Effects of spontaneous and forced running on activation of hypothalamic corticotropin-releasing hormone neurons in rat

1. Effects of spontaneous and forced running on activation of hypothalamic corticotropin-releasing hormone neurons in rats

2. Introduction Stressors such as immobilization, restraint, foot shock, & communication box activate CRH-containing neurons in the PVN Acute physical stress � treadmill running � induces strong CRH mRNA expression in the PVN

3. Introduction Physical exercise = stressor Physical exercise triggers the HPA axis starting with the CRH neurons CRH neurons project to brain areas involved in mood/affect Depression, anti-anxietyDepression, anti-anxiety

4. HPA axis

5. Introduction Forced physical exercise (running/swimming) produces negative adaptations to stress responses with activation of CRH neurons Therefore, physical exercise could alter psychological effects

6. Introduction Spontaneous physical exercise could be beneficial to all aspects of health, so� Effects of CRH neuron activation by physical exercise should differ between spontaneous & forced

7. Purpose of the Study Compare hypothalamic CRH neuronal activation during spontaneous wheel runners (SWR) & forced wheel runners (FWR) with double-staining for c-Fos and CRH in the PVN C-Fos - a transcription factor and fxn�l marker of neuronal activityC-Fos - a transcription factor and fxn�l marker of neuronal activity

8. Materials & Methods Twenty adult male Wistar rats Individual housed cages attached to voluntarily accessible running wheels unlocked in all cages for habituation 1 week before testing 12h light/dark cycle Ad libitum access to food and H2O

9. Figure 1