ENVIRONMENTAL STRESS AND BIOLOGICAL AGEING

Age and Motivation in Mice: Performance and Learning in a Spatial Water Maze

Performance and learning of a spatial water maze was investigated in 120 male C57BL/6J mice of three ages, 30, 150, and 365 days old. Motivation was manipulated by varying the water temperature (12.5, 23–5, 34.5, or 45.5°C). The results indicated that swimming performance was affected significantly by both age and motivation, with older animals requiring longer swimming time to escape at ail temperature levels. Swimming time decreased at extreme water temperatures for all age groups, with the greatest effect evident in the oldest age group. No age differences in learning as measured by errors or days to criterion were found. Extreme water temperatures (12.5 and 45.5°C) improved learning for all age groups.

Behavioral characterization of a mouse model of premature immunosenescence

In previous studies we have shown that differences in life span among members of Swiss mouse populations appear to be related to their performance in a T-maze, with a slow performance ("slow" mice) being linked to an impaired immune function and a shorter life span when compared to "fast" mice, which led us to propose the slow mice as a model of immunosenescence. In the present study we demonstrate that in a tightrope test of neuromuscular vigor and coordination the slow mice show a worse performance, needing more time to complete the task. Moreover, these animals show a decreased locomotor activity and an increased level of emotionality/anxiety in three standard behavioral tests (the holeboard, the open field and the plus-maze) when compared to fast mice. All these behavioral features were most marked in the slow females. The results also indicate that slow animals show a decreased chemotaxis of macrophages and lymphocytes, as well as a reduced lymphoproliferative response to mitogens. The data supports our claim that slow or hyperemotional mice, in which immune and neurobehavioural functions appear to be impaired, may be a useful model of premature aging.

Relation between exploratory activity and immune function in aged mice: a preliminary study

Previous studies show that fast exploration of a T-shaped maze by mature mice may predict an above average longevity. Since the nervous and the immune systems work in a coordinated fashion, and it seems that these two homeostatic systems both influence organismic aging and suffer a senescent decline, we have performed a comparative study of the above behavioral parameter and different functions of three representative immune cells: lymphocytes, macrophages and natural killer (NK) cells obtained from old (76 +/- 1 weeks of age) female OF1-Swiss mice. At 70 weeks of age the mice were divided into a 'fast' and a 'slow' group, containing 100 and 0%, respectively, of animals able to explore the 50 cm-long first arm of the maze in 20 s or less. At 76 +/- 1 weeks of age the animals were sacrificed, the peritoneal cell suspensions were obtained and the immune organs (axillary nodes, spleen and thymus) were isolated. The following leukocyte functions were studied in peritoneal macrophages: adherence to substrate, mobility (spontaneous and chemotaxis), ingestion of particles and superoxide anion production whereas mobility, lymphoproliferative response to the mitogen Con A and NK activity were studied in the immune-organ leukocyte suspensions. The results show that the aged fast mice have better immune functions than the aged slow mice.

An antistress and antiaging neurometabolic therapy. Accelerated lipofuscinolysis and stimulated anabolic regeneration by the antagonic-stress synergistic formula

In both stress and aging, an etiopathogenic analysis demonstrates in the brain some common mechanisms and reciprocal accelerating relationships: hypoanabolism (decrease of RNA and protein synthesis), coupled with hypercatabolism (increase of oxidative stress-lipid peroxidation, with waste product accumulation: lipofuscinage pigment and water-insoluble proteins). For therapeutical intervention in these antihomeostatic processes, we successively (1972-1992) developed a neurometabolic antioxidative therapy--finally represented by a specific antistress and antiaging synergistic formula, Antagonic-Stress. Its homeostatic actions have been demonstrated in the stressed aging brains by reestablishing the anabolism/catabolism balance: anabolic regeneration by increasing total RNA, total proteins and water-soluble proteins, coupled with catabolic regulation by accelerated lipofuscinolysis and age pigment elimination (neuronal-->glial-->capillary route) and decreasing of water-insoluble proteins. Specific, synergistic, and superior actions of Antagonic-Stress multiple formula vs. antistress and antiaging monotherapy have been demonstrated by preclinical and clinical studies, confirming our results.

An evaluation of progressive muscle relaxation on stress related symptoms in a geriatric population

Ten highly anxious women, between the ages of sixty-nine and eighty-four, participated in a five month study designed to test the hypothesis that progressive muscle relaxation would reduce psychosocial stress in a group of high risk senior citizens. The women, who had lost their husbands within the last five years, responded to an offer extended to nervous senior citizens to participate in a relaxation study. Five women were assigned to the treatment group and five to a control group. The treatment group received two weeks of baseline evaluation, ten weeks of one hour in vivo relaxation training, and ten weeks of home practice using taped instructions. The control group had an identical schedule except instead of progressive relaxation training they received a pseudorelaxation procedure and had no home practice. All participants were evaluated prior to training, at the end of training, and ten weeks after training. Participants were also measured on the following factors: 1) state and trait anxiety, 2) self-report muscle tension, 3) hours to fall asleep, 4) number of nocturnal awakenings, and 5) headaches. Results indicate significant differences on all five measures between the experimental and control group. With the exception of trait anxiety, the experimental group manifested significant improvements on the remaining five measures from baseline to end of training. For state anxiety, a significant improvement continued during the ten weeks of home practice following the end of training.