title: Decreased neuron loss and memory dysfunction in pilocarpine-treated rats pre-exposed to hypoxia.
abstract: Preconditioning can induce a cascade of cellular events leading to neuroprotection against subsequent brain insults. In this study, we investigated the chronic effects of hypoxic preconditioning on spontaneous recurrent seizures (SRS), neuronal death, and spatial memory performance in rats subjected to pilocarpine (Pilo)-induced status epilepticus (SE). Rats underwent a short hypoxic episode (7% O2+93% N2; 30min on two consecutive days) preceding a 4-h SE (HSE group). Control groups were rats submitted to SE only (SE), rats subjected to hypoxia only (H) or normoxia-saline (C). Animals were monitored for the occurrence of SRS, and spatial memory performance was evaluated in the radial-arm maze. Hippocampal sections were analyzed for cell death and mossy fiber sprouting at 1 or 60days after SE. Compared to SE group, HSE had increased SE latency, reduced number of rats with SRS, reduced mossy fiber sprouting at 60days, and reduced cell death in the hilus and the CA3 region 1 and 60days after SE. Additionally, HSE rats had better spatial memory performance than SE rats. Our findings indicated that short hypoxic preconditioning preceding SE promotes long-lasting protective effects on neuron survival and spatial memory.
authors.affiliation: Department of Neuroscience and Behavioral Sciences, Ribeirão Preto School of Medicine, University of São Paulo, Ribeiãro Preto 14049-900, Brazil.
authors.forename: Raquel Araujo
authors.initials: RA
authors.lastname: Do Val-da Silva
authors.affiliation: Department of Neuroscience and Behavioral Sciences, Ribeirão Preto School of Medicine, University of São Paulo, Ribeiãro Preto 14049-900, Brazil.
authors.forename: José Eduardo
authors.initials: JE
authors.lastname: Peixoto-Santos
authors.affiliation: Department of Neuroscience and Behavioral Sciences, Ribeirão Preto School of Medicine, University of São Paulo, Ribeiãro Preto 14049-900, Brazil.
authors.forename: Renata Caldo
authors.initials: RC
authors.lastname: Scandiuzzi
authors.affiliation: Department of Neuroscience and Behavioral Sciences, Ribeirão Preto School of Medicine, University of São Paulo, Ribeiãro Preto 14049-900, Brazil.
authors.forename: Priscila Alves
authors.initials: PA
authors.lastname: Balista
authors.affiliation: Department of Physiology and Pathology, Araraquara School of Dentistry, São Paulo State University, Brazil.
authors.forename: Mirian
authors.initials: M
authors.lastname: Bassi
authors.affiliation: Department of Physiology, Ribeiãro Preto School of Medicine, University of São Paulo, Ribeirao Preto 14049-900, Brazil.
authors.forename: Mogens Lesner
authors.initials: ML
authors.lastname: Glass
authors.affiliation: Brain Institute, Federal University of Rio Grande do Norte, Natal 59056-450, Brazil.
authors.forename: Rodrigo Neves
authors.initials: RN
authors.lastname: Romcy-Pereira
authors.affiliation: Department of Molecular Biology, São José do Rio Preto Medical School, São José do Rio Preto 15090-000, Brazil.
authors.forename: Orfa Yineth
authors.initials: OY
authors.lastname: Galvis-Alonso
authors.affiliation: Department of Neuroscience and Behavioral Sciences, Ribeirão Preto School of Medicine, University of São Paulo, Ribeiãro Preto 14049-900, Brazil. Electronic address: jpleite@fmrp.usp.br.
authors.forename: João Pereira
authors.initials: JP
authors.lastname: Leite
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D006624:Hippocampus / Q000473:pathology*; D019194:Ischemic Preconditioning; D008297:Male; D008569:Memory Disorders / Q000473:pathology / Q000517:prevention & control*; D009474:Neurons / Q000473:pathology*; D000066829:Neuroprotection; D010862:Pilocarpine; D017208:Rats, Wistar; D065852:Spatial Memory; D013226:Status Epilepticus / Q000473:pathology / Q000523:psychology / Q000628:therapy*
chemical_list: D010862:Pilocarpine
keywords: hypoxic preconditioning; memory deficit; mossy fiber sprouting; neuronal death; pilocarpine-induced status epilepticus; temporal lobe epilepsy