Interactive Effects Between Exercise and Serotonergic Pharmacotherapy on Cortical Reorganization After Spinal Cord Injury.
In rat models of spinal cord injury, at least 3 different strategies can be used to promote long-term cortical reorganization: (1) active exercise above the level of the lesion; (2) passive exercise below the level of the lesion; and (3) serotonergic pharmacotherapy. Whether and how these potential therapeutic strategies-and their underlying mechanisms of action-interact remains unknown. Methods In spinally transected adult rats, we compared the effects of active exercise above the level of the lesion (treadmill), passive exercise below the level of the lesion (bike), serotonergic pharmacotherapy (quipazine), and combinations of the above therapies (bike+quipazine, treadmill+quipazine, bike+treadmill+quipazine) on long-term cortical reorganization (9 weeks after the spinal transection). Cortical reorganization was measured as the percentage of cells recorded in the deafferented hindlimb cortex that responded to tactile stimulation of the contralateral forelimb. Results Bike and quipazine are "competing" therapies for cortical reorganization, in the sense that quipazine limits the cortical reorganization induced by bike, whereas treadmill and quipazine are "collaborative" therapies, in the sense that the reorganization induced by quipazine combined with treadmill is greater than the reorganization induced by either quipazine or treadmill.



These results uncover the interactive effects between active/passive exercise and serotonergic pharmacotherapy on cortical reorganization after spinal cord injury, emphasizing the importance of understanding the effects of therapeutic strategies in spinal cord injury (and in other forms of deafferentation) from an integrated system-level approach.
Hospital Nacional de Parapléjicos, Servicio de Salud de Castilla-La Mancha, Toledo, Spain Hospitales de Madrid, Móstoles, Spain CEU-San Pablo University, Madrid, Spain.
Guglielmo
G
Foffani
Drexel University College of Medicine, Philadelphia, PA, USA.
Jed
J
Shumsky
Drexel University, Philadelphia, PA, USA.
Eric B
EB
Knudsen
Drexel University, Philadelphia, PA, USA.
Patrick D
PD
Ganzer
Drexel University College of Medicine, Philadelphia, PA, USA Drexel University, Philadelphia, PA, USA karen.moxon@drexel.edu.
Karen A
KA
Moxon
D000200:Action Potentials / Q000187:drug effects; D000704:Analysis of Variance; D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects* / Q000473:pathology / Q000502:physiology*; D004195:Disease Models, Animal; D005080:Exercise Test; D005081:Exercise Therapy / Q000379:methods*; D005106:Exploratory Behavior / Q000187:drug effects / Q