TITLE:
Local infusion of low, but not high, doses of alcohol into the anterior ventral tegmental area causes release of accumbal dopamine
AUTHORS:
Elisabet Jerlhag, Jörgen A. Engel
KEYWORDS:
Alcohol; Ventral Tegmental Area; Nucleus Accumbens; Dopamine; Rats
JOURNAL NAME:
Open Journal of Psychiatry,
Vol.4 No.1,
January
7,
2014
ABSTRACT: The
mesolimbic dopamine system consisting of dopaminergic neurons projecting from the ventral tegmental
area (VTA) to the nucleus accumbens (N.Acc.) mediates the reinforcing effects
of addictive drugs including alcohol. Given that VTA is a heterogeneous area
and that alcohol, in rather low doses, interacts directly with ligand-gated ion
channels, we hypothesised that low, rather than high, doses of alcohol into the
VTA activate the mesolimbic dopamine system and that alcohol may have different
effects in the anterior and posterior parts of the VTA. The present study was
undertaken to investigate this hypothesis. The present series of experiment
show that infusion of a low dose of alcohol (20 mM) into the anterior, but not
posterior, part of the VTA increases accumbal dopamine release in rats. In
addition, higher doses of alcohol (100 or 300 mM) into the anterior or
posterior part of the VTA do not affect the release of dopamine in the N.Acc.,
suggesting that low doses of alcohol can activate the mesolimbic dopamine
system via mechanisms in the VTA. These data contribute to understanding the
neuronal mechanisms underlying the dependence-producing
properties of alcohol and could tentatively contribute to that new
treatment strategies for alcohol use disorder can be developed.