Detection of vasopressin messenger RNA in cells within the bed nucleus of the stria terminalis by in situ hybridization histochemistry

In situ hybridization histochemistry and quantitative autoradiography were used to confirm the presence of cells within the bed nucleus of the stria terminalis (BNST) which express the vasopressin (VP) gene and to assess the biosynthetic capacity of these cells throughout the rostrocaudal extent of the nucleus. Brain sections from adult male Wistar rats were hybridized with a 35S-labeled 48-base oligonucleotide probe. Clusters of grains were present over cells in the BNST. Cells were parvocellular in appearance and signal over cells was determined to be specific since it was abolished by RNase pretreatment or incubation with 100-fold excess unlabeled probe. The distribution of VP-mRNA containing cells in the BNST corresponds closely to that previously reported by immunocytochemistry. No clear-cut rostral to caudal gradient was found for gene expression as measured by grains/cell. In situ hybridization techniques can provide a powerful tool to study the regulation of central VP pathways in the BNST.