Effects of protein synthesis inhibitors on sleep and amygdala-kindled seizure thresholds in cats

This study examined the effects of protein synthesis inhibitors on sleep and seizure susceptibility in amygdala-kindled cats. Six cats with stable seizure thresholds were treated with 150 mg/kg of chloramphenicol or its cogener, thiamphenicol, at 12-h intervals over a 30-h period. State pattern variables were monitored continuously during the first 18 h. At 30 h, kindled seizure thresholds were measured in terms of minimum stimulus intensities (microA) required to elicit generalized tonic clonic convulsions. All cats were exposed to both drugs, with a 1-week intertrial interval and the order of drug treatment counterbalanced. Rapid eye movement (REM) sleep was significantly attenuated after chloramphenicol but was unaffected by thiamphenicol, as previously shown. Seizure thresholds were unaltered regardless of changes in sleep state physiology. The results extend previous work showing that protein synthesis inhibitors which suppress REM sleep increase seizure susceptibility only in animals that are either highly predisposed to seizures or that display REM sleep disruption as the sole sleep deficit associated with their seizure condition.