GABA(B) receptor gene expression is not altered in cocaine-sensitized rats.
Recent behavioral and neurobiological data indicate that GABA(B) receptor transmission is involved in cocaine-induced hyperactivity and reinforcement. GABA(B) receptor gene expression in cocaine-sensitized rats was examined in this study. Rats were injected with cocaine (15 mg/kg, daily, i.p.) or saline for 5 consecutive days, and challenged with the same dose of cocaine after a 1-, or 20-day hiatus. The locomotor activities of rats were recorded after challenge, and the rats were killed 24 hr later. GABA(B)R1a, 1b, and GABA(B)R2 mRNA in discrete brain regions was detected by RPA and In Situ Hybridization; GABA(B)R1a protein was measured by Western blotting. Rats pretreated with cocaine developed a hyperactivity to the cocaine challenge after a 1-day or 20-day hiatus, but GABA(B)R subunit mRNA and GABA(B)R1a protein densities in the targeted regions showed no significant difference compared to those in control rats. These data indicate that GABA(B) receptor gene expression is not necessarily relevant to the behavioral sensitization of cocaine.
Li
Jinyuan
J
Department of Cell Biology and Anatomy, Finch University of Health Sciences/The Chicago Medical School, 3333 Green Bay Road, North Chicago, IL 60064, USA.
Olinger
Anthony B
AB
Dassow
Michael S
MS
Abel
Marc S
MS
D000818:Animals; D001921:Brain / Q000378:metabolism; D003042:Cocaine / Q000008:administration & dosage* / Q000494:pharmacology; D004334:Drug Administration Schedule; D015870:Gene Expression / Q000187:drug effects*; D008297:Male; D009043:Motor Activity / Q000187:drug effects* / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D018080:Receptors, GABA-B / Q000235:genetics* / Q000378:metabolism; D012016:Reference Values
D012333:RNA, Messenger; D018080:Receptors, GABA-B; D003042:Cocaine