all you have got to do is be that one person to breathe in at the wrong time, and suddenly you have been infected with a virus that is not only potentially lethal to people. It could cause a future pandemic. We sent you the samples from these bats. HARI SREENIVASAN: Daszak and his team have used mathematical models to try to understand what is driving these diseases. DR. PETER DASZAK: We went back to every known example of emerging disease, HIV, Ebola, West Nile virus, SARS, plotted where it originated. And we said, what are the things that are going on in those places? The two big drivers are growing human populations, land use change, and high wildlife diversity. HARI SREENIVASAN: Rapid global response to disease outbreaks is essential to stopping transmission and saving lives. But Daszak and his team of virus hunters believe that forecasting where outbreaks are most likely to occur is a critical part of a defensive strategy needed to prevent outbreaks before they emerge. For the “PBS NewsHour,” I’m Hari Sreenivasan. The post Why southern China is a hotbed for disease development appeared first on PBS NewsHour.

Watch Video | Listen to the AudioGWEN IFILL: Next: As we have seen with recent pandemics, emerging diseases like Zika and Ebola can cross continents and oceans with uncontrolled speed. Scientists are identifying areas where new infectious diseases are most likely to emerge, where there are high risks of animal viruses passing to humans. One of those areas is Southern China. Hari Sreenivasan brings us this report, which was produced in collaboration with Global Health Frontiers. DR. PETER DASZAK, President, EcoHealth Alliance: We’re in Guilin in Southern China, in one of the most beautiful parts of China with these amazing limestone hills and valleys and very scenic and picturesque. HARI SREENIVASAN: Peter Daszak is the president of EcoHealth Alliance, a nonprofit organization based in New York dedicated to protecting wildlife and public health from the emergence of disease. DR. PETER DASZAK: The reason we’re here is, we’re interested in the risk of new diseases emerging out of the wildlife trade in China, just like SARS did a few years ago and just like ultimately HIV did in Africa 40-odd years ago. If we can get to the source of where they come from and reduce the risk, we could solve a huge problem and save millions of lives, rather than waiting for them to emerge and try to mop it up afterwards. HARI SREENIVASAN: At markets across China, like this one, people come in daily to buy chickens and ducks. DR. PETER DASZAK: It increases the risk of a pathogen like avian flu from spreading, because you have got live chickens. If one of them is infected, it brings the virus in, and it spreads to this flock over a few hours, and then those animals are taken to all distant parts of the region. Now, you could see this activity anywhere in the world. This is just like what happens in rural America and rural parts of Europe. But the difference is, here, we’re in a hot zone for emerging diseases. This is a place where we have repeatedly seen outbreaks from poultry moving into people and spreading globally. HARI SREENIVASAN: Natural habitats can also contribute to the spread of viruses. DR. PETER DASZAK: We have got people fishing in the river. We have got people washing in the river. We know there is sewage coming directly from the houses into the river. There is not much wildlife here, but wild ducks will come down to this river as well and mix in and migrate with the viruses and spread them backwards and forwards into this mix. It’s a big mixing vessel for pathogens. HARI SREENIVASAN: At a goose farm, Daszak and his team are looking for signs of avian flu. DR. PETER DASZAK: The idea is that, if we can catch the viruses they carry here, we can prevent them going to market and potentially spreading the disease. OK, ready. We take swabs from the mouth, and we take cloacal swabs. We put them in viral transport medium and then ship them in liquid nitrogen to the lab for testing. Avian flu is a virus that’s common in many types of birds. But especially in poultry and waterfowl, it’s a real killer. And some of these strains can also jump directly into people. So that’s the problem. HARI SREENIVASAN: Viruses that can cross over and infect humans have led to previous pandemics, including the most devastating in recorded world history, the 1918 flu, which killed more people than the First World War, more than 500 million infected worldwide, and as many as 100 million deaths over a two-year period. DR. PETER DASZAK: We’re trying to say, where is the next avian flu going to come from? Can we see it before it becomes a pandemic problem and stop it? There you go. I look at this a little bit like earthquakes. We know earthquakes can be devastating. We know they’re pretty rare, and we know where they happen. So, this is the same for pandemics. We know that this is a hot spot for pandemics. We know why it happens, but what we’re not doing with pandemics that we are doing with earthquakes is reducing the damage initially. This has been going on for 5,000 years. HARI SREENIVASAN: Working with EcoHealth Alliance in this part of China is field operations manager Dr. Guangjian Zhu, a biologist trained in the ecology of bats, which are known to be the source of the SARS virus. DR. GUANGJIAN ZHU, Field Operations Manager: It’s really urgent to teach people how to deal with the virus and just change our normal behavior to decrease the risk of virus transfer. DR. PETER DASZAK: This is a big tourist cave. Shall we go? HARI SREENIVASAN: Daszak is concerned about a bat cave that is a popular tourist destination. DR. PETER DASZAK: You have got the Rhinolophus horseshoe bats right here in this cave with all these tourists going through. DR. GUANGJIAN ZHU: Yes. DR. PETER DASZAK: Yes. The bats here in this cave are the same bats that carry SARS virus. Bats live in the cave all day long, because they’re nocturnal. And when they’re up there, they urinate and defecate, right on top of the tourists that are walking through. And all you have got to do is be that one person to breathe in at the wrong time, and suddenly you have been infected with a virus that is not only potentially lethal to people. It could cause a future pandemic. We sent you the samples from these bats. HARI SREENIVASAN: Daszak and his team have used mathematical models to try to understand what is driving these diseases. DR. PETER DASZAK: We went back to every known example of emerging disease, HIV, Ebola, West Nile virus, SARS, plotted where it originated. And we said, what are the things that are going on in those places? The two big drivers are growing human populations, land use change, and high wildlife diversity. HARI SREENIVASAN: Rapid global response to disease outbreaks is essential to stopping transmission and saving lives. But Daszak and his team of virus hunters believe that forecasting where outbreaks are most likely to occur is a critical part of a defensive strategy needed to prevent outbreaks before they emerge. For the “PBS NewsHour,” I’m Hari Sreenivasan. The post Why southern China is a hotbed for disease development appeared first on PBS NewsHour.

