Evidence for a colocalization of oxytocin mRNA and galanin in magnocellular hypothalamic neurons: a study combining in situ hybridization and immunohistochemistry

Abstract

The possible colocalization of oxytocin (OT) and galanin (GAL) was studied by combining, on the same cryostat sections, in situ hybridization (ISH) for OT mRNA with a tritiated oligonucleotide probe and immunohistochemistry (ICC) of GAL. Many cells were either labelled by ISH (OT mRNA containing cells), or by ICC (GAL contianing cells). Moreover, some magnocellular neurons in the supraoptic and paraventricular nuclei were labelled for both OT mRNA and GAL. These results demonstrate that some magnocellular neurons of the rat hypothalamus contain both GAL and OT. This approach is suitable for studying the intracellular distribution of OT gene expression and mature GAL under different physiological or experimental conditions.