CHARACTERIZATION AND CONTENT OF VIP AND VIP MESSENGER-RNA IN RAT FORE-BRAIN NEURONS

HPLC, gel chromatography, Northern analysis and non-isotopic in situ h ybridization have been used to characterize for the first time the nat ure of vasoactive intestinal polypeptide mRNA and peptide in the rat t halamus and suprachiasmatic nucleus. Both these hitherto unstudied are as were shown to contain VIP-like immunoreactivity and VIP mRNA indist inguishable from those found in the rat cerebral cortex. Non-isotopic in situ hybridization with an alkaline phosphatase labelled antisense oligonucleotide specific for VIP mRNA and densitometry revealed that r elative levels of VIP mRNA per cell were highest in the suprachiasmati c nucleus and lowest per cell in the thalamus of the rat brain areas i nvestigated.