Brain Plasticity Induced By Environment and Pregnancy

Publisher Website
Google Scholar
Abstract
Histological studies of brains from rats experiencing enriched (EC) or impoverished (IQ environmental conditions were carried out. Cerebral cortical depth measurements, body weights and endocrine organ weights were taken from the following groups of animals: male rats in EC vs. IC, non-pregnant female rats in EC vs. IC, pregnant rats from EC and IC, and the offspring from EC and IC parents. Male and female rats lived separately in their EC and IC cages from 60 to 90 days of age. Then one EC male lived with one EC female, and one IC male with one IC female, in a small cage for five days. After mating, all animals were returned to their original conditions with slight alterations. After birth, the parents and offspring were weighed, anesthetized, and perfused with 10% formol-saline. Transverse sections from the frontal, somesthetic, and occipital cortex were taken A separate group of non-pregnant female rats was treated in a similar manner, except that instead of mating a male and female two females were placed together. The EC male and EC non-pregnant female developed a greater cortical depth than their IC littermates. The cortex of the post-partum female did not show this difference. It became apparent that the IC cortex was stimulated during pregnancy, thus removing the EC vs. IC differences found with the non-pregnant female. No significant differences were noted in pups from EC vs. IC parents in number of offspring, number of implantation sites, or in cortical depth measures. However, the pups from the EC parents had significantly greater body weights than pups from IC parents.