VIP AND PACAP POTENTIATE THE ACTION OF GLUTAMATE ON BDNF EXPRESSION IN MOUSE CORTICAL-NEURONS

In view of the neurotrophic effect of vasoactive intestinal peptide (V IP), the regulation of brain-derived neurotrophic factor (BDNF) expres sion by VIP and the related peptide pituitary adenylate cyclase-activa ting polypeptide (PACAP) was analysed by Northern blot in primary cult ures of cortical neurones, Results reported in this article demonstrat e that VIP and PACAP stimulate the expression of BDNF mRNA in primary cultures of cortical neurones and astrocytes. In primary cultures of c ortical neurones, induction of BDNF mRNA by VIP and PACAP is completel y inhibited by the N-methyl-D-aspartate (NMDA) receptor antagonists MK -801 and AP5, therefore indicating that VIP and PACAP do not stimulate BDNF expression directly but rather by potentiating the effect of glu tamate tonically released by neurones and acting at NMDA receptors. In addition to its neurotrophic effects, BDNF has been shown to be invol ved in neuronal plasticity and results reported here suggest that by s timulating BDNF expression, VIP and PACAP could modulate synaptic plas ticity in the cerebral cortex.