1985 — 1994 |
Cohen, Bernard |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Visual Control of the Oculomotor System @ Mount Sinai School of Medicine of Cuny
This study proposes to investigate the coordinate basis for visual processing of retinal slip information in the pretectum (PT) and accessory optic system (AOS) of the monkey. This will be done by finding the planes of visual surround motion that produce maximal excitation and inhibition in neurons in these regions. Alert rhesus and cynomolgus monkeys will be used. They will be trained to watch spots of light projected on a screen. Using a planetary projector, motion of the visual surround will be produced in various planes around axes going through the center of the head. Visual motion in other planes will also be used. PT and AOS units, recorded extracellularly, will be identified wherever possible by antidromic and orthodromic stimulation. They will be tested to determine which planes of visual surround motion produce the greatest and least response. We anticipate that the maximum and minimum response planes of many PT and AOS neurons will be parallel to the planes of the semicircular canals. Effects of changes in eye position will be tested to determine if a central representation of retinal slip in stimulus planes is represented in activity of PT and AOS neurons. At regions where unt activity is associated with motion in various spatial planes, we will electrically stimulate and determine the plane of the induced eye movements. Electrolytic and chemical lesions will be made in PT and AOS and effects on OKN and OKAN will be determined. The visual cortex will be lesioned and effects on the response of PT and AOS neurons to surround motion will be noted. Finally, the pathways by which activity reaches the vestibular nuclei from PT and AOS will be determined. When this work is completed, we should have a clearer idea of how retinal slip related to head motion is coded, and over what pathways it projects to the brainstem. We should also understand better the organization of the subcortical visual system that sends activity to the vestibular system to help stabilize gaze during head movements.
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0.966 |
1985 — 1991 |
Cohen, Bernard |
T32Activity Code Description: To enable institutions to make National Research Service Awards to individuals selected by them for predoctoral and postdoctoral research training in specified shortage areas. |
Interdisciplinary Research Training in Neurobiology @ Mount Sinai School of Medicine of Cuny |
0.966 |
1985 — 1991 |
Cohen, Bernard |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
The Oculomotor System and Body Postural Mechanisms @ Mount Sinai School of Medicine of Cuny
Movement of the head about axes tilted from the vertical (off-vertical axis rotation) has a dramatic effect on the vestibulo-ocular reflex (VOR). It enhances compensatory responses and suppresses post-rotatory responses. Thus the effect of a rotating gravity vector on the VOR is similar to that of vision. The object of this research is to determine where in the labyrinth activity related to rotating gravity vectors arises, and how it is processed centrally. Specifically we wish to determine how it couples to the velocity storage mechanism in the VOR that is responsible for lengthening the time constant of the VOR and generating slow phases of nystagmus. This integrator also serves as a focus for visual-vestibular interactions. In the proposed experiments we will study the dynamics of eye movements during vertical and off vertical rotations and during rotation of the visual surround. These stimuli induce per and post rotatory nystagmus and optokinetic nystagmus (OKN) and optokinetic after nystagmus (OKAN). Extracellular unit activity will be recorded in the vestibular nerve the vestibular nuclei, the prepositus nucleus and the flocculus. Extracellular activity and eye movements will be analyzed in the time and frequency domains and compared to predictions made from central system models of the VOR. This research should help elucidate how and where gravity is sensed by the labyrinth, how visual and vestibular sensory information is combined centrally and how they contribute to production of compensatory eye movement against head movements in all planes.
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0.966 |
1992 — 2009 |
Cohen, Bernard |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Oculomotor System and Body Postural Mechanisms @ Mount Sinai School of Medicine of Cuny
The nodulus and uvula of the vestibulo-cerebellum appear to play an important role in controlling a process in the vestibular system that is responsible for producing its dominant time constant and low frequency characteristics. We have termed this process "velocity storage" because it stores or holds activity related to head velocity and to the velocity of slow phases of nystagmus. The aim of the research is to determine how the nodulus and uvula control velocity storage in the vestibulo-ocular reflex (VOR) and to show how and where this control is manifested in the vestibular nuclei. This will be done in lesion, stimulation and single unit recording studies in rhesus monkeys. We also plan to determine the contribution of the inferior olive to habituation of the VOR and to plastic modification of the gain of the VOR and of OKN and OKAN. Experiments involve study of the dynamics of eye movements induced by angular rotation and surround movement before and after lesions of the nodulus and uvula, stimulation of the nodulus and uvula to show the effect on nystagmus induced by rotation, and recording of activity of single neurons in the nodulus and uvula and in the vestibular nuclei associated with animal or surround rotation. It will be determined how this activity is changed during visual suppression of the VOR or during tilts that cause nystagmus to decline rapidly or be "dumped". Extracellular activity and eye movements will be analyzed in the time domain and compared to predictions made from modelling the VOR before and after lesions. Animals will be trained with spectacles that magnify or reduce its visual field to alter the gain of the VOR plastically and effects of nodulus and uvula lesions on the plastic adaptation will be studied. This research should establish the role of the nodulus and uvula in controlling low frequency components of the VOR and show how and where in the vestibular nuclei this control is established. We also hope to determine those cells in the vestibular nuclei that are responsible for producing velocity storage and how their firing frequencies are adapted by the vestibulo-cerebellum.
