Gender diference in a febril seizures model in young postnatal rats.

ALICIA ROSSI; FLORENCIA RODRIGUEZ; ANDREA PECILE; PAULA SARCHI; ALBERTO JAVIER RAMOS

MEDICINA (BUENOS AIRES)

MEDICINA (BUENOS AIRES)

Lugar: Buenos Aires; Año: 2021 vol. 81

0025-7680

GENDER DIFFERENCES IN A FEBRILE SEIZURE MODEL IN YOUNG POSTNATALRATSAlicia R. Rossi, Florencia Rodríguez, Andrea Pecile, Paula Sarchi, A. Javier Ramos.IBCN UBA-CONICET, Facultad de Medicina, UBA.A significant percentage of patients with Temporal Lobe Epilepsy report a history ofcomplex febrile seizures during childhood. Using an animal model of hyperthermicseizures (HS), we have previously shown that male HS-exposed rats have lowerconvulsive threshold, microgliosis and moderate reactive gliosis with an atypicalastrocytes distribution in the pyriform cortex (CP) and other brain structures, whilefemale have higher convulsive threshold and exhibit lower reactive gliosis andmicrogliosis. Here, we extended the study by analyzing neuronal survival and theresponse of peripheral immune system. Rat pups (10-11 days old) were placed in aglass chamber, and their core temperature was raised by a regulated stream of heatedair (39-42°C). Body temperature was measure at baseline, seizure onset and every 2min during the seizures. Hyperthermic temperatures (39.5-42°C) were maintained for30 min. The seizures onset was monitored behaviorally, and consisted of an acutesudden arrest of hyperthermia-induced tonic freeze postures and occasional oralautomatism (biting and chewing) and often body flexion. Rats were then placed on acool surface, monitored for 5 min before being returned to their mothers. At 35 days oldrats were deeply anesthetized, fixed and brains and spleen processed for histologicaltechniques, immunohistochemistry and morphometrical studies. We observed thatthere was a significant increase in the proinflammatory phenotypes of Iba-1+ microgliain males while females showed a decrease in the area occupied by Iba-1+ cells.Cortical neurons presented altered NeuN+ profiles in layer II of CP, being moreprominent in females. Both sexes showed an activation of the white pulp, evidenced byan intense disorganization of Malpighi corpuscles. Our results strongly suggest thatmales are more susceptible to HS exposure and this could be related to their futuresusceptibility to develop epilepsy. Supported by PICT2017-2203 and UBACYT