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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, METHODS, RESULTS. Meshes: Animals, Anticonvulsants, Antidepressive Agents, Behavior, Animal, Depression, Depressive Disorder, Disease Models, Animal, Electroencephalography, Epilepsy, Absence, Ethosuximide, Exploratory Behavior, Immobility Response, Tonic, Male, Models, Genetic, Motor Activity, Rats, Rats, Inbred Strains, Rats, Wistar, Seizures, Swimming.
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Are spike-wave discharges necessary for the expression of behavioral depression-like symptoms? Context: The WAG/Rij strain of rats, a well-established model for absence epilepsy, has comorbidity for depression. These rats exhibit depression-like behavioral symptoms such as increased immobility in the forced swimming test and decreased sucrose intake and preference (anhedonia). These depression-like behavioral symptoms are evident in WAG/Rij rats, both at 3-4 and 5-6 months of age, with a tendency to aggravate in parallel with an increase in seizure duration. Here we investigated whether the behavioral symptoms of depression could be prevented by the suppression of absence seizures. Ethosuximide (ETX; 300 mg/kg/day, in the drinking water) was chronically applied to WAG/Rij rats from postnatal day 21 until 5 months. Behavioral tests were done before the cessation of the treatment. Electroencephalography (EEG) recordings were made before and after cessation of treatment to measure seizure severity at serial time-points. ETX-treated WAG/Rij rats exhibited no symptoms of depression-like behavior in contrast to untreated WAG/Rij rats of the same age. Moreover, treated WAG/Rij rats did not differ from control age-matched Wistar rats. ETX treatment led to almost complete suppression of spike-wave discharges (SWDs) in 5-6 month old WAG/Rij rats. Discontinuation of chronic treatment was accompanied by a gradual emergence of SWDs; however, a persistent reduction in seizure activity was still present 47 days after discontinuation of the chronic treatment.
assistant
The results suggest that seizure activity is necessary for the expression of depression-like behavioral symptoms and confirm that epileptogenesis can be prevented by early and chronic treatment. Final Decision: yes