Repeated cocaine administration increases GABA(B(1)) subunit mRNA in rat brain.
The effects of a single and repeated administration of cocaine on GABA(B) receptor subunit mRNA was investigated in rat brain by in situ hybridization. Following a single administration of cocaine, no significant change was observed in any brain regions examined, neither 1 h nor 24 h after administration. During repeated administration of cocaine, behavioral sensitization with increased stereotyped behavior was observed. A significant increase in the level of GABA(B(1)) mRNA was observed in the nucleus accumbens (11.4%), CA1 field of the hippocampus (16.8%), and thalamus (16.5%) 1 day after repeated administrations of cocaine for 14 consecutive days. The level of mRNA returned to the basal level 1 week after the final injection of repeated cocaine treatment. The observed changes in the mRNA level after the repeated cocaine may imply changes of GABA(B(1)) subunit in molecular mechanisms which underlie development of behavioral sensitization.
Yamaguchi
Mika
M
Department of Psychiatry, Institute of Clinical Medicine, Institute of Basic Medical Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
Suzuki
Toshihito
T
Abe
Shuzo
S
Baba
Atsuomi
A
Hori
Takafumi
T
Okado
Nobuo
N
D000818:Animals; D001921:Brain / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D003042:Cocaine / Q000494:pharmacology*; D019970:Cocaine-Related Disorders / Q000378:metabolism / Q000503:physiopathology; D018765:Dopamine Uptake Inhibitors / Q000494:pharmacology*; D004334:Drug Administration Schedule; D004361:Drug Tolerance / Q000502:physiology; D008297:Male; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D012333:RNA, Messenger / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D018080:Receptors, GABA-B / Q000235:genetics*; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology; D015854:Up-Regulation / Q000187:drug effects* / Q000502:physiology; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D018765:Dopamine Uptake Inhibitors; D012333:RNA, Messenger; D018080:Receptors, GABA-B; D005680:gamma-Aminobutyric Acid; D003042:Cocaine