Saccadic eye movements elicited by intracortical microstimulation in the frontal eye field of the alert monkey

$58 CLIMBING FIBER PROJECTIONS FROM THE INFERIOR OLIVE TO THE PARASAGITTAL ZONES OF THE RABBIT'S UVULA YU S A T O & NEAL H. BARMACK* Neurological Sciences Institute, 97209, U. S. A.

1120 N. W. 20th Avenue, Portland, Oregon

In the pigmented rabbit's, injections of horseradish peroxidase (HRP) were made in the various parts of the uvula. Differential localization of labeled cells due to the retrograde axonal transport of HRP was studied in the inferior olive. Findings indicate topographycally organized projections to the cerebellar parasagittal zones. The caudal part of the nucleus beta projects contralaterally to the most medial zone (caudal beta zone) of the uvula. The rostral part of the nucleus beta projects to a more laterally located zone (rostral beta zone). The caudolateral part of the medial accessory olive (MAO) projects to a zone (caudolateral MAO zone) located laterally to the rostral beta zone. The dorsomedial cell colunm projects to a zone (dorsomedial cell column zone) located in the intermediate part of the uvula. The rostrolateral part of the MAO projects to the most lateral zone (rostrolateral MAO zone) of the uvula. The ventral lamellae of the principal olive (PO) project to a zone (ventral lamellae of PO zone) located between the rostrolateral MAO zone and the dorsomedial cell column zone.

SACCADIC IN T H E HISAO

EYE

MOVEMFMTS

FRONTAL SUZUKI,

EYE

ELICITED

FIELD

MASAO

OF

AZUMA*

Using (SEM)

alert

elicited

frontal

eye

mrearcuate

by

The

that

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was

generally

contralateral

amplitude

was

its in

the

wheras

arcuate

medial lateral

for

SEMs

were

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visual

neurons

the

SEM

part

site

sulcus.

changed

part

of

evoked

extended

inferior

the

to

to

toward located

by

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into

the

small

usually

in

the

within

at

stimulating

the

The

the

the

bank

of

SEM vectors

hemisphere,

deep

a site

in

inferior

anterior

elicited ones.

the

the

stimulating

area

movements

(ICMS)

the of

of M e d i c i n e ,

eye

in

stimulating

cortical

was

saccadic

direction

the

stimulation,

generation

deed

The

due

the

School

microstimulation

SEM was

the

NAKAYAMA*

University

examined

intracortical

field. area

we

MICROSTIMULATION

MONKEY

HIROFUMI

Hirosaki

monkeys,

INTRACORTICAL

THE ALERT and

Department of P h y s i o l o g y , H i r o s a k i 036, J a p a n .

BY

while

site:

The

large

SEMs,

lowest

threshold

cortical

receptive sites.

ICMS

layers.

field

of