Cognitive deficits in the rat chronic mild stress model for depression: relation to anhedonic-like responses

TY - JOUR

T1 - Cognitive deficits in the rat chronic mild stress model for depression: relation to anhedonic-like responses

AU - Henningsen, Kim

AU - Andreasen T., Jesper

AU - Bouzinova, Elena V.

AU - Jayatissa, Magdalena Niepsuj

AU - Jensen, Morten S

AU - Redrobe, John P

AU - Wiborg, Ove

PY - 2009/3/2

Y1 - 2009/3/2

N2 - The chronic mild stress (CMS) protocol is widely used to evoke depressive-like behaviours in laboratory rats. The aim of the present study was to examine the effects of chronic stress on cognitive performance. About 70% of rats exposed to 7 weeks of chronic mild stress showed a gradual reduction in consumption of a sucrose solution, indicating an anhedonic-like state. The remaining rats did not reduce their sucrose intake, but appeared resilient to the stress-induced effects on sucrose intake. Cognitive profiling of the CMS rats revealed that chronic stress had a negative effect on performance in the spontaneous alternation test, possibly reflecting a deficit in working memory. This effect was independent of whether the stressed rats were anhedonic-like or stress-resilient as measured by their sucrose intake. CMS did not influence performance in passive avoidance and auditory cued fear conditioning, however, in rats displaying an anhedonic-like profile, CMS increased freezing behaviour in contextual fear conditioning.

AB - The chronic mild stress (CMS) protocol is widely used to evoke depressive-like behaviours in laboratory rats. The aim of the present study was to examine the effects of chronic stress on cognitive performance. About 70% of rats exposed to 7 weeks of chronic mild stress showed a gradual reduction in consumption of a sucrose solution, indicating an anhedonic-like state. The remaining rats did not reduce their sucrose intake, but appeared resilient to the stress-induced effects on sucrose intake. Cognitive profiling of the CMS rats revealed that chronic stress had a negative effect on performance in the spontaneous alternation test, possibly reflecting a deficit in working memory. This effect was independent of whether the stressed rats were anhedonic-like or stress-resilient as measured by their sucrose intake. CMS did not influence performance in passive avoidance and auditory cued fear conditioning, however, in rats displaying an anhedonic-like profile, CMS increased freezing behaviour in contextual fear conditioning.

KW - Acoustic Stimulation

KW - Analysis of Variance

KW - Animals

KW - Avoidance Learning

KW - Body Weight

KW - Cognition

KW - Conditioning, Classical

KW - Cues

KW - Depression

KW - Disease Models, Animal

KW - Exploratory Behavior

KW - Fear

KW - Feeding Behavior

KW - Freezing Reaction, Cataleptic

KW - Male

KW - Memory

KW - Movement

KW - Rats

KW - Rats, Wistar

KW - Stress, Physiological

KW - Sucrose

U2 - 10.1016/j.bbr.2008.10.039

DO - 10.1016/j.bbr.2008.10.039

M3 - Journal article

C2 - 19038290

SN - 0166-4328

VL - 198

SP - 136

EP - 141

JO - Behavioural Brain Research

JF - Behavioural Brain Research

IS - 1

ER -