Ethanol's effect on intracellular signal pathways in prenatal rat cortical neurons is GABAB1 dependent.
To confirm the modulation role of GABA(B) on ethanol' effects, we studied the effects of ethanol on the neuronal intracellular signals, protein kinase A (PKA) and cAMP-response element binding protein (CREB), by using a system where GABA(B1) receptors were specifically knocked down in the in vitro cultivated cortical neurons. The results showed that the PKA alpha subunit was increased with ethanol treatment, and could be further increased by administering baclofen and phaclofen. By contrast, baclofen and/or phaclofen could decrease ethanol's up-regulation effects on PKA alpha subunit expression in primary cultured cortical neurons in which the GABA(B1) receptor was specifically knocked down using GABA(B1) receptor RNA interference. Furthermore, these effects could lead to changes of phospho (p)-CREB expression, which showed the same expression pattern as PKA. Finally, we observed changes of GABA(B1), PKA, and p-CREB distribution within the same neuronal cells. These results showed that the GABA(B) receptors are critical to ethanol's cellular effects, which occur via modulating the PKA and CREB transcription pathway, and may be an underlying cause of ethanol's effects.
Lee
H Y
HY
Division of Life Science, College of Natural Sciences and Applied Life Science (Brain Korea 21), Gyeongsang National University, Chinju 660-701, South Korea.
Li
S P
SP
Park
M S
MS
Bahk
Y H
YH
Chung
B C
BC
Kim
M O
MO
D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D002492:Central Nervous System Depressants / Q000494:pharmacology*; D002540:Cerebral Cortex / Q000187:drug effects* / Q000378:metabolism; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D004622:Embryo, Mammalian; D000431:Ethanol / Q000494:pharmacology*; D005455:Fluorescent Antibody Technique; D007424:Intracellular Fluid / Q000187:drug effects / Q000378:metabolism; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D034741:RNA, Small Interfering; D051381:Rats; D017207:Rats, Sprague-Dawley; D018080:Receptors, GABA-B / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects* / Q000502:physiology; D014162:Transfection
D002492:Central Nervous System Depressants; D017362:Cyclic AMP Response Element-Binding Protein; D034741:RNA, Small Interfering; D018080:Receptors, GABA-B; D000431:Ethanol; D017868:Cyclic AMP-Dependent Protein Kinases