Chronic stress is implicated as a risk factor for Alzheimer's disease (AD) and other neurodegenerative disorders. Although the specific mechanisms linking stress exposure and AD vulnerability have yet to be fully determined, our laboratory and others have shown that acute and repeated restraint stress in rodents leads to an increase in hippocampal tau phosphorylation (tau-P) and tau insolubility, a critical component of tau pathology in AD. Although tau phosphorylation induced by acute psychological stress is dependent on intact signaling through the type 1 corticotropin-releasing factor receptor, how sex steroids or other modulators contribute to this effect is unknown. A naturally occurring attenuation of the stress response is observed in female rats at the end of pregnancy and throughout lactation. To test the hypothesis that decreased sensitivity to stress during lactation modulates stress-induced tau-P, cohorts of virgin, lactating and weaned female rats were subjected to 30 min of restraint stress or no stress (control) and were killed 20 min or 24 h after the episode. Exposure to restraint stress induced a significant decrease in tau-P in the hippocampus of lactating rats killed 20 min after stress compared to lactating controls and virgins subjected to stress treatment. Lactating rats killed 24 hr after restraint stress exposure showed significant elevation in tau-P compared to lactating cohorts killed 20 min after stress. Levels of tau-P in these latter cohorts did not differ signficantly from control animals. Furthermore, glycogen synthase kinase (GSK)3-α levels were significantly decreased in stressed lactating animals at both timepoints. This suggests a steep, yet transient stress-induced dephosphorylation of tau, influenced by GSK3, in the hippocampus of lactating rats.

Non-communicable diseases, particularly cardiovascular diseases, are the leading cause of decreased life expectancy and death in Latin America and the Caribbean. Although a lifestyle, which includes no tobacco use, good nutrition, and regular physical activity is touted as key to health, the environmental, racial, social and economic conditions, which underpin lifestyle are often ignored or considered only secondarily. Placing the main responsibility on a patient to change their lifestyle or to simply comply with pharmacological treatment ignores the specific conditions in which the individual lives. Furthermore, there are major disparities in access to both healthy living conditions as well as access to medical care. There is sufficient evidence to support advocating for policies that support healthy living, particularly healthy food choices. Progress is being made to improve the food environment with enactment of front of package nutritional labels. However, policies were enacted only after intense regional research and advocacy supporting their implementation. Government officials must rise above the pressures of commercial interests and support health-promoting policies or be exposed as self-interest groups themselves. Strong advocacy is required to persuade officials that all policies should take health into consideration both to improve lives and economies.