Posttetanic potentiation in decentralized and nondecentralized superior cervical ganglia of the cat.
The present investigation was aimed to answer the following elementary, though important question concerning the sympathetic ganglion: Do the decentralized preganglionic terminals retain their full capacity to develop posttetanic potentiation (PTP) before substantial Wallerian degeneration takes place? Experiments were performed on the cat superior cervical ganglion in situ, and they followed a factorial design. The factors were: tetanization (supramaximal pulses, 0.2 ms, 24 Hz, 30 s), acute decentralization, and moderate hexamethonium blockade (5 mg/kg). Two levels were dealt with, namely, the indicated maneuvers were either performed or not performed. PTP was was measured in the S2 wave and the following variables were studied: decay constant, area under the curve and delay to summit occurrence. The analysis of variance showed that decentralization did not affect the development of PTP. Therefore, the nondegenerated terminals are fully capable of sustaining PTP, without the aid of the preganglionic cell bodies.
Morales
M A
MA
Alonso-deFlorida
F
F
D000200:Action Potentials; D000818:Animals; D001339:Autonomic Fibers, Preganglionic / Q000502:physiology*; D001340:Autonomic Nerve Block; D002415:Cats; D005728:Ganglia, Sympathetic / Q000502:physiology*; D006584:Hexamethonium Compounds; D009119:Muscle Contraction; D013562:Sympathectomy; D009435:Synaptic Transmission; D013997:Time Factors
D006584:Hexamethonium Compounds