This study investigated the representation of acoustic motion in different fields of auditory cortex of the rufous horseshoe bat, Rhinolophus rouxi. Motion in horizontal direction (azimuth) was simulated using successive stimuli with dynamically changing interaural intensity differences presented via earphones. The mechanisms underlying a specific sensitivity of neurons to the direction of motion were investigated using microiontophoretic application of γ-aminobutyric acid (GABA) and the GABAA receptor antagonist bicuculline methiodide (BMI). In the first part of the study, responses of a total of 152 neurons were recorded. Seventy-one percent of sampled neurons were motion-direction sensitive. Two types of responses could be distinguished. Thirty-four percent of neurons showed a directional preference exhibiting stronger responses to one direction of motion. Fifty-seven percent of neurons responded with a shift of spatial receptive field position depending on the direction of motion. Both effects could occur in the same neuron depending on the parameters of apparent motion. Most neurons with contralateral receptive fields exhibited directional preference only with motion entering the receptive field from the opposite direction (i.e. the ipsilateral part of the azimuth). Receptive field shifts were opposite to the direction of motion. Specific combinations of spatio-temporal parameters determined the motion-direction-sensitive responses. Velocity was not encoded as a specific parameter. Temporal parameters of motion and azimuthal position of the moving sound source were differentially encoded by neurons in different fields of auditory cortex. Neurons with a directional preference in the dorsal fields can encode motion with short interpulse intervals, whereas direction preferring neurons in the primary field can best encode motion with medium interpulse intervals. Furthermore, neurons with a directional preference in the dorsal fields are specialized for encoding motion in the midfield of azimuth, whereas direction preferring neurons in the primary field can encode motion in lateral positions. In the second part of the study, responses were recorded from additional 69 neurons. Microiontophoretic application of BMI influenced the motion-direction sensitivity of 53 % of neurons. In 21 % of neurons the motion-direction sensitivity was decreased by BMI by decreasing either directional preference or receptive field shift. In neurons with a directional preference, BMI increased the spike number for the preferred direction in about the same amount as for the non-preferred direction. Thus, inhibition was not direction specific. In contrast, BMI increased motion-direction sensitivity by either increasing directional preference or magnitude of receptive field shifts in 22 % of neurons. An additional 10 % of neurons changed their response from a receptive field shift to a directional preference under BMI. In these 32 % of neurons, the observed effects could often be better explained by adaptation of excitation than by inhibition. The results suggest, that motion information is differentially processed in different fields of the auditory cortex of the rufous horseshoe bat. Thus, functionally organized pathways for the processing of different parameters of auditory motion seem to exist. The fact that cortex specific GABAergic inhibition contributes to motion-direction sensitivity in at least a part of cortical neurons is supportive for the notion that the auditory cortex plays an important role in further processing the neural responses to apparent motion brought up from lower levels of the auditory pathway.

