抄録
The amygdala and dopaminergic innervation thereonto are considered to cooperatively regulate emotional states and behaviors. In the present experiments, we investigated the effects of dopamine on lateral amygdala (LA) neurons by whole cell recordings in rat brain slices. Bath-application of dopamine induced slow afterdepolarization (sADP) in LA neurons. This sADP lasted for more than 5 seconds and was induced by dopamine in a concentration-dependent manner. D1 receptor agonists induced the same sADP. Previous reports have repeatedly suggested that sADP could be triggered by calcium influx. Consistently, calcium channel blockers or chelating intracellular calcium inhibited the present dopamine-induced sADP. A membrane conductance decreased at the peak of sADP current (IsADP). Also, the present IsADP was suppressed by including cesium in the pipette solution. The I-V relationship of net IsADP induced by dopamine was shifted as the external concentration of potassium was raised. The reversal potential of the net IsADP was identical to that of potassium. These results suggest that the present dopamine-induced modulation of LA neuron excitability may depend on decrease in potassium current. [J Physiol Sci. 2007;57 Suppl:S225]
