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Recent years have seen staggering progress in our understanding of the nervous system and molecular genetics. The methods and intellectual framework of neuroscience are currently in a position to take us farther and faster than ever before toward an understanding of mechanisms that produce normal and abnormal behavior and cognition, and, equivalently, of how the nervous system carries out its tasks. However, in our view there has been an overwhelming tendency in neuroscience and molecular genetics, for behavioral phenomena and behaviorally important processes to recede into the background while cellular and molecular processes become the focus of analysis and explanation. However, the nervous system evolved largely for the production and control of behavior, and natural selection acts on phenotypes not directly on genes. This central theme of our training program is that neural and genetic mechanisms can be best understood in the context of the behaviors they mediate.
Therefore, this program is specifically designed to prepare students for careers in behavioral neuroscience teaching and research. This is the goal of the present training program. We educate suitably oriented students in both modern neuroscience AND in related psychological phenomena such as learning, perception, emotion, motivation, cognition, and mental illnesses. Moreover, we will provide students with experience specifically designed to make them better able to do psychologically informed neuroscience research and neuroscientifically informed behavioral research. One example, is the ability to recognize the functional importance of particular components of learning-related anatomical circuits and see how that function is realized within different circuits by application (e.g., fear-amygdala, eyeblink-cerebellum) of the Rescorla-Wagner learning algorithm to inhibitory feedback within those circuits [Fanselow,(1998), Neuron, 20,625-627]. Another example comes from neuroimaging of human color vision where psychologically informed work has shown that fMRI "activation" responds to color stimuli as would be predicted by color opponent processes known from psychophysics [Engel, et al., (1997), Nature, 388, 68-71]. A third is using memory distinctions born in human cognitive psychology to predict differential learning deficits in humans arising from different forms of neural pathology and to discover cognitive deficits that were previously unknown [Knowlton et al., (1996) Science, 273, 1399-1402.] Our mission is the training of researchers who will be able to draw compelling connections between behaviorally important processes and their neural and genetic substrates. Our program does this by (1) providing students with lecture and seminar coursework that educates them both in modern neuroscience?these courses taught by Interdepartmental Program in Neuroscience (NSIDP) faculty-- and in psychology and behavioral neuroscience. (2) Offering weekly current research seminars throughout the entire course of training in which behaviorally oriented neuroscientists from all across campus and conventionally trained psychologists (both faculty and graduate students) discuss and debate journal articles and local research relevant to understanding the neural bases of behavior, and (3) apprenticeship (culminating in doctoral thesis projects) in laboratories involved in behavioral neuroscience research. We believe that we are in an especially good position to carry out such a program effectively because of the large and distinguished pool of neuroscientific and psychological expertise at UCLA. The large size of both the neuroscience establishment and the psychology faculty at UCLA assure that the training we provide has unusual depth and breadth. This approach of back-and-forth integration between basic neuroscience, behavior and cognition is unique feature of our program. The Academic Environment Prospective Graduate students apply to either the the PH.D. Program in Psychology or The Neuroscience Interdisciplinary Program (NSIDP) administered by UCLA?s Brain Research Institute . Prospective Postdoctoral fellows first contact one of the Program Faculty The Psychology Department has 68 full time faculty, 152 graduate students, and 31 postdoctoral fellows. We currently have 2,880 undergraduate majors, with 712 in the special Psychobiology program. The National Research Council placed UCLA?s Psychology Department in 2nd place in its most recent ranking of graduate programs. As another indicator of our success, the Department is awarded about $14 million dollars in annual extramural support. Since 1981, seven Psychology Department graduate students received the American Psychological Association award for best Ph.D. thesis and an additional 6 were finalists. The Brain Research Institute has approximately 257 faculty members representing 20 academic departments. All UCLA faculty whose research focuses on the nervous system are members; the areas of expertise covered by the membership are comprehensive and range from molecular/genetic neuroscience to behavioral neuroscience and include many individuals doing work directly on or related to mental and nervous system disorders. The membership publishes over a thousand papers per year and has grant support totaling over $500 million. The Institute functions as the