Cells in neonatal rat hypothalamus primary culture--an immunofluorescence study.

Hypothalami from 1 day neonatal rats were dissociated and cultured for 4-16 days. Using immunofluorescence and antisera against neurofilament (NF) peptides, glial fibrillary acidic protein (GFAP), galactocerebroside and fibronectin we have distinguished neurons, astrocytes, oligodendrocytes and fibroblast-like cells in culture. Astrocytes initially grew as islets of 15-30 cells which dispersed as the culture aged. These cells, together with fibronectin-reactive flat cells, formed a monolayer upon which ovoid and process-bearing cells grew after 4 days in culture. Neurofilament-positive neurons constituted 5-10% of the total cell population. In maturing cultures the number of neurons decreased and fibroblasts increased. Oligodendrocytes represented less than 1% of total cell population. These studies emphasize the necessity of using the complementary techniques of morphology and immunocytochemistry for the characterization of hypothalamic neural cells in vitro.