Acetylcholine Metabolism in Normal and Epileptogenic Brain Tissue. Failure to Repeat Previous Findings

¹ From the Donner Laboratory of Experimental Neurochemistry, Montreal Neurological Institute, and the Department of Neurology and Neurosurgery, McGill University, Montreal, Canada

Production of bound acetylcholine (ACh) by human epileptogenic cerebral cortex, when incubated in vitro in a high potassium medium, was found to be on the average only very slightly lower than by normal human tissue; production of free ACh was appreciably lower. The presence of glutamine in the medium apparently did not affect the true bound or free ACh. Production of bound ACh by cat cerebral cortex was about the same with tissue from animals suffering convulsions following injections of methionine sulfoximine as with tissue from normal animals. Production of both bound and free ACh during incubation of slices of cerebral cortex of cats and rats was decreased by lowering the oxygen tension. This effect was not reversed by the presence of glutamine. Tissue from anesthetized cats and rats produced no more bound ACh during incubation than did tissue from normal animals. Low concentrations of glutamine cause contraction of the eserinized leech muscle.