RT Journal Article
SR Electronic
T1 Opiate influences on nucleus accumbens neuronal electrophysiology: dopamine and non-dopamine mechanisms
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 3538
OP 3546
DO 10.1523/JNEUROSCI.09-10-03538.1989
VO 9
IS 10
A1 Hakan, RL
A1 Henriksen, SJ
YR 1989
UL http://www.jneurosci.org/content/9/10/3538.abstract
AB Single-unit recordings of nucleus accumbens septi (NAS) neurons in halothane-anesthetized rats revealed that microinfusions of morphine into the ventral tegmental area (VTA) primarily inhibited spontaneously active NAS units. These inhibitory effects were reversed by alpha- flupenthixol (s.c.), suggesting a role for dopamine (DA) in the observed opiate-induced effect. VTA opiate microinfusions also inhibited the evoked (driven) responses of silent cells (spontaneously inactive) in the NAS elicited by stimulation of hippocampal afferents to the NAS. In addition, this inhibition of driven response was reversed by naloxone (s.c.) but not by alpha-flupenthixol, implying a VTA-mediated non-DA mechanism. Morphine applied iontophoretically to cells within the NAS inhibited spontaneous activity but not fimbria- driven cellular activity, suggesting that the systemic effects of opiates on NAS activity can be mediated directly in the NAS as well as through VTA afferents. Moreover, since VTA-induced inhibition of fimbria-driven activity was reversed by systemic opiates, opiates also can exert effects through other, as yet unidentified NAS afferent systems.