Stimulation of in vivo dopamine transmission in the bed nucleus of stria terminalis by reinforcing drugs

Abstract

Drugs of abuse preferentially increase dopamine transmission in the shell of the nucleus accumbens. This area is considered as a transition between the striatum and the extended amygdala a complex neural system that includes the central amygdala and the bed nucleus of stria terminalis, areas that, like the nucleus accumbens shell, are heavily innervated by mesolimbic dopamine neurons originating in the ventral tegmental area. Given the anatomical and neurochemical relationships and similarities with the nucleus accumbens shell it was of interest to investigate whether the dopamine transmission of the bed nucleus of stria terminalis shares with the accumbens shell the peculiar responsiveness to drugs of abuse. To this end we studied by microdialysis with concentric probes, the effect of drugs of abuse on extracellular dopamine in the bed nucleus of stria terminalis. We report that morphine, nicotine, cocaine, ethanol, and the selective dopamine uptake inhibitor GBR 12909 increase effectively and dose dependently extracellular dopamine in the bed nucleus of stria terminalis. These results indicate that the bed nucleus of stria terminalis shares with the nucleus accumbens shell a peculiar sensitivity to the dopamine stimulant actions of drugs of abuse.