Febrile convulsions in developing rats induce a hyperanxious phenotype later in life

Exposure of rodent pups to hyperthermia constitutes one of the best known models of febrile seizures. Studies designed to evaluate the behavioral impact of heat-induced convulsions (HCs) have focused mainly on hippocampus-dependent tasks and produced rather conflicting results. In this study, we assessed, in detail, developmental milestones, emotional behavior, and cognitive performance in animals submitted to HCs on Postnatal Day 10. There was no alteration in the acquisition of neurological reflexes, but there was an anticipation of eye opening in animals exposed to hyperthermia. As adults, the locomotor and exploratory behavior of these rats was unaffected. Interestingly, animals exposed to hyperthermia displayed signs of increased anxiety in the elevated-plus maze, although these signs were not associated with increased susceptibility to depression-like behavior. Additionally, we failed to observe impairments in spatial and working memory tasks. In conclusion, HCs at a particular period of neurodevelopment determine a hyperanxious phenotype later in life.