Eric Knudsen
Stanford University
Project start date: 2012-01-20
Project end date: 2013-11-30
Sponsored Links Excellgen http://Excellgen.com
Grants awarded to Eric Knudsen
NEURAL MECHANISMS OF VISUAL AND AUDITORY STIMULUS SELECTION
Eric Knudsen
Stanford University, 340 Panama Street, Stanford, Ca 94305-6203
Grant 5R01EY019179-31 from National Eye Institute
Abstract: Understanding the cellular mechanisms that underlie attention is crucial for developing effective treatments for the many psychiatric and learning disorders that affect attention. We have developed experimental protocols in the barn owl that allow us to study the cellular basis of a fundamental component of attention, stimulus selection, in quantitative detail. The aim of the proposed research is to analyze characteristics of bottom-up (automatic) and top-down stimulus selection at the neuronal level and to elucidate mechanisms that underlie these processes. The properties of bottom-up and top-down stimulus selection will be studied in the optic tectum, a structure known to be involved in spatial attention. The effects of multiple, simultaneous sensory stimuli on neuronal responses will be measured as the salience and location of competing stimuli are varied parametrically. Top-down signals (originating in the forebrain) that bias stimulus selection will be activated by electrical microstimulation. Finally, the respective roles of specialized cholinergic and GABAergic nuclei in bottom-up and top-down stimulus selection will be explored with electrophysiology and pharmacological inactivation experiments. The mechanisms by which the brain selects stimuli for attention are not known. In addition, the effects of cholinergic input on information processing in the brain are not understood. Many debilitating conditions (e.g., Schizophrenia, Autism, ADHD) include dysfunctions of stimulus selection, and others (e.g., Alzheimer´s, Parkinson´s, Down´s) are associated with dysregulation of cholinergic transmission. An understanding of the cellular mechanisms of stimulus selection and the function of cholinergic circuits is crucial for developing treatments that can mitigate or remediate the devastating effects of these conditions. PUBLIC HEALTH RELEVANCE Many debilitating, psychiatric conditions (such as Schizophrenia, Autism and Attention Disorder) include dysfunctions of attention, and others (such as Alzheimer´s, Parkinson´s and Down´s Syndrome) are associated with dysregulation of cholinergic circuitry in the brain. The proposed research will explore the cellular mechanisms of attention and the functional properties of cholinergic circuits. The results from this research will provide crucial information that may help in the development of treatments that can mitigate or remediate the devastating effects of these psychiatric conditions
Keywords: AD/HD; ADHD; Affect; Alzheimer; Alzheimer disease; Alzheimer sclerosis; Alzheimer syndrome; Alzheimer`s; Alzheimer`s Disease; Alzheimers Dementia; Alzheimers disease; Anterior Quadrigeminal Body; Area; Attention; Attention deficit hyperactivity disorder; Attention-Deficit Disorder, Predominantly Hyperactive-Impulsive Type; Autism; Autism, Early Infantile; Autism, Infantile; Autistic Disorder; Barn Owls; Brain; Cell Communication and Signaling; Cell Nucleus; Cell Signaling; Characteristics; Corpora quadrigemina, superior colliculus; Dementia, Alzheimer Type; Dementia, Primary Senile Degenerative; Dementia, Senile; Dependence; Disease; Disorder; Down Syndrome; Down`s Syndrome; Downs Syndrome; Dysfunction; Electrophysiology; Electrophysiology (science); Encephalon; Encephalons; Fore-Brain; Forebrain; Functional disorder; Hyperactivity Disorder NOS; Hyperactivity Disorder, Predominantly Hyperactive-Impulsive Type; Hyperkinetic Syndrome; Idiopathic Parkinson Disease; Intracellular Communication and Signaling; Kanner`s Syndrome; Langdon Down syndrome; Learning Disorders; Lewy Body Parkinson Disease; Location; Measurement; Measures; Mediating; Mongolism; Nerve Cells; Nerve Unit; Nervous; Nervous