Nerve growth factor regulation of choline acetyltransferase gene expression in rat embryo basal forebrain cultures

Nerve growth factor (NGF) increases the activity of choline acetyltransferase (ChAT), the synthetic enzyme for acetylcholine, in rat basal forebrain neurons both in vivo and in vitro. In poly(A)+ RNA isolated from cultures prepared from the embryonic (E15) rat basal forebrain, radiolabeled probes from the human ChAT gene detected a 3,700 nt and a less abundant 2,300 nt transcript. After growth in the presence of NGF, the abundance of both mRNAs was increased approximately twofold, paralleling the increase in ChAT enzyme activity. In vivo, the human ChAT probes detected a single 3,700 nt form of ChAT mRNA in both embryonic and adult rat basal forebrain. These results suggest that the NGF-mediated increase in ChAT activity in basal forebrain cultures is regulated at the transcriptional level.