Experimental Febrile Seizures in Young Postnatal Rats Have a Long-Lasting Effect in Epileptic Threshold and Astroglial Morphology

ALICIA ROSSI; MIRIANA MARIUSSI ; PAULA SARCHI; ALEJANDRO VILLARREAL; RAMOS AJ

Congreso; Reunion Anual de la Sociedad Argentina de Investigacion en Neurociencias 2018; 2018

Sociedad Argentina de Investigación en Neurociencias

Retrospective studies in adult epilepsy patients show an initialprecipitating injury, usually febrile seizures, during childhoodbetween 6 months and 5 years of age. Using an animalmodel of hyperthermic seizures (HS), we here investigatedthe consequences of early HS young rats. Rat pups (10-11postnatal, PND) were placed in a glass chamber, and theircore temperature was raised and hyperthermia (39.5?42.5C) was maintained for 30 min. The seizures onset wasmonitored behaviorally and consisted of an acute suddenarrest of hyperthermia-induced tonic freeze postures andoccasional oral automatism (biting and chewing) and oftenbody flexion. Rats were then placed on a cool surface, monitoredfor 5 min before being returned to their mothers. AtPND37-39 rats were exposed to repeated pilocarpine subconvulsivedoses (10 mg/kg). We observed a significativereduction in the convulsive threshold in HS-exposed animalscompared with controls. Another group of animals (PND35)was deeply anesthetized, fixed, and brains processed forimmunohistochemistry. HS animals showed neuronal alterationswith NeuN relocalization to the cytoplasm, moderatereactive gliosis with an atypical astrocytes distribution in thepyriform cortex and other brain structures. Our results suggestthat HS exposure early in the postnatal brain developmentproduce long-lasting effects in animals, which could berelated to their future susceptibility to develop epilepsy.This study was supported by grants from UBACYT andPICT 2015-1451.