J. David Dickman, Ph.D.
Associate Professor
Anatomy and Neurobiology
Research Associate Professor
Otolaryngology
Neurosciences Program
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Office Phone: 314-747-7221
Lab Phone: 314-747-7224
Other Phone:
FAX: 314-747-7206
Box: 8108
Lab Address: Central Institute for the Deaf Research Building, 4560 Clayton Ave., Room 2130
Email: ddickman@wustl.edu
Website: http://vestibular.wustl.edu
Keywords: spatial orientation; motion detection; vestibular; development; navigation
Short Research Description: Neural mechanisms underlying motion detection and spatial orientation |
Research Abstract:
My laboratory is examining the neural mechanisms responsible for motion detection and spatial orientation. We are also actively investigating the role of gravity as an epigenetic reference for the development of movement receptors and motion related behaviors such as gaze control. Currently, we are involved in three major projects.
First, we are investigating the neural basis for detection of the Earth's magnetic field by homing pigeons. We have identified small iron magnetite particles in the third otolith vestibular receptor ogran, which could be used as an inclined compass for use in homing and migrational navigation. Neural recordings from these receptors are being perfomed while manipulating the spatial direction and magnitude of magnetic fields relative to the Earth and the bird's head. Behavioral experiments are planned to examine the necessity for magnetic field detection in homing pigeons during spatial orientation tasks.
Second, we are examining the synthesis of afferent information from the different vestibular receptor organs by central brainstem neurons. How is fine discrimination for directional motion encoded for orientation in three-dimensional space? Electrophysiological recordings from single and clusters of vestibular neurons are obtained while separately stimulating discrete receptor populations in both birds and primates. Intracellular dyes are injected in some neurons in order to determine axonal target patterns that can be correlated with the previously characterized response properties.
Third, we are investigating gravity as a trophic determinant for the development of vestibular receptors and the central neural organization of motion related behavior. Developing quails and mice are reared in either normal (1g), hypergravity (1.5 - 3g), or microgravity environments (.003g, STS flights or International Space Station) in order to examine the structural, functional, and behavioral elements affected by altered gravity exposure. |
Selected Publications:
Zakir M, Dickman, JD. Regeneration of vestibular otolith afferents following ototoxic damage. J Neuroscience 2006 26:2882-2893.
Haque A, Dickman JD. Vestibular gaze stabilization: Different behavioral strategies for arboreal and terrestrial birds. J Neurophysiol 2005 93:1165-1173.
Angelaki DE, Shaikh AG, Green AM, Dickman JD. Neurons compute internal models of the physical laws of motion. Nature 2004 430:560-564.
Dickman JD, Angelaki DE. Dynamics of vestibular neurons during rotational motion in alert rhesus monkeys. Exp Brain Res 2004 155:91-101.
Hughes I, Blasiole B, Huss D, et al. Otopetrin is required for otolith formation in the zebra fish Danio rerio. Dev Biol 2004 276:391-402. |