More specifically, loss (or gain) of expression of disease-related genes below or outside expected trajectories and homeostatic range may mark the onset of cellular deficits, leading to disturbances in higher biological scales (microcircuitry, brain region, neural network), in turn promoting the onset of symptoms as the emerging properties of a deregulated system.

In this model, factors that affect the trajectory of these age-related changes will determine the timing and potential severity of the initial molecular deficits (Figure 4). The identification of moderators, which place individuals on “at-risk” Inhibitors,research,lifescience,medical Inhibitors,research,lifescience,medical trajectories, may provide critical information on mechanisms of disease onset. Conversely, factors that delay age-related changes, or that place individuals on “protected” trajectories, may provide critical information on the nature of resiliency, and may offer insight into designing preventive strategies. In short, biological moderators of agedependent trajectories of gene function may represent candidate targets for therapeutic EPZ004777 approaches and for promoting resiliency against brain

disorders, Inhibitors,research,lifescience,medical including psychiatric disorders. Figure 4. A proposed age-by-disease molecular interaction model. The graph depicts the age-dependent change in expression that is frequently observed for genes that are otherwise implicated in brain-related disorders (a decrease is shown

here). Progression below … Implications for future investigations of mechanisms of age and brain-related Inhibitors,research,lifescience,medical disorders Environmental and genetic factors are obvious candidate moderators of an age-by-disease interaction, but identifying their impact on biological aging of the brain may require Inhibitors,research,lifescience,medical new experimental strategies. Differences in molecular ages can be assessed in the mid-life range using postmortem brain samples (Figure 4, green shading) since molecular aging displays continuous, life-long, and mostly linear trajectories in adult subjects.7,46 In contrast, when conducting studies to demonstrate associations of biological moderators with functional outcomes in live already subjects, it is important to note that brain reserve capacity may buffer functional changes from occurring until years later. The presence of functional declines (emotionality, cognition, health) may be better assessed during later age periods of reduced reserve (ie, over 60 to 65 years of age; Figure 4, yellow shading), where at-risk subjects may start experiencing variable rates of functional declines, while protected individuals may be experiencing more successful aging.