RT Journal Article
SR Electronic
T1 Glutamate Receptor-Dependent Modulation of Dopamine Efflux in the Nucleus Accumbens by Basolateral, But Not Central, Nucleus of the Amygdala in Rats
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 1137
OP 1145
DO 10.1523/JNEUROSCI.22-03-01137.2002
VO 22
IS 3
A1 John G. Howland
A1 Pornnarin Taepavarapruk
A1 Anthony G. Phillips
YR 2002
UL http://www.jneurosci.org/content/22/3/1137.abstract
AB Dopaminergic neurotransmission in the nucleus accumbens (NAc) and neural processes in the basolateral (BLA) and central (CeN) amygdala nuclei are implicated in associative reward learning. Given their direct and indirect connections with the NAc and ventral tegmental area (VTA), both the BLA and CeN may regulate the mesoaccumbens dopamine (DA) system in rewarding situations. Electrical stimulation of the BLA (20 Hz, 10 sec, 300 μA) induced a long-lasting 25 ± 4% increase in DA efflux in the NAc, measured by microdialysis in freely moving rats, whereas comparable stimulation of the CeN had no effect. Reverse dialysis of either the NMDA receptor antagonist APV (100 μm) or the AMPA–kainate receptor antagonist DNQX (100 μm), but not the metabotropic glutamate receptor antagonist (±)-amino-4-carboxy-methyl-phenylacetic acid (100 μm), into the NAc blocked the stimulation-evoked increase in DA efflux in the NAc. VTA infusion of lidocaine (lido; 4%) significantly reduced basal DA levels for ∼30 min but failed to suppress the increase in NAc DA efflux resulting from BLA stimulation. Additionally, infusions of lido (4%) into the medial prefrontal cortex failed to block the stimulation-evoked increase in NAc DA efflux. These data support the hypothesis that the BLA can directly modulate DA efflux through local mechanisms in the NAc, independent of an action on DA cell bodies in the VTA. The finding that brief activation of the CeN had no long-lasting effects on DA efflux in the NAc suggests an important degree of functional independence between the CeN and BLA.