| Project/Area Number |
61570076
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
Neurophysiology and muscle physiology
|
|---|
| Research Institution | Toho University |
|---|
Principal Investigator |
OKIHIDE Hikosaka Toho Univeristy Schoo of Medicine Associatr pprofessor, 医学部, 助教授 (70120300)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
MASASHIRO Sakamoto Toho University School of Medicine Lecturer, 医学部, 助手 (40130364)
|
|---|
| Project Period (FY) |
1986 – 1987
|
| Project Status |
Completed (Fiscal Year 1987)
|
| Budget Amount *help |
¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1987: ¥200,000 (Direct Cost: ¥200,000)
Fiscal Year 1986: ¥1,400,000 (Direct Cost: ¥1,400,000)
|
|---|
| Keywords | Basal ganglia / Caudata nucleus / Eye movemetn / Memory / Saccade / Monkey / ニューロン / 黒質網様部 |
|---|
| Research Abstract |
We have ashown that thr basal ganglia play an importnat fole in the initiation of saccafic eye movements. Neutons in the monkey substantia nigra pars reticulata, an output area of the basal ganglia, tonically inhibit saccade-related neurons in the superior colliculs. With a cessation of spike discharges the nigra neurons remove the inhibition thereby allowing the colliculus cells to be activated,producinga saccade to the contralateral side. We have shown that a high proportion of neutons in the caudate nucleus, which has been shown to project to the substantia nigra, discharge before voluntary saccades. OF particular interest was the neurtons that showed discheages only when the monkey made saccades to the remembered position of a visual target. Using electrophysiological technique we showed that the saccaderelated neurons in the substantia nigra indeed receive powerful inhibitory inputs from the caudate nucleus. We inserted two microelectrodes into the monkeys brain,one into the subst
… More
antia nigra fro single unit recording and the other into the caudate nucleus for single unit recording and microstimulation. After identifying a saccade-related neuron in the substantia nigra we stimulated the caudate nucleus with sigle pulse currents (duration:0.2msec,less than 100 uA). Nearly half of saccaderelated neurons in the substantia nigra were inhibited by the caudate stimulation. The latencies of the inhibition were mostly between 15 and 20 nsec The effect of the stimulation depended on the position of the elecrode in the caudata nucleus. It was shown by changing the depth of the stimulating electrode while a nigra neuron was recorded. The most effective site was in the central part of the caudata where saccaderelated neutons were most frequently encountered. These results suggest that the saccade-related decrease in spike activity of substantia nigra neurons is induced by direct inhibition from the caudate mucleus. In other words, the basal ganglia may contribute to the initiation of voluntary saccades through disinhibiton og the superior colliculs. Less
|
