GABA transmission in the nucleus accumbens is altered after withdrawal from repeated cocaine.

摘要: Repeated cocaine causes enduring changes in dopamine and glutamate transmission the nucleus accumbens, terminals synapse on GABAergic accumbens neurons. The present study demonstrates that there are GABA at 3 weeks after discontinuing daily injections. No-net flux microdialysis revealed a significant increase basal levels of extracellular cocaine-treated rats. elevated was normalized by blocking voltage-dependent Na+ channels provided increased tone GABA(B) presynaptic autoreceptors heteroreceptors because receptors produced greater elevation GABA, dopamine, compared with control subjects. For many G-protein-coupled receptors, agonist can cause receptor desensitization. Consistent desensitization, baclofen-stimulated GTPgammaS binding reduced, reduction G-protein coupling accompanied reduced Ser phosphorylation GABA(B2) subunit. No effect repeated found total GABA(B1) or protein. Together, these data demonstrate withdrawal from treatment produces an depends neuronal activity. may be mediated part functional desensitization likely result diminished receptor.