Correlation between Changes in Stress-Induced Corticosterone Secretion and GR mRNA Levels

The current study was conducted to determine the potential relationship between stress-induced corticosterone secretion and corticosteroid receptor mRNA levels after 5 days of intermittent stress. In particular, we were interested in the rate at which animals terminate a stress response, and how this termination may be altered by repeated stress. Adult male Sprague-Dawley rats were subjected to either 5 days of restraint stress or 5 days of an unpredictable stress paradigm. Restraint-stress induced corticosterone secretion was measured on Days 1 and 5 in both groups, and animals were killed on Day 6. Glucocorticoid receptor (GR), and mineralocorticoid (MR) mRNA levels were determined using in-situ hybridization techniques. Five days of restraint stress caused an habituation of the plasma corticosterone response to stress measured 60 and 90 min post-stress initiation; this pattern of corticosterone secretion was not observed in the animals subjected to unpredictable stress. Five days of either stress paradigm did not alter MR mRNA levels measured within the hippocampus or GR mRNA levels within the hippocampus or the medial parvocellular division of the paraventricular nucleus of the hypothalamus (mpPVN). However, an individual's GR mRNA levels measured within the CA1/2 region of the hippocampus and the mpPVN were significantly correlated with the degree of habituation of the corticosterone response to stress measured on Day 5. This suggests that an increase in the rate of termination of the stress response and levels of GR within the hippocampus and mpPVN may be functionally related.     

The MAVRIC-C and MAVRIC-P: a preliminary reliability and validity study

We administered the Measure of Aggression, Violence, and Rage in Children (MAVRIC; Bass, Geenens, & Popper, 1993a, 1993b), a questionnaire assessing the severity of reactive, impulsive aggression, to 28 prepubertal psychiatrically hospitalized children and 54 prepubertal lowrisk nonpatients and their mothers. Cross-informant reliability was supported between the MAVRIC-Child Version (MAVRIC-C; Bass et al., 1993a) and MAVRIC-Parent Version (MAVRIC-P; Bass et al., 1993b), r = .62, p < .001. Convergent validity was supported with the Aggressive Behavior factor of the Child Behavior Checklist (Achenbach, 1991a) for the MAVRIC-C, r = .62, p < .001, and MAVRIC-P, r = .74, p < .001. Both versions were also associated with disruptive behavior disorders, inpatient status, and assaultive behavior. We discuss the differences in the perception of aggression as a function of informant.