[Impaired memory following repeated pentylenetetrazol treatments in kindled mice]

Epilepsy is characterized by recurrent seizures, which are caused by excessive discharges from cerebral neurons. Currently, antiepileptic drugs that possess sodium channel blocking activities and also mediate GABA-ergic systems are primarily used to prevent epileptic seizure. However, approximately 40% of patients with epilepsy suffer from interictal psychiatric comorbidities in clinical practice. Furthermore, it is unclear whether epilepsy is associated with psychic function. The aim of the present study was to clarify the effects of kindling-induced epileptic seizures on psychic functioning using behavioral pharmacological tests. Pentylenetetrazol (PTZ)-kindled mice demonstrated no significant differences in locomotor activity and muscle relaxation compared with naïve mice. PTZ-kindled mice also demonstrated cognitive impairment in the objective location test, but no significant effects of PTZ-kindling were observed in the Y-maze test. These findings suggested that PTZ-kindling impairs reference memory, but not working memory. These results suggest that, with respect to their psychic functioning, PTZ-kindled mice have specific characteristics.