Pentylenetetrazole kindling affects sleep in rats

The aim of the study was to define sleep disturbances in pentylenetetrazole (PTZ)-kindled rats and to explore the effects of the nootropic drug piracetam (Pir; 100 mg/kg) and the noncompetitive N-methyl-D-aspartate (NMDA)-antagonist MK-801 (0.3 mg/kg), which normalized learning performance in PTZ-kindled rats, on altered sleep parameters.

This is the first report showing a significant reduction in paradoxical sleep (PS) as a consequence of PTZ kindling. A correlation analysis revealed a significant correlation between seizure severity and PS deficit.

Pir did not interfere with seizure severity, and the substance did not ameliorate the PS deficit. However, the substance disconnected the correlation between seizure severity and PS deficit. MK-801, which reduced the severity of kindled seizures, counteracted the PS deficit efficaciously.

The results suggest that seizure severity and alterations in sleep architecture are two factors in the comprehensive network underlying learning impairments associated with epilepsy. Considering the results obtained in the experiments with Pir, reduction of seizure severity does not guarantee the reduction of impairments in the domain of learning.