The systemic response of male mice to differential housing: A path-analytical approach

Path analysis was used to examine the effects of grouping/individual housing, duration of differential housing (13 days or 10 weeks), and the age at which differential housing was initiated (at weaning or 4 months) on the physiology of male TT strain mice. Variables studied included body and relative ventral prostate, left testis and left adrenal gland weights, and plasma corticosterone level and (Na+) /(K+) ratio. Compared with grouped counterparts, individual housing produced lower adrenal weights and plasma corticosterone levels, but higher prostate weights. This housing condition also suppressed the plasma (Na+)/(K+) ratio, probably through an action on aldosterone secretion. The adrenal response to differential housing thus appears to be at a number of levels, involving at least two separate components. No evidence was found to support the notion that the gonadal response to grouping is mediated via the adrenal gland, although prolonged grouping does generate reduced testicular weights.