| Project/Area Number |
18500314
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Neurophysiology and muscle physiology
|
|---|
| Research Institution | Kinki University |
|---|
Principal Investigator |
INASE Masahiko Kinki University, School of Medicine, Professor (80249961)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
CHIBA Atsushi Kinki University, School of Medicine, Assistant Professor (30155311)
OSHIO Ken-ichi Kinki University, School of Medicine, Assistant Professor (30296751)
|
|---|
| Project Period (FY) |
2006 – 2007
|
| Project Status |
Completed (Fiscal Year 2007)
|
| Budget Amount *help |
¥3,720,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥420,000)
Fiscal Year 2007: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
Fiscal Year 2006: ¥1,900,000 (Direct Cost: ¥1,900,000)
|
|---|
| Keywords | Cerebral Cortex / Prefrontal Cortex / Basal Ganglia / Striatum / Duration Discrimination / Visual stimuli / Neuronal Activity / Neurophysiology / 時間弁別課題 / ニューロン活動 / サル / 時間情報処理 |
|---|
| Research Abstract |
We have been conducting neurophysiological experiments to reveal neuronal mechanisms for temporal information processing in the prefrontal-basal ganglia circuit. Monkeys were trained to perform a duration discrimination task. In the task, two visual cues were presented successively in different duration (0.2〜1.6 sec). Each cue presentation was followed by a 1-sec delay period. The subjects were instructed to choose a longer presented cue after the second delay period. Single-unit activity was recorded from the prefrontal cortex and the striatum while the monkeys were performing the task.
Prefrontal neurons showed phasic activity during the first cue period. The activity had peak time around 800ms that was close to the midpoint between long and short cue duration. This activity might have functioned for filtering cue duration to discriminate between long and short cues. In the first delay period prefrontal neurons exhibited differential activity following long and short cues. In the neurons with preference for long cues the delay activity after longer cues was uniformly high regardless of cue duration, but that after shorter cues was uniformly low. This binary change in the delay activity indicates that the prefrontal cortex could represent cue duration categorically as long or short. Striatal neurons phasically responded during the first and second delay periods. Responses during the first delay period changed depending on the first cue duration. Activity of populations of these neurons correlated with the first cue duration positively or negatively. Responses during the second delay period differed between long-short and short-long trials. These findings suggest that striatal neurons could encode cue duration with monotonically changing responses and discrimination results between the two cue durations.
|
