PACAP has a neurotrophic effect on cultured basal forebrain cholinergic neurons from adult rats

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a member of t he vasoactive intestinal polypeptide gene family (VIP) that was originally isolated from rat hypothalamus. The high affinity PACA-P receptor, PAC1, is expressed in the basal forebrain area of adult, as well as developing rat brain. Hippocampus, a targeting area of basal forebrain cholinergic neurons , contains PACAP Thus, hippocampal-derived PACAP may have an effect on basa l forebrain cholinergic neurons. Indeed, we have reported that PACAP showed neurotrophic effects on these neurons in embryonic and early postnatal cul ture. Here we report that PACA-P has a neurotrophic effect on adult choline rgic neurons in culture. PACAP increases the number of choline acetyltransf erase immunoreactive neurons about 2-fold. A similar effect was observed on treatment with cAMP analogue but not nerve growth factor. PACAP also impro ved the survival and neurite outgrowth of total neurons. These results indi cate that PACAP acts as a neurotophic factor even on adult neurons in vitro . (C) 2001 Elsevier Science BY All rights reserved.