EVENT

Neuronal thresholds and choice-related activity of otolith afferent fibers during heading perception

Xiong-jie Yu*, J. David Dickman, Gregory C. DeAngelis, and Dora E. Angelaki*

 

Abstract

How activity of sensory neurons leads to perceptual decisions remains a challenge to understand. Correlations between choices and single neuron firing rates have been found early in vestibular processing, in the brainstem and cerebellum. To investigate the origins of choice-related activity, we have recorded from otolith afferent fibers while animals performed a fine heading     discrimination task. We find that afferent fibers have similar discrimination thresholds as central cells, and the most sensitive fibers have thresholds that are only twofold or threefold greater than perceptual thresholds. Unlike brainstem and cerebellar nuclei neurons, spike counts from afferent fibers do not exhibit trial-by-trial correlations with perceptual decisions. This    finding may reflect the fact that otolith afferent responses are poorly suited for driving heading perception because they fail to discriminate self-motion from changes in orientation relative to gravity. Alternatively, if choice probabilities reflect top-down inference signals, they are not relayed to the vestibular periphery.

 

Significance

One major goal of systems neuroscience over the past decades has been to understand how the activity of sensory neurons mediates perception in simple decision-making tasks. It has remained fundamentally unclear whether and how the activity of primary sensory afferents limits behavior and contributes to decisions. We have tackled these issues by recording, for the first time to our knowledge, from otolith afferents during a heading discrimination task. We show otolith afferents have sensitivity comparable to central neurons, with some approaching behavior. However, they do not exhibit significant choice-related activity,indicating that downstream transformations of vestibular signals are necessary for vestibular activity to become predictive of the animal’s choices. These findings have important implications for understanding how choice-related activity arises in sensory pathways.  

 

Link on PNAS                        

 


2016-05-06 READ MORE

报告题目:Neural mechanism of emotion and social behaviour

报告人:Prof. Hailan Hu

主持人:Prof. Anna Wang Roe

演讲时间:2016年3月29日3:00-3:45PM

演讲地点: 华家池校区科学楼207室

报告人简介:胡海岚博士于1996年在北京大学获得学士学位,2002年于加州大学伯克利分校获得神经生物学博士。2003年-2008年在美国冷泉港实验室和弗吉尼亚大学从事博士后研究工作,2008年12月2015年4月在中国科学院上海生命科学研究院担任研究员、博士生导师,自2015年5月起任职浙大。近五年来,主持中国科学院2008年“百人计划”(终期评估优秀), 2012国家杰出青年科学基金等多个项目,并作为骨干参加了科技部973重大科学问题导向项目和中国科学院战略性先导科技专项(B类)的研究工作。获得的荣誉包括国家杰出青年基金(2012),中国科学院优秀导师奖(2012、2014)和明治生命科学杰出奖(2013)。实验室致力于研究情绪与社会行为的分子与神经环路机制。近六年来在情绪效价的神经编码(Nature Neuroscience,2014)、抑郁症发生的核心分子机制(Science,2013),以及社会等级的神经基础(Science,2011)等方向,取得了一系列既有理论意义又有潜在应用价值的系统性原创成果。先后受邀在国际权威综述期刊Trends in neuroscience(2014)和Annual Review in Neuroscience(2016)撰写综述。为Science和Neuron等杂志的特邀审稿人。培养多名优秀博士毕业生,共获得中科院院长特别奖、恒源祥英才奖一等奖各2人次,吴瑞奖学金、国家奖学金、张香桐奖学金一等奖、强生一等奖等各1人次。

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报告题目:GABAergic system: From circuit, function to disease

报告人:Prof. Xiao-Ming Li

主持人:Prof. Anna Wang Roe

演讲时间:2016年3月  29日3:45-4:30PM

演讲地点: 华家池校区科学楼207室

报告人简介:

李晓明,医学博士、浙江大学教授和博士生导师;国家杰出青年基金获得者,教育部“长江学者”特聘教授,中组部国家“万人计划”创新领军人才、 科技部中青年科技创新领军人才, 浙江省卫生高层次创新人才等。现任浙江大学医学院副院长、浙江大学神经科学研究所常务副所长,研究组组长,兼任浙江大学医学院附属邵逸夫医院脑科中心主任、浙江省神经科学学会秘书长等。2003年毕业于原第一军医大学,获医学博士学位,多年来从事神经系统疾病的临床、教学和科研工作。作为课题负责人在研课题有国家重大科学研究计划、国家自然科学基金项目(包括重点、杰青、重大研究计划、创新研究群体)等。作为主要完成人获得国家自然科学奖二等奖、省科技进步奖一等奖、 中华医学科技奖二等奖、高校科研成果二等奖等奖项。李晓明博士实验室的长远目标是通过对不同神经突触神经环路的研究,寻求治疗神经精神疾病如脑缺血损伤、精神分裂症、孤独症以及癫痫病等的靶分子并提供相应的治疗策略。在突触和神经环路的发育和分子调控领域,尤其在精神分裂症癫痫等疾病的发病机制方面取得重要研究成果。代表性论文以通讯作者发表在国际著名杂志如《Nature Neuroscience》、 《Journal of Neuroscience》、《Cerebral Cortex[4] 》等上,并被国际同行发表专文正面评述。

 


2016-03-29 READ MORE

报告题目:Brain MRI with improved spatial and spectral resolutions at 7T

报告人:宗小鹏

主持人:Prof. Anna Wang Roe

演讲时间:9月28日上午9点-10点

演讲地点:玉泉校区周亦卿科技大楼 516室

报告人简介:Education and research experience:

1998, 应用物理学士, 中国科技大学

2007, Ph.D in experimental condensed matter physics, Iowa State University

2008, Postdoctoral research associate, Dep. of Neuroscience, Baylor College of Medicine

2009 – 2011, Visiting research associate, Dep. of Radiology, Michigan State Univ.

