Nerve growth factor-induced excitation of selected neurons in the brain which is blocked by a low-affinity receptor antibody.

We have investigated the electrophysiological effects of nerve growth factor (NGF) on single-neuron activity in central nervous system (CNS) grafts of septum, spinal cord, and hippocampus in oculo. NGF was found to have slow-onset, long-lasting excitatory effects on the spontaneous firing of neurons in septal grafts, while no such effects were found in neurons of either hippocampal or spinal cord grafts. Pretreatment with an antibody against the p75 low-affinity NGF receptor blocked the NGF-induced excitations. A second NGF application caused much stronger excitatory responses in sensitive neurons. Our data suggest that forebrain cholinergic neurons may be selectively sensitive to NGF also at the neurophysiological level, responding by excitations, and that NGF upregulates these responses within less than an hour.