System, Brain; Neural Cell; Neurocyte; Neurons; Neurophysiology / Electrophysiology; Noise; Nucleus; Optic Tectum; Paralysis Agitans; Parkinson; Parkinson Disease; Parkinson`s; Parkinson`s disease; Parkinsons disease; Pattern; Physiopathology; Primary Parkinsonism; Primary Senile Degenerative Dementia; Process; Property; Property, LOINC Axis 2; Prosencephalon; Protocol; Protocols documentation; Research; Role; Schizophrenia; Schizophrenic Disorders; Signal Transduction; Signal Transduction Systems; Signaling; Site; Stimulus; Structure; Superior Colliculus; Tectums, Optic; Testing; Transmission; Trisomy 21; Visual; attention deficit hyperactive disorder; auditory stimulus; base; biological signal transduction; cholinergic; chromosome 21 trisomy syndrome; congenital acromicria syndrome; dementia of the Alzheimer type; dementia praecox; disease/disorder; effective therapy; electrical microstimulation; experiment; experimental research; experimental study; gaze; information processing; intervention development; microstimulation; morbus Down; neural; neural mechanism; neuromechanism; neuronal; pathophysiology; perceptual stimulus; physicochemical phenomena related to the senses; primary degenerative dementia; pseudohypertrophic progressive muscular dystrophy; public health relevance; relating to nervous system; research study; response; schizophrenic; senile dementia of the Alzheimer type; sensory stimulus; social role; superior colliculus Corpora quadrigemina; therapy development; transmission process; treatment development; trisomy 21 syndrome; visual stimulus; visual tectum
Project start date: 1980-04-01
Project end date: 2013-08-31
Budget start date: 1-SEP-2010
Budget end date: 31-AUG-2011
PFA/PA: PA-07-070
5R01EY019179-31 (2010): $629252
5R01EY019179-30 (2009): $625313
ANALYSIS OF SPACE BY THE AUDITORY SYSTEM
Eric Knudsen
Stanford University Stanford, Ca 94305
Grant 5R01DC000155-11 from National Institute On Deafness And Other Communication Disorders IRG: HAR
Abstract: The auditory system derives the location of a sound source from multiple acoustic cues. The strategies of information processing used by the auditory system to evaluate and integrate these cues will be studied with extracellular recording techniques in the barn owl. Neuronal activity that reflects auditory spatial analysis is found in the optic tectum, where neurons are sharply tuned for sound source location and are organized according to their spatial tuning to form a physiological map of space. Digitally synthesized sounds delivered dichotically and in a free-field will be used to elucidate the integrative basis of their spatial tuning and of the space map. The underlying processes involve the real-time analysis of time-varying complex signals, the comparison and exact evaluation of differences in signals at the two ears, and the detection of particular sets of cues that are associated with appropriate locations in space. Revealing the mechanisms by which these functions are carried out will broaden substantially our understanding of information processing in the nervous system. Auditory experience during early life shapes sound localization behavior and the spatial tuning of neurons in the optic tectum; pilot studies indicate that early visual experience has a similar influence on these auditory functions. Behavioral experiments will investigate the role of vision in the development of sound localization. The sensitive and critical periods will be elucidated and the neural basis of this developmental plasticity will be sought. Answers to questions such as how and where experience exerts its influence on brain development and what causes the brain to become refractory to this influence after the end of the critical period will provide a foundation for formulating optimal therapeutic procedures for the prevention of perceptual handicaps (such as language impairment and learning disorders) and the recovery of mental function, especially among individuals who have suffered sensory losses early in life.
