The development of sexual behavior in the rat: role of preadult nutrition and environmental conditions.

Rats were subjected to pre- and postnatal undernutrition by restricting the food intake of their mothers (U); another group of rats was normally fed (N). Each nutrition group was divided into 3 subgroups by varying the degree of environmental stimulation: animals in the Max group were stimulated by handling and enriched rearing conditions; the Min group rats were subjected to social isolation; rats in the control condition (C) were raised under ordinary laboratory conditions. The onset of sexual activity was not affected in the U-C male rats, but was delayed in both U-Min and N-Min rats. Although no difference existed in the age of puberty between the N-Max and N-C animals, the U-Max rats displayed an advancement of puberty by 7 days in comparison to the U-C rats. Undernutrition did not affect female sexual maturation; however the Max condition delayed this process in both nutrition groups.