Influence Of Maternal Separation Research Articles

The influence of maternal separation on the development of voiding and behavior in rat pups

Aim:This study aimed to investigate the effects of early-life stress resulting from maternal separation (MS) on urinary function and behavioral changes. Methods:We categorized 85 rat pups into control and MS groups. Two groups of each sex during post-weaning (3 weeks old) and maturity (9 weeks old) were compared. Urinary function was evaluated using metabolic cages and continuous cystometry. Morphological changes were assessed based on bladder weight and staining. In behavioral experiments, spatial working memory using the Y-maze and anxiety-like behavior in the elevated plus-maze were assessed. Results:In the metabolic cage test, the single voiding volume decreased in the 3-week-old male and female MS groups. In continuous cystometry, the intercontraction interval was shortened in the 9-week-old male and female MS groups. MS showed a significant change in bladder weight and wall thickness in 3-week-old females. Conversely, a change in bladder wall thickening was observed in male rats aged 9 weeks. In the Y-maze, no differences were found in alternation. In the elevated plus-maze test, the 3-week-old MS groups of both sexes had fewer entries into the open arm and slower mean velocities, while the 9-week-old groups had a greater number of entries into the open arm and a faster average speed. Conclusion:MS affects voiding behavior and bladder activity during the early phase of maturation. After growth, bladder overactivity and less anxiety-like hyperactivity co-exist, suggesting that early-life stress due to MS may have lasting effects on common neural circuits related to urinary function and behavior.

The Influence of Maternal Separation on Humoral and Cellular Immunity in Farmed Deer

The effect of maternal separation on in vivo and in vitro immune parameters was studied in young hybrid deer. Groups of fawns separated from their mothers either 2 days prior to or 7 days post immunization with keyhole limpet hemocyanin were compared with a control group of immunized, unseparated fawns. Animals separated prior to antigenic challenge had significantly higher concentrations of antigen-specific IgG in their serum than control animals. There was no influence on the humoral immune response in animals separated following immunization. In contrast, Con A transformations were transiently depressed in separated animals compared to the control group. The time separation was imposed relative to challenge and therefore influenced the subsequent immune response.

The influence of maternal separation on plasma concentrations of ACTH, epinephrine, and norepinephrine in guinea pig pups

Preweaning guinea pigs were placed into a test cage either alone or with their mother for 10, 30, or 90 min, or were placed into the cage alone for 24 hr. At 30 and 90 min, pups exhibited higher plasma levels of ACTH if alone than if with the mother. This effect was not apparent at 10 min, and ACTH levels of pups tested alone were no longer greater than baseline levels at 24 hr. These results provide further evidence that brief maternal separation can serve as a potent stimulus for activation of the hypothalamo-pituitary-adrenal system in this species. Plasma epinephrine and norepinephrine concentrations of pups tested alone were not significantly greater than those of pups tested with their mothers. But, pups tested alone for 10 and 30 min did show an elevation of epinephrine and norepinephrine over baseline levels. That is, the combined influence of separation and other aspects of the manipulation (e.g., exposure to novelty) evoked sympathetic responses. In addition, the number of vocalizations emitted by pups during the first 30 min of isolation in the test cage was positively correlated with concentrations of ACTH, epinephrine, and norepinephrine following 24 hr of this procedure, but not following 90 min or at baseline. Thus, the initial behavioral response appears to be predictive of the levels of both hypothalamo-pituitary-adrenal and sympathetic activity 24 hr after separation is initiated.