Neuronal-Glial Mechanisms of Exercise-Evoked Stress Robustness

  • Monika Fleshner
  • Benjamin N. Greenwood
  • Raz Yirmiya
Part of the Current Topics in Behavioral Neurosciences book series (CTBN, volume 18)


Stress robustness by definition, incorporates both stress resistance (organisms endure greater stressor intensity or duration before suffering negative consequences) and stress resilience (organisms recover faster after suffering negative consequences). Factors that influence stress robustness include the nature of the stressor, (i.e., controllability, intensity, chronicity) and features of the organism (i.e., age, genetics, sex, and physical activity status). Here we present a novel hypothesis for how physically active versus sedentary living promotes stress robustness in the face of intense uncontrollable stress. Advances in neurobiology have established microglia as an active player in the regulation of synaptic activity, and recent work has revealed mechanisms for modulating glial function, including cross talk between neurons and glia. This chapter presents supporting evidence that the physical activity status of an organism may modulate stress-evoked neuronal-glial responses by changing the CX3CL1-CX3CR1 axis. Specifically, we propose that sedentary animals respond to an intense acute uncontrollable stressor with excessive serotonin (5-HT) and noradrenergic (NE) activity and/or prolonged down-regulation of the CX3CL1-CX3CR1 axis resulting in activation and proliferation of hippocampal microglia in the absence of pathogenic signals and consequent hippocampal-dependent memory deficits and reduced neurogenesis. In contrast, physically active animals respond to the same stressor with constrained 5-HT and NE activity and rapidly recovering CX3CL1-CX3CR1 axis responses resulting in the quieting of microglia, and protection from negative cognitive and neurobiological effects of stress.


Stress resistance Microglia Fractalkine Exercise 





Beta Adrenergic Receptor


Brain Derived Neurotrophic Factor


CX3C Chemokine or Fractalkine


CX3C Chemokine 1 Receptor or Fractalkine receptor








Tumor Necrosis Factor Alpha


Uncontrollable stressor


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Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  • Monika Fleshner
    • 1
  • Benjamin N. Greenwood
    • 1
  • Raz Yirmiya
    • 2
  1. 1.Department of Integrative Physiology and The Center for NeuroscienceUniversity of ColoradoBoulderUSA
  2. 2.Department of PsychologyThe Hebrew University of JerusalemJerusalemIsrael

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