1. Wheel Running and Fluoxetine Antidepressant Treatment Have Differential Effects in the Hippocampus and the Spinal Cord C. Engesser-Cesar, A. J. Anderson, and C. W. Cotman

2. Hypothesis Exercise and antidepressants independently increase hippocampus (BDNF) and neurogenesis. Exercise and antidepressants independently increase hippocampus (BDNF) and neurogenesis. Effects are on BDNF synergistic Effects are on BDNF synergistic

3. Background Information Brain-derived neurotrophic factor (BDNF) is capable of mediating the beneficial effects of exercise on brain plasticity, supports the health and functioning of glutamatergic neurons, promotes differentiation, neurite (process) extension, and the survival of a variety of neuronal populations (1). Brain-derived neurotrophic factor (BDNF) is capable of mediating the beneficial effects of exercise on brain plasticity, supports the health and functioning of glutamatergic neurons, promotes differentiation, neurite (process) extension, and the survival of a variety of neuronal populations (1).

4. Exercise Improves Various neurological conditions Various neurological conditions Age-related neurodegenerationAge-related neurodegeneration DepressionDepression Alzheimer’s diseaseAlzheimer’s disease Traumatic brain injuryTraumatic brain injury Spinal cord injurySpinal cord injury

5. Animals C57BL/10 female mice (n=112) C57BL/10 female mice (n=112) 2 months old 2 months old Acclimatized for 1 week, 7 days of antibiotic admin Acclimatized for 1 week, 7 days of antibiotic admin Excluded for difficulty with wheel running Excluded for difficulty with wheel running Food and water ad libitum Food and water ad libitum 12h light/dark cycle 12h light/dark cycle Randomly assigned Randomly assigned

6. Animals No Wheel Running Wheel RunningControl5mg/kg fluoxetine10mg/kg fluoxetine25mg/kg fluoxetine 14 animals/group

7. Methods and Materials

8. 21 days of fluoxetine treatment 21 days of fluoxetine treatment With or without wheel runningWith or without wheel running Daily i.p. injections Daily i.p. injections 6 animals from each group got BrdU injections on final 7 days 6 animals from each group got BrdU injections on final 7 days Killed 24h after last fluoxetine injection Killed 24h after last fluoxetine injection Staggered over 4 days (estrous) Staggered over 4 days (estrous)

9. Fluoxetine Decreased running distance Decreased running distance High dose group ran significantly less by the end of the experiment High dose group ran significantly less by the end of the experiment Increased weight gain Increased weight gain

10. Exercise and Fluoxetine Together, increase cell proliferation and survival in the hippocampus Together, increase cell proliferation and survival in the hippocampus IGF-1: positively linked to hippocampal neurogenesis IGF-1: positively linked to hippocampal neurogenesis Seen with: Exercise-mediated recovery from traumatic brain injurySeen with: Exercise-mediated recovery from traumatic brain injury Fluoxetine administration Fluoxetine administration BDNF: positively linked to hippocampal neurogenesis BDNF: positively linked to hippocampal neurogenesis is activated more rapidly when used in combination is activated more rapidly when used in combination with exercise and antidepressants (Cotman 2002) with exercise and antidepressants (Cotman 2002)

11. Spinal Cord Examined rostral, thoracic, lumbar Examined rostral, thoracic, lumbar Spinal cord IGF-1 protein did not change with wheel running, and decreased with fluoxetine (high dose) Spinal cord IGF-1 protein did not change with wheel running, and decreased with fluoxetine (high dose) Cytogenesis also decreased with fluoxetine (dose dependent) Cytogenesis also decreased with fluoxetine (dose dependent) BDNF did not change in rostral or lumbar after running or fluoxetine treatment BDNF did not change in rostral or lumbar after running or fluoxetine treatment Wheel running and fluoxetine did not protect against spinal cord injury Wheel running and fluoxetine did not protect against spinal cord injury

12. Rostral Cord

13. Lumbar Cord

14. Thoracic Cord

15. Effects of exercise and fluoxetine on spinal cord IGF-1 protein significantly decreased with administration of fluoxetine IGF-1 protein significantly decreased with administration of fluoxetine No neurogenesis No neurogenesis Decreased cytogenesis Decreased cytogenesis

16. Spinal Cord Injury No benefit for pre-injury exercise for SCI recovery No benefit for pre-injury exercise for SCI recovery Post-injury exercise and/or fluoxetine may be protective (not explored here) Post-injury exercise and/or fluoxetine may be protective (not explored here) Trophic factors or cytogenesis could be a recovery mechanismTrophic factors or cytogenesis could be a recovery mechanism Decreased BrdU in spinal cord ?? Decreased BrdU in spinal cord ??

