Electrocorticographic effects of topically applied scopolamine

Area of Science:

• Neuroscience
• Pharmacology

Background:

• Scopolamine is a known anticholinergic drug.
• Its effects on electrocorticography (ECoG) in unanesthetized animals with spinal transection require further elucidation.

Purpose of the Study:

• To investigate the electrocorticographic effects of topically applied scopolamine in unanesthetized cats.
• To explore the dose-dependent actions of scopolamine on cortical activity and seizure generation.

Main Methods:

• Electrocorticography (ECoG) was performed on cats with high cervical transection.
• Scopolamine was applied topically to the cerebral cortex in varying concentrations.
• Effects were observed, and interventions like eserine were used for antagonism.

Main Results:

• Low-dose topical scopolamine antagonized seizure activity and abolished acoustically evoked cortical responses.
• High-dose topical scopolamine (10-20%) induced large amplitude sharp waves and paroxysmal activity.
• Intravenous eserine antagonized the effects of low-dose scopolamine.

Conclusions:

• Scopolamine's seizure-suppressing effect may stem from its cholinolytic action.
• High concentrations of scopolamine can induce convulsive activity via depolarizing, synchronizing, and acetylcholine-releasing mechanisms.