Ethanol modulates GABA(B) receptor expression in cortex and hippocampus of the adult rat brain.
Using in situ hybridization, RNase protection assay and Western blot, we studied the effects of ethanol on the expression levels of GABA(B) receptor mRNA and protein in the cortex and hippocampus from adult rat brain. The results showed that ethanol significantly increased GABA(B1) and GABA(B2) receptor protein expression in the cortex, whereas only GABA(B2) was increased in the hippocampus. GABA(B) receptor agonist baclofen could partially reverse the effect of ethanol. Further studies of the mRNA levels defined that GABA(B1) mRNA levels were significantly increased in the hippocampus, with no significant changes of GABA(B2) mRNA levels. Moreover, GABA(B1) and GABA(B2) receptor mRNA levels were increased on 3-week ethanol treatment. Finally, GABA(B) agonist baclofen and antagonist phaclofen showed significant decreasing effects on GABA(B1) receptor mRNA levels in the cortex, but not in the hippocampus. These results were further confirmed by in situ hybridization. Thus, the present results showed the effects of ethanol on GABA(B) receptors in the cortex and hippocampus, implying the possible role of GABA(B) receptor in ethanol effects. The effects of GABA(B) receptor agonist and antagonist suggested that the possible mechanisms underlying that GABA(B) receptor modulated the behavioral effect induced by ethanol.
Li
Shu Peng
SP
Division of Life Science and Applied Life Science (Brain Korea 21), Gyeongsang National University, Chinju 660-701, South Korea.
Park
Moon Seok
MS
Jin
Guang Zhen
GZ
Kim
Jong Hun
JH
Lee
Hye Lyoung
HL
Lee
Yu La
YL
Kim
Jin Hoi
JH
Bahk
Jong Yoon
JY
Park
Tae Ju
TJ
Koh
Phil Ok
PO
Chung
Bong Chul
BC
Kim
Myeong Ok
MO
D000704:Analysis of Variance; D000818:Animals; D015153:Blotting, Western / Q000379:methods; D002492:Central Nervous System Depressants / Q000494:pharmacology*; D002540:Cerebral Cortex / Q000187:drug effects* / Q000378:metabolism; D000431:Ethanol / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects*; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism; D017403:In Situ Hybridization / Q000379:methods; D008297:Male; D010088:Oxidoreductases / Q000187:drug effects; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D018080:Receptors, GABA-B / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D013997:Time Factors
D002492:Central Nervous System Depressants; D012333:RNA, Messenger; D018080:Receptors, GABA-B; D000431:Ethanol; C036322:GABA dehydrogenase; D010088:Oxidoreductases