[The spontaneous electrical activity of the isolated rabbit superior cervical ganglion].
Spontaneous electric activity (mean amplitude of impulses--200-300 muV and frequency--0.0m-2.9 Hz/s) was observed in isolated rabbit superior cervical symphathetic ganglia using the sucrose-gap method. This spontaneous activity was completely abolished by d-tubocurarine (5-10(-5) M) and hexamethonium (1-10(-4) M). The frequency of the spontaneous discharges was increased by doubling of osmotic pressure, increasing of [K]0 and adding theophilline or ethanol to perfusing solution. These findings suggest that the activity observed is due to spontaneous release of the transmitter by preganglionic nerve endings. However tetrodotoxin in relatively low concentrations (2.5-5-10(-7) g/ml) reversibly inhibited this activity. In high [Ca]0 solutions spontaneous discharges of an isolated ganglion were reduced or completely blocked. These facts suggest that the action potential generation mechanisms also participate in the spontaneous activity of the isolated cervical sympathetic ganglion.
D000200:Action Potentials; D000818:Animals; D004594:Electrophysiology; D005725:Ganglia, Autonomic / Q000187:drug effects / Q000502:physiology*; D006584:Hexamethonium Compounds / Q000494:pharmacology; D008564:Membrane Potentials; D011817:Rabbits; D013570:Synaptic Membranes; D013779:Tetrodotoxin / Q000494:pharmacology
D006584:Hexamethonium Compounds; D013779:Tetrodotoxin
Spontannaia élektricheskaia aktivnost' izolirovannogo verkhnego sheĭnogo simpaticheskogo gangliia krolika