17. Results In the hippocampus fluoxetine increases BDNF, cytogenesis, and neurogenesis In the hippocampus fluoxetine increases BDNF, cytogenesis, and neurogenesis Dose dependentDose dependent

18. Results BDNF was not induced by exercise BDNF was not induced by exercise but increased by fluoxetinebut increased by fluoxetine Hippocampal IGF-1 protein not affected by fluoxetine, exercise, or both Hippocampal IGF-1 protein not affected by fluoxetine, exercise, or both Fluoxetine decreased IGF-1 protein in all three regions of the spinal cord Fluoxetine decreased IGF-1 protein in all three regions of the spinal cord

19. Results Decreased trend of BrdU positive cells in exercise animals Decreased trend of BrdU positive cells in exercise animals Fluoxetine also decreases BrdU Fluoxetine also decreases BrdU Decrease in cell proliferation

20. BDNF and Serum IGF1

21. IGF1 hippocampal results

22. Neurogenesis and Cytogenesis BrdU represents new cells DCX represents new neurons

23. a Control animal, cytogenesis and neurogenesis in the hippocampus

24. b Wheel running with 25mg/kg fluoxetine dose animal, cytogenesis and neurogenesis in the hippocampus

25. Neurogenesis and cytogenesis results Increased dentate granule cell layer DCX increases, not BrdU with fluoxetine Fluoxetine and exercise combined no effect on cytogenesis or neurogenesis Fluoxetine and exercise combined no effect on cytogenesis or neurogenesis

26. Cell numerical density

27. De Foubert Graph Four days of Prozac

28. De Foubert Graph Seven days of Prozac

29. De Foubert Graph Fourteen days of Prozac

30. De Foubert results Herein, 21 days of wheel running and fluoxetine administration increased BDNF cells in hippocampus Herein, 21 days of wheel running and fluoxetine administration increased BDNF cells in hippocampus Dependent on length of treatment Dependent on length of treatment

31. Discussion Exercise or fluoxetine did not increase IGF-1 as previously seen No change in BDNF protein with exercise in female mice Gender, strain, or amount of exercise could effect BDNF protein High dose fluoxetine increased hippocampal BDNF protein

32. Discussion Wheel running did not effect BDNF in hippocampus Exercise and fluoxetine may use different mechanisms for BDNF increase No change in IGF-1 in hippocampus High dose fluoxetine increased cytogenesis and neurogenesis in hippocampus

33. Discussion No increase in BDNF in spinal cord High dose fluoxetine decreased IGF-1 No increase cytogenesis/neurogenesis in spinal cord with any treatment No pre-injury exercise helped SCI

34. Conclusion Fluoxetine increased BDNF, cytogenesis, and neurogenesis in the hippocampus Fluoxetine decreased IGF-1 and cytogenesis in the spinal cord

35. References 1. Cotman, C. W., and C. Engesser-Cesar. Exercise enhances and protects brain function. Exerc. Sport Sci Rev. 30:75-79, 2002. 1. Cotman, C. W., and C. Engesser-Cesar. Exercise enhances and protects brain function. Exerc. Sport Sci Rev. 30:75-79, 2002. 2. De Foubert, G., S. L. Carney, C. S. Robinson, E. J. Destexhe, R. Tomlinson, C. A. Hicks, T. K. Murray, J. P. Gaillard, C. Deville, V. Xhenseval, C. E. Thomas, M. J. O’Neill, and T. S. C. Zetterstrom. Fluoxetine-induced change in rat brain expression of brain-derived neurotrophic factor varies depending on length of treatment. J. Neurosci. 128:597-604, 2004 2. De Foubert, G., S. L. Carney, C. S. Robinson, E. J. Destexhe, R. Tomlinson, C. A. Hicks, T. K. Murray, J. P. Gaillard, C. Deville, V. Xhenseval, C. E. Thomas, M. J. O’Neill, and T. S. C. Zetterstrom. Fluoxetine-induced change in rat brain expression of brain-derived neurotrophic factor varies depending on length of treatment. J. Neurosci. 128:597-604, 2004 3. van Praag, H., G. Kempermann, and F. H. Gage. Running increases cell proliferation and neurogenesis in the adult mouse dentate gyrus. Nature Neurosci. 2:266-270, 1999 3. van Praag, H., G. Kempermann, and F. H. Gage. Running increases cell proliferation and neurogenesis in the adult mouse dentate gyrus. Nature Neurosci. 2:266-270, 1999