Solitary hypothalamic neurons inherently express vasopressin and tyrosine hydroxylase

Hypothalamic neurons were grown as single cells in three-dimensional culture. Solitary neurons lacking cell contacts were immunocytochemically examined for inherent expression of vasopressin (VP), tyrosine hydroxylase (TH), and luteinizing hormone releasing hormone (LHRH). Immunoreactive VP and TH were detected within a day. Sixty to eighty-five percent of neurons displayed homogeneously distributed reaction product for VP or TH. One percent exhibited intense punctate staining of somas and varicosities. Few neurons stained for LHRH. Results indicate that hypothalamic neurons can express appropriate neuropeptides and transmitter-specific products without contacting other neurons or nonneuronal cells. Thus, this culture system may provide a useful model to study intrinsic neuronal processes.