| The Michael Group University of Pittsburgh |
|---|
|
The dopamine patchwork of the rat nucleus accumbens core The dopamine (DA) terminal
field in the rat dorsal striatum is organized as a patchwork of domains
that show distinct DA kinetics. The rate and short-term plasticity of
evoked DA release, the rate of DA clearance and the actions of several
dopaminergic drugs are all domain-dependent. The patchwork arises in
part from local variations in the basal extracellular concentration of
DA, which establishes an autoinhibitory tone in slow but not fast
domains. The present study addressed the hypothesis that a domain
patchwork might also exist in the nucleus accumbens core (NAcc), a DA
terminal field that is deeply involved in reward processing and the
mechanisms underlying substance abuse. DA recordings in the NAcc by
fast-scan voltammetry during electrical stimulation of the medial
forebrain bundle confirmed that the NAcc contains a patchwork of fast
and slow domains showing significantly different rates of evoked DA
release and DA clearance. Moreover, the NAcc domains are substantially
different from those in the dorsal striatum. There were no signs in the
NAcc of short-term plasticity of DA release during multiple consecutive
stimuli, and no signs of a domain-dependent autoinhibitory tone. Thus,
the NAcc domains are distinct from each other and from the domains of
the dorsal striatum.
|
||||||