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0.966 |
1997 — 2001 |
Cohen, Bernard |
P01Activity Code Description: For the support of a broadly based, multidisciplinary, often long-term research program which has a specific major objective or a basic theme. A program project generally involves the organized efforts of relatively large groups, members of which are conducting research projects designed to elucidate the various aspects or components of this objective. Each research project is usually under the leadership of an established investigator. The grant can provide support for certain basic resources used by these groups in the program, including clinical components, the sharing of which facilitates the total research effort. A program project is directed toward a range of problems having a central research focus, in contrast to the usually narrower thrust of the traditional research project. Each project supported through this mechanism should contribute or be directly related to the common theme of the total research effort. These scientifically meritorious projects should demonstrate an essential element of unity and interdependence, i.e., a system of research activities and projects directed toward a well-defined research program goal. |
Spatial Orientation &Plasticity in the Vestibular Syste @ Mount Sinai School of Medicine of Nyu
Spatial orientation can be defined operationally as the ability to align internal spatial vectors with gravito-inertial acceleration (GIA). Accurate alignment of these internal vectors to GIA is critical for balance and maintenance of gaze during locomotion, and plasticity is necessary to correct imbalances. The central themes of the Program Project are to understand the neural basis for spatial orientation and plasticity in the vestibular system. A multifaceted approach will be used that includes modeling, human and animal behavioral studies, single unit analysis, and molecular studies of neurotransmission. The proposed Program Project consists of two model-based behavioral and single unit studies in the monkey and rabbit to determine how spatial orientation is controlled by the nodulus and uvula. This will be done by comparing the dynamics of unit activity to those of eye velocity during tilts of gravitoinerial acceleration vector, by doing comparative behavior studies in these frontal and lateral eyed animals, and in determining how focused lesions in various parts of the zonal structure of the nodulus and uvula affect orientation vectors of velocity storage. A molecular/anatomical study will focus on nitric oxide and related molecules as well as on excitatory amino acid receptors involved during developmental in the vestibular system and in adaptation of parameters related to spatial orientation and gain control in the vestibulo-ocular reflex (VOR). A fourth study will determine how spatial orientation is manifest in the eye and head movements of freely moving human subjects with and without velocity storage during angular locomotion. Two core modules will support research in all of the projects. Through this study of spatial orientation and plasticity in the VOR, it is anticipated that important insights will be obtained about how information related to the GIA vector is coded and adapted by the vestibulo-cerebellum and vestibular nuclei, what role this coding plays in maintenance of posture and balance during locomotion, and how locomotion and maintenance of gaze is disordered when orientation to the GIA is disturbed.
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0.966 |
1997 — 2002 |
Cohen, Bernard |
P30Activity Code Description: To support shared resources and facilities for categorical research by a number of investigators from different disciplines who provide a multidisciplinary approach to a joint research effort or from the same discipline who focus on a common research problem. The core grant is integrated with the center's component projects or program projects, though funded independently from them. This support, by providing more accessible resources, is expected to assure a greater productivity than from the separate projects and program projects. |
Core--Electronics/Computer @ Mount Sinai School of Medicine of Cuny
biomedical equipment; vision; computer center; biomedical facility;
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0.966 |
1997 — 2001 |
Cohen, Bernard |
P01Activity Code Description: For the support of a broadly based, multidisciplinary, often long-term research program which has a specific major objective or a basic theme. A program project generally involves the organized efforts of relatively large groups, members of which are conducting research projects designed to elucidate the various aspects or components of this objective. Each research project is usually under the leadership of an established investigator. The grant can provide support for certain basic resources used by these groups in the program, including clinical components, the sharing of which facilitates the total research effort. A program project is directed toward a range of problems having a central research focus, in contrast to the usually narrower thrust of the traditional research project. Each project supported through this mechanism should contribute or be directly related to the common theme of the total research effort. These scientifically meritorious projects should demonstrate an essential element of unity and interdependence, i.e., a system of research activities and projects directed toward a well-defined research program goal. |
Core--Support Module For Animal Studies @ Mount Sinai School of Medicine of Cuny
biomedical facility; laboratory rat; laboratory rabbit;
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0.966 |
1997 — 2001 |
Cohen, Bernard |
