In situ hybridization with complementary synthetic oligonucleotide and immunocytochemistry: a combination of methods to study transcription and secretion of oxytocin by hypothalamic neurons.

We have constructed an icosameric, anti-sense oligodeoxyribonucleotide probe derived from the published sequence of rat oxytocin gene precursor that was used for in situ hybridization, combined with immunostaining, to characterize the biosynthetic and secretory activity of hypothalamic oxytocin neurons. The population of hybridized neurons overlapped with the pattern of oxytocin immunoreactive cells, except for a fraction of these cells which remained unhybridized. A number of hybridized neurons remained unstained. The differential proportion of hybridized and immunostained neurons are interpreted as differences in secretory turnover of endocrine neurons.