S. Hayley et al., Central monoamine activity in genetically distinct strains of mice following a psychogenic stressor: effects of predator exposure, BRAIN RES, 892(2), 2001, pp. 293-300
The effects of psychogenic stressors, rat exposure and fox urine odor, on c
entral monoamine functioning was assessed in two inbred strains of mice. BA
LB/cByJ and C57BL/6ByJ, thought to be differentially reactive to stressors.
These stressors markedly increased NE utilization. as reflected by MHPG ac
cumulation, in the locus coeruleus, hippocampus. prefrontal cortex and cent
ral amygdala. Likewise, the 5-HT metabolite, 5-HIAA, was elevated in hippoc
ampus. prefrontal cortex and central amygdala, and to some extent DOPAC acc
umulation was increased in the prefrontal cortex. In most brain regions, th
e neurochemical effects of the stressors were comparable in the two mouse s
trains. However, central amygdala 5-HIAA elevations as well as DOPAC increa
ses in the prefrontal cortex elicited by fox odor were greater in C57BL/6By
J than in BALB/cByJ mice. Although BALB/cByJ mice are more behaviorally rea
ctive than C57BL/6ByJ mice, and also show greater corticosterone elevations
in response to neurogenic and systemic stressors, it was previously shown
that differential corticosterone changes were not elicited by a predator ex
posure. Taken together with earlier findings, it appears that despite great
er behavioral reactivity/anxiety, the strain-specific neurochemical changes
elicited may be situation-specific such that the profile apparent in respo
nse to neurogenic and systemic stressors may not be evident in response to
predator-related threats. (C) 2001 Elsevier Science B.V. All rights reserve
d.