title: Chronic restraint increases apoptosis in the hippocampus of rats with high responsiveness to fear stimuli.
abstract: This study examined the effects of chronic restraint stress and corticosterone treatment on the apoptosis-related processes in the dentate gyrus of the rat hippocampus. This study compared high (HR) and low anxiety rats (LR) (as defined by their behaviour during the contextual fear test, i.e., the duration of a freezing response was the discriminating variable). The results demonstrate that chronic restraint stress increased the number of caspase-3 immunoreactive cells in the HR group, whereas repeated corticosterone treatment increased the number of caspase-3 immunoreactive cells in both the HR and LR groups. This finding suggests that higher susceptibility to fear stimuli predisposes rats to increased apoptosis in the hippocampus after exposure to chronic stressors. This new animal model of HR and LR rats can be used to study the mechanisms underlying the relationship between higher levels of anxiety and greater vulnerability to stress.
authors.affiliation: Department of Neurochemistry, Institute of Psychiatry and Neurology, 9 Sobieskiego Street, 02-957 Warsaw, Poland. Electronic address: mlehner@ipin.edu.pl.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Lehner
authors.affiliation: Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, 1b Banacha Street, 02-097 Warsaw, Poland.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Wisłowska-Stanek
authors.affiliation: Department of Neurochemistry, Institute of Psychiatry and Neurology, 9 Sobieskiego Street, 02-957 Warsaw, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Skórzewska
authors.affiliation: Department of Neurochemistry, Institute of Psychiatry and Neurology, 9 Sobieskiego Street, 02-957 Warsaw, Poland; Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, 1b Banacha Street, 02-097 Warsaw, Poland.
authors.forename: Adam
authors.initials: A
authors.lastname: Płaźnik
mesh_terms: D000818:Animals; D017209:Apoptosis; D002908:Chronic Disease; D005239:Fear; D006624:Hippocampus / Q000473:pathology*; D008297:Male; D017208:Rats, Wistar; D012149:Restraint, Physical; D013315:Stress, Psychological / Q000473:pathology* / Q000523:psychology
keywords: Anxiety level; Apoptosis; Chronic corticosterone; Chronic stress; Hippocampus; Individual differences