Sun, 1 Jan 1995 12:00:00 +0100 http://epub.ub.uni-muenchen.de/3197/ http://epub.ub.uni-muenchen.de/3197/1/032.pdf Kleiser, A.; Schuller, Gerd Kleiser, A. und Schuller, Gerd (1995): Responses of Collicular Neurons to Acoustic Motion in the Horseshoe Bat Rhinolophus rouxi. In: Naturwissenschaften, Vol. 82, Nr. 7: pp. 337-340.

The functional role of GABA and glycine in monaural and binaural signal analysis was studied in single unit recordings from the central nucleus of the inferior colliculus (IC) of horseshoe bats (Rhinolophus rouxi) employing microiontophoresis of the putative neurotransmitters and their antagonists bicuculline and strychnine. Most neurons were inhibited by GABA (98%; N= 107) and glycine (92%; N = 118). Both neurotransmitters appear involved in several functional contexts, but to different degrees. Bicuculline-induced increases of discharge activity (99% of cells; N= 191) were accompanied by changes of temporal response patterns in 35 % of neurons distributed throughout the IC. Strychnine enhanced activity in only 53% of neurons (N= 147); cells exhibiting response pattern changes were rare (9%) and confined to greater recording depths. In individual cells, the effects of both antagonists could markedly differ, suggesting a differential supply by GABAergic and glycinergic networks. Bicuculline changed the shape of the excitatory tuning curve by antagonizing lateral inhibition at neighboring frequencies and/or inhibition at high stimulation levels. Such effects were rarely observed with strychnine. Binaural response properties of single units were influenced either by antagonization of inhibition mediated by ipsilateral stimulation (bicuculline) or by changing the strength of the main excitatory input (bicuculline and strychnine).

Doppler shift compensation behaviour in horseshoe bats, Rhinolophus rouxi, was used to test the interference of pure tones and narrow band noise with compensation performance. The distortions in Doppler shift compensation to sinusoidally frequency shifted echoes (modulation frequency: 0.1 Hz, maximum frequency shift: 3 kHz) consisted of a reduced compensation amplitude and/or a shift of the emitted frequency to lower frequencies (Fig. 1). Pure tones at frequencies between 200 and 900 Hz above the bat's resting frequency (RF) disturbed the Doppler shift compensation, with a maximum of intererence between 400 and 550 Hz (Fig. 2). Minimum duration of pure tones for interference was 20 ms and durations above 40 ms were most effective (Fig. 3). Interfering pure tones arriving later than about 10 ms after the onset of the echolocation call showed markedly reduced interference (Fig. 4). Doppler shift compensation was affected by pure tones at the optimum interfering frequency with sound pressure levels down to –48 dB rel the intensity level of the emitted call (Figs. 5, 6). Narrow bandwidth noise (bandwidth from ± 100 Hz to ± 800 Hz) disturbed Doppler shift compensation at carrier frequencies between –250 Hz below and 800 Hz above RF with a maximum of interference between 250 and 500 Hz above resting frequency (Fig. 7). The duration and delay of the noise had similar influences on interference with Doppler shift compensation as did pure tones (Figs. 8, 9). Intensity dependence for noise interference was more variable than for pure tones (-32 dB to -45 dB rel emitted sound pressure level, Fig. 10). The temporal and spectral gating in Doppler shift compensation behaviour is discussed as an effective mechanism for clutter rejection by improving the processing of frequency and amplitude transients in the echoes of horseshoe bats.

