Behavioural and Electrophysiological Features of WAG/Rij Rats with Different Forms of Genetic Epilepsy

WAG/Rij rats are widely used as a genetic model of absenceepilepsy. Approximately 15–50% rats of the strain are susceptibleto audiogenic seizures. WAG/Rij rats demonstrate depressive-likebehavior. After preliminary sound provocation an increased levelof anxiety was found in audiogenic susceptible WAG/Rij subgroup.Electrophysiological and behavioral studies suggest the involvementof the dopaminergic system in both absence and audiogenic epilepsy.An increased binding density to dopamine receptors was found inthe dorsal striatum subregions in audiogenic prone rats comparedto non-audiogenic. The study aims were (1) to determine whetherbehavioral changes in WAG/Rij rats were genetically determined orinduced by prior sound stimulation; (2) how regions of the dorsal striatumwith different density of dopamine receptors in subpopulations ofWAG/Rij rats are involved in the absence epilepsy control. The studywas conducted using two rat groups: WAG/Rij–nonAGS (absence epilepsy)and WAG/Rij–AGS (mixed epilepsy). The study was performed usingtests: “Elevated plus maze,” “Forced swimming” and “Three chambersociability test.” High-frequency deep brain stimulation was performedfor evaluation of dorsal striatum involvement in the absence seizure control.After experiments animals were tested for the susceptibility toaudiogenic seizures. It demonstrated that the increased level ofanxiety in WAG/Rij–AGS rats is genetically determined, while depressive-likebehavior in WAG/Rij rats is not dependent on a predisposition toaudiogenic seizures. Abnormalities in social behavior were observedin WAG/Rij–AGS rats. Stimulation of the dorsal striatum indicatesdifferences in the control of absence and mixed forms of epilepsyin the WAG/Rij–AGS and WAG/Rij–non-AGS subpopulations.