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Homeostatic  chronic  low stress results in low to moderate levels of CRF in the LC in association with  enhanced Extra-Dimensional Shifting and optimal executive decision making. However, acute or chronic severe stress is linked to  high levels of CRF in the LC and this may  contribute to a shift from optimal executive function necessary for goal-directed behavior toward an iterative decision response. 

In healthy environments, this variable tonicity is a readout for adaptation  when goal-oriented behavior is relaxed so that the individual uses pro-forma decisions  even when novel environmental stimuli are encountered.

During aging these pathways lose flexibility due to a decrease in executive decision making linked to the senescence phenotype that may impair neural circuitry via inflammation, over or under activation and lack of control over  immune cell responses.

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