2012 – Jun. 2013, Research associate, Dep. of Radiology, Univ. of Pittsburgh

Jul. 2013 – present, MR Physicist/ research associate, Biomedical Research Imaging Center, Univ. of North Carolina at Chapel Hill.

报告内容简介:

High field MRI can offer much increased signal to noise ratio (SNR) and better spectral resolution.  This talk will present two promising applications of 7 T high-field MRI in which such improvements are indispensable.  In the first application, the high spatial resolution attainable only at 7 T (0.4×0.4×0.4 mm3) enabled a detailed morphology study of the perivascular spaces (PVS) in human brain which has been increasingly recognized to play an important role in the glymphatic system for clearing metabolic wastes from the brain.  I will present our detailed simulation and experimental studies that aims to achieve the optimal sequence parameters for imaging the PVS.  For the first time, quantitative morphological features of PVS were obtained from the optimized images using a semi-automatic segmentation approach. Measuring the morphological features of PVS may prove useful for understanding their pathophysiological significance in the neurovascular diseases, as enlarged PVS are commonly observed in a number of neurological disorders.  In the second application, the increased spectral resolution at 7 T allowed the CEST (chemical exchange saturation transfer) effects from labile protons with different chemical shifts to be well separated in the z-spectrum.  As a result, a 5-pool model was successfully applied to extract the concentration and exchange rates of the labile protons, which may alleviate the long-standing quantification issue of CEST MRI and improve its utility in probing the biochemical changes in human diseases.

 

2015-09-28 READ MORE

报告题目:Functional architecture of face processing in macaques

报告人:Dr. Ning Liu

主持人:Prof. Anna Wang Roe

演讲时间:9月28日上午8点-9点

演讲地点:玉泉校区周亦卿科技大楼516室

报告人简介:Education and research experience:

Dr. Liu received bachelor's degrees in both Biological Sciences and Computer Science & Technology from the University of Science and Technology of China (USTC) in 2002. As a graduate student, she then studied the mechanisms of perception and attention in human and non-human primates in the Laboratory of Primate Cognitive Neuroscience at the Kunming Institute of Zoology, Chinese Academy of Science (CAS). After obtaining her Ph.D., Dr. Liuhas been working with Dr. Leslie G. Ungerleider in the Laboratory of Brain and Cognition at National Institute of Mental Health (NIMH) as a Post Doctoral fellow. From then, her research has focused on revealing the neural mechanisms underlying the processing of socially important visual information, such as faces and facial expressions.

 

报告内容简介:

As social animals, both human and non-human primates have developed excellent skills in recognizing and discriminating a wide variety of faces. Accordingly, one of the most active fields in system neuroscience is to understand the neural mechanisms underlying face processing. Revealing these mechanisms is important not only for understanding how the brain processes complex stimuli, but also for developing better treatment for neurological and psychiatric disorders, such as prosopagnosia (inability to recognize faces) and autism (face perception deficits). Previous studies have identified multiple face-selective regions in the temporal and frontal lobes, which respond more strongly to faces than non-face objects, as well as multiple face-responsive regions (e.g., the amygdala), which may process changeable aspects of faces (e.g., facial expression). This talk will present a series ofstudies conducted in awake monkeys,combining fMRI, pharmacological manipulation, behavioral assessment and etc., toexplore the functional network formed by these regions, which specifically processes face-related information.

 


2015-09-28 READ MORE
2015-04-10 READ MORE
2015-04-07 READ MORE

    Dr. He Cui received his bachelor degree from Tsinghua University in 1994 and a master degree from Chinese Academy of Sciences in 1997. Then he went to US and earned a PhD in Neuroscience from University of Illinois at Urbana-Champaign in 2003. After completing his postdoctoral training in California Institute of Technology in 2008, he started his own monkey lab in Medical College of Georgia. He was named an Alfred P. Sloan Foundation Fellow in 2010 and received a research award from Whitehall Foundation in 2011. His research focuses on neural mechanisms underlying sensorimotor control which will ultimately help to reveal new principles for guiding therapy and developing treatments for people with brain disorders affecting decision making and motor control.

   Although important advances have been made in understanding neural coding of sensory and motor variables, most studies have emphasized purely reactive movements toward static targets, in which sensory stimuli and motor parameters are seamlessly linked, making it fundamentally incapable of determining whether the observed neural activity reflects sensory stimuli or predicts future movements. Consequentially, a specific role of the posterior parietal cortex (PPC), an important cortical sensorimotor interface, has been an intense debate for a long time. In the last decade, we have designed a variety of sophisticated behavioral paradigms that allow decoupled sensory input and behavioral output, including non-spatial decision making, sequential arm movement, and flexible manual interception, to examine PPC activity in the rigorous behavioral contexts. In these voluntary, dynamic, and flexible stimulus-response contingencies, converging evidence suggested that the PPC explicitly convey information concerned with the upcoming movement, suggesting an intimate role in forward prediction and motor planning.

 


2015-04-07 READ MORE
2015-03-17 READ MORE
2015-01-26 READ MORE
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