1. The functional role of brainstem structures in the emission of echolocation calls was investigated in the rufous horseshoe bat, Rhinolophus rouxi, with electrical low-current microstimulation procedures. 2. Vocalizations without temporal and/or spectral distortions could be consistently elicited at low threshold currents (typically below 10 A) within three clearly circumscribed brainstem areas, namely, the deep layers and ventral parts of the intermediate layers of the superior colliculus (SC), the deep mesencephalic nucleus (NMP) in the dorsal and lateral midbrain reticular formation and in a distinct area medial to the rostral parts of the dorsal nucleus of the lateral lemniscus. The mean latencies in the three vocal areas between the start of the electrical stimulus and the elicited vocalizations were 47 msec, 38 msec and 31 msec, respectively. 3. In pontine regions and the cuneiform nucleus adjacent to these three vocal areas, thresholds for eliciting vocalizations were also low, but the vocalizations showed temporal and/or spectral distortions and were often accompanied or followed by arousal of the animal. 4. Stimulus intensity systematically influenced vocalization parameters at only a few brain sites. In the caudo-ventra1 portions of the deep superior colliculus the sound pressure level of the vocalizations systematically increased with stimulus intensity. Bursts of multiple vocalizations were induced at locations ventral to the rostral parts of the cuneiform nucleus. No stimulus-intensity dependent frequency changes of the emitted vocalizations were observed. 5. The respiratory cycle was synchronized to the electrical stimuli in all regions where vocalizations could be elicited as well as in more ventrally and medially adjacent areas not yielding vocalizations on stimulation. 6. The possible functional involvement of the vocal structures in the audio-vocal feedback system of the Dopplercompensating horseshoe bat is discussed.

The glyoxylic-acid-induced fluorescence technique was applied to demonstrate patterns of catecholaminergic innervation within the auditory brainstem of echolocating bats and the house mouse. In the cochlear nucleus of the rufous horseshoe bat (Rhinolophus rouxi) and the mustache bat (Pteronotus parnelli), species-specific catecholaminergic innervation patterns are found that contrast with the relatively homogeneous innervation in the rodent. In both bats the subnuclei of the cochlear nucleus receive a differentially dense supply of catecholaminergic fibers, and within the subnuclei, the catecholamine innervation densities can be correlated with the tonotopic frequency representation. The areas devoted to the high-frequency echolocation calls are less densely innervated than those regions which are responsive to lower frequencies. Apart from this common scheme, there are noteworthy distinctions between the two bats which correlate with specialized cytoarchitectural features of the cochlear nucleus. The marginal cell group, located medially to the anteroventral cochlear nucleus of Pteronotus, receives the densest supply of catecholaminergic fibers of all auditory nuclei. This plexus is formed by a morphologically distinct population of catecholaminergic fibers.

1. Horseradish peroxidase was applied by iontophoretic injections to physiologically identified regions of the laryngeal motor nucleus, the nucleus ambiguus in the CF/FM batRhinolophus rouxi. 2. The connections of the nucleus ambiguus were analysed with regards to their possible functional significance in the vocal control system, in the respiration control system, and in mediating information from the central auditory system. 3. The nucleus ambiguus is reciprocally interconnected with nuclei involved in the generation of the vocal motor pattern, i.e., the homonomous contralateral nucleus and the area of the lateral reticular formation. Similarly, reciprocal connections are found with the nuclei controlling the rhythm of respiration, i.e., medial parts of the medulla oblongata and the parabrachial nuclei. 4. Afferents to the nucleus ambiguus derive from nuclei of the descending vocalization system (periaqueductal gray and cuneiform nuclei) and from motor control centers (red nucleus and frontal cortex). 5. Afferents to the nucleus ambiguus, possibly mediating auditory influence to the motor control of vocalization, come from the superior colliculus and from the pontine nuclei. The efferents from the pontine nuclei are restricted to rostral parts of the nucleus ambiguus, which hosts the motoneurons of the cricothyroid muscle controlling the call frequency.

