Electrophysiological responses of human spinal neurons in culture.

Cell cultures were prepared from human fetal spinal cord and maintained in vitro for 30-100 days. Neurons were identified electrophysiologically by their ability to develop action potentials in response to intracellular depolarizing current pulses and in sister cultures by immunohistochemical and electron microscopic techniques. Extracellular applications of gamma-aminobutyric acid, glycine or histamine evoked hyperpolarizations which were associated with increases in membrane conductance. These data and the ultrastructural demonstrations of synapses suggest a functional differentiation of neurons in these cultures.