Diurnal circadian clock gene expression is altered in models of genetic and acquired epilepsy

Abstract

ObjectivesGrowing evidence demonstrates a relationship between epilepsy and the circadian system. However, relatively little is known about circadian function in disease states, such as epilepsy. This study aimed to characterize brain and peripheral core circadian clock gene expression in rat models of genetic and acquired epilepsy.MethodsFor the Genetic Absence Epilepsy Rats from Strasbourg (GAERS) study we used 40 GAERS and 40 non‐epileptic control (NEC) rats. For the kainic acid status epilepticus (KASE) study, we used 40 KASE and 40 sham rats. Rats were housed in a 7am:7pm light‐dark cycle. Hypothalamus, hippocampus, liver, and small intestine samples were collected every 3 hours throughout the light period. We then assessed core diurnal clock gene expression of per1, cry1, clock and bmal1.ResultsIn the GAERS rats, all tissues exhibited significant changes in clock gene expression (p<0.05) when compared to NEC. In the KASE rats, there were fewer effects of the epileptic condition in the hypothalamus, hippocampus, or small intestine (p>0.05) compared to shams.SignificanceThese results indicate marked diurnal disruption to core circadian clock gene expression in rats with both generalized and focal chronic epilepsy. This could contribute to epileptic symptomology and implicate the circadian system as a viable target for future treatments.