Research Interests:
We study the neural mechanisms underlying the control of balance
and spatial orientation. The broad objectives are: 1) to define
strategies used by the central nervous system (CNS) for controlling
gaze and posture; and 2) to characterize the interaction in the
CNS among signals dependent on the motion and gravity sensors in
the inner ear and vision.
Experimental protocols for human subjects and animals use a multi-axis
rotator and a movable force platform. Experiments with humans involve
both normal subjects and those with inner ear or CNS diseases, the
latter including the autosomal dominant cerebellar ataxias. We take
measurements of the eyes, head, and body position and orientation
during rotation of the subject and/or the visual surrounding, and
during movement of the surface on which the subject stands. One
animal project uses rats to study the neurochemical changes in the
CNS that accompany compensation for inner ear disease and to correlate
the neurochemistry with the activity of single neurons. Another
animal project uses transgenic mice that carry an ataxia gene. The
aim is to quantify the movement deficits and to correlate them with
the pattern and time course of neurodegeneration due to different
ataxia genes and their promoters. Mathematical modeling uses techniques
of control systems analysis and neural networks to provide a conceptual
framework for the experimental results and to predict possible mechanisms
whereby the CNS can adapt to changes in the environment, such as
micro-gravity, that can affect movement and posture.
Selected Publications:
(For a comprehensive list of recent publications, refer to PubMed, a service provided by the National Library of Medicine.)
Engel KC, Anderson JH, Gomez CM, Soechting JF. Deficits in ocular and manual tracking due to episodic ataxia type 2. Mov Disord. 2004 Jul;19(7):778-87.
Engle, KC, Anderson, JH, Soechting, JF. Oculomotor Tracking in
Two Dimensions. J Neurophysiol 81:1597-1602, 1999.
Gomez, CM, Thompson, RM, Gammack, JT, Perlman, SL, Dobyns, WB,
Truwit, CL, Zee, DS, Clark, HB, Anderson, JH. Spinocerebellar ataxia
type 6: Gaze-evoked and vertical nystagmus, Purkinje cell degeneration,
and variable age of onset. Ann Neurol, 42:993-950, 1997.
Nelson, S.R., R.P. DiFabio, and J.H. Anderson. 1995. Vestibular
and sensory interaction deficits assessed by dynamic platform posturography
in patients with multiple sclerosis. Annals of Otology, Rhinology,
Laryngology 104:62-68.
Recent Graduate Students
Chao Young Lee (Ph.D., Biomedical Engineering, 1993; parallel,
distributed neural network modeling of the vestibular system). Research
Scientist with private company.
Galen Kaufman (Ph.D., Veterinary Biology, 1993; neurochemistry
of the vestibular system). Postdoctoral fellow in the laboratory
of Dr. Adrian Perachio, University of Texas, Galveston.
|