<abstract xmlns="http://www.w3.org/1999/xhtml">One of the most frequent forms of epilepsy in humans is temporal lobe epilepsy. Characteristic to this form of the disease is the frequent pharmacoresistance and the association with behavioural disorders and cognitive impairment. The objective of our study was to establish the degree of cognitive impairment in a rat model of temporal lobe epilepsy after an initial epileptogenic exposure but before of the onset of the effect of long-duration epilepsy. Methods. For the experiment we used 11 rats. Status epilepticus was induced by systemic administration of a single dose of pilocarpine. The animals were continuously video-monitored to observe the occurrence of spontaneous recurrent seizures; during weeks 9-10 we performed eight-arm radial maze testing in order to assess the cognitive impairment. Results. Animals developed spontaneous recurrent seizures after a 14-21 day latency with a daily average seizure density of 0.79±0.43 during weeks 9-10. Epileptic rats had significantly more working memory errors per session, more reference memory errors and the number of visited arms was also significantly higher. Accuracy was also lower in the pilocarpine treated group. Interestingly significant differences disappeared after six days of trials. Conclusions. Our study shows behavioural deficits occurring after 9-10 weeks of epilepsy in the pilocarpine model of epilepsy applied to juvenile rats. In contrast to previous studies, we showed that juvenile rats with short duration of epilepsy are able to learn the behavioural task, therefore a morphopathological and/or behavioural “no-return point” regarding the development of severe cognitive impairment is not reached by status epilepticus alone.</abstract>

One of the most frequent forms of epilepsy in humans is temporal lobe epilepsy. Characteristic to this form of the disease is the frequent pharmacoresistance and the association with behavioural disorders and cognitive impairment. The objective of our study was to establish the degree of cognitive impairment in a rat model of temporal lobe epilepsy after an initial epileptogenic exposure but before of the onset of the effect of long-duration epilepsy. Methods. For the experiment we used 11 rats. Status epilepticus was induced by systemic administration of a single dose of pilocarpine. The animals were continuously video-monitored to observe the occurrence of spontaneous recurrent seizures; during weeks 9-10 we performed eight-arm radial maze testing in order to assess the cognitive impairment. Results. Animals developed spontaneous recurrent seizures after a 14-21 day latency with a daily average seizure density of 0.79±0.43 during weeks 9-10. Epileptic rats had significantly more working memory errors per session, more reference memory errors and the number of visited arms was also significantly higher. Accuracy was also lower in the pilocarpine treated group. Interestingly significant differences disappeared after six days of trials. Conclusions. Our study shows behavioural deficits occurring after 9-10 weeks of epilepsy in the pilocarpine model of epilepsy applied to juvenile rats. In contrast to previous studies, we showed that juvenile rats with short duration of epilepsy are able to learn the behavioural task, therefore a morphopathological and/or behavioural “no-return point” regarding the development of severe cognitive impairment is not reached by status epilepticus alone.

Spatial memory deficits in juvenile rats with pilocarpine induced temporal lobe epilepsy

Department of Physiology, University of Medicine and Pharmacy Tirgu Mures

Acta Marisiensis - Seria Medica

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

One of the most frequent forms of epilepsy in humans is temporal lobe epilepsy. Characteristic to this form of the disease is the frequent pharmacoresistance...

Spatial memory deficits in juvenile rats with pilocarpine induced temporal lobe epilepsy

Published Online: Dec 04, 2014

Page range: 191 - 195

Received: Oct 17, 2014

Accepted: Oct 25, 2014

DOI: https://doi.org/10.2478/amma-2014-0040

Keywords
epilepsy, hippocampus, cognitive impairment

© by K Orbán-Kis

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Spatial memory deficits in juvenile rats with pilocarpine induced temporal lobe epilepsy

Published Online: Dec 04, 2014

Page range: 191 - 195

Received: Oct 17, 2014

Accepted: Oct 25, 2014

DOI: https://doi.org/10.2478/amma-2014-0040

Keywordsepilepsy, hippocampus, cognitive impairment

© by K Orbán-Kis

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
epilepsy, hippocampus, cognitive impairment