Fetal alcohol syndrome (FAS) is a developmental neuropathology resulting from in utero exposure to ethanol; many of ethanol's effects are likely to be mediated by the neurotransmitter γ-aminobutyric acid (GABA).
We studied modulation of the neurotransmitter receptor GABABR and its capacity for intracellular signal transduction under conditions of ethanol treatment (ET) and RNA interference to investigate a potential role for GABA signaling in FAS.
ET increased GABAB1R protein levels, but decreased protein kinase A-α (PKA-α), calcium/calmodulin-dependent protein kinase II (CaMKII) and phosphorylation of cAMP-response element binding protein (p-CREB), in cultured hippocampal neurons harvested at gestation day 17.5.
To elucidate GABAB1R response to ethanol, we observed the effects of a GABABR agonist and antagonist in pharmacotherapy for ethanol abuse.
Baclofen increased GABABR, CaMKII and p-CREB levels, whereas phaclofen decreased GABABR, CaMKII and p-CREB levels except PKA-α.
Furthermore, when GABAB1R was knocked down by siRNA treatment, CaMKII and p-CREB levels were reduced upon ET.
We speculate that stimulation of GABAB1R activity by ET can modulate CaMKII and p-CREB signaling to detrimental effect on fetal brain development.
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