academic and cultural center of the UCLA neuroscience community and has as its explicit goals (1) to increase understanding of how the brain works, how it develops, and how it responds to experience, injury, and disease and (2) to make UCLA the preeminent center for translation of such basic knowledge into help for people with neurological and neuropsychiatric disorders. The Institute organizes and co-sponsors, along with member departments, the Joint Seminars in Neuroscience, which bring outstanding speakers to campus each week that classes are in session. These speakers span the full range of neuroscience and are an important part of the education of trainees as well as the continuing education of faculty The Institute maintains a number of core facilities available to the membership including the newly opened Carol Moss Spivak Cell Imaging Facility, which includes a variety of state of the art tools including a multiphoton scanning microscope, as well as laboratories for general microscopic techniques, electron microscopy, and mass spectrometry. An especially important facility for our program in cognitive neuroscience (described below) is the Ahmanson-Lovelace Brain Mapping Center. This campus facility provides students with the opportunity to learn functional imaging techniques and perform original research in collaboration with a faculty mentor. The Center features two research-dedicated MR scanners (1.5 and 3 Tesla). Within the Psychology department, the Functional Imaging Analysis core facility offers data storage and high-performance workstations for analysis of fMRI data. Faculty and staff from both the Psychology Department and Brain Mapping Center provide training in fMRI experimental design and data analysis to graduate students and postdoctoral fellows. The Psychology Department maintains several unique animal facilities that are essential for an integrative behavioral neuroscience program such as ours. One is the vivarium containing rats, primates, mice and pidgeons. The Psychology Department houses and maintains UCLA?s Behavioral Testing Core Facility. Researchers across campus come to this facility to learn how and to conduct research on behaviorally phenotyping mutant animals. In summary, the training environment is that of a preeminent university with an on campus medical school, a leading psychology department, a leading neuroscience program, all of which are physically contiguous. Certainly, this has facilitated our long history of inter-area and interdisciplinary training. Organization of the Training Faculty The program is organized into four Concentrations that have extensive connections with each other. 1) Neuroscience of Mental Disorders (Barad, Bilder, Cannon, Grijalva, Jentsch, London, Mayer, Minor, Tache) Many widely held concepts regarding the neuroscience of mental illness depended upon empirical research on the neurobiology of cognition, learning and vision. For example, experimental studies of the neurobiology of the non-human primate prefrontal cortex by Fuster, Goldman-Rakic and others constrained and directed virtually every modern conceptualization of the neurobiology of schizophrenia. Additionally, hypotheses for pathophysiology in obsessive-compulsive disorder are eliciting more attention to and basic research on the neurobiology of habit learning systems. Finally, neural substrates mediating extinction of conditioned fear is increasingly driving ideas about the treatment of anxiety disorders. While broad-based neuroscience research is therefore key to attacking the problems associated with mental illness treatment, additional emphasis must be placed on training new scientists capable of speaking the language both of empirical neuroscience and neuropsychiatry. 2) Learning and Memory: (Balleine, Blair, Blaisdell, Buonomono, Fanselow, Glanzman, Krasne, Silva) The UCLA psychology department is a premier center of research on learning and memory. Our faculty are engaged in studying learning at every level of analysis: genetic, molecular, cellular, physiological, behavioral, cognitive, and clinical. We are home to a diverse group of researchers that share a common interest in learning and memory research, and this environment fosters a level of innovation and collaboration that exceeds any other comparable institution. 3. Vision: (Engel, Green, Kellman, Shams, Liu, Ringach, Schein) The goal of the vision concentration is to train the next generation of scientists in the joint analysis of brain and behavior. Vision is one of the most important model systems for behavioral neuroscience, since it provides opportunities for quantitative comparison of brain and behavior at many levels of analysis. Training students in this discipline will greatly further NIMH?s mission, first by providing fundamental techniques for linking neural activity to behavior, but also by providing training in the application of these techniques to understand the neural bases of mental illness. 