Keywords: BRAIN, NEURAL PATHWAYS AND TRACTS, AUDITORY PATHWAYS, EAR, HEARING, AUDITORY DISCRIMINATION, ENVIRONMENT, ORIENTATION, PHYSICAL PROPERTIES, SOUND, SENSORY-PERCEPTUAL PROCESSES, SPATIAL PERCEPTION, BRAIN, MESENCEPHALON, COLLICULUS SUPERIOR, EAR, HEARING, AUDIOSTIMULUS, EAR, HEARING, BINAURAL HEARING, EYE, VISUAL PERCEPTION, SPATIAL PERCEPTION VISUAL, INFORMATION PROCESSING AND CONTROL (NEURAL), NERVOUS SYSTEM, NEURONS, AXONS, NEUROBIOLOGY, DEVELOPMENTAL, NEUROPHYSIOLOGY, NEUROPLASTICITY, PSYCHOLOGY, NEUROPSYCHOLOGY, SENSORY DEPRIVATION, VISUAL DEPRIVATION, STIMULUS-RESPONSE, neuroanatomy, neurophysiology, psychobiology, ANIMALS, CHORDATES, BIRDS, BIOMEDICAL SYSTEMS AUTOMATED, COMPUTER PROCESSING OF LABORATORY DATA, electrophysiology, histology
Project start date: 1980-04-01
Project end date: 1991-06-30
5R01DC000155-18 (1997): $360168
5R01DC000155-16 (1995): $339910
Eric Knudsen
Stanford University Stanford, Ca 94305
Grant 5R01DC000155-15 from National Institute On Deafness And Other Communication Disorders IRG: HAR
Abstract: Sensory experience during early life can have profound and long-lasting effects on brain function. During critical periods in brain development, patterns of neural connectivity are especially susceptible to the shaping influence of experience. The proposed research will investigate, at the cellular and molecular levels, how experience modifies the brain and what mechanisms underlie critical periods. The results could have a major impact on our ability to treat a wide variety of human dysfunctions, particularly those resulting from birth defects, childhood disease or injury which necessarily entail abnormal environmental influences on brain development. The experimental system is a portion of the central auditory pathway in barn owls that is involved with sound localization; the barn owl s hearing, sound localization capabilities and associated neural pathways are similar to those of humans. Behavioral studies have shown that sound localization is shaped powerfully by an interaction of auditory and visual experience during early life, and the sensitive and critical periods have been characterized in detail. A neural correlate of the behavioral plasticity has been found in the optic tectum (superior colliculus), where neurons respond to both auditory and visual stimuli in a space-specific manner. Large adaptive changes in the auditory spatial tuning of these neurons are induced during early life either by chronic monaural occlusion (which changes the values of sound localization cues) or prismatic displacement of the visual field (which changes the locations to which cue values correspond). Neurophysiological, pharmacological and anatomical techniques will be used to study the mechanisms that underlie these experience-dependent changes. Digitally synthesized sound delivered through earphones will be used to describe the changes in auditory spatial tuning in terms of changes in unit tuning for localization cues. The sites in the auditory pathway where the adaptive changes take place will be identified physiologically using acute and chronic unit recording. A variety of histological techniques will be used to search for anatomical correlates of the plasticity. Once the site of plasticity is determined, the dynamics of the adjustment process, the nature of the instructive signal, and the pharmacological basis of the process will be investigated. With this information in hand, cellular and molecular correlates of the sensitive and critical periods that regulate these adaptive changes will be determined, and attempts will be made to block or restore the plasticity. The results of this research will reveal general principles of brain development, the consequences of early normal and abnormal experience, and the strategies used by the brain to deal adaptively with different kinds of sensory challenges.
