Long-term modifications of epileptogenesis and hippocampal rhythms after prolonged hyperthermic seizures in the mouse.

Neurobiol Dis

INSERM, U836, F-38000 Grenoble, France; Univ. Grenoble Alpes, GIN, F-38000 Grenoble, France; CHU de Grenoble, Hôpital Michalon, F-38000 Grenoble, France.

Published: September 2014

AI Article Synopsis

  • The study investigates the effects of prolonged hyperthermic seizures on the hippocampal activity of mice, specifically looking at how these seizures might influence mesio-temporal lobe epilepsy (MTLE).
  • Researchers performed experiments on C57BL/6J mice, observing changes in hippocampal rhythms and seizure susceptibility after exposure to hyperthermic conditions at a young age (postnatal day 10).
  • Results indicated that while one episode of hyperthermic seizures didn't directly cause increased seizure activity later, it did accelerate the development of epilepsy and created imbalances in hippocampal functions, affecting seizure dynamics in adult mice.

Article Abstract

Complex febrile seizures are often reported in the history of patients with mesio-temporal lobe epilepsy (MTLE) but their role in its physiopathology remains controversial. We postulated that prolonged hyperthermic seizures might, as a "single-hit", modify the hippocampal rhythms, facilitate epileptogenesis and influence subsequent epilepsy when a second-hit already exists or subsequently occurs. To test this hypothesis, we examined the effects of hyperthermic seizures (30min at 40-41°C) at postnatal day 10 on hippocampal activity in C57BL/6J mice in comparison to their littermates in sham conditions (22°C), with or without another insult. Using local field potential, we observed an asymmetry in the hippocampal susceptibility to seize in hyperthermic conditions. When these mice were adult, an asymmetrical increase of low frequency power was also recorded in the hippocampus when compared to sham animals. Using two different "two-hit" protocols, no increase in seizures or hippocampal discharge frequency or duration was observed, either in mice with a genetic CA3 dysplasia (Dcx knockout), or in mice injected with kainate into the dorsal hippocampus at P60. However, in the latter condition, which is reminiscent of MTLE, the hyperthermic seizures accelerated epileptogenesis and decreased the power in the high frequency gamma band, as well as decreasing the coherence between hippocampi and the involvement of the contralateral hippocampus during hippocampal paroxysmal discharges. Our data suggest that a single episode of prolonged hyperthermic seizures does not induce per se, but accelerates epileptogenesis and could lead to an asymmetrical dysfunction in the hippocampal rhythmicity in both physiological and pathological conditions.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.nbd.2014.05.025DOI Listing

Publication Analysis

Top Keywords

hyperthermic seizures
20
prolonged hyperthermic
12
hippocampal rhythms
8
hippocampal
7
seizures
7
hyperthermic
6
long-term modifications
4
epileptogenesis
4
modifications epileptogenesis
4
epileptogenesis hippocampal
4

Similar Publications

Febrile seizures (FSs) are defined as seizures occurring in children aged 6 months to 5 years with a background of elevated body temperature. It is one of the most common neurological disorders of childhood, emphasizing the importance of understanding the causes of FSs and their impact on the developing nervous system. However, there are significant limitations to the technologies currently available for studying the etiology and pathophysiology of seizures in humans.

View Article and Find Full Text PDF
Article Synopsis
  • A 35-year-old male suffered a life-threatening overdose at the festival, experiencing seizures and hyperthermia, leading to his emergency intubation and treatment for multiple organ failure.
  • The case emphasizes the need for quick medical intervention to save lives after MDMA overdoses and highlights the importance of raising awareness about the risks associated with using this drug at music events.
View Article and Find Full Text PDF
Article Synopsis
  • Febrile seizures are a common type of convulsion in kids, and this study aims to understand how they happen by looking closely at brain cells in rats.
  • The researchers heated the rats to make them have seizures, then used special microscopes to see what happened to the brain cells.
  • They found that the brain cells showed serious damage when the rats were heated, which could help scientists find ways to prevent seizures in children in the future.
View Article and Find Full Text PDF
Article Synopsis
  • Extreme heat from climate change is linked to a rise in infectious diseases and heat-related health issues, making it crucial to understand how heat, inflammation, and disease interact.
  • In neonates, the TRPV1 channel, sensitive to heat and inflammation, affects breathing and may make them more prone to seizures during heat stress.
  • Research on neonatal rats showed that inflammation from LPS lowers seizure thresholds during heat stress; blocking TRPV1 reduced seizure risk and improved breathing efficiency, indicating that inflammation worsens respiratory issues and seizure susceptibility through TRPV1 in vagus neurons.
View Article and Find Full Text PDF

Febrile seizures during early childhood may result in central nervous system developmental disorders. However, the specific mechanisms behind the impact of febrile seizures on the developing brain are not well understood. To address this gap in knowledge, we employed a hyperthermic model of febrile seizures in 10-day-old rats and tracked their development over two months.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!