Abstract:

Muscarinic M1 and M2 receptors are widely distributed in the brain and contribute to various physiological and pathological functions. It is well known that enhancement of cholinergic activity produces convulsions in animals. Pilocarpine, the M1 muscarinic receptor agonist, is commonly used to induce seizures in rodents. On the other hand it has been reported that fasted rats and mice pretreated with the M1 and M2 receptor antagonist atropine, scopolamine or biperiden develop convulsions after food intake indicating cholinergic hypoactivity as the underlying mechanism. This review will present pharmacological data for the M1 and M2 receptors in the brain and focus on the contrasting findings related to their contribution to convulsions.

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