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Effects of the muscarinic antagonists pirenzepine and gallamine on spontaneous and evoked responses of rat cerebral cortical neurones
Author(s) -
Swanson Thomas H.,
Phillis John W.
Publication year - 1988
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.1476-5381.1988.tb11515.x
Subject(s) - pirenzepine , muscarinic acetylcholine receptor , acetylcholine , chemistry , stimulation , gallamine triethiodide , neuroscience , oxotremorine , nucleus basalis , efferent , endocrinology , receptor , medicine , psychology , afferent , cholinergic neuron , biochemistry
1 The muscarinic receptor antagonists gallamine and pirenzepine were iontophoretically applied to rat cerebral cortical cholinoceptive neurones, including corticospinal neurones, to assess their effects on spontaneous firing, and firing induced by: stimulation of the nucleus basalis magnocellularis (NBM); contralateral hindpaw stimulation; application of acetylcholine (ACh); and application of glutamate. 2 Both compounds potently inhibited firing induced by ACh iontophoresis, whilst neither compound consistently altered firing induced by application of glutamate. 3 Gallamine was very effective and pirenzepine less effective, at inhibiting both spontaneous firing and the delayed firing induced by NBM stimulation. The short‐latency excitations elicited by NBM stimulation were enhanced by these muscarinic antagonists. 4 Gallamine and pirenzepine enhanced cortical cholinoceptive cell firing induced by contralateral hindpaw stimulation. 5 It is concluded that gallamine depresses spontaneous activity more than pirenzepine, and that both compounds can affect the cortical cell firing evoked by stimulation of the NBM and of thalamo‐cortical afferent fibres.