Relationship between acetylcholine content and release in the cat's cerebral cortex.

TLDR: Cortical acetylcholine (ACh) release and content were measured in non-anesthetized pretrigeminally sectioned or in Dial-ansthetized cats.

Abstract: Cortical acetylcholine (ACh) release and content were measured in non-anesthetized pretrigeminally sectioned or in Dial-anesthetized cats. In 28 pretrigerninally sectioned cats a very highly significant negative correlation between ACh content and output was found. In the same preparations, 15 mg/kg pentobarbital or electrolytic lesion in the rostral midbrain decreased ACh output and increased content. Atropine (1 mg/kg i.v. or 1 μg/ml topically) increased ACh output fourfold without significantly altering content. A larger dose of atropine (25 mg/kg i.v.) increased output ninefold and decreased ACh content. In Dial-anesthetized preparations, picrotoxin-induced ACh release was accompanied by a decrease in ACh content. Pretreatment with atropine in the same preparation resulted in an enhanced effect of picrotoxin on both output and content while atropine alone (1 mg/kg i.v.) raised ACh output without decreasing content. In pretrigerminally sectioned non-anesthetized preparations, hemicholinium-3 (HC-3) did...