演題番号 : P1-b05
籾山 俊彦 / Toshihiko Momiyama:1
1:東京慈恵会医科大学 薬理学講座 / Department of Pharmacology, Jikei University School of Medicine
It has been suggested that dopamine (DA) is released from not only axon terminals in the projection area, but also from neuronal soma or dendrites of dopaminergic neurons in the midbrain. However the release mechanisms of DA remain unknown. In the present study, electrochemical detention of DA was carried out from soma of a single dopaminergic neuron in the substantia nigra pars compacta (SNc) or ventral tegmental area (VTA) in slice preparations obtained from 14-18 day old rats, using carbon nanotube (CNT) electrodes. CNT was filled in glass pipettes pulled for patch-clamp recording. The CNT electrode was attached to the soma of dopaminergic neurons, and DA release was electrochemically detected as current events using a patch-clamp amplifier (Axopatch 200B) at a holding potential of +500-+700 mV. Furthermore, whole-cell recording was done from the same dopaminergic neuronal soma simultaneously with detection of DA release. In several dopaminergic neurons, DA release was synchronously detected with action potential firings. These findings suggest that DA is released from the soma of dopaminergic neurons depending on the neuronal activity.