Effects of prior housing on endocrine responses to differential caging in male TO-strain mice

Abstract

Two possible reasons which may account for the inconsistent reports of adrenal and gonadal functioning in individually and group-housed mice were studied. The influence of the prior housing condition on the response to differential housing was examined. Continuously grouped or isolated mice were found to have lower corticosterone levels than those paired then isolated or isolated then paired. The influence of rehousing was apparent 32 days afterwards. The results support the suggestion that changing the housing condition of mice is stressful. The possible effect on endocrine function of different numbers of dominant and subordinate mice in different sized groups was examined. The findings did not support previous work which had found a similarity between dominant and isolated mice: it seems that the conditions used in particular experiments are critical to the results.

Effects of male social status on reproductive success and on behavior in mice (Mus musculus).

“…Rivier, Rivier, and Vale (1986) reported inhibition of reproductive functions in stressed rats. Subordinates, as well as stressed subjects, are characterized by lighter preputial and seminal vesicle weights (Benton & Brain, 1979), higher basal corticosterone level (Benton, Brain, & Goldsmith, 1979), lower circulating androgens and lower rate of testosterone synthesis (McKinney & Desjardins, 1973), and lower follicle-stimulating and luteinizing hormones (Bronson, 1973). These physiological modifications involving the pituitary—gonadal axis may be responsible for an impairment of subordinate sperm fertilizing capability (Brain, 1972).…”

Effects of Dense Housing on the Growth of Reproductive Organs, Plasma Testosterone Levels and Fertility of Male Mice

“…Unlike the spermatogenic function, the endocrine function of the testis is severely affected by the increasing population size, as demonstrated by the significant alterations in plasma levels of testosterone and weights of seminal vesicles. A decreased sex accessory weight was also reported in different conditions of housing (Christian, 1955/3;Brain & Nowell, 1970, 1971McKinney & Desjardins, 1973;Benton et al 1979). From weaning to 50 days there was a strong inhibition of secretion of testosterone in the increased population group and the pubertal increase of androgen levels was delayed until 50-60 days.…”

“…Other studies, using differential housing conditions, i.e. isolation compared with grouping (Brain & Nowell, 1970, 1971Benton, Brain & Goldsmith, 1979) and immature males paired with either intact or castrated adult males (McKinney & Desjardins, 1973), have reported modifications of gonadal function in mice. The size of population probably does not affect spermatogenic maturation since the first fertile matings and the appearance of spermatozoa in the seminiferous tubules occurred at the same time in both groups.…”

Influence of age on isolation stress‐stimulated carcinogen‐metabolizing enzymes of rats

“…Furthermore, recent studies indicate that social isolation may be a unique form of stress: in mice this treatment may cause behavioral changes resulting in development of dominant and aggressive behavior in isolated individuals, whereas in rats it has been demonstrated that the housing and handling prior to isolation determines the extent of the reaction to the treatment [Benton et al, 1979;Redgate and Eleftheriou, 19781. Thus, social isolation may be of limited applicability for the experimental investigation of stress, but it is apparent, however, that the age of animals in any investigation involving stress is an important determinant of the severity of the response to this treatment.…”