4. Cognitive Neuroscience: (Bookheimer, Fried, Holyoak, Hummel, Knowlton, Poldrack, Zaidel) Cognitive neuroscience is a rapidly advancing field that seeks to discover the neural basis of human cognitive processes. UCLA has a particularly strong group of cognitive neuroscientists with active research programs who are well integrated with the larger behavioral neuroscience community. These faculty provide a range of opportunities for trainees to gain expertise in techniques used including functional neuroimaging, neuropsychological testing, and computational modeling. Moreover, there are particular strengths in a number of domains of cognitive neuroscience, including the study of human learning and memory, perception and object recognition, and executive function. In addition to there being a number of faculty who specialize in cognitive neuroscience, UCLA offers a number of resources that are available to trainees for research in this area. Foremost is the Ahmanson-Lovelace Brain Mapping Center, which is on the UCLA Campus. This Center houses a Siemens Allegra 3T head-only scanner and a Sonata 1.5T whole-body scanner. The Ahmanson Lovelace Center has a training program in fMRI procedures. In addition, there is a functional neuroimaging core in the Psychology Department with shared computing and software resources. A major focus of this core facility is to provide training in fMRI analysis techniques. Program Faculty: Mark Barad Mechanisms of fear extinction and other forms of inhibitory learning. Dr. Barad?s laboratory studies the extinction of conditioned fear in mice as a paradigm of inhibitory learning and as the explicit model for behavior therapy of human anxiety disorders. The work depends largely on behavioral pharmacology using both systemic injections and infusions of drugs directly into the amygdala and other regions of interest as well as electrophysiological studies of LTP in the amygdala to analyze correlates of extinction learning at the synaptic level. Currently, the lab is focused on strengthening the correlation between physiology and extinction learning in the amygdala, on determining the synaptic mechanisms for the expression of extinction learning, and on translating basic findings on extinction in the mouse into clinical trials for human anxiety disorder treatment. Robert Bilder Neuropsychology, genetics and psychopharmacology of schizophrenia Structural and functional neuroimaging to better understand working memory and executive deficits, and the effects of genes, drugs and schizophrenia on these processes. Current projects include: longitudinal neuroimaging of first episode schizophrenia, functionalimaging of novel antipsychotic drug effects and fMRI studies of perceptual competency and maintenance in working memory. Further studies may be directed at exploring how these processes are affected by differences in certain candidate genes and psychopharmacological treatments. Bernard Balleine Motivational control of basic learning processes and their neural substrates Research in Dr Balleine?s laboratory examines issues in emotion and motivation and, in particular, the involvement of these processes in the organization and control of basic learning processes in rodents. The current research program is divided into four independent projects in this domain investigating: [1] the role of motivational systems in Pavlovian conditioning; [2] emotional and mnemonic processes in instrumental conditioning; [3] the relationship between evaluative conditioning and incentive learning in instrumental conditioning and [4] the role of thalamo-cortico-limbic circuits in the acquisition of instrumental performance. Hugh T. Blair Neural substrates of learning, memory, and emotion My research investigates how learning alters neurons and synapses to form memories using experimental techniques such as single-unit recording of neural activity in awake rats, intracranial drug infusions during behavioral experiments, and computational modeling of the nervous system. Currently, we are studying how neural plasiticity in the amygdala underlies the rapid formation of long-lasting memories during emotional learning, how the hippocampus and other brain regions are involved in learning about spatial environments and events that occur there and we are performing detailed computer simulations of nerve cells to investigate how synaptic plasticity is governed by cellular signaling mechanisms. Aaron P. Blaisdell Animal cognition and behavior My central interest lies in how animals represent their world and how these representations subserve information processes. We use Pavlovian and instrumental conditioning procedures to study how rats and pigeons solve problems involving cause-effect relations and how they integrate separate experiences to perform inferences. Current topics include: How do rats form temporal maps between events they experience, such as between a CS and a US? How do pigeons acquire spatial maps of the world? How does Pavlovian conditioning support cognitive representations (e.g., temporal and spatial maps)? These proximate mechanisms of behavior can shed light on how the ultimate function of behavior is served and will guide the exploration for the links between behavior, psychology, and neuroscience. Susan Bookheimer Language organization and development My research uses functional magnetic resonance imaging (fMRI) to isolate pathways involved in various aspects of language processing, with a focus on identifying parallel language systems. Additionally, our lab studies language development and developmental disorders including autism, Asperger's and dyslexia, to identify core deficits at the neural level that differentiate sub-groups of children with these syndromes. A related research focus is in memory and