Keywords: auditory discrimination, auditory pathway, orientation, sound, auditory stimulus, binaural hearing, cue, developmental neurobiology, experience, glutamate receptor, neural information processing, neural plasticity, neuroanatomy, neurophysiology, neuropsychology, psychobiology, space perception, stimulus /response, superior colliculus, visual deprivation, Aves, computer graphics /printing, computer processing of laboratory data, computer program /software, electrophysiology, histology
Project start date: 1980-04-01
Project end date: 1998-06-30
5R01DC000155-15 (1994): $324485
ANALYSIS OF SPACE BY THE AUDITORY SYSTEM
Eric Knudsen
Stanford University Stanford, Ca 94305
Grant 5R01DC000155-14 from National Institute On Deafness And Other Communication Disorders IRG: HAR
Abstract: Sensory experience during early life can have profound and long-lasting effects on brain function. During critical periods in brain development, patterns of neural connectivity are especially susceptible to the shaping influence of experience. The proposed research will investigate, at the cellular and molecular levels, how experience modifies the brain and what mechanisms underlie critical periods. The results could have a major impact on our ability to treat a wide variety of human dysfunctions, particularly those resulting from birth defects, childhood disease or injury which necessarily entail abnormal environmental influences on brain development. The experimental system is a portion of the central auditory pathway in barn owls that is involved with sound localization; the barn owl s hearing, sound localization capabilities and associated neural pathways are similar to those of humans. Behavioral studies have shown that sound localization is shaped powerfully by an interaction of auditory and visual experience during early life, and the sensitive and critical periods have been characterized in detail. A neural correlate of the behavioral plasticity has been found in the optic tectum (superior colliculus), where neurons respond to both auditory and visual stimuli in a space-specific manner. Large adaptive changes in the auditory spatial tuning of these neurons are induced during early life either by chronic monaural occlusion (which changes the values of sound localization cues) or prismatic displacement of the visual field (which changes the locations to which cue values correspond). Neurophysiological, pharmacological and anatomical techniques will be used to study the mechanisms that underlie these experience-dependent changes. Digitally synthesized sound delivered through earphones will be used to describe the changes in auditory spatial tuning in terms of changes in unit tuning for localization cues. The sites in the auditory pathway where the adaptive changes take place will be identified physiologically using acute and chronic unit recording. A variety of histological techniques will be used to search for anatomical correlates of the plasticity. Once the site of plasticity is determined, the dynamics of the adjustment process, the nature of the instructive signal, and the pharmacological basis of the process will be investigated. With this information in hand, cellular and molecular correlates of the sensitive and critical periods that regulate these adaptive changes will be determined, and attempts will be made to block or restore the plasticity. The results of this research will reveal general principles of brain development, the consequences of early normal and abnormal experience, and the strategies used by the brain to deal adaptively with different kinds of sensory challenges.
Keywords: auditory discrimination, auditory pathway, orientation, sound, space perception, auditory stimulus, binaural hearing, cue, developmental neurobiology, experience, glutamate receptor, neural information processing, neural plasticity, neuroanatomy, neurophysiology, neuropsychology, psychobiology, stimulus /response, superior colliculus, visual deprivation, visual space perception, Aves, computer graphics /printing, computer processing of laboratory data, computer program /software, electrophysiology, histology
Project start date: 1980-04-01
Project end date: 1998-06-30
5R01DC000155-14 (1993): $304071
5R01DC000155-13 (1992): $252703
Mechanisms Of Instructed Learning In The Auditory System
Eric Knudsen
Stanford University Stanford, Ca 94305
Grant 5R01DC005601-05 from National Institute On Deafness And Other Communication Disorders IRG: ZRG1
Abstract: Much of what the brain learns from experience, including language and sound identification and localization, is acquired through the mechanisms of supervised learning. In supervised learning, plasticity in one network of neurons is regulated or guided by information from another network. Our knowledge of the mechanisms of plasticity has increased tremendously over the past decade. In contrast, our knowledge of the mechanisms that regulate and instruct plasticity remains primitive.The calibration of the auditory system s map of space by the visual system is a well-characterized example of supervised learning. In the barn owl, the site in the auditory pathway where visual signals exert there effects, and the structural and functional changes they cause, have been determined. However, the properties of the instructive signals themselves, and the mechanisms by which they exert their effects, remain a mystery.The proposed research will study the instructive signals that calibrate the auditory space map in the owl. Extracellular electrophysiological techniques will be used to measure responses of instructive neural activity to visual, auditory and cross-modal parameters of stimulation. Pharmacological techniques will be used to determine the neurotransmitters that mediate the instructive signals, and the contribution of neuromodulators to the regulation of auditory plasticity. Anatomical techniques will be used to identify the source of input that gates the instructive activity. Behavioral techniques will be used to study the properties of the instructive signal as it occurs naturally in trained animals. Finally, we will manipulate the instructive signal in an attempt to train neural responses to specific auditory stimuli.This research aims at understanding, in detail, mechanisms that instruct neural plasticity. A thorough knowledge of these instructive mechanisms and the principles by which they operate will add substantially to our understanding of how the nervous system learns from experience. This, in turn, may lead to improved methods for teaching both normal and learning disabled children, as well as to improved therapeutic strategies for maximizing the restoration of function to patients following neurological injury or disease.
