title: Effect of chronic stress on short and long-term plasticity in dentate gyrus; study of recovery and adaptation.
abstract: Stress dramatically affects synaptic plasticity of the hippocampus, disrupts paired-pulse facilitation and impairs long-term potentiation (LTP). This study was performed to find the effects of chronic restraint stress and recovery period on excitability, paired-pulse response, LTP and to find probable adaptation to very long stress in the dentate gyrus. Thirty-eight male Wistar rats were randomly divided into four groups of Control, Rest-Stress (21 days stress), Stress-Rest (recovery) and Stress-Stress (42 days stress: adaptation). Chronic restraint stress was applied 6-h/day. Input-output functions, paired-pulse responses and LTP were recorded from the dentate gyrus while stimulating the perforant pathway. We found that chronic stress attenuated the responsiveness, paired-pulse response and LTP in the dentate gyrus. A 21-day recovery period, after the stress, improved all the three responses toward normal, indicating reversibility of these stress-related hippocampal changes. There was no significant adaptation to very long stress, probably due to severity of stress.
authors.affiliation: Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: M
authors.initials: M
authors.lastname: Radahmadi
authors.affiliation: Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: N
authors.initials: N
authors.lastname: Hosseini
authors.affiliation: Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran. Electronic address: nasimi@med.mui.ac.ir.
authors.forename: A
authors.initials: A
authors.lastname: Nasimi
mesh_terms: D000223:Adaptation, Psychological / Q000502:physiology; D000818:Animals; D002908:Chronic Disease; D018891:Dentate Gyrus / Q000503:physiopathology*; D004195:Disease Models, Animal; D004558:Electric Stimulation; D017774:Long-Term Potentiation / Q000502:physiology*; D008297:Male; D008839:Microelectrodes; D019580:Perforant Pathway / Q000503:physiopathology; D011897:Random Allocation; D017208:Rats, Wistar; D020127:Recovery of Function / Q000502:physiology; D012149:Restraint, Physical; D013315:Stress, Psychological / Q000503:physiopathology*
keywords: LTP; adaptation; paired pulse; plasticity; recovery; stress