Dissociation of dopamine release in the nucleus
accumbens from intracranial self-stimulation
by
Garris PA, Kilpatrick M, Bunin MA,
Michael D, Walker QD, Wightman RM.
Department of Biological Sciences,
Illinois State University,
Normal 61790-4120, USA.
Nature 1999 Mar 4; 398(6722):67-9

ABSTRACT

Mesolimbic dopamine-releasing neurons appear to be important in the brain reward system. One behavioural paradigm that supports this hypothesis is intracranial self-stimulation (ICS), during which animals repeatedly press a lever to stimulate their own dopamine-releasing neurons electrically. Here we study dopamine release from dopamine terminals in the nucleus accumbens core and shell in the brain by using rapid-responding voltammetric microsensors during electrical stimulation of dopamine cell bodies in the ventral tegmental area/substantia nigra brain regions. In rats in which stimulating electrode placement failed to elicit dopamine release in the nucleus accumbens, ICS behaviour was not learned. In contrast, ICS was acquired when stimulus trains evoked extracellular dopamine in either the core or the shell of the nucleus accumbens. In animals that could learn ICS, experimenter-delivered stimulation always elicited dopamine release. In contrast, extracellular dopamine was rarely observed during ICS itself. Thus, although activation of mesolimbic dopamine-releasing neurons seems to be a necessary condition for ICS, evoked dopamine release is actually diminished during ICS. Dopamine may therefore be a neural substrate for novelty or reward expectation rather than reward itself.

rTMS
Pleasure
Wired snails
Anxiety and ICSS
The Wired Society
Dopamine overflow
The neural basis of pleasure
The humour centre of the brain?
Intracranial self-stimulation enhances neurogenesis

Refs
HOME
HedWeb
BLTC Research
Designer Drugs
Paradise-Engineering
Utopian Pharmacology
The Hedonistic Imperative
When Is It Best To Take Crack Cocaine?