Anticonvulsive Action of Increased Calcium Concentration in Cerebrospinal Fluid

Perfusion of the inferior horn of the lateral ventricle with an artificial cerebrospinal fluid (CSF) containing 3.3 to 6.6 millimolar/liter of calcium (Ca++) has a strong anticonvulsive action in chronic, awake cats. This action was almost equally evident when the dorsal hippocampus was stimulated by any of these agents: repetitive electrical stimulation; increased potassium (K+) in the perfused CSF; infusion of penicillin, pentylenetetrazol, L-glutamate, or a combination of acetylcholine and edrophonium. The assumption is made that increased Ca++ has this wide anticonvulsant property probably by blocking the action of K+.