Manganese-enhanced magnetic resonance imaging (MEMRI) reveals brain circuitry involved in responding to an acute novel stress in rats with a history of repeated social stress.

摘要: Abstract Responses to acute stressors are determined in part by stress history. For example, a history of chronic results facilitated responses novel stressor and this facilitation is considered be adaptive. We previously demonstrated that repeated exposure rats the resident–intruder model social emergence two subpopulations characterized different coping stress. The submissive subpopulation failed show developed passive strategy Porsolt forced swim test. Because response has been implicated propensity develop certain psychiatric disorders, understanding unique circuitry engaged these would advance our etiology stress-related pathology. An ex vivo functional imaging technique, manganese-enhanced magnetic resonance (MEMRI), was used identify distinguish brain regions differentially activated an (15 min) with compared controls. Specifically, Mn 2 + administered intracerebroventricularly prior brains were later imaged reveal structures. When controls, all showed greater activation specific striatal, hippocampal, hypothalamic, midbrain regions. further distinguished significantly amygdala, bed nucleus stria terminalis, septum, suggesting may form circuit mediating individuals adopt strategies. finding circuits exposed implicates role for determining individual strategies responding stressors. Finally, data underscore utility MEMRI behavioral responses.