Identification of insulin receptor-containing cells in primary cultures of rat brain

Abstract

1. Primary cultures of fetal rat brain consist of monolayer of large, flat cells of nonneuronal origin and smaller phase dark cells. 2. Neuron-specific enolase antibody was used to identify immunoreactive cells as neurons and these were present singly or in clusters on top of nonneuronal cells. 3. Incubation of these cultures with fluorescein-labelled insulin (FTC-insulin) resulted in the staining of 5-10% cells in a bright patchy green pattern, which are of neuronal and of nonneuronal morphology. 4. A faint green staining was seen when cultures were incubated with an excess of unconjugated insulin and FTC-insulin indicating that unconjugated insulin competes for the binding of fluorescein-insulin. 5. These results indicate that specific binding sites for insulin are present both on neurons and on nonneuronal cells in cultures of fetal rat brain.