P01Activity Code Description: For the support of a broadly based, multidisciplinary, often long-term research program which has a specific major objective or a basic theme. A program project generally involves the organized efforts of relatively large groups, members of which are conducting research projects designed to elucidate the various aspects or components of this objective. Each research project is usually under the leadership of an established investigator. The grant can provide support for certain basic resources used by these groups in the program, including clinical components, the sharing of which facilitates the total research effort. A program project is directed toward a range of problems having a central research focus, in contrast to the usually narrower thrust of the traditional research project. Each project supported through this mechanism should contribute or be directly related to the common theme of the total research effort. These scientifically meritorious projects should demonstrate an essential element of unity and interdependence, i.e., a system of research activities and projects directed toward a well-defined research program goal. |
Gaze Compensation During Angular Locomotion @ Mount Sinai School of Medicine of Cuny
Research is proposed to determine the characteristics of gaze produced by head and eye movements during angular locomotion in humans. Normal human subjects will walk or run on a circular treadmill. Their eye movements will be recorded in three dimensions with a video technique and head and body movements with optical methods. It will be determined whether gaze is stabilized in space during angular locomotion, whether the head and eyes both contribute to gaze stabilization, whether the time constant of the aVOR is prolonged by the somatosensory input during angular walking, and whether gaze is spatially oriented to the tilt of gravio-inertial acceleration produced by the centripetal linear acceleration during angular locomotion. Studies will also be done to determine how gaze stabilization during angular locomotion compares to that during tangential centrifugation while standing and during walking in place. It will be determined how the angular VOR (aVOR) is adapted by prolonged walking and how orientation of gaze is disrupted by the absence of velocity storage. Critical parameters that cause adaptation of vestibular time constants during angular walking will be determined. Based on studies in the monkey, it is predicted that the head and eyes of humans will contribute to compensatory gaze nystagmus as angular locomotion rates rise. It is also predicted that gaze velocity in space (Gs), which is the sum of eye in head (Eh) and head on body (Hb) velocity will orient with the trunk to the vector of gravito-inertial acceleration to maintain balance, regardless of the speed of angular walking. It is anticipated that a loss of velocity storage will be associated with a reduction in balance capability, measured by the goodness of alignment of the body vertical to gravito-inertial acceleration. Through a study of how vision, linear acceleration and the somatosensory system affect gaze, this research should give new understanding to the functional role of velocity storage in supporting gaze during locomotion.
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0.966 |
2002 — 2011 |
Cohen, Bernard |
P30Activity Code Description: To support shared resources and facilities for categorical research by a number of investigators from different disciplines who provide a multidisciplinary approach to a joint research effort or from the same discipline who focus on a common research problem. The core grant is integrated with the center's component projects or program projects, though funded independently from them. This support, by providing more accessible resources, is expected to assure a greater productivity than from the separate projects and program projects. |
Core Center @ Mount Sinai School of Medicine of Nyu
DESCRIPTION (provided by applicant): A large and diverse group of researchers studies vestibular function at the Mount Sinai School of Medicine and at Brooklyn College. Research supported by the NIDCD, the NEI, NASA and the NSBRI. The range of research includes basic studies utilizing molecular biological and immunohistochemical techniques, behavioral and single unit studies of rabbits and monkeys, studies of the oculomotor and locomotor capacity of normal humans, subhuman primates and patients with disease of the vestibular system, and studies of the effects of orbital space flight on the vestibular and autonomic nervous systems. A common thread through much of the research is to determine the characteristics and neural bases of spatial orientation and locomotion. Other research is devoted to defining vestibular control of the autonomic system, the cellular and molecular basis of vestibular adaptation and the molecular biology of vestibular development. There is considerable interaction among members of the group, but it could be enhanced to our general benefit. There are also many services and technical advances that are currently too costly or too complex to develop in a single project and which would foster better research in every area. We are applying for such services through a Core Center Grant. Two Research Cores are proposed: Theodore Raphan will direct a Computer, Networking and Electronic Module and Sergei Yakushin, Ph.D., an Engineering and Mechanical Maintenance Module. Bernard Cohen, M.D. and Theodore Raphan, Ph.D., will serve as Core Director and Associate Director, respectively. The goal of the proposed Core Center is to promote the research of each group by providing essential services, technical advances and new methodologies that are too expensive or complex for any one group to carry or develop individually. A second goal is to provide an intellectual nexus through the Core Center that will help unite the group and promote interactions among research teams. Through the last objective, we anticipate that the perspectives of the various groups will be broadened and that the Core Center will foster interdisciplinary studies that will enhance achievement of our common research goals.