memory disorders. We are exploring the organization of memory in with fMRI using newly developed methods for high-resolution functional imaging to delineate the functional architecture of the hippocampus. This includes segmentation and unfolding the hippocampus, identifying unique patterns of activity in hippocampal sub-regions during the learning process. Dean Buonomano Learning, memory, and the neural basis of temporal information processing Sensory stimuli, such as speech, are rich in temporal information on the time scale of tens to hundreds of milliseconds. The primary goal of my laboratory is to understand the neural basis of temporal information processing. Specifically, what are the neural mechanisms underlying the perception of time, and how do neurons develop selective responses to features such as order, duration, and intervals. The main approach in my laboratory involves: 1.) understanding the dynamics of local cortical networks in response to temporal stimuli; 2.) the characterization of time-dependent neuronal properties, and 3.) studying short- and long-term synaptic plasticity. My laboratory also relies on computer simulations of artificial neural networks, and behavioral experiments aimed at characterizing temporal processing. Tyrone Cannon Molecular genetics of mental illness This laboratory focuses on the cognitive neuroscience and genetics of schizophrenia, particularly in relation to neural systems mediating working memory and episodic memory. Related projects evaluate prenatal influences on brain and behavioral development, animal models (transgenic) of psychopathology, and prevention of schizophrenia. Stephen Engel The neural basis of perceiving color and form We study human vision and cognition combining psychological measurements with data from functional brain imaging. A central goal of the research is to link quantitative measurements of perception to fMRI data by analyzing both kinds of data in terms of the representations and computations that underlie vision. Specific topics under investigation include color perception, basic mechanisms of form perception, and perceptual learning. As one example, we are currently measuring the effects of adaptation to colored patterns on the perception of, and brain responses to, other colored patterns. We can model both kinds of data as resulting from a loss of responsiveness in neurons that are jointly tuned to color and form. Michael Fanselow The neural basis of Pavlovian fear conditioning using rats and transgenic mice as models We are engaged in a multi-leveled analysis of fear-related behavior using rats and transgenic mice as subjects to determine how fear is learned and how fear-related memories are stored in the brain focusing on forebrain regions such as the amygdala and hippocampus. We also examine how fear gets translated into specific behaviorsfocusing on midbrain regions such as the periaqueductal gray. Specific projects examine the roles of glutamatergic, cholinergic and GABAergic systems within these structures in association formation and memory storage. We are also interested in time-dependent changes in memory consolidation and how fear of places differs from fear of temporally restricted unimodal stimuli. We also try to understand anxiety disorders from a perspective that mixes both neurothology and neurobiology. Itzhak Fried Human single-unit recordings during cognition Fried?s laboratory is one of few in the world performing chronic recordings of single-neuron activity in awake, conscious humans. Using a clinical opportunity afforded by epilepsy patients under evaluation for surgery, with electrodes implanted in deep brain areas, the group records directly from individual neurons during cognitive tasks. The focus is on representation of conscious visual perception and declarative memory in the medial temporal lobe. Findings indicate that these neurons (1) respond to the percept rather than the image falling on the retina, (2) are reactivated during visual recall or imagery with the same specificity as during encoding, (3) exhibit activity during encoding that predicts future recollection, and (4) underlie human spatial navigation. This is a rare opportunity to bridge nonhuman findings with human neuroimaging findings, in elucidating neuronal networks underlying human cognition. David L. Glanzman Neurobiology of learning and memory Our interests are in the cell biology of learning and memory in the marine snail Aplysia californica. This simple nervous system provides a useful experimental model for a cellular analysis of the mechanisms underlying habituation, sensitization, and classical conditioning. Another advantage of Aplysia is that neurons that mediate specific reflexes may be dissociated from the animal's nervous system and placed into cell culture, where they reform their original synaptic connections. These in vitro synapses are ideal for cellular studies of synaptic plasticity. We discovered that in vitro sensorimotor synapses exhibit long-term potentiation (LTP), a form of synaptic plasticity, a possible cellular mechanism of associative learning. We have found that LTP of sensorimotor synapses contributes to classical conditioning in Aplysia. Future research concerns (i) determining the cellular mechanisms of expression of LTP of sensorimotor synapses; and (ii) determining how LTP interacts with other cellular