Keywords: auditory pathway, learning, neural information processing, neural plasticity, stimulus /response, acetylcholine, auditory stimulus, gamma aminobutyrate, inferior colliculus, neuron, neurotransmitter, neurotransmitter receptor, norepinephrine, superior colliculus, visual stimulus, behavior test, behavioral /social science research tag, electrophysiology, owl
Project start date: 2002-07-15
Project end date: 2007-12-30
5R01DC005601-05 (2006): $352277
Sponsored Links Excellgen http://Excellgen.com
5R01DC005601-04 (2005): $360617
5R01DC005601-03 (2004): $360485
5R01DC005601-02 (2003): $360357
1R01DC005601-01 (2002): $360235
ANALYSIS OF SPACE BY THE AUDITORY SYSTEM
Eric Knudsen
Stanford University Stanford, Ca 94305
Grant 5R01DC000155-23 from National Institute On Deafness And Other Communication Disorders IRG: HAR
Abstract: Experience plays a critical role in shaping the structural and functional properties of the developing central nervous system. When experience is rich and normal, it leads to a brain that is optimized for the individual. When experience is chronically abnormal, however, as a consequence of disease, defects, injury or dysfunction, for example, experience can lead to abnormal structure and function. For the many pathways that are subject to sensitive periods, these effects result in permanent neurological disability. The proposed research investigates, at the systems, cellular and molecular levels, the effects of experience on the developing central auditory system. The research focuses on the pathways that process spatial information, pathways that are known in relative detail. The effects of experience on these pathways are dramatic and readily quantified. The barn owl is studied because the space processing pathways are particularly well developed in this species, and the sensitive periods have been established. Extracellular neurophysiological, pharmacological and anatomical techniques will be combined with dichotic sound stimulation to characterize both the effects of abnormal sensory experience and the ability of the auditory system to recover normal function following restoration of normal experience. The effects of two different sensory challenges will be compared abnormal vision and abnormal hearing. In the midbrain space processing pathway, where sites of plasticity are already known, the research emphasizes the cellular and molecular mechanisms of plasticity and sensitive periods (the roles of anatomical reorganization, specific neurotransmitter receptors, neurotrophins, and sex steroids). Also, the anatomical source and nature of the instructive signal that governs this plasticity will be explored. In the forebrain space processing pathway, the research concentrates on identifying sites of plasticity and characterizing the properties of the plasticity. This research aims to provide a mechanistic understanding of the effects of experience on the developing central auditory system. Knowledge of the aspects of neuronal connectivity that are altered by experience and how these alterations are implemented may lead to improved therapeutic strategies for the many individuals who suffer from or have suffered from prolonged periods of abnormal sensory experience. In addition, the results should teach us much about the normal structure, function and development of the central auditory system.