Cochlear microphonic (CM) and evoked neural (N-1) potentials were studied in two species of Doppler shift compensating bats with the aid of electrodes chronically implanted in the scala tympani. Potentials were recorded from animals fully recovered from the effects of anesthesia and surgery. InPteronotus p. parnellii andRhinolophus rouxi the CM amplitude showed a narrow band, high amplitude peak at a frequency about 200 Hz above the resting frequency of each species. InPteronotus the peak was 25–35 dB higher in amplitude than the general CM level below or above the frequency of the amplitude peak. InRhinolophus the amplitude peak was only a few dB above the general CM level but it was prominent because of a sharp null in a narrow band of frequencies just below the peak. The amplitude peak and the null were markedly affected by body temperature and anesthesia. InPteronotus high amplitude CM potentials were produced by resonance, and stimulated cochlear emissions were prominent inPteronotus but they were not observed inRhinolophus. InPteronotus the resonance was indicated by a CM afterpotential that occurred after brief tone pulses. The resonance was not affected by the addition of a terminal FM to the stimulus and when the ear was stimulated with broadband noise it resulted in a continual state of resonance. Rapid, 180 degree phase shifts in the CM were observed when the stimulus frequency swept through the frequency of the CM amplitude peak inPteronotus and the frequency of the CM null inRhinolophus. These data indicate marked differences in the physiological properties of the cochlea and in the mechanisms responsible for sharp tuning in these two species of bats.

1. Acoustic reflections from a wing beating moth to an 80 kHz ultrasonic signal were recorded from six different incident angles and analyzed in spectral and time domains. The recorded echoes as well as independent components of amplitude and frequency modulations of the echoes were employed as acoustic stimuli during single unit studies. 2. The responses of single inferior colliculus neurons to these stimuli were recorded from four horseshoe bats,Rhinolophus ferrumequinum, a species which uses a long constant frequency (CF) sound with a final frequency modulated (FM) sweep during echolocation. All neurons responding to wing beat echoes reliably encoded the fundamental wing beat frequency as well as the more refined frequency and amplitude modulations. 3. These neurons may provide the bat a neural mechanism to detect periodically moving targets against a cluttered background and also to discriminate various insect species on the basis of their wing beat patterns.

The activity of the external (motor) branch of the superior laryngeal nerve (SLN), innervating the cricothyroid muscle, was recorded in the greater horseshoe bat,Rhinolophus ferrumequinum. The bats were induced to change the frequency of the constant frequency (CF) component of their echolocation signals by presenting artificial signals for which they Doppler shift compensated. The data show that the SLN discharge rate and the frequency of the emitted CF are correlated in a linear manner.

The motoneurons innervating the laryngeal muscles were localized in the rufous horseshoe bat,Rhinolophus rouxi, using the HRP method. HRP was applied to the cricothyroid muscle and to the cut end of the recurrent laryngeal nerve. Labeled motoneurons were found in two completely separated regions of the nucleus ambiguus. The motoneurons innervating the cricothyroid muscle via the superior laryngeal nerve (SLN) are located withinn the ventrolateral portion of the nucleus reaching the caudal pole of the motor nucleus of the facial nerve. The motoneurons innervating the other intrinsic laryngeal muscles via the recurrent laryngeal nerve (RLN) are situated in the caudal half of the nucleus ambiguus. The innervation is strictly homolateral.