mechanisms during classical conditioning. Michael Green Cognitive deficits in schizophrenia Research in this laboratory is devoted to the treatment and understanding of neurocognitive aspects of schizophrenia, including: 1) psychopharmacological interventions for cognitive deficits, 2) cognitive prediction of functional outcome in schizophrenia, 3) the neural basis of visual processing deficits in schizophrenia, 4) novel approaches to psychosocial intervention, 5) the role of social cognition in community outcome, and 6) the genetics of endophenotypes in schizophrenia. The laboratory supports several large-scale clinical trial studies of interventions, family studies of schizophrenia, and the studies utilize electrophysiological, cognitive performance, and neuroimaging methods. Carlos V. Grijalva Psychobiology of stress, behavior, and bodily diseases in animal models. Brain and behavioral mechanisms involved in feeding behavior and gastrointestinal function. Our research focuses on four general areas: (1) brain mechanisms involved in the control and modulation of gastrointestinal functions as they pertain to the development of gastro-duodenal ulcers, (2) CNS mechanisms and general metabolic processes and their interplay in the mobilization of bodily fuels (e.g., blood glucose and lipids) in response to psychological, physical, and pharmacological stressors, (3) central and peripheral mechanisms involved in thermoregulation, and (4) studies on brain and regulatory processes involved in ingestive behaviors, with a primary emphasis on the underlying causes of anorexia. Keith Holyoak Cognitive Neuroscience of thinking and reasoning, Much of my work has focused on the question of how people use analogies to solve problems and understand novel situations. Research in my lab combines several different approaches to investigate thinking and reasoning, using the methods of cognitive science and cognitive neuroscience. In cognitive studies of reasoning, college students are asked to identify ways in which analogous situations relate to one another, and to use analogies to draw inferences. These studies are complemented by similar neuropsychological experiments with brain-damaged individuals, studies which try to determine how the human brain supports thinking. The major focus is on the role of the prefrontal cortex in higher cognition. In addition, computer simulation models are used to provide detailed explanations of how thinking is accomplished within the constraints imposed by our limited working memory. John Hummel The representation and processing of relational structure in vision and cognition My research concerns the representation and processing of relational (i.e., structured; symbolic) information in human and artificial systems. How can neural architectures generate, represent and manipulate relational structures? How does the human mind's solution to this problem manifest itself in observable behavior? My collaborators and I investigate these questions both in vision (e.g., How do we represent the spatial relations among an object's parts?) and in thinking and reasoning (How do we draw analogies between familiar and novel situations? How do we reason using analogies, schemas and rules?). My collaborators and I build explicit algorithmic (neural network) models of these processes, and test the models' predictions in experiments with human subjects. J. David Jentsch Neuropsychopharmacology; animal models for schizophrenia. Understanding the cellular, chemical and molecular basis of cognitive deficits in schizophrenia is the ultimate goal of the research being undertaken in my laboratory. Our first goal is to understand the neural basis of cognition in otherwise normal rodents and primates. Using receptor selective pharmacological agents, regionally-specific lesions or drug infusions and/or microstimulation of brain structures, we are attempting to understand how cognitive processes such as visuospatial attention, spatial working memory and executive functions arise. Conversely, we are employing experimental models of cognitive dysfunction to explore concepts about the pathophysiological substrates of behavioral impairments. Our goal is to weave these parallel lines of research together into a coherent circuit model for cognitive deficits in schizophrenia. Philip Kellman Human object, space, and motion perception, perceptual learning, and visual cognition Research in our laboratory focuses on (1) human object, space and motion perception, and (2) perceptual learning. We use experimental and computational methods to understand the information, processes and mechanisms leading to recovery of contours, surfaces and objects, especially in cases where the inputs are fragmentary in space and/or time. We also focus on empirical tests and modeling of human abilities to discover through experience features and relationships that improve classification performance, especially where these involve complex and abstract spatial relationships. We apply some of our findings on the latter topics to developing new approaches to training and education in domains such as mathematics and science learning, aviation and radiology. Barbara Knowlton Neural substrates of memory A major focus of the lab is to describe the characteristics of different memory systems in terms of their psychological characteristics and anatomical