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0.966 |
2007 |
Cohen, Bernard |
P30Activity Code Description: To support shared resources and facilities for categorical research by a number of investigators from different disciplines who provide a multidisciplinary approach to a joint research effort or from the same discipline who focus on a common research problem. The core grant is integrated with the center's component projects or program projects, though funded independently from them. This support, by providing more accessible resources, is expected to assure a greater productivity than from the separate projects and program projects. |
Administration Core @ Mount Sinai School of Medicine of Nyu |
0.966 |
2008 — 2011 |
Cohen, Bernard |
P30Activity Code Description: To support shared resources and facilities for categorical research by a number of investigators from different disciplines who provide a multidisciplinary approach to a joint research effort or from the same discipline who focus on a common research problem. The core grant is integrated with the center's component projects or program projects, though funded independently from them. This support, by providing more accessible resources, is expected to assure a greater productivity than from the separate projects and program projects. |
Center Administrative @ Icahn School of Medicine At Mount Sinai
Investigators at the Mount Sinai School of Medicine and Brooklyn College of the City University of New York (CUNY) holding research grants from the NIDCD and with NIH projects in the area of the Program Goals of the NIDCD are applying to renew the grant that supports the Core Center over the last five years. One thread through several of the research projects is to determine the characteristics and neural bases of spatial orientation and locomotion. Other research is devoted to defining vestibular control of the autonomic system, the cellular and molecular basis of vestibular adaptation, and the molecular biology .of vestibular development. A second thread is to develop a better understanding of early immediate gene changes associated with adaptation to vestibular stimulation. A third thread is to develop models of neural function that can be used to provide new pathways to study disease. An important aspect of the collaboration is for translational research on Parkinson locomotion, autonomic function, and motion sickness. There has been considerable interaction among members of the group due to the support provided by the CORE. There have also been advances due to the high level of services and technical support and development that have fostered better research in every area. Theodore Raphan will direct a Computer, Networking, and Electronic Module;Sergei Yakushin, Ph.D. will direct an Engineering and Mechanical Maintenance Module. Bernard Cohen and Theodore Raphan will serve as Core Director and Associate Director, respectively. The goal of the proposed Core Center is to promote the research of each group by providing essential services, technical advances, and new methodologies that are too expensive or complex for any one group to carry or develop individually. A second goal is to provide an intellectual nexus through the Core Center that will help unite the group and promote interactions among research teams. The third is to establish translational research that will benefit patients with problems in locomotion, motion sickness, and autonomic function. Through the last objective, we anticipate that the perspectives of the various groups will be broadened and that the Core Center will foster interdisciplinary studies that will enhance achievement of our common research goals.
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0.966 |
2013 — 2015 |
Cohen, Bernard |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Vestibular Control of the Vasovagal Response @ Icahn School of Medicine At Mount Sinai
DESCRIPTION (provided by applicant): Neurogenic (vasovagal) syncope (VVS) is a significant medical problem. The faint is preceded by a Vasovagal Response (VVR), characterized by a sudden drop in arterial blood pressure (BP) and heart rate (HR). VVS and VVRs are diagnosed using a tilt test, a vestibular stimulus. Despite being relatively common, the neural basis of the VVR and the role of the vestibular system in inducing VVRs are not known. Moreover, there is no small animal model of VVRs. We recently showed that low frequency sinusoidal galvanic vestibular stimulation (sGVS) induces VVRs in anesthetized rats. As in humans, VVRs are also induced in rats by tilt. In the proposed research we will characterize the physiological properties of VVRs in rats, thereby establishing a useful small animal model of human VVRs. We propose that VVRs are induced by strong, repeated stimulation of the vestibulo-sympathetic reflex (VSR), which maintains blood flow to the brain during changes in head position relative to gravity. Aim 1 will characterize the transitions from normal VSR to VVRs using pulses and sinusoids of galvanic stimulation to show that VVRs occur when the VSR is appropriately stimulated. Nose up tilt and Translation-While-Rotating (TWR) will be used to determine the axes of stimulation that are most likely to produce VVRs. Additionally, the low frequency oscillations in HR and BP that are produced by sGVS and tilt reflect activation of Mayer waves, thought to be of fundamental importance in maintaining BP stability. In Aim 2 these oscillations will be modeled using a novel concept in which Mayer wave function is represented by a non-linear relaxation oscillator. In Aim 3, single unit neurophysiological studies in otolith-recipient portions of the caudal vestibular nuclei will identify the functional characteristics and physiological signature of VVR- related neurons. Together, the proposed research will establish a model of VVS, document how the vestibular system controls BP, and demonstrate that VVRs are adaptive compensatory responses that serve to re- equilibrate BP after major perturbations.
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0.966 |