Acute social defeat reduces neurotrophin expression in brain cortical and subcortical areas in mice.
Acute social defeat in mice activates the hypothalamic-pituitary-adrenal axis (HPA) and induces long-term behavioral changes, including exaggerated fear responses and inhibition of territorial behavior. Stress-induced hormonal and neurotransmitter release may contribute to disruption of expression of genes important for cell survival, neuronal plasticity, and neuronal remodeling. Brain-derived neurotrophic factor (BDNF) is a neurotrophic factor associated with structural cellular changes that occur during nervous system development and contributes to neural plasticity in the adult brain. In rats, acute (1-2 h) restraint stress transiently reduces BDNF mRNA expression in the hippocampus, a region important in the memory and in HPA regulation; restraint stress also decreases BDNF expression in the basolateral amygdala (BLA), a region important for fear consolidation and emotional memory. We hypothesized that a brief (10 min) exposure to intense social stress, a more naturalistic stressor than restraint stress, would also reduce BDNF mRNA in the hippocampus and BLA of mice. In the present study, we examined the time course of expression of BDNF mRNA expression in the hippocampus and amygdala, as well as other subcortical and cortical brain regions, following acute social stress. In situ hybridization analysis for BDNF mRNA expression showed that there was a significant decrease in BDNF mRNA expression in all regions studied in mice 24 h after social defeat when compared to control (naive) mice (P<0.05). These findings support our hypothesis that BDNF mRNA levels are reduced by social stress, and may have implications for brain plasticity and behavioral changes following social stress.
Pizarro
José M
JM
Division of Neuroscience, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910-7500, USA.
Lumley
Lucille A
LA
Medina
Wilma
W
Robison
Christopher L
CL
Chang
Wenling E
WE
Alagappan
Arun
A
Bah
Mariama J
MJ
Dawood
Mustansir Y
MY
Shah
Jinesh D
JD
Mark
Brian
B
Kendall
Nadia
N
Smith
Mark A
MA
Saviolakis
George A
GA
Meyerhoff
James L
JL
D000818:Animals; D002540:Cerebral Cortex / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009414:Nerve Growth Factors / Q000096:biosynthesis*; D012919:Social Behavior; D013315:Stress, Psychological / Q000378:metabolism*
D009414:Nerve Growth Factors