Impaired executive functions in experimental model of temporal lobe epilepsy

Abstract

with approximately 65 million people affected worldwide, epilepsy is one of the most common, chronic and serious neurological disease 1,2,3,4 . temporal lobe epilepsy (tLE) is the commonest form of human epilepsy, affecting approximately 40% of patients and often resistant to antiepileptic drugs 5,6,7 . From the structural and functional points of view, tLE is often associated with specific structural abnormalities that affect limbic structures as well as frontal lobe, which is associated with cognitive processes, including executive functions, working memory (wM), decision making, planning, cognitive flexibility and sustained attention 8,9 . Epilepsy is frequently associated with some psychiatry comorbities, such as attention deficit hyperactivity disorder (ADhD) and autism spectrum disorder (ASD). the prevalence of ADhD in children with epilepsy is higher than in general population, being estimated in 30-40% 10,11,12 . Although there is a well-established relationship between the two disorders, the underlying mechanisms are still unclear and more research needs to be performed. thus, the animal models allow investigate many issues related to epilepsy in the absence of iatrogenic neurobehavioral abnormalities. Based on these, the present study aimed to investigate ADhD-like behaviour in male rats with pilocarpine-induced tLE. AbStrACtObjective: The present study aimed to investigate cognitive and behavioural changes consistent with attention deficit hyperactivity disorder (ADHD -like behavior in male Wistar rats with temporal lobe epilepsy (TLE). Method: Male Wistar rats at 25 day of age were submitted to animal model of TLE by pilocarpine injection (350 mg/kg, ip) and a control group received saline 0.9%. The animals were continuously video monitored up to the end of experiments. The behavioural tests (open field, elevated plus maze and operant conditioning box) started from 60 days postnatal. Results: Animals with TLE exhibited elevated locomotor activity, reduced level of anxiety-related behavior, impulsivity and impaired visuospatial working memory. Conclusion: Taken as a whole, we concluded that animals with TLE exhibited some cognitive and behavioural changes consistent with ADHD-like behavior.Keywords: Epilepsy, temporal lobe; executive function; pilocarpine; memory, short-term. reSumo Objetivo: O presente estudo teve como objetivo investigar as alterações cognitivas e comportamentais consistentes com o comportament de transtorno de deficit de atenção e hiperatividade (TDAH) -like em ratos Wistar machos com epilepsia do lobo temporal (ELT). Método: Ratos Wistar machos com 25 dias de vida foram submetidos a modelo animal de ELT pela injeção de pilocarpina (350 mg / kg, ip) e grupo controle recebeu salina 0,9%. Os animais foram monitorados continuamente por vídeo até ao final dos experimentos. Os testes comportamentais (campo aberto, labirinto em cruz elevado e caixa de condicionamento operante) começaram a partir de 60 dias pós-natal. Resultados: Os animais com ELT exibiram aumento da atividade locomoto...

Effects of fish oil supplementation on spatial memory in rats with pilocarpine‐induced epilepsy assessed using the Morris Water Maze test

“…In addition, we found that the swimming speed was significantly increased in experimental rats (data not shown). This result is consistent with previous studies showing that rats with pilocarpine‐induced epilepsy exhibit attention deficit hyperactivity disorder‐like behaviours, such as increased locomotor activity and impulsivity [33, 34]. Together, these cognitive and behavioural abnormalities likely contribute to the impaired performance of epileptic rats in the MWM task.…”

Impaired Response to Mismatch Novelty in the Li2+-Pilocarpine Rat Model of TLE: Correlation with Hippocampal Monoaminergic Inputs

“…Thus, animals, although likely now less fearful, spent more time in the periphery exploring the holes, as evidenced by the number of nose-pokes (9.0 ± 0.7, n = 16). SRS animals behaved similarly when exposed to the holeboard, since the total number of rearings (8.6 ± 1.0, n = 16) was only a bit higher for SRS animals than the one performed by Sham animals, while the number of nose-pokes was slightly lower (7.8 ± 1.2, n = 16), yet the total distance travelled by SRS animals (26.1 ± 2.7 m, n = 16) in the holeboard was double the one travelled by Sham animals (13.0 ± 1.4 m, n = 16), as occurring in virtually all other tests, a reflection of their anxious and attention deficit-like behaviour, as previously described [37,38].…”

Impaired response to mismatch novelty in the Li2+-pilocarpine rat model of TLE: correlation with hippocampal monoaminergic inputs

“…Thus, animals although likely now less fearful, spent more time in the periphery exploring the holes, as evidenced by the number of nose-pokes (9.0±0.7, n=16). SRSs animals behaved similarly when exposed to the holeboard, since the total number of rearings (8.6±1.0, n=16) was only a bit higher for SRSs animals than the one performed by Sham animals, while the number of nose-pokes was slightly lower (7.8±1.2, n=16), yet the total distance travelled by SRSs animals (26.1±2.7m, n=16) in the holeboard was double the one travelled by Sham animals (13.0±1.4m, n=16), as occurring in virtually all other tests, a reflection of their anxious and attention deficit -like behaviour, as previously described [35,36].…”