Dissociation of dopamine release in the nucleus accumbens from intracranial self-stimulation.

摘要: Mesolimbic dopamine-releasing neurons appear to be important in the brain reward system1,2. One behavioural paradigm that supports this hypothesis is intracranial self-stimulation (ICS), during which animals repeatedly press a lever stimulate their own electrically3,4,5,6. Here we study dopamine release from terminals nucleus accumbens core and shell by using rapid-responding voltammetric microsensors7 electrical stimulation of cell bodies ventral tegmental area/substantia nigra regions. In rats stimulating electrode placement failed elicit accumbens, ICS behaviour was not learned. contrast, acquired when stimulus trains evoked extracellular either or accumbens. could learn ICS, experimenter-delivered always elicited release. rarely observed itself. Thus, although activation mesolimbic seems necessary condition for actually diminished ICS. Dopamine may therefore neural substrate novelty8 expectation9 rather than