| Project/Area Number |
15500292
|
|---|
| 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 | National Institute for Physiological Sciences (2004)
Okazaki National Research Institutes (2003) |
|---|
Principal Investigator |
MOMIYAMA Toshihiko National Institute for Physiological Sciences, Department of Cerebral Research, Associate Professor, 大脳皮質機能研究系, 助教授 (20230055)
|
|---|
| Project Period (FY) |
2003 – 2004
|
| Project Status |
Completed (Fiscal Year 2004)
|
| Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2004: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2003: ¥2,400,000 (Direct Cost: ¥2,400,000)
|
|---|
| Keywords | dopamine / depolarization / glutamate / slice / retrograde messenger / D2-lioke receptor / basal ganglia / patch-clamp / 腹側被蓋野 / 興奮性シナプス / D2型受容型 / ノックアウトマウス / 抗体 / 興奮性シナプス後電流 / D_2型受容体 / 抑制 |
|---|
| Research Abstract |
Whole-cell patch-clamp study was carried out to elucidate physiological roles of dopamine (DA) using midbrain slices of the mice (P13-21). EPSCs mediated by non-NMDA glutamate receptors were evoked in the ventral tegmental dopaminergic neurons by focal stimulation at the holding potential of -60 mV. Application of a depolarizing pulse to 0 mV for 5 s inhibited the EPSCs by 42.8 ± 3.1% (n=16) in wild type mice. The magnitude of depolarization-induced inhibition of EPSCs (DSE) was significantly (P<0.05) reduced to 7.3 ± 9.9% (n=5) in the presence of a D2-like receptor antagonist, sulpiride (5 μM), in the bathing solution. DSE amplitude was also significantly (P<0.05) small in slices obtained from D2 receptor deficient mice (7.3 ± 2.0%, n=17). DSE was also observed by action potential generation induced by depolarizing pulses in the current-clamp mode (36.5 ± 5.9%, n=5). These results suggest that DA released from dopaminergic neurons acts on presynaptic D2 receptors to inhibit glutamate release, implying a role of DA as a retrograde messenger in the central nervous system.
|
