Social factors and puberty in female rats

Abstract

ABSTRACT The effects of postweaning social conditions on the age of puberty were studied in female rats from an early-and a late-maturing strain. The postweaning living conditions consisted of the presence or absence of an adult rat (intact or gonadectomized male, or intact female), or of bedding soiled by adult males. The infantile females exposed to these conditions were caged either singly or with three peers. Puberty was studied in terms of first ovulation, verified always by ovarian histology. Females of the late-maturing strain living without peers reached puberty about 2 days earlier than females that grew up in groups of four, irrespective of the presence or absence of an adult animal. In neither strain was puberty accelerated by the presence of intact males or the soiled bedding of such males. These results do not support the view that in the rat pheromones from adult males enhance puberty in females, contrary to what is known to happen in the mouse. J. Endocr. (1985) 104, 309–313