Mice overexpressing corticotropin-releasing factor show brain atrophy and motor dysfunctions.
Chronic stress and persistently high glucocorticoid levels can induce brain atrophy. Corticotropin-releasing factor (CRF)-overexpressing (OE) mice are a genetic model of chronic stress with elevated brain CRF and plasma corticosterone levels and Cushing's syndrome. The brain structural alterations in the CRF-OE mice, however, are not well known. We found that adult male and female CRF-OE mice had significantly lower whole brain and cerebellum weights than their wild type (WT) littermates (347.7+/-3.6mg vs. 460.1+/-4.3mg and 36.3+/-0.8mg vs. 50.0+/-1.3mg, respectively) without sex-related difference. The epididymal/parametrial fat mass was significantly higher in CRF-OE mice. The brain weight was inversely correlated to epididymal/parametrial fat weight, but not to body weight. Computerized image analysis system in Nissl-stained brain sections of female mice showed that the anterior cingulate and sensorimotor cortexes of CRF-OE mice were significantly thinner, and the volumes of the hippocampus, hypothalamic paraventricular nucleus and amygdala were significantly reduced compared to WT, while the locus coeruleus showed a non-significant increase. Motor functions determined by beam crossing and gait analysis showed that CRF-OE mice took longer time and more steps to traverse a beam with more errors, and displayed reduced stride length compared to their WT littermates. These data show that CRF-OE mice display brain size reduction associated with alterations of motor coordination and an increase in visceral fat mass providing a novel animal model to study mechanisms involved in brain atrophy under conditions of sustained elevation of brain CRF and circulating glucocorticoid levels.
Goebel
Miriam
M
CURE/Digestive Diseases Research Center and Center for Neurobiology of Stress, Department of Medicine, David Geffen School of Medicine, UCLA and VA GLA Healthcare System, Los Angeles, CA, USA.
Fleming
Sheila M
SM
Million
Mulugeta
M
Stengel
Andreas
A
Taché
Yvette
Y
Wang
Lixin
L
D000818:Animals; D001284:Atrophy; D001921:Brain / Q000473:pathology* / Q000503:physiopathology; D003346:Corticotropin-Releasing Hormone / Q000096:biosynthesis* / Q000235:genetics; D004195:Disease Models, Animal; D005260:Female; D005684:Gait; D008297:Male; D051379:Mice; D009043:Motor Activity; D009068:Movement; D011597:Psychomotor Performance; D012737:Sex Factors
D003346:Corticotropin-Releasing Hormone