The effects of carbamazepine on an appetitive-to-aversive transfer task: Comparison to untreated and phenytoin

1. Concerns over negative consequences resulting from chronic maintenance w ith antiepileptic medications have led to increased research regarding such impairments, often with disparate results. The authors have previously rep orted that phenytoin profoundly impairs the ability of adult rats, in compa rison to controls, to learn a tone-signaled active avoidance response after learning a tone-signaled appetitive response (Banks et al., 1995; Banks et al., 1999). Such results lend further support to the suggestion that pharm acological treatment itself can produce cognitive difficulties that are com parable to those experienced by epileptic patients (Meador, 1994; Smith et al., 19X7). 2. In the present experiments, the authors have continued their investigati on of antiepileptic compounds by treating rats with carbamazepine, another commonly prescribed "first-line defense" antiepileptic medication. In compa rison to intact animals, carbamazepine-treated rats demonstrate variable de ficiencies in the acquisition of the secondarily acquired avoidance respons e. 3. This result is in agreement with the finding for phenytoin-treated anima ls, albeit to a lesser degree. Continuing experiments are needed to investi gate the relative nature of the deficits produced by such antiepileptic med ications, as well as the underlying neurobiological mechanism(s).