Age-dependent decline in learning and memory performances of WAG/Rij rat model of absence epilepsy

Ayşe Karson,Nurbay Ateş,Feyza Arıcıoğlu,Tijen Utkan,Fuat Balcı

doi:10.1186/1744-9081-8-51

Abstract

Recent clinical studies revealed emotional and cognitive impairments associated with absence epilepsy. Preclinical research with genetic models of absence epilepsy however have primarily focused on dysfunctional emotional processes and paid relatively less attention to cognitive impairment. In order to bridge this gap, we investigated age-dependent changes in learning and memory performance, anxiety-like behavior, and locomotor activity of WAG/Rij rats (a valid model of generalized absence epilepsy) using passive avoidance, Morris water maze, elevated plus maze, and locomotor activity cage. We tested 5 month-old and 13 month-old WAG/Rij rats and compared their performance to age-matched Wistar rats. Results revealed a decline in emotional and spatial memory of WAG/Rij rats compared to age-matched Wistar rats only at 13 months of age. Importantly, there were no significant differences between WAG/Rij and Wistar rats in terms of anxiety-like behavior and locomotor activity at either age. Results pointed at age-dependent learning and memory deficits in the WAG/Rij rat model of absence epilepsy.

Highlights

Growing number of studies started to indicate that epilepsy is not restricted to recurrent seizures and emphasize that neuropsychological symptoms are part of its clinical profile [1,2]
We examined learning and memory performance of 5 months and 13 months old Wistar-Albino-Glaxo from Rijswijk (WAG/Rij) rats and agematched Wistar controls in passive avoidance and Morris water maze, two tasks that are well-characterized in terms of their behavioral, neuroanatomical, and neurochemical bases
There were no significant differences between WAG/Rij and age-matched Wistar rats either at 5 months (p = .71) or 13 months of age (p = .07)

Summary

Introduction

Growing number of studies started to indicate that epilepsy is not restricted to recurrent seizures and emphasize that neuropsychological symptoms are part of its clinical profile [1,2]. Emotional and cognitive dysfunction impacts academic performance and social life in drug-resistant epilepsy and benign epileptic syndromes including absence epilepsy, a neurological disorder that lacks structural deficits and responds well to treatment [2,3,4,5,6,7]. In addition to neuropsychiatric comorbidities, recent studies investigated the time course of neurocognitive impairments in epileptic patients [8,9,10,11,12]. Hermann et al reported progressive cognitive abnormalities in temporal lobe epilepsy patients over a 4-year period compared to age- and sex-matched healthy controls [9]. Hommet et al compared adolescents and young adults in complete recovery from benign childhood epilepsy with centrotemporal spikes (BECTS) and childhood absence epilepsy (CAE) [8].

Methods

Results

Conclusion