Keywords: animal developmental psychology, developmental neurobiology, hearing, psychoacoustics, space perception, auditory cortex, auditory nuclei, auditory pathway, experience, hormone regulation /control mechanism, neural information processing, neural plasticity, neurotransmitter receptor, neurotrophic factor, sex hormone, behavioral /social science research tag, owl
Project start date: 1980-04-01
Project end date: 2003-06-30
5R01DC000155-23 (2002): $387411
5R01DC000155-22 (2001): $378999
5R01DC000155-21 (2000): $370827
5R01DC000155-20 (1999): $362899
Eric Knudsen
Stanford University Stanford, Ca 94305
Grant 2R01DC000155-19 from National Institute On Deafness And Other Communication Disorders IRG: HAR
Abstract: Experience plays a critical role in shaping the structural and functional properties of the developing central nervous system. When experience is rich and normal, it leads to a brain that is optimized for the individual. When experience is chronically abnormal, however, as a consequence of disease, defects, injury or dysfunction, for example, experience can lead to abnormal structure and function. For the many pathways that are subject to sensitive periods, these effects result in permanent neurological disability. The proposed research investigates, at the systems, cellular and molecular levels, the effects of experience on the developing central auditory system. The research focuses on the pathways that process spatial information, pathways that are known in relative detail. The effects of experience on these pathways are dramatic and readily quantified. The barn owl is studied because the space processing pathways are particularly well developed in this species, and the sensitive periods have been established. Extracellular neurophysiological, pharmacological and anatomical techniques will be combined with dichotic sound stimulation to characterize both the effects of abnormal sensory experience and the ability of the auditory system to recover normal function following restoration of normal experience. The effects of two different sensory challenges will be compared abnormal vision and abnormal hearing. In the midbrain space processing pathway, where sites of plasticity are already known, the research emphasizes the cellular and molecular mechanisms of plasticity and sensitive periods (the roles of anatomical reorganization, specific neurotransmitter receptors, neurotrophins, and sex steroids). Also, the anatomical source and nature of the instructive signal that governs this plasticity will be explored. In the forebrain space processing pathway, the research concentrates on identifying sites of plasticity and characterizing the properties of the plasticity. This research aims to provide a mechanistic understanding of the effects of experience on the developing central auditory system. Knowledge of the aspects of neuronal connectivity that are altered by experience and how these alterations are implemented may lead to improved therapeutic strategies for the many individuals who suffer from or have suffered from prolonged periods of abnormal sensory experience. In addition, the results should teach us much about the normal structure, function and development of the central auditory system.
Keywords: animal developmental psychology, developmental neurobiology, hearing, psychoacoustics, space perception, auditory cortex, auditory nuclei, auditory pathway, experience, hormone regulation /control mechanism, neural information processing, neural plasticity, neurotransmitter receptor, neurotrophic factor, sex hormone, behavioral /social science research tag, owl
Project start date: 1980-04-01
Project end date: 2003-06-30
2R01DC000155-19 (1998): $377619
NEURAL CONTROL OF GOAL DIRECTED HEAD MOVEMENT
Eric Knudsen
Stanford University Stanford, Ca 94305
Grant 5R01NS027687-03 from National Institute Of Neurological Disorders And Stroke IRG: NEUB
Abstract: Brain mechanisms that program head movements will be studied in the barn owl as a model system for understanding principles of motor system organization and sensorimotor integration. The owl s optic nerve tectum (superior colliculus) issues commands that redirect the head to stimulus sources; the site activity in the tectum represents the direction and magnitude of the desired movement. The motor code is "high-order" in that it specifies a change in orientation, but not the forces that must be generated in particular muscles to accomplish the movement. This place code for movement is subsequently transformed into an intermediate code by 4 independent saccade generators which represent orthoganal (up, down, left and right) vector components if the desired movement. This transformation of motor command signals will be studied using microstimulation, neurophysiological, anatomical, and behavioral techniques; barn owls are chosen because they make extremely accurate, rapid head movements. Specifically, we will determine which nuclei in the brainstem are responsible for transforming the place code into vector component code, and the physiological and anatomical mechanisms by which the transformation is accomplished. In addition, we will address such fundamental issues as how the motor command signals are calibrated by visual experience and whether the commands for head movement are issued in a head-centered or a body-centered frame of reference. The results of these studies will elucidate the computational strategies that underlie motor control in a complex, multi-articulated system. In addition, these studies will teach us about how the brain represents desired movements, how and what components of movement are processed in parallel, and how information is translated from one code to another and from one reference system to another. Knowledge of how the brain programs and executes movements will be important to the development of prosthetics, robotics and computational theory, and to our understanding and appreciation of principles of brain function. Such information will also provide a foundation for accurate interpretation of clinical signs relating to head movement control (such as spasmodic torticollis, supranuclear palsy, etc.), for diagnosis of movement disorders of central origin, and for designing optimal therapies and corrective procedures for certain classes of motor dysfunction.
