Dexamethasone attenuates low-frequency brainwave disturbances following acute seizures induced by pentylenetetrazol in Wistar rats.

Seizures are neurological disorders triggered by an imbalance in the activity of excitatory and inhibitory neurotransmitters in the brain. When triggered chronically, this imbalance can lead to epilepsy. Critically, many of the affected individuals are refractory to treatment. Given this, anti-inflammatory drugs, in particular glucocorticoids, have been considered as a potential antiepileptogenic therapy. Glucocorticoids are currently used in the treatment of refractory patients, although there have been contradictory results in terms of their use in association with antiepileptic drugs, which reinforces the need for a more thorough investigation of their effects. In this context, the present study evaluated the effects of dexamethasone (DEX, 0.6 mg/kg) on the electroencephalographic (EEG) and histopathological parameters of male Wistar rats submitted to acute seizure induced by pentylenetetrazol (PTZ). The EEG monitoring revealed that DEX reduced the total brainwave power, in comparison with PTZ, in 12 h after the convulsive episode, exerting this effect in up to 36 h (p < 0.05 for all comparisons). An increase in the accommodation of the oscillations of the delta, alpha, and gamma frequencies was also observed from the first 12 h onwards, with the accommodation of the theta frequency occurring after 36 h, and that of the beta frequency 24 h after the seizure. The histopathological analyses showed that the CA3 region and hilum of the hippocampus suffered cell loss after the PTZ-induced seizure (control vs. PTZ, p < 0.05), although DEX was not able to protect these regions against cell death (PTZ vs. DEX + PTZ, p > 0.05). While DEX did not reverse the cell damage caused by PTZ, the data indicate that DEX has beneficial properties in the EEG analysis, which makes it a promising candidate for the attenuation of the epileptiform wave patterns that can precipitate refractory seizures.

Ribeiro RM ，da Silveira EP ，Santos VC ，Teixeira LL ，Santos GS ，Galvão IN ，Hamoy MKO ，da Silva Tiago AC ，de Araújo DB ，Muto NA ，Lopes DCF ，Hamoy M ... -  《-》

Anticonvulsant effect of Marsilea quadrifolia Linn. on pentylenetetrazole induced seizure: a behavioral and EEG study in rats.

Marsilea quadrifolia Linn (MQ) extract has been used traditionally as sedative and antiepileptic drug in India. To investigate the anticonvulsive potential of MQ extracts by using behavior and electroencephalographic (EEG) analysis on pentylenetetrazole (PTZ) induced seizure model in rats. For anticonvulsant effect, 60minutes after administration of MQ, behavior and EEG were analyzed during PTZ (60mg/kg) induced seizures. Changes of EEG power, latency of onset of seizure, seizure severity score, and duration of epileptic seizure were determined. Both the water and ethanol extract of MQ increased the latency of seizure but also decreased duration of epileptic seizure and seizure severity score. This reduction of seizure severity was also observed in EEG recording and EEG power analysis. The effectiveness of MQ ethanol extract is better than MQ water extract. Both water and ethanol extract of MQ were effective in reducing the severity of behavioral and EEG seizures induced by PTZ in rats. This study justifies the traditional use of this plant in epilepsy.

Sahu S ，Dutta G ，Mandal N ，Goswami AR ，Ghosh T ... -  《-》

Additive anticonvulsant effects of creatine supplementation and physical exercise against pentylenetetrazol-induced seizures.

Rambo LM ，Ribeiro LR ，Oliveira MS ，Furian AF ，Lima FD ，Souza MA ，Silva LF ，Retamoso LT ，Corte CL ，Puntel GO ，de Avila DS ，Soares FA ，Fighera MR ，Mello CF ，Royes LF ... -  《-》

Effects of acute administration of 4-allyl-2,6-dimethoxyphenol in mouse models of seizures.

Epilepsy, a chronic neurological disorder characterized by recurrent unprovoked seizures, presents a substantial challenge in approximately one-third of cases exhibiting resistance to conventional pharmacological treatments. This study investigated the effect of 4-allyl-2,6-dimethoxyphenol, a phenolic compound derived from various natural sources, in different models of induced seizures and its impact on animal electroencephalographic (EEG) recordings. Adult male Swiss albino mice were pre-treated (i.p.) with a dose curve of 4-allyl-2,6-dimethoxyphenol (50, 100, or 200 mg/kg), its vehicle (Tween), or standard antiepileptic drug (Diazepam; or Phenytoin). Subsequently, the mice were subjected to different seizure-inducing models - pentylenetetrazole (PTZ), 3-mercaptopropionic acid (3-MPA), pilocarpine (PILO), or maximal electroshock seizure (MES). EEG analysis was performed on other animals surgically implanted with electrodes to evaluate brain activity. Significant results revealed that animals treated with 4-allyl-2,6-dimethoxyphenol exhibited increased latency to the first myoclonic jerk in the PTZ and PILO models; prolonged latency to the first tonic-clonic seizure in the PTZ, 3-MPA, and PILO models; reduced total duration of tonic-clonic seizures in the PTZ and PILO models; decreased intensity of convulsive seizures in the PTZ and 3-MPA models; and diminished mortality in the 3-MPA, PILO, and MES models. EEG analysis indicated an increase in the percentage of total power attributed to beta waves following 4-allyl-2,6-dimethoxyphenol administration. Notably, the substance protected from behavioral and electrographic seizures in the PTZ model, preventing increases in the average amplitude of recording signals while also inducing an increase in the participation of theta and gamma waves. These findings suggest promising outcomes for the tested phenolic compound across diverse pre-clinical seizure models, highlighting the need for further comprehensive studies to elucidate its underlying mechanisms and validate its clinical relevance in epilepsy management.

Ribeiro LR ，Dos Santos AMF ，da Cruz Guedes E ，Bezerra TLDS ，de Souza TL ，Filho JMB ，de Almeida RN ，Salvadori MGDSS ... -  《-》

Dexmedetomidine decreases seizure threshold in a rat model of experimental generalized epilepsy.

Mirski MA ，Rossell LA ，McPherson RW ，Traystman RJ ... -  《ANESTHESIOLOGY》