Colocalization of NGF receptor immunoreactivity and [3H]GABA uptake activity in developing rat septum/diagonal band neurons in vitro.

Neurons in the septum (SEP) and vertical limb of the diagonal band (vDB) of 6-day-old rats were dissociated and cultured for 3 days. Cells with high affinity uptake mechanism for gamma-aminobutyric acid (GABA) were identified autoradiographically using 16 nM [3H]GABA. Cells that expressed nerve growth factor (NGF) receptor immunoreactivity were identified immunocytochemically using MC192, a monoclonal antibody against NGF receptor. Double labeling experiments combining [3H]GABA uptake with immunostaining for NGF receptor showed that 46% of the NGF receptor-immunoreactive cells accumulated [3H]GABA. The result was discussed in relation to a possible involvement of the developing septal GABAergic neurons in NGF-induced neuronal survival.