The connections of the inferior colliculus, the mammalian midbrain auditory center, were determined in the greater horseshoe bat (Rhinolophus ferrumequinum), using the horseradish peroxidase method. In order to localize the auditory centers of this bat, brains were investigated with the aid of cell and fiber-stained material. The results show that most auditory centers are highly developed in this echolocating bat. However, the organization of the central auditory system does not generally differ from the mammalian scheme. This holds also for the organization of the superior olivary complex where a well-developed medial superior olivary nucleus was found. In addition to the ventral and dorsal nuclei of the lateral lemniscus a third well-developed nucleus has been defined which projects ipsilaterally to the inferior colliculus and which was called the intermediate nucleus of the lateral leminiscus. All nuclei of the central auditory pathway project ipsi-, contra-, or bilaterally to the central nucleus of the inferior colliculus with the exception of the medial nucleus of the trapezoid body and the medial geniculate body. The tonotopic organization of these projections and their possible functions are discussed in context with neurophysiological investigations.

The activity of the recurrent laryngeal nerve (RLN) was recorded in the greater horseshoe bat,Rhinolophus ferrumequinum. Respiration, vocalization and nerve discharges were monitored while vocalizations were elicted by stimulation of the central gray matter. This stimulation evoked either expiration or expiration plus vocalization depending on the stimulus strength. When vocalization occurred it always took place during expiration. Recordings from the RLN during respiration showed activity during the inspiration phase, but when vocalization occurred there was activity during inspiration and expiration. These results are consistent with the view that the RLN innervates muscles which control the opening and closing of the glottis. During vocalization the vocal folds are closely approximated and the discharge patterns of the nerve suggests that it controls the muscles which start and end each pulse.

Single neurons in the inferior colliculus of the Greater Horseshoe bat, Rhinolophus ferrumequinum, showed two broad categories of response patterns to sinusoidally frequency (SFM) or amplitude (SAM) modulated stimuli. Tonic responding cells (best excitatory frequency (BEF) between 10 and 90 kHz) showed a rough sinusoidal modulation of the discharge pattern to SFM. Transient responding neurons, generally showing on- or off-responses to pure tones, (BEF between 65 and 88 kHz), displayed highly synchronized discharge patterns to SFM-cycles (Fig. 1). Modulation rates between 20 and 100 Hz were most effective and some neurons encoded modulation rates up to 350 Hz (Figs. 2 and 3). The SFM responses were best synchronized to the modulation envelope for center frequencies in the upper portion of the tuning curve (Figs. 4 and 5). Sharply tuned neurons with BEF around 80 kHz had the lowest threshold for modulation depth (± 10 Hz or 0.025%) (Fig. 6). In general, SAMs evoked the same type of response patterns and were encoded down to modulation index of 3% (Fig. 7). The fine frequency and amplitude discriminations for periodical modulations by collicular neurons is discussed as related to the detection and discrimination performance of bats, when preying on flying insects in clustered surroundings.

1. The inferior colliculus of 8 Greater Horseshoe bats (Rhinolophus ferrumequinun) was systematically sampled with electrode penetrations covering the entire volume of the nucleus. The best frequencies and intensity thresholds for pure tones (Fig. 2) were determined for 591 neurons. The locations of the electrode penetrations within the inferior colliculus were histologically verified. 2. About 50% of all neurons encountered had best frequencies (BF) in the frequency range between 78 and 88 kHz (Table 1, Fig. 1A). Within this frequency range the BFs between 83.0 and 84.5 kHz were overrepresented with 16.3% of the total population of neurons (Fig. 1B). The frequencies of the constant frequency components of the echoes fall into this frequency range. 3. The representation of BFs expressed as number of neurons per octave shows a striking correspondence to the nonuniform innervation density in the afferent innervation of the basilar membrane (Bruns and Schmieszek, in press). The high innervation density of the basilar membrane in the frequency band between 83 and 84.5 kHz coincides with the maximum of the distribution of number of neurons per octave across frequency in the inferior colliculus (Fig. 1 C). 4. The disproportionate representation of frequencies in the auditory system of the greater horseshoe bat is described as an acoustical fovea functioning in analogy to the fovea in the visual system. The functional importance of the Doppler-shift compensation for such a foveal mechanism in the auditory system of horseshoe bats is related to that of tracking eye movements in the visual system.