substrates. In one set of studies we are examining habit learning, which appears to depend on the basal ganglia. This type of learning appears to be distinguishable from declarative (explicit) learning in that it is nonconscious, incremental independent of the medial temporal lobe memory system. We are conducting behavioral and neuroimaging studies of patients with Parkinson?s disease in parallel with work in animal models to examine the role of the basal ganglia in habit learning. We are also interested in how two kinds of declarative memory, episodic memory and familiarity, differ at the neural level. Frank Krasne Neural mechanisms of crayfish escape behavior: Integration and plasticity. This laboratory investigates the neurophysiology of escape behavior in the crayfish with special interest in learning like phenomena and the integrative processes involved in making decision to execute particular behavior patterns. Most recently the laboratory has been most concerned with projects on (1) habituation of escape responses with special reference to the relationships and interactions between habituation due to extrinsic inhibition by higher centers and intrinsic changes in the properties of circuitry within the escape response circuit and (2) schedule-dependence of serotonergic modulation in which serotonergic modulation can be either facilitatory or inhibitory, depending on precise application schedule. Zili Liu Visual perceptual learning and organization of motion perception, shape recognition, and computation Research in the Liu Laboratory studies human visual perception by integrating psychophysics, computation, and neural imaging. A central goal of this research is to characterize the nature of visual perceptual representations of shape and motion. Specific topics under investigation include shape from motion, perceptual learning of motion discrimination, and shape recognition. Shape from motion studies, using psychophysical and Bayesian statistical methods, the constraints under which a definite percept is achieved when the physical stimulus in principle gives rise to multiple solutions. For motion perceptual learning, we study the degree to which learning is direction specific and the possible neural substrates. Shape recognition likewise studies the degree of abstraction of learned. Edythe London Molecular and functional imaging of addiction Dr. London?s research aims to develop a better understanding of addictive disorders, using a translational approach toward rational design of therapeutics. Ongoing projects focus on the neurobiology of substance abuse and development of new probes for the study of brain function by external imaging. Using positron emission tomography (PET) scanning and magnetic resonance imaging, current projects concern dependence on methamphetamine and nicotine. The questions asked in human research relate to the links between genetics, cognitive function, affect and vulnerability to drug abuse and the maintenance of dependence. Correlative studies in animal models of addiction will relate altered neuronal function with gene expression, as affected by drug treatments. Emran Mayer Translational research studies on brain gut interactions in health and disease Dr. Mayer?s heads an NIH center studying the interactions between the nervous and the digestive systems at the cellular, behavioral and human level. A particular emphasis in these studies is on the role of stress in altering brain gut interactions and in modulating visceral pain perception. We are interested in the role of the primary afferent neurons innervating the intestine in transducing visceral mechanical and chemical stimuli to the spinal cord. We also examine the neurobiological mechanisms underlying the development of chronic visceral hyperalgesia in different animal models of stress, with a particular emphasis on the role of central stress mediators such as CRF and substance P. We are evaluating these various models to determine their validity for common human visceral pain conditions such as irritable bowel syndrome and interstitital cystitis. Human patients are studied with various non-invasive techniques including EEG, functional brain imaging and assessment of startle responses. Thomas Minor Behavioral, brain, and endocrine mechanisms in anxiety and depression. The lab uses animal models to examine behavioral and neurobiological facets of anxiety and depression. We are currently focusing on the events that mediate the transition from anxious to depressive behavior states. The role of neural metabolic fatigue and compensatory adenosine regulation in this transition between emotional states has been the examined in detail during the last several years. Recent projects have added to this focus by detailing the pivotal role played by the immune system and brain cytokines in depressive symptomatology. We are also concerned with new treatments for depression, including glucose, neurotrophins, and thyrotrophins. Russ Poldrack The cognitive neuroscience of learning and memory Our lab uses functional neuroimaging to examine the neural systems involved in learning and memory. One focus of the lab is on the interaction between memory systems based in the basal ganglia and medial temporal lobe. This question is being examined using classification learning to test hypotheses about how memory system engagement can be modulated