Elsevier

Neuroscience

Volume 62, Issue 3, October 1994, Pages 641-645
Neuroscience

Nonlinear relationship between impulse flow, dopamine release and dopamine elimination in the rat brainin vivo

https://doi.org/10.1016/0306-4522(94)90465-0Get rights and content

Abstract

Central dopaminergic neurons exhibit two kinds of discharge activity: single spikes and bursts of two to six action potentials.2,4–6,8 Since these neurons can switch from one discharge pattern to the other whereas the mean discharge rate remains little affected, bursts may be more potent in triggering the release of their neurotransmitter, dopamine.4,6,8 Electrical stimulations mimicking the bursting pattern were actually twice as potent as regularly spaced stimulations to enhance the dopamine extracellular concentration.3,12 This suggested that dopamine release might be facilitated by increasing the impulse flow frequency.3 The high extracellular overflow evoked by a burst might also be due to accumulation of the released dopamine whereas, at lower frequencies, dopamine might be readily eliminated between every action potential.10,19 In the present study the dopamine overflow evoked by electrical stimulation of the dopaminergic pathway was measuredin vivo by carbon fibre electrodes combined with continuous amperometry.1 We observed a small facilitation of the release per pulse during stimulations mimicking a burst but only in mesolimbic areas. The high extracellular dopamine level evoked by a burst was mainly due to accumulation of the released dopamine.

Reference (21)

There are more references available in the full text version of this article.

Cited by (0)

View full text