NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Role of the flocculus of the cerebellum in motor learning of the vestibulo-ocular reflexStructure-function studies at the systems level are an effective method for understanding the relationship of the central nervous system to behavior. Motor learning or adaptation of the vestibulo-ocular reflex is a clear example wherein this approach has been productive. During a vestibulo-ocular reflex the brain converts a head velocity signal, transduced through the vestibular semicircular canals, into an eye movement command delivered to the extraocular muscles. If the viewed target remains on the fovea of the retina, the reflex is compensatory, and its gain, eye velocity/head velocity, is one. When the image of the viewed object slips across the retina, visual acuity decreases, and the gain of the reflex, which is no longer one, is plastically adapted or adjusted until retinal stability is restored. The anatomic substrate for this plasticity thus involves brain structures in which visual-vestibular interaction can potentially occur, as well as vestibular and visual sensory and oculomotor motor structures. Further, it has been known for many years that removal of the flocculus of the cerebellum permanently precludes further vestibulo-ocular reflex adaptation, demonstrating the involvement of the cerebellum in this behavior. Maekawa and Simpson (J Neurophysiol 1973;36: 649-66) discovered that one visual input to the flocculus involved the accessory optic system and the inferior olive. Ensuing work has demonstrated that the visual signals used to adapt the vestibulo-ocular reflex are transmitted by this accessory optic system to the flocculus and subsequently to brain stem structures involved in vestibulo-ocular reflex plasticity. Presently the inclusive list of anatomic sites involved in vestibulo-ocular reflex circuitry and its adaptive plasticity is small. Our laboratory continues to believe that this behavior should be caused by interactions within this small class of neurons. By studying each class of identified neuron and its interactions with others within the list, we hope to ultimately understand the mechanisms used by the brain in the expression of this behavior.
Document ID
20040172557
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Highstein, S. M.
(Washington University School of Medicine St. Louis, Missouri 63110, United States)
Date Acquired
August 22, 2013
Publication Date
September 1, 1998
Publication Information
Publication: Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery
Volume: 119
Issue: 3
ISSN: 0194-5998
Subject Category
Life Sciences (General)
Distribution Limits
Public
Copyright
Other
Keywords
Non-NASA Center
NASA Discipline Neuroscience

Available Downloads

There are no available downloads for this record.
No Preview Available