Electrophysiological properties of tissue-cultured nerve cells from senescent mouse

Nerve cells were isolated from dorsal root ganglia of senescent mouse (C57 black, male) by collagenase and were grown on collagen-coated plastic dishes. The nerve cells extended their neurites and survived for more than 3 weeks in vitro. Intracellular recording with a glass microelectrode revealed that, although their resting membrane potential was small, the tissue-cultured nerve cells recovered membrane excitability after continuous hyperpolarization by DC current passage. Both Na and Ca spikes were elicited in thus hyperpolarized nerve cells. Some nerve cells generated tetrodotoxin-resistant Na spikes.