爪蟾胚胎脊髓胆碱能神经元上两类非去极化激...

Two types of nondepolarizing-activated calcium channels on the spinal cholinergic neurons from embryonic Xenopus laevis]

Single calcium channel current was studied on the identified spinal cholinergic neurons from embryonic Xenopus laevis with patch clamp method. The results indicate that some calcium channels show opening activity at resting membrane potential. According to the characteristics of conductance and kinetics of such channels, they could be divided into two types: a stretch sensitive Type-NS with a slope conductance of 7.5 pS (mean open time 0.58 ms at resting membrane potential) and a Type-NL with a slope conductance of 16.7 pS (and two opening times of 2 ms and 19.3 ms). Both types of channel are predominantly active at resting potential and negative membrane phases. It is suggested that they may be involved in the calcium-dependent neuronal events at resting state.