Reduction in anxiety levels, increased locomotor activity and deficits in working memory in rats with temporal lobe epilepsy

A epilepsia e caracterizada por crises espontaneas recorrentes, desencadeadas pela hiperexcitabilidade neuronal, acometendo aproximadamente 50 milhoes de pessoas no mundo. Dentre as epilepsias, a epilepsia do lobo temporal (ELT) e a mais comum e afeta cerca de 40% dos pacientes. O Transtorno do Deficit de Atencao e Hiperatividade (TDAH) representa uma das comorbidades mais comum da epilepsia com prevalencia maior do que 30%. A DSM-IV subdivide o TDAH em tres tipos, no primeiro tipo se observa o predominio de sintomas de desatencao; o segundo ha predominancia de hiperatividade/impulsividade e; o terceiro se caracteriza pela combinacao dos dois primeiros tipos. Embora exista uma relacao bem definida entre epilepsia e TDAH, os mecanismos dessa comorbidade ainda nao foram completamente esclarecidos. O objetivo do presente estudo foi analisar alteracoes comportamentais TDAH-like em ratos Wistar machos com ELT induzida pelo metodo da pilocarpina. Foram utilizados os testes de campo aberto, labirinto em cruz elevado e caixa de condicionamento operante para avaliacao dos comportamentos. Os resultados apresentados mostram evidencias que animais adultos com ELT pelo modelo da pilocarpina apresentaram aumento da atividade locomotora e reducao do nivel de ansiedade, prejuizo na memoria de trabalho viso-espacial, sem evidencias de impulsividade. Os resultados nao permitem descartar a possibilidade de deficit de atencao e apontam para a presenca de hiperatividade, sintomas caracteristicos de TDAH, porem mais estudos serao necessarios para avaliar a atencao e a impulsividadeEpilepsy is characterized by recurrent spontaneous seizures triggered by neuronal hyperexcitability, affecting approximately 50 million people worldwide. Among the epilepsy, temporal lobe epilepsy (TLE) is the most common and affects about 40% of patients. Disorder Attention Deficit Hyperactivity Disorder (ADHD) is one of the most common comorbidities of epilepsy with greater than 30% prevalence. The DSM - IV subdivided the ADHD into three types, the first type is observed the predominance of symptoms of inattention; the second, predominance of hyperactivity / impulsivity and; the third is characterized by the combination of the first two types. Although there is a well defined relationship between epilepsy and ADHD, the mechanisms of this comorbidity were poorly understood. The aim of this study was to assess ADHD-like behavioral changes in male Wistar rats with TLE induced by pilocarpine method. Tests of open field, elevated plus maze and operant conditioning box were used to assess the behaviors. The results show evidence that adult animals with TLE by pilocarpine model presented increased locomotor activity and reduced level of anxiety like behavior, impairment in visuospatial working memory, with no evidence of impulsivity. The results don’t dismiss the possibility of attention deficit and point to the presence of hyperactivity, characteristic symptoms of ADHD, but more studies are necessary to evaluate the attention and impulsivity.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)BV UNIFESP: Teses e dissertaçõe

Early life seizures in female rats lead to anxiety-related behavior and abnormal social behavior characterized by reduced motivation to novelty and deficit in social discrimination

Previously, we demonstrated that male Wistar rats submitted to neonatal status epilepticus showed abnormal social behavior characterized by deficit in social discrimination and enhanced emotionality. Taking into account that early insult can produce different biological manifestations in a gender-dependent manner, we aimed to investigate the social behavior and anxiety-like behavior in female Wistar rats following early life seizures. Neonate female Wistar rats at 9 days postnatal were subject to pilocarpine-induced status epilepticus and the control received saline. Behavioral tests started from 60 days postnatal and were carried out only during the diestrus phase of the reproductive cycle. in sociability test experimental animals exhibited reduced motivation for social encounter and deficit in social discrimination. in open field and the elevated plus maze, experimental animals showed enhanced emotionality with no changes in basal locomotor activity. the results showed that female rats submitted to neonatal status epipepticus showed impaired social behavior, characterized by reduced motivation to novelty and deficit in social discrimination in addition to enhanced emotionality.MACKPESQUISAFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Presbyterian Mackenzie Univ, Neurobiol Lab, BR-01302907 São Paulo, SP, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Neurol & Neurosurg, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Neurol & Neurosurg, São Paulo, BrazilWeb of Scienc

Impaired executive functions in experimental model of temporal lobe epilepsy

ABSTRACT Objective 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