title: Early and late neurodegeneration and memory disruption after intracerebroventricular streptozotocin.
abstract: Glucose metabolism and insulin signaling disruptions in the brain have been proposed as a likely etiology of Alzheimer's disease. The aim of the present study was to investigate the time course of cognitive impairments induced by intracerebroventricular injection of streptozotocin (STZ) in rats and correlate them with the ensuing neurodegenerative process. Early and late effects of STZ were evaluated by using the reference and working memory versions of the Morris' water maze task and the evaluation of neurodegenerative markers by immunoblotting and the Fluoro-Jade C histochemistry. The results revealed different types of behavioral and neurodegenerative responses, with distinct time courses. We observed an early disruption on the working memory as early as 3h after STZ injections, which was followed by degenerative processes in the hippocampus at 1 and 15 days after STZ injections. Memory disruption increases over time and culminates with significant changes in amyloid-beta peptide and hyperphosphorylated Tau protein levels in distinct brain structures. These findings add information on the Alzheimer's disease-like STZ animal model and on the mechanisms underlying neurodegenerative processes.
authors.affiliation: Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Av. Professor Lineu Prestes, 1524, São Paulo, SP, 05508-900, Brazil.
authors.forename: Taisa Oliveira
authors.initials: TO
authors.lastname: Santos
authors.forename: Caio Henrique Yokoyama
authors.initials: CH
authors.lastname: Mazucanti
authors.forename: Gilberto Fernando
authors.initials: GF
authors.lastname: Xavier
authors.forename: Andréa Silva
authors.initials: AS
authors.lastname: Torrão
mesh_terms: D016229:Amyloid beta-Peptides / Q000378:metabolism; D000704:Analysis of Variance; D000818:Animals; D001786:Blood Glucose; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D005452:Fluoresceins; D005786:Gene Expression Regulation / Q000187:drug effects; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D007276:Injections, Intraventricular; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D008569:Memory Disorders / Q000139:chemically induced*; D008570:Memory, Short-Term / Q000187:drug effects; D009043:Motor Activity / Q000187:drug effects; D019636:Neurodegenerative Diseases / Q000139:chemically induced*; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time / Q000187:drug effects; D013311:Streptozocin / Q000008:administration & dosage*; D013997:Time Factors; D016875:tau Proteins / Q000378:metabolism
chemical_list: D016229:Amyloid beta-Peptides; D001786:Blood Glucose; D005452:Fluoresceins; D005904:Glial Fibrillary Acidic Protein; C534582:fluoro-jade C; D016875:tau Proteins; D013311:Streptozocin; D002795:Choline O-Acetyltransferase