1. In awake Greater Horseshoe bats (Rhinolophus ferrumequinum) the responses of 64 inferior colliculus neurons to electrically elicited vocalizations (VOC) and combinations of these with simulated echoes (AS: pure tones and AS(FM): sinusoidally frequency-modulated tones mimicking echoes from wing beating insects) were recorded. 2. The neurons responding to the species-specific echolocation sound elicited by electrical stimulation of the central grey matter had best frequencies between 76 and 86 kHz. The response patterns to the invariable echolocation sound varied from unit to unit (Fig. 1). 3. In 26 neurons the responses to vocalized echolocation sounds markedly differed from those to identical artificial ones copying the CF-portion of the vocalized sound (AS). These neurons reacted with a different response to the same pure tone whether it was presented artificially or vocalized by the bat (Fig. 2). In these neurons vocalization activities qualitatively alter the responsiveness to the stimulus parameters of the echoes. 4. A few neurons neither responded to vocalization nor to an identical pure tone but discharged when vocalization and pure tone were presented simultaneously. 5. In 2 neurons synchronized encoding of small frequency-modulations of the pure tone (mimicking an echo returning from a wing beating prey) occurred only during vocalization. Without vocalization the neurons did not respond to the identical stimulus set (Fig. 3). In these neurons vocalization activities enhanced FM-encoding capabilities otherwise not present in these neurons. 6. FM-encoding depended on the timing between vocalization and frequency-modulated signal (echo). As soon as vocalization and FM-signal no more overlapped or at least 60–80 ms after onset of vocalization synchronized firing to the FM was lost (4 neurons) (Fig. 4). 7. 4 neurons weakly responded to playbacks of the bat's own vocalization 1 ms after onset of vocalization. But when the playback frequency was shifted to higher frequencies by more than 400 Hz the neurons changed firing patterns and the latency of the first response peak (Fig. 5). These neurons sensitive to frequency shifts in the echoes returning during vocalization may be relevant to the Doppler-shift compensation mechanism in Greater Horseshoe bats.

The compensation of Doppler-shifts by the bat, Rhinolophusferrumequinum, functions only when certain temporal relations between the echo and the emitted orientation sound are given. Three echo configurations were used: a) Original orientation sounds were electronically Doppler-shifted and played back either cut at the beginning (variable delay) or at the end (variable duration) of the echo. b) Artificial constant frequency echoes with variable delay or duration were clamped to the frequency of the emitted orientation sound at different Doppler-shifts. c) The echoes were only partially Doppler-shifted and the Doppler-shifted component began after variable delays or had variable durations. With increasing delay or decreasing duration of the Doppler-shifted echo the compensation amplitude for a sinusoidally modulated + 3 kHz Dopplershift (modulation rate 0.08 Hz) decreases for all stimulus configurations (Figs. 1, 2, 3). The range of the Doppler-shift compensation system is therefore limited by the delay due to acoustic travel time to about 4 m distance between bat and target. In this range the overlap duration of the echo with the emitted orientation sound is always sufficiently long, when compared with data on the orientation pulse length during target approach from Schnitzler (1968) (Fig. 5).

The greater horseshoe bat (Rhinolophus ferrumequinum) emits echolocation sounds consisting of a long constant-frequency (CF) component preceeded and followed by a short frequency-modulated (FM) component. When an echo returns with an upward Doppler-shift, the bat compensates for the frequency-shift by lowering the emitted frequency in the subsequent orientation sounds and stabilizes the echo image. The bat can accurately store frequency-shift information during silent periods of at least several minutes. The stored frequency-shift information is not affected by tone bursts delivered during silent periods without an overlap with an emitted orientation sound. The system for storage of Doppler-shift information has properties similar to a sample and hold circuit with sampling at vocalization time and with a rather flat slewing rate for the stored frequency information.

Thu, 1 Jan 1976 12:00:00 +0100 http://epub.ub.uni-muenchen.de/3154/ http://epub.ub.uni-muenchen.de/3154/1/009.pdf Schuller, Gerd; Suga, Nobuo Schuller, Gerd und Suga, Nobuo (1976): Laryngeal Mechanisms for the Emission of CF-FM Sounds in the Doppler-Shift Compensating Bat, Rhinolophus ferrumequinum. In: Journal of Comparative Physiology A, Vol. 107: pp. 253-262.

