Seizure frequency in pilocarpine-treated rats is independent of circadian rhythm

Bajorat, Rika; Wilde, Marleen; Sellmann, Tina; Kirschstein, Timo; Köhling, Rüdiger

doi:10.1111/j.1528-1167.2011.03200.x

Cited by 45 publications

(45 citation statements)

References 13 publications

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“…As seen in human condition, seizure activity is highly variable among animals and occurs in clusters with seizures free-intervals 20,21 . Bajorat et al 21 using video-EEG in pilocarpine model identified three patterns of seizure distribution during the course of recording: a) > 3/day and evenly distributed seizures, b) > 2/day and again evenly distributed seizures and c) > 3/day and seizures clustered with seizure-free intervals. in our study, the average of seizures was 1.34 per week, being lower than observed by Bajorat et al 21 .…”

Section: Discussionmentioning

confidence: 99%

“…Bajorat et al 21 using video-EEG in pilocarpine model identified three patterns of seizure distribution during the course of recording: a) > 3/day and evenly distributed seizures, b) > 2/day and again evenly distributed seizures and c) > 3/day and seizures clustered with seizure-free intervals. in our study, the average of seizures was 1.34 per week, being lower than observed by Bajorat et al 21 . we do not rule that the low accuracy of the video monitoring may have contributed to underestimate the seizure activity.…”

Section: Discussionmentioning

confidence: 99%

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Impaired executive functions in experimental model of temporal lobe epilepsy

Ramos

Carreiro

Scorza

et al. 2016

Arq. Neuro-Psiquiatr.

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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...

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Impaired executive functions in experimental model of temporal lobe epilepsy

Ramos

Carreiro

Scorza

et al. 2016

Arq. Neuro-Psiquiatr.

View full text Add to dashboard Cite

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“…For example, pilocarpine-treated rats exhibited twice as many spontaneous seizures during the light phase as compared to the dark phase, a rhythm that remained intact and governed by the clock even when animals were maintained in constant darkness (Quigg, 2000). However, a more recent study reported spontaneous seizures elicited by pilocarpine treatment in rats was independent of the circadian cycle (Bajorat et al, 2011), an effect likely due to dependence on underlying sleep architecture (Matos et al, 2010b). In a model of electrically-induced status epilepticus, dentate gyrus neurons exhibited enhanced electrical excitability that corresponded with the time of day of enhanced seizure susceptibility (Matzen et al, 2012).…”

Section: Discussionmentioning

confidence: 99%

BMAL1 controls the diurnal rhythm and set point for electrical seizure threshold in mice

Gerstner

Smith

Lenz

et al. 2014

Front. Syst. Neurosci.

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The epilepsies are a heterogeneous group of neurological diseases defined by the occurrence of unprovoked seizures which, in many cases, are correlated with diurnal rhythms. In order to gain insight into the biological mechanisms controlling this phenomenon, we characterized time-of-day effects on electrical seizure threshold in mice. Male C57BL/6J wild-type mice were maintained on a 14/10 h light/dark cycle, from birth until 6 weeks of age for seizure testing. Seizure thresholds were measured using a step-wise paradigm involving a single daily electrical stimulus. Results showed that the current required to elicit both generalized and maximal seizures was significantly higher in mice tested during the dark phase of the diurnal cycle compared to mice tested during the light phase. This rhythm was absent in BMAL1 knockout (KO) mice. BMAL1 KO also exhibited significantly reduced seizure thresholds at all times tested, compared to C57BL/6J mice. Results document a significant influence of time-of-day on electrical seizure threshold in mice and suggest that this effect is under the control of genes that are known to regulate circadian behaviors. Furthermore, low seizure thresholds in BMAL1 KO mice suggest that BMAL1 itself is directly involved in controlling neuronal excitability.

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“…In this study, we have video monitored all animals 12 h a day, 5 days a week, along the 9 months after status. These hours were preferentially at light time (7 am–7 pm) based on that no differences were reported in terms of clustered seizures or circadian rhythm for both KA and PILO models (51, 52). However, despite that, it is still possible that some spontaneous seizures were missed along the study, so future studies with more extensive monitoring could produce different results.…”

Section: Discussionmentioning

confidence: 99%

Changes in Hippocampal Volume are Correlated with Cell Loss but Not with Seizure Frequency in Two Chronic Models of Temporal Lobe Epilepsy

et al. 2014

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Kainic acid (KA) or pilocarpine (PILO) have been used in rats to model human temporal lobe epilepsy (TLE) but the distribution and severity of structural lesions between these two models may differ. Magnetic resonance imaging (MRI) studies have used quantitative measurements of hippocampal T2 (T2HP) relaxation time and volume, but simultaneous comparative results have not been reported yet. The aim of this study was to compare the MRI T2HP and volume with histological data and frequency of seizures in both models. KA- and PILO-treated rats were imaged with a 2 T MRI scanner. T2HP and volume values were correlated with the number of cells, mossy fiber sprouting, and spontaneous recurrent seizures (SRS) frequency over the 9 months following status epilepticus (SE). Compared to controls, KA-treated rats had unaltered T2HP, pronounced reduction in hippocampal volume and concomitant cell reduction in granule cell layer, CA1 and CA3 at 3 months post SE. In contrast, hippocampal volume was unchanged in PILO-treated animals despite detectable increased T2HP and cell loss in granule cell layer, CA1 and CA3. In the following 6 months, MRI hippocampal volume remained stable with increase of T2HP signal in the KA-treated group. The number of CA1 and CA3 cells was smaller than age-matched CTL group. In contrast, PILO group had MRI volumetric reduction accompanied by reduction in the number of CA1 and CA3 cells. In this group, T2HP signal was unaltered at 6 or 9 months after status. Reductions in the number of cells were not progressive in both models. Notably, the SRS frequency was higher in PILO than in the KA model. The volumetry data correlated well with tissue damage in the epileptic brain, suggesting that MRI may be useful for tracking longitudinal hippocampal changes, allowing the assessment of individual variability and disease progression. Our results indicate that the temporal changes in hippocampal morphology are distinct for both models of TLE and that these are not significantly correlated to the frequency of SRS.

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Seizure frequency in pilocarpine-treated rats is independent of circadian rhythm

Cited by 45 publications

References 13 publications

Impaired executive functions in experimental model of temporal lobe epilepsy

Impaired executive functions in experimental model of temporal lobe epilepsy

BMAL1 controls the diurnal rhythm and set point for electrical seizure threshold in mice

Changes in Hippocampal Volume are Correlated with Cell Loss but Not with Seizure Frequency in Two Chronic Models of Temporal Lobe Epilepsy

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