Perfect cellular platform for electrophysiology:acutely isolated vagal ganglion neurons from adult canines / 中国药理学与毒理学杂志

ABSTRACT

OBJECTIVE To establish a platform of electrophysiology using vagal ganglion neurons (VGNs) isolated from adult canines. METHODS The VGNs were enzymatically isolated from adult canines of either gender and cultured under experimental conditions. Action potential (AP), repetitive firing, voltage-gated outward K+ currents (IK) and hyperpolarization-mediated inward currents (Ih) were recorded under current-and voltage-clamp configurations before and after treatment. RESULTS Analysis of AP waveform showed that ① inaddition to traditionally classified myelinated A- and unmyelinated C-types, myelinated Ah-types could also be identified in females rather than in males; ② step current depolarization evoked a stimulus intensity-dependent repetitive discharge, and to reach a similar firing frequency, the lowest stimulus intensity was required for A-types, a similar or slightly higher stimulus intensity was needed for Ah-types, and the highest stimulus intensity was required for C-types;③tetro?dotoxin significantly reduced the rate of depolarization and positively shifted the AP firing threshold of Ah-types, and iberiotoxin dramatically increased the neuroexcitability of Ah-types;④all tested neurons functionally expressed IK and Ih, and the current density for both channels on average was A-types>Ah-types>C-types; ⑤ although the distribution of afferent types of VGNs differed between males and females, the known difference in discharge profiles of A- and C-types isolated from male and female rats was not studied here. CONCLUSION The VGNs can be successfully isolated from adult canines, AP, IK and Ih can be recorded. The tight seal can be held for at least 30 min, which may be enough for pharmacological investigation.