Citation

Marks WN, Cavanagh ME, Greba Q, Cain SM, Snutch TP, Howland JG. Eur. J. Neurosci. 2015; 43(1): 25-40.

Affiliation

Department of Physiology, University of Saskatchewan, Saskatoon, SK, Canada, S7N 5E5.

Copyright

(Copyright © 2015, Federation of European Neuroscience Societies, Publisher John Wiley and Sons)

DOI

10.1111/ejn.13110

PMID

26490879

Abstract

Behavioural, neurological, and genetic similarities exist in epilepsies, their psychiatric comorbidities, and various psychiatric illnesses, suggesting common etiological factors. Rodent models of epilepsy are used to characterize the co-morbid symptoms apparent in epilepsy and their neurobiological mechanisms. The present study was designed to assess Pavlovian fear conditioning and latent inhibition in a polygenetic rat model of absence epilepsy, Genetic Absence Epilepsy Rats from Strasbourg (GAERS) and the Non-Epileptic Control (NEC) strain. Electrophysiological recordings confirmed the presence of spike-wave discharges in young adult GAERS but not NEC rats. A series of behavioural tests designed to assess anxiety-like behaviour (elevated plus maze, open field, acoustic startle response) and cognition (Pavlovian conditioning and latent inhibition) were subsequently conducted on male and female offspring.

RESULTS showed that GAERS exhibited significantly higher anxiety-like behaviour, a characteristic reported previously. In addition, using two protocols that differed on shock intensity, we found that both sexes of GAERS displayed exaggerated cued and contextual Pavlovian fear conditioning and impaired fear extinction. Fear reinstatement to the CS following unsignaled footshocks did not differ between the strains. Male GAERS also showed impaired latent inhibition in a paradigm using Pavlovian fear conditioning suggesting that they may have altered attention, particularly related to previously irrelevant stimuli in the environment. Neither the female GAERS nor NECs showed evidence of latent inhibition in our paradigm. Together, the results suggest that GAERS may be a particularly useful model for assessing therapeutics designed to improve the emotional and cognitive disturbances associated with absence epilepsy. This article is protected by copyright. All rights reserved.

Language: en