Wed, 1 Jan 1975 12:00:00 +0100 http://epub.ub.uni-muenchen.de/3153/ http://epub.ub.uni-muenchen.de/3153/1/008.pdf Schuller, Gerd; Beuter, Karl; Rübsamen, R. Schuller, Gerd; Beuter, Karl und Rübsamen, R. (1975): Dynamic Properties of the Compensation System for Doppler Shifts in the Bat, Rhinolophus ferrumequinum. In: Journal of Comparative Physiology A, Vol. 97: pp. 113-125.

In 5 roosting bats the resting frequency, that is the mean frequency of the cf-portion of consecutive sounds, is kept constant with a standard deviation which varies between 30 120 Hz in different bats and at different days. In 15 bats the emitted sounds were electronically shifted in frequency and played back as artificial echoes. Upward frequency shifts were responded by a decrease of the emission frequency. This frequency compensation occurred at frequency shifts of up to 4400 Hz in all bats and up to 6000 ttz in a few bats. The frequency decrease in different bats over the whole compensation range was 50-300 tIz smaller than the frequency shifts in the echoes. The echoes, therefore, returned at a frequency, called the reference frequency, which was by this compensation offset higher than the resting frequency. The standard deviations of the emission frequency in compensating bats were only slightly larger than in roosting bats and the same in the whole compensation range. All bats started to compensate frequency shifts when they were slightly larger than the compensation offset. Downward frequency shifts were not responded by a change of the emission frequency, but the accuracy with which the emission frequency was kept decreased somewhat. From these results it is concluded that the Doppler shift compensation system of the Horseshoe bats compares the echo frequency with the reference frequency and compensates deviations of upward frequency shifts.

Sat, 1 Jan 1972 12:00:00 +0100 http://epub.ub.uni-muenchen.de/3150/ http://epub.ub.uni-muenchen.de/3150/1/005.pdf Schuller, Gerd Schuller, Gerd (1972): Echoortung bei Rhinolophus ferrumequinum mit frequenzmodulierten Lauten. Evoked Potentials im Colliculus inferior. In: Journal of Comparative Physiology A, Vol. 77, Nr. 3: pp. 306-331.

Fri, 1 Jan 1971 12:00:00 +0100 http://epub.ub.uni-muenchen.de/3183/ http://epub.ub.uni-muenchen.de/3183/1/003.pdf Schnitzler, Hans-Ulrich; Neuweiler, Gerhard; Schuller, Gerd Schnitzler, Hans-Ulrich; Neuweiler, Gerhard und Schuller, Gerd (1971): Antworten des Colliculus inferior der Fledermaus Rhinolophus euryale anf tonale Reizung. In: Naturwissenschaften, Vol. 58, Nr. 12: p. 627.

1. The auditory threshold curve of averaged evoked potentials of the colliculus inferior in Rhinolophus /errum equinum to pure tone stimulation from 1 to 100 kHz is presented (Fig. 1). For pure tone frequencies lower than 14 ktIz thresholds steeply rise from 20 to 110 db. The steepness of the acoustical filter for 83.3 kHz signals and the frequency of the echoes heard by Greater Horseshoe Bats is accentuated by averaging methods. Because of averaging, evoked potentials thresholds are lowered by about 20 db compared to those obtained by non-averaging methods. 2. Prominent off-responses in evoked potentials appear for three stimulus frequency ranges: 3-10 kHz with a peak at 5 ktIz, 20-40 kHz with a peak at 20 kHz and 80.0-82.6 kHz with a peak at 81.5 kHz (Fig. 2). 3. It is unlikely that beat note frequencies play any role for echolocation. 4. The relevance of these results to echolocation in Horseshoe Bats is discussed, especially as to Doppler shift information contained in the constant frequency part of echoes.

Collicular evoked potentials in Rhinolophus ferrum equinum show very prominent responses to the final frequency modulated part of a acoustic stimulus, simulating the natural echolocation sound.