title: Alterations in gamma-aminobutyric acid(B) receptor binding in the rat brain after reinstatement of cocaine-seeking behavior.
abstract: We examined neuroadaptive changes in GABA(B) receptor binding following reinstatement of cocaine-seeking behavior in rat brain structures using a "yoked" procedure and quantitative autoradiographic analysis. To estimate the distribution of GABA(B) receptors in several brain areas, we used [(3)H]CGP 54626, a GABA(B) receptor antagonist. The binding of [(3)H]CGP 54626 in the nucleus accumbens and the amygdaloid complex was decreased by about 20% in rats that actively administered cocaine. Similar decreases were seen in the animals that were passively administered cocaine; these rats also demonstrated decreased GABA(B) receptor binding in the prefrontal and frontal cortices, septum and dorsal striatum. The binding of [(3)H]CGP 54626 in several rat brain areas was decreased during 10-day withdrawal from self-administered cocaine. The cocaine-priming dose (10 mg/kg, ip) induced a significant increase of [(3)H]CGP 54626 binding in the core of the nucleus accumbens, substantia nigra (reticular part), prefrontal and frontal cortices and septum in rats withdrawn from cocaine self-administration. The presentation of the conditioned stimulus (tone + light) associated with previous cocaine self-administration induced a significant decrease of [(3)H]CGP 54626 binding in the mediodorsal thalamic nucleus and amygdaloid complex in the rats withdrawn from cocaine self-administration. Increases in GABA(B) receptor binding in limbic regions during cocaine-induced reinstatement likely reflect motivational states that were present during active drug self-administration.
authors.affiliation: Department of Pharmacology, Institute of Pharmacology, Polish Academy of Science, Smetna 12, PL 31-343 Kraków, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Frankowska
authors.forename: Karolina
authors.initials: K
authors.lastname: Wydra
authors.forename: Agata
authors.initials: A
authors.lastname: Faron-Górecka
authors.forename: Magdalena
authors.initials: M
authors.lastname: Zaniewska
authors.forename: Maciej
authors.initials: M
authors.lastname: Kuśmider
authors.forename: Marta
authors.initials: M
authors.lastname: Dziedzicka-Wasylewska
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Filip
mesh_terms: D000818:Animals; D001345:Autoradiography; D001522:Behavior, Animal / Q000187:drug effects; D001921:Brain / Q000378:metabolism*; D003042:Cocaine / Q000008:administration & dosage*; D019970:Cocaine-Related Disorders / Q000378:metabolism*; D008297:Male; D009943:Organophosphorus Compounds / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D018080:Receptors, GABA-B / Q000378:metabolism*; D012646:Self Administration
chemical_list: D009943:Organophosphorus Compounds; D018080:Receptors, GABA-B; C107353:CGP 54626; D003042:Cocaine