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Published on: September 16, 2015
Cocaine-induced adaptations in D1 and D2 accumbens projection neurons (a dichotomy not necessarily synonymous with
Rachel J Smith1, Mary Kay Lobo, Sade Spencer
1Department of Neurosciences, Medical University of South Carolina, 173 Ashley Avenue, 403 BSB, Charleston, SC 29425, USA.
Abstract:
Cocaine exposure causes enduring neuroadaptations in ventral striatum, or nucleus accumbens (NAc), an area critically involved in reward learning and relapse of drug seeking. Medium spiny neurons (MSNs) in striatum are dichotomous in their expression of either D1 or D2 dopamine receptors, along with other receptors and neuropeptides. In dorsal striatum, these two subpopulations show non-overlapping innervation of distinct terminal fields via the direct or indirect pathways. However, NAc D1-MSNs and D2-MSNs are not fully segregated in this manner, with both cell types innervating ventral pallidum. Recent studies show that D1-MSNs and D2-MSNs play opposing roles in cocaine-associated behaviors. Further, cocaine induces differential adaptations in these two subpopulations in NAc, including changes to synaptic plasticity, glutamatergic signaling, and spine morphology.
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