CORRELATION BETWEEN TEMPORAL SIMPLE-SPIKE RATE OF THE FLOCCULAR MIDDLE ZONE AND EYE MOVEMENTS DURING OPTOKINETIC RESPONSES IN CATS.
TOSHIHIRO KITAMA’, AKIHITO MIZUKOSHI’. TAKEHIKO and YU SATO’ ‘Dept. of Physiology and ‘Dept. of Otolaryngology, 409-3898, Japan
UENO’, LIJAN HONG-GE’
Univ., Tamaho, Yamanashi
It has been shown that the floccular middle zone of the cat controls eye movements plane.
We studied relationship between
and the eye movement
using a multiple linear regression
SS activities represent
were large whereas acceleration
SS firing preceded
of eye movements
by the linear sum of the
were small, and
The results suggest that
the eye movements.
A CEREBELLAR-PLASTICITY-BASED SIMULATION OF OCULAR FOLLOWING RESPONSES
cells in the middle zone
and position) during optokinetic
SS fuing was well reconstructed
simple spike(SS) activities ofpurkinje
in the horizontal
during optokinetic response. OF THE ACQUISITION
OF THE PROPERTIES
lATR human info. Proc. Res. Labs,, Kyoto 2Niigata Univ. school of med. 3Natl. Inst. Physiol. SElectrotechnical Lab., Ibaraki, Japan
Sci., Aichi 4CREST,
Using a realistic model which reconstructs simple and complex spikes, we propose a simulation model to reproduce the acqutsition of OFR properties in adult animals and behavioral data during adaptive changes of OFR. In this model, learning sites are placed at the synapses between parallel fibers or inhibitory cells and Purkinje cells. Climbing fiber inputs to Purkinje cells were assumed to prefer upward or contraversive stimulus motion at birth. Preferred directions of the parallel fiber and inhibitory cell inputs were set so as to cover 360 degrees in total. The efficacy of the parallel fiber and inhibitory cell inputs on the Purkinje cells was changed plastically by LTD. LTP, and rebound potentiation. After the repetition of the standard velocity step of the large field visual stimulus in various directions, those Purkinje cells that received climbing fiber inputs preferring upward motion, increased their firing rate for downward stimuli and decreased it for upward stimuli. Those Purkinje cells that received climbing fiber inputs preferring con&aversive motion, increased their firing rate for ipsiversive stimuli and decreased it for contraversive stimuli. Even when the visual stimulus moved, the eyes did not move before the repetition of the stimuli; eye movements started following the visual stimulus only after the repetition. Using the same model, repeated exposure to speed steps involving abrupt increases or decreases in speed resulted in increases or decreases, respectively, in the OFR elicited by the standard speed step stimulus. The synaptic transmission efficacy required changing even when the firing of the parallel liber inputs and inhibitory cell inputs preceded the complex spikes. We also discuss whether the various kinds of parallel fiber firing properties can produce the reported uniform kind of simple spike firing properties by our model RECONSTRUCTION
320 I. SUGIHARA.
OF SINGLE OLIVOCEREBELLAR
IN THE RAT CEREBELLAR
H -S. WU and Y. SHINODA
Tokyo Medical and Dental University School of Medicine.
I 13-8519. Japan. Single olivocerebellar
from the rat inferior olivary
amine injected mto the nucleus. was reconstructed. which terminated as a climbing
nucleus. that were labeled with biotinylated
Each axon (n=l I so far) gave rise to 2
- I7 thick collaterals, rach of
All CFs of some single axons terminated in a single lobule. while CFs of other
single axons were separated mto two or three groups that terminated in diffet-ent lobules.
Branchings usuallv occurred in the
white matter near the cerebellar nucleus or in the deep potlion of the folial white matter and occasionally in the distal portton of the folium or in the granular layer. which was usually less than 200 pm. trees of the Purkimc iells.
All CF termmalx of a single axon aerc located in a thin longitudinal in each lobule.
Supported by CREST
This strip was approximately
strip. the width of
parallel to the planes of the dendritic