by task demands and stimulus characteristics. Another set of studies examines the role of executive processing in skill acquisition and the neural changes associated with automaticity. Other studies are examining the role of particular prefrontal regions in executive function, with a particular focus on inhibitory processes. Dario Ringach Neurophysiology and psychophysics of vision; cortical prostheses The goal of my research is to understand how the visual cortex represents and processes information. Also, we are working to develop cortical prostheses to restore functional vision in the blind. We currently use high-density electrode arrays to investigate the representation and processing of the visual image by neural populations in primary visual cortex. These recordings shed light into how receptive field properties vary across the cortical orientation map. The same electrode arrays are being used to study how one can safely stimulate cortical tissue electrically to control a large population of cells. This will allow the development of methods to ?input? information to the brain necessary for the design of cortical interfaces in patients. Stan Schein Exocytosis and endocytosis in ribbon synapses in the retina We study synaptic terminals in primate retina that exocytose quanta of glutamate at a high tonic rate and have synaptic ribbons. Rods absorb a single photon and hyperpolarize just one millivolt. Cones signal small achromatic and chromatic contrast. Bipolar cells depolarize by just a few millivolts. Because their signals are very small, we suggest that release by these terminals must be regular in time in order for the signal to be transmitted to their synaptic targets. Regular release may also be necessary in hair cells, similarly supersensitive and conveying small signals. High release rates require high rates of endocytosis. We study the location and properties of clathrin-mediated endocytosis, along with mechanisms of self-assembly of clathrin cages. Ladan Shams Visual and multisensory perception Our lab is concerned with how information is integrated from multiple sensory modalities into a coherent percept of the world, and especially how visual perception is affected by other sensory modalities. Perception has been viewed as a modular function with different sensory modalities operating as separate and independent modules. Our findings, on the other hand, have been among those that have started a shift towards an integrated and interactive paradigm of sensory processing. Our research tackles the question of multisensory integration at various levels: phenomenology of cross-modal interactions using behavioral studies, the brain circuitry involved in these interactions using ERP and fMRI, and the computational principles underlying mutlisensory integration using statistical modeling. Alcino Silva Transgenic approaches to learning and memory in mice We are interested in the molecular, cellular, and circuit processes that underlie the storage and recall of information. We use a variety of techniques including transgenic manipulations, pharmacology, in vitro and in vivo electrophysiology, neuroanatomical lesions, and behavioral analysis. The focus of our studies is on hippocampal dependent learning and memory and implicate a variety of hippocampal mechanisms in learning and memory, including long-term potentiation, short-term plasticity, and the slow afterhyperpolarization. We found mutations that affect the stability of these synaptic changes and memory (but not learning). Our laboratory is also interested in applying these findings to the development of treatments for learning and memory disorders, such as those observed with aging and neurofibromatosis type 1 (NF1). Recently we have reversed the learning impairments in an NF1 animal model, with either a Ras mutation or with an inhibitor that affects the farnesylation (and the activation) of Ras. Yvette Tach? Brain-gut interactions and stress-induced alterations of gastric and colonic motor function The objectives of the Tach? laboratory are to enhance our knowledge of the underlying mechanisms of brain-gut interactions and how they relate to the pathophysiology of gut function. Based on the lab's previous findings, current research is focused on establishing 1) the interactions between gut peptides, ghrelin, PYY and secretin and brain regulation of feeding behavior; 2) the role corticotropin-releasing hormone (CRF) receptors in mediating stress-related alterations of gut dysfunction and modulation of colitis and viscerosensibility; and 3) the cross talk between the immune system and neural regulation of gut function through modulation of CRF signaling pathways. Eran Zaidel The cognitive neuroscience of hemispheric specialization and interhemispheric interaction Our lab focuses on hemispheric relations in attention, perception, and language. The two hemispheres serve as a model system for studying modularity and control in the mind/brain, with special attention to error monitoring. We combine different subject populations -- normal subjects, split-brain patients and hemisphere-damaged patients, as well as subjects with ADHD, congenital dyslexia and schizophrenia), and different approaches -- behavioral, anatomical and physiological, including EEG/ERP, fMRI, PET and TMS. Recent work includes self-modulation of brain functions by EEG feedback. |