Transcript Developmental and Pathophysiological Studies of Vestibular

Development and Pathophysiology of Central Vestibular System
Kenna D. Peusner, PhD
Professor of Anatomy and Cell Biology
George Washington University Medical Center
Ross Hall, 208, 209, 211, 213, & 215
994-3489, [email protected]
Funding from NIH
“ Synaptic Transmission during Neuronal Differentiation” (R01 DC00970)
“Development of Vestibular Nuclei Neurons” (R01 DC05004)
Vestibular system disorders
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The vestibular system controls posture and balance.
Dizziness is a common symptom reported by patients. In 55% of patients
with dizziness symptoms, the cause is due to vestibular pathology.
In pediatric patients, vestibular symptoms are uncommon as a chief
complaint because children (18 months to three years) rely more heavily on
vision than on vestibular and proprioceptive senses.
However, 50-95% of children with congenital and acquired hearing
impairment have vestibular abnormalities. Developmental delays due to
vestibular disorders include impaired learning, postural coordination, and
motor skills.
Balance disorders become very common with increasing age. About 35% of
people over 75 years suffer from balance problems.
Patients with unilateral peripheral vestibular lesions (acoustic neuroma)
undergo recovery of function in about one week, called vestibular
compensation.
Technical Approaches used in the laboratory
During vestibular compensation, spontaneous
spike firing is lost in vestibular nucleus
neurons in the brain. About a week later,
recovery of spike firing occurs, coincident
with behavioral recovery.
Vm (mV)
40
0
-40
-80
100 ms
Spontaneous and evoked spike activity
Spontaneous synaptic activity
+10 mV
Inhibitory events
-60 mV
Excitatory events
Immunolabeling of protein targets
and confocal imaging of neurons
Scientists presently working in the laboratory
Kenna D. Peusner, PhD : PI
Anastas Popratiloff, MD, PhD: Immunocytochemistry and confocal imaging
Mei Shao, MD, PhD: Patch-clamp electrophysiology on brain slices
John Ramcharitar, PhD: Patch-clamp electrophysiology on brain slices
Adria Gottesman-Davis: Third year graduate student in IBS
Xudong Cai: Research Assistant
June Hirsch, PhD: Consultant in electrophysiology, Paris, France