The effects of hemicholinium-3 (Hc-3) during tetanic (TP) and posttetanic potentiation (PTP) on sympathetic ganglion.
An electrophysiological analysis has been made of the synaptic plasticity in the eighth sympathetic ganglion of the toad. The mean amplitude of Compound Action Potential (CAP) recorded extracellularly was taken as a measure of the synaptic transmission. Repetitive stimulation of the preganglionic axonal fibers at 50 Hz for 40 seconds in the presence of Hc-3 led to facilitatory and depressant actions on ganglionic synaptic transmission. Hc-3 in the presence of elevated extracellular Ca2+ concentration (5.4 mM) increased Tetanic Potentiation (TP) and Posttetanic Potentiation (PTP) on eighth sympathetic ganglion. Hc-3 plus 3,4-diaminopyridine (3,4-DAP) increased synaptic transmission, TP, and PTP from postganglionic CAP responses to supramaximal preganglionic stimulation.
D015761:4-Aminopyridine / Q000031:analogs & derivatives*; D000200:Action Potentials / Q000187:drug effects; D000077770:Amifampridine; D000631:Aminopyridines / Q000494:pharmacology; D000818:Animals; D001001:Anura; D002118:Calcium / Q000494:pharmacology; D004558:Electric Stimulation; D004594:Electrophysiology; D005728:Ganglia, Sympathetic / Q000187:drug effects* / Q000502:physiology; D006426:Hemicholinium 3 / Q000494:pharmacology*; D009119:Muscle Contraction; D013569:Synapses / Q000187:drug effects / Q000502:physiology; D009435:Synaptic Transmission / Q000187:drug effects
D000631:Aminopyridines; D006426:Hemicholinium 3; D015761:4-Aminopyridine; D000077770:Amifampridine; D002118:Calcium