Some antiepileptic compounds impair learning by rats in a Morris water maze.
In the present experiments, we investigated the effects of several commonly employed antiepileptic drugs on the performance of adult rats in a Morris water maze task. We found that phenytoin treatment produced the most deleterious performance impairments across all days of training, and that these performance deficits are not likely due to any general sensorimotor impairments. Carbamazepine had milder, but detectable negative effects, as carbamazepine-treated animals exhibited initial acquisition deficits, but rapidly achieved escape levels comparable to controls. In marked contrast, valproate and ethosuximide had no detectable effects on learning in the water maze. These results parallel previous findings in rats treated with these compounds and tested in an instrumental learning task, and are in general agreement with the human clinical literature. To the extent that one might wish to minimize learning deficits associated with maintenance on antiepileptic drugs, phenytoin is definitely not the treatment of choice, while valproate or ethosuximide are apparently much less disruptive.
Churchill
James D
JD
Department of Psychology, Indiana University, Bloomington 47405-7007, USA.
Fang
Pei-Chun
PC
Voss
Steven E
SE
Besheer
Joyce
J
Herron
Annette L
AL
Garraghty
Preston E
PE
D000818:Animals; D000927:Anticonvulsants / Q000009:adverse effects*; D002220:Carbamazepine / Q000009:adverse effects; D004924:Escape Reaction / Q000187:drug effects*; D005013:Ethosuximide / Q000009:adverse effects; D008297:Male; D018782:Maze Learning / Q000187:drug effects*; D010672:Phenytoin / Q000009:adverse effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time / Q000187:drug effects; D013028:Space Perception / Q000187:drug effects*; D013037:Spatial Behavior / Q000187:drug effects; D013550:Swimming; D014635:Valproic Acid / Q000009:adverse effects
D000927:Anticonvulsants; D002220:Carbamazepine; D005013:Ethosuximide; D014635:Valproic Acid; D010672:Phenytoin