Two types of cutaneous reflexes for the small muscles of the hand in man

s104

TWO TYPES OF CUTANEOUSREFLEXES FOR THE SMALL MUSCLES OF THE HANDIN MAN. YUKARI OHKI, TAKAMI SUZUKI*, Department Mitaka-shi,

Tokyo

Cutaneous

of

reflexes

from

the hand in man during own finger seemed

tips

were

to

phases,

more

the short

(not

than

muscle

into

than

in most of after

finger

University

School

of

and of

after

type

stimulation)

The second

could

be

index

Medicine,

6-20-Z

the various

small

observed

responses,

similar

Shinkawa,

for

successive

perception.

excitatory

minimi muscle.

the

in

later

The effects (from about and

inhibitory seen

with a marked excitation

the

first

dorsal

Stephens,

part

of

to their

This was commonly

was short-lasting and

muscles

stimuli

was long-lasting

Garnett

to

muscles,

threshold

typically

(cf.

finger

responses

digiti

type

finger

of with

in the abductor

the

late

twice

The first

for

For those

at a strength

hand muscles.

100 msec),

were investigated

contraction.

two types.

150 msec

additional

tips

voluntary

previously

stimulation

stimulation,

the

steady

as we reported

more

Kyorin

most effective

to be divided

30 msec

Physiology,

181, Japan.

of

the

interosseous With stronger

1980). first

type.

were

also

recruited.

FORELIMB SKIN DEAFFEHENTATION IMPAIRED LIMB MOVEMENTS IN THE CAT SHIGJZRU KITAZAWA. _YQKO_ent . .

gf BrainResear&J&ulty of Me&cm

of Neurophysiology. Instituy

. . ~oQJQ,_@~-~_~o-~su.

Tokyo 113.Jw

The role of skin afferents in motor control was examined in cats by comparing forelimb movements before and after cutting forelimb skin nerves, superficial radial (SR), skin branches of ulcer (LJI)and median (Medl nerves, in varied combinations and sequences. Trained forelimb movements of taking a piece of food in a tube were impaired tier

denervation. Section of 1 or 2 nerves produced subtle im-

pairments which disappeared in only 5-10 trials. After successive section of ail 3 nerves, however, a series of movements, paw insertion into the tube, grasping the food, bringing it to mouth with supination was all impaired, while routine movements including locomotion looked normal. Insertion into a tube started to recover after 4-7 weeks and progressively improved to reach a slightly subnormal level in 2-3 weeks. Other movements improved later, and were successful at higher rates when tested with a transparent tube than with an opaque tube, suggesting a compensatory role of visual information. The results indicate the importance of skin sensory signals in voluntary forelimb movements.

AXONAL

TRAJECTORIES

ACTIVATED

SECONDARY

IN MESODIENCEPHALIC

JUNCTION

VESTIBULAR

SATOSHI

IKOMA,

Departments

NAKAO',

AND

Tottori

University

School

Axonal

projection

of posterior

to

the

HISAAKI

NEURONS.

mesodiencephalic

anesthetized of the

latencies

site. MLF

PC

were

stitial the

with

found

for

their

Forel's

field

to

frequently

Cajal, H,

the

the

issue

Forel's axonal

Yonago

natural

systematic

and

tracking and

branches

axonal H,

through

branches

central

coursed

in the

gray

mesodiencephalic

in the

the

in all and

in

stimulation

in each

nucleus

neurons

investigated electrical

measured

oculomotor their

Japan.

currents

were

field

683,

threshold

activation

SHOZO

*Physiology,

vestibular(PC)

electrophysiologically by

CANAL-

HOSOGAI', and

secondary

microelectrode,

antidromic

projecting

of

to

POSTERIOR MASAE

86 Nishi-machi,

identified

subjected

stimulating

to

were

CAT

Otorhinolaryngology

canal-activated

junction

the

neurons

nucleus

of Medicine,

PC neurons, were

labyrinth,

junction and

cats.

of

OF

MATSUO,

pA)

contralateral

of

thalamus

mediolateral

(<30

stimulation

the

inter-

as well. direction.

In