TY - JOUR
T1 - The effects of chronic stress on hippocampal morphology and function
T2 - An evaluation of chronic restraint paradigms
AU - McLaughlin, Katie J.
AU - Gomez, Juan L.
AU - Baran, Sarah E.
AU - Conrad, Cheryl
PY - 2007/8/3
Y1 - 2007/8/3
N2 - Chronic restraint stress for 6 h/21 days causes hippocampal CA3 apical dendritic retraction, which parallels spatial memory impairments in male rats. Recent research suggests that chronic immobilization stress for 2 h/10 days induces CA3 dendritic retraction [Vyas, A., Mitra, R., Shankaranarayana Rao, B.S., Chattarji, S., 2002. Chronic stress induces contrasting patterns of dendritic remodeling in hippocampal and amygdaloid neurons. J. Neurosci. 22, 6810-6818.] and questions whether CA3 dendritic retraction and spatial memory deficits can be produced sooner than found following 6 h/21 days of restraint stress. Therefore, this study investigated the effects of four different durations of chronic restraint stress (varied by hours/day and total number of days) and the subsequent effects on hippocampal CA3 morphology and spatial memory in the same male Sprague-Dawley rats. The results showed that only rats exposed to the 6 h/21 days restraint paradigm exhibited CA3 apical dendritic retraction, consistent spatial memory deficits, and decreased body weight gain compared to experimental counterparts and controls. While chronically stressing a rat with wire mesh restraint has a physical component, it acts primarily as a psychological stressor, and these findings support the interpretation that chronic psychological stress produces hippocampal-dependent cognitive deficits that are consistent with hippocampal structural changes. Differences in stress effects observed across different studies may be due to rat strain, type of stressor, and housing conditions; however, the current findings support the use of chronic restraint stress, with wire mesh, for 6 h/21 days as a reliable and efficient method to produce psychological stress and to cause CA3 dendritic retraction and spatial memory deficits in male Sprague-Dawley rats.
AB - Chronic restraint stress for 6 h/21 days causes hippocampal CA3 apical dendritic retraction, which parallels spatial memory impairments in male rats. Recent research suggests that chronic immobilization stress for 2 h/10 days induces CA3 dendritic retraction [Vyas, A., Mitra, R., Shankaranarayana Rao, B.S., Chattarji, S., 2002. Chronic stress induces contrasting patterns of dendritic remodeling in hippocampal and amygdaloid neurons. J. Neurosci. 22, 6810-6818.] and questions whether CA3 dendritic retraction and spatial memory deficits can be produced sooner than found following 6 h/21 days of restraint stress. Therefore, this study investigated the effects of four different durations of chronic restraint stress (varied by hours/day and total number of days) and the subsequent effects on hippocampal CA3 morphology and spatial memory in the same male Sprague-Dawley rats. The results showed that only rats exposed to the 6 h/21 days restraint paradigm exhibited CA3 apical dendritic retraction, consistent spatial memory deficits, and decreased body weight gain compared to experimental counterparts and controls. While chronically stressing a rat with wire mesh restraint has a physical component, it acts primarily as a psychological stressor, and these findings support the interpretation that chronic psychological stress produces hippocampal-dependent cognitive deficits that are consistent with hippocampal structural changes. Differences in stress effects observed across different studies may be due to rat strain, type of stressor, and housing conditions; however, the current findings support the use of chronic restraint stress, with wire mesh, for 6 h/21 days as a reliable and efficient method to produce psychological stress and to cause CA3 dendritic retraction and spatial memory deficits in male Sprague-Dawley rats.
KW - Chronic restraint stress
KW - Hippocampus
KW - Spatial memory
KW - Sprague-Dawley
UR - http://www.scopus.com/inward/record.url?scp=34447558468&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=34447558468&partnerID=8YFLogxK
U2 - 10.1016/j.brainres.2007.05.042
DO - 10.1016/j.brainres.2007.05.042
M3 - Article
C2 - 17603026
AN - SCOPUS:34447558468
SN - 0006-8993
VL - 1161
SP - 56
EP - 64
JO - Brain Research
JF - Brain Research
IS - 1
ER -