The effect of dexphenmetrazine and acetyldexphenmetrazine upon epileptic electrographic activities in the brain of the turtle.

The effect of acetyldexphenmetrazine (ADP) and dexphenmetrazine (DP) on normal and epileptic electrographic activities in the cortical and thalamic structures of the turtle brain were studied in curarized and artificially ventilated animals. Both drugs almost exclusively influenced cortical activities. The effect of low doses of ADP and DP was similar--they desynchronized cortical activity and suppressed the activity of a cortical penicillin focus. They also elevated the cortical response to optic stimuli. Higher doses of ADP continued to suppress both normal and epileptic cortical activities. Higher doses of DP had a two phase effect with enhancement of epileptic activity in the first phase. Continuous trains of theta activity appeared after low doses of ADP and very often after both low and high doses of DP. The findings are discussed in terms of comparative physiology of the brain.