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Electrophysiology of neuroeffector transmission in the isolated, innervated trachea of the guinea‐pig
Author(s) -
McCaig Dorothy J.
Publication year - 1986
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1986.tb11184.x
Subject(s) - depolarization , hyperpolarization (physics) , stimulation , electrophysiology , phentolamine , superior cervical ganglion , spike potential , vagus nerve , chemistry , medicine , neuroscience , biology , organic chemistry , nuclear magnetic resonance spectroscopy
1 Intracellular recordings were made from cells of the guinea‐pig trachealis muscle. Some cells were electrically quiescent while others exhibited spontaneous slow waves. 2 In quiescent cells, stimulation of the cervical vagus nerve evoked transient depolarization. Occasionally there was a single depolarization, but more often there were several fluctuations in potential. 3 In spontaneously active cells, vagal stimulation induced a transient increase in amplitude of the slow waves without affecting their frequency. 4 Depolarizing responses could be obtained with a single pulse applied to the vagus nerve, and responses increased in amplitude with number of pulses (up to 16 pulses), and with frequency of stimulation (up to 20 Hz). Depolarization did not give rise to spike discharge. 5 Responses to vagal stimulation were blocked by atropine. 6 In the presence of neostigmine, vagally‐mediated depolarization was augmented and abortive spikes were observed in a number of cells. 7 In quiescent cells, repetitive stimulation of the sympathetic stellate ganglion evoked slight hyperpolarization. 8 In spontaneously active cells, sympathetic stimulation evoked attenuation, or temporary cessation of slow wave discharge, with or without hyperpolarization. 9 Sympathetic‐induced hyperpolarization and suppression of slow waves were both blocked by propranolol, but unaffected by phentolamine. 10 Electrical changes associated with sympathetic stimulation may be of minor importance in the initiation of relaxation.