Dopaminergic and Noradrenergic Substrates of Positive Reinforcement: Differential Effects of d- and l-Amphetamine

Science  09 Feb 1973:
Vol. 179, Issue 4073, pp. 575-577
DOI: 10.1126/science.179.4073.575


Intracranial self-stimulation was elicited from electrodes located in either the lateral hypothalamus or substantia nigra of the rat. Facilitatory effects of d- and l-isomers of amphetamine on self-stimulation were assessed. The d-isomer was seven to ten times more effective than the l-isomer at the hypothalamic placement, whereas the two isomers were equipotent for substantia nigra electrodes. These data support the hypothesis that both dopaminergic and noradrenergic systems subserve positive reinforcement.