Keywords: brain stem, head movement, neural information processing, neuromuscular system, saccade, sensorimotor system, superior colliculus, biological model, electrostimulus, neuroanatomy, neurophysiology, neuropsychology, stimulus /response, visual feedback, Aves, electromyography, histology
Project start date: 1990-04-01
Project end date: 1994-03-31
5R01NS027687-03 (1992): $148823
Sponsored Links Excellgen http://Excellgen.com
Analysis Of Space By The Auditory System
Eric Knudsen
Stanford University Stanford, Ca 94305
Grant 5R01DC000155-28 from National Institute On Deafness And Other Communication Disorders IRG: ZRG1
Abstract: Adaptive plasticity in the central nervous system is essential for the recovery of function following injury, stroke or neurological disease or following the restoration of hearing with prosthetics. Although the capacity for brain plasticity is great during early life, it becomes substantially more restricted in adults. This research focuses on the capacity for plasticity in the adult central nervous system, the factors that control it, and ways to maximize it. We will explore the mechanisms by which experience shapes the functional and anatomical properties of the central auditory system in adult barn owls. In the midbrain auditory localization pathway, adaptive changes in cellular structure and function can be quantified rigorously and detected with high sensitivity. Manipulations of sensory experience cause dramatic functional, physiological and anatomical changes in juvenile owls. This research will test the effects of similar manipulations of experience on adult owls and will explore environmental and psychological factors that may regulate this plasticity. Reorganization of the midbrain auditory pathway will be induced in adults by exposing them to various proven regimes of sensory experience. Plasticity will be assessed with behavioral, neurophysiological, anatomical and pharmacological techniques. The influence of attention and arousal on plasticity will be determined by exposing owls to sessions of sensorimotor enrichment. In addition, the effects of natural stressors, such as social dominance, crowding and environmental change, on cellular plasticity will be measured. The mechanisms of action of these psychological factors (attention, arousal and stress) and the neuromodulatory systems that they engage will be investigated. We will compare and contrast the mechanisms of plasticity in adults with those that have been shown to operate in juveniles. The results of this research will increase our understanding of exactly how experience shapes the functional properties of the adult central auditory system. Knowledge of the cellular mechanisms that underlie adaptive plasticity and of the regulation of these mechanisms by psychological state will help to formulate optimal strategies for teaching and optimal therapies for rehabilitation following brain injury, disease or remediation of genetic defects.
Keywords: auditory pathway, developmental neurobiology, neural plasticity, psychoacoustics, space perception, animal developmental psychology, auditory cortex, auditory nuclei, experience, hearing, neural information processing, neurotransmitter, neurotransmitter receptor, behavioral /social science research tag, immunocytochemistry, owl
Project start date: 1980-04-01
Project end date: 2008-06-30
5R01DC000155-28 (2007): $348968
5R01DC000155-27 (2006): $359685
5R01DC000155-26 (2005): $367808
5R01DC000155-25 (2004): $367697
2R01DC000155-24 (2003): $366883
NERVOUS SYSTEM REGENERATION AND PLASTICITY
Eric Knudsen
Stanford University Stanford, Ca 94305
Grant 5T32NS007158-25 from National Institute Of Neurological Disorders And Stroke IRG: NST
Project start date: 1979-07-01
Project end date: 2006-12-31
5T32NS007158-25 (2004): $26049
5T32NS007158-20 (1999): $247818
5T32NS007158-19 (1998): $113724
5T32NS007158-18 (1997): $209300
ANALYSIS OF SPACE BY THE AUDITORY SYSTEM
Eric Knudsen
Stanford University Stanford, Ca 94305
Grant 5R01DC000155-17 from National Institute On Deafness And Other Communication Disorders IRG: HAR
Project start date: 1980-04-01
Project end date: 1998-06-30
5R01DC000155-17 (1996): $346317
Sponsored Links Excellgen http://Excellgen.com
NERVOUS SYSTEM REGENERATION AND PLASTICITY
Eric Knudsen
Stanford University Stanford, Ca 94305
Grant 5T32NS007158-17 from National Institute Of Neurological Disorders And Stroke IRG: NST
Project start date: 1979-07-01
Project end date: 2000-06-30
5T32NS007158-17 (1996): $202028
5T32NS007158-15 (1994): $200259
5T32NS007158-14 (1993): $171617
5T32NS007158-13 (1992): $194816