Physostigmine-insensitive behavioral excitatory effects of atropine in squirrel monkeys.

摘要: Abstract Lever press responses of squirrel monkeys were maintained under a multiple schedule in which the first response after 3 min produced either food or electric shock depending on prevailing stimulus. Atropine sulfate (0.3–3 mg/kg, IM) given immediately before experimental sessions disrupted temporal pattern responding and dose-related decrease rates food- shock-maintained responding. Increases occurred when 1 mg/kg atropine was to 2-hr pretreatment. Qualitatively similar effects obtained with scopolamine suggesting that time-dependent increases may be general consequence muscarinic receptor blockade. Response patterning changes rate also by coadministration physostigmine both session. have been observed previously administration rate-decreasing doses direct-acting agonist oxotremorine. Physostigmine did not reverse alteration pretreatment; decreases induced immediate pretreatment blocked physostigmine. Thus, distinct from its rate-increasing effects. Whereas appear involve receptors, not. Such nonmuscarinic behavioral excitatory actions expressed muscarinic-related are oxotremorine, overridden excessive stimulation, perhaps triggered acetylcholine turnover associated atropine.