title: Behavioral effects and CRF expression in brain structures of high- and low-anxiety rats after chronic restraint stress.
abstract: The aim of our study was to investigate the influence of chronic restraint stress (5 weeks, 3h/day) on behavior and central corticotropin-releasing factor (CRF) expression in rats selected for high (HR) and low anxiety (LR). The conditioned freezing response was used as a discriminating variable. Moreover, we assessed the influence of acute restraint on CRF expression in the brain in HR and LR rats. We found that chronic restraint induced symptoms of anhedonia (decreased consumption of 1% sucrose solution) in HR rats. In addition, HR restraint rats showed an increased learned helplessness behavior (immobility time in the Porsolt test) as well as neophobia in the open field test vs. LR restraint and HR control rats. These behavioral changes were accompanied by a decreased expression of CRF in the paraventricular nucleus of the hypothalamus (pPVN) and the dentate gyrus of the hippocampus (DG) compared to the HR control and LR restraint rat groups, respectively. The acute restraint condition increased the expression of CRF in the pPVN of HR rats compared to the HR control group, and enhanced the expression of CRF in the CA1 area and DG of LR restraint animals compared to the HR restraint and LR control rats, respectively. The present results indicate that chronic restraint stress in high anxiety rats attenuated CRF expression in the pPVN and DG, which was probably due to detrimental actions on the hippocampus-hypothalamus-pituitary-adrenal gland feedback mechanism, thus modulating the stress response and inducing anhedonia and depressive-like symptoms.
authors.affiliation: Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, Centre for Preclinical Research and Technology CePT, 1B Banacha Street, 02-097 Warsaw, Poland. Electronic address: awislow@yahoo.com.
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: Małgorzata
authors.initials: M
authors.lastname: Lehner
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 Experimental and Clinical Pharmacology, Medical University of Warsaw, Centre for Preclinical Research and Technology CePT, 1B Banacha Street, 02-097 Warsaw, Poland.
authors.forename: Paweł
authors.initials: P
authors.lastname: Krząścik
authors.affiliation: Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, Centre for Preclinical Research and Technology CePT, 1B Banacha Street, 02-097 Warsaw, Poland; Department of Neurochemistry, Institute of Psychiatry and Neurology, 9 Sobieskiego Street, 02-957 Warsaw, Poland.
authors.forename: Adam
authors.initials: A
authors.lastname: Płaźnik
mesh_terms: D059445:Anhedonia / Q000502:physiology; D000818:Animals; D001007:Anxiety / Q000378:metabolism* / Q000473:pathology; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D003346:Corticotropin-Releasing Hormone / Q000378:metabolism*; D003863:Depression / Q000378:metabolism; D019422:Dietary Sucrose; D005106:Exploratory Behavior / Q000502:physiology; D005239:Fear / Q000502:physiology; D005247:Feeding Behavior / Q000502:physiology / Q000523:psychology; D046352:Freezing Reaction, Cataleptic / Q000502:physiology; D006380:Helplessness, Learned; D007150:Immunohistochemistry; D008297:Male; D009043:Motor Activity / Q000502:physiology; D010551:Personality / Q000502:physiology; D017208:Rats, Wistar; D012149:Restraint, Physical; D013315:Stress, Psychological / Q000378:metabolism* / Q000473:pathology
chemical_list: D019422:Dietary Sucrose; D003346:Corticotropin-Releasing Hormone
keywords: CRF-immunocytochemistry; High anxiety rats; Hippocampus; Low anxiety rats; Paraventricular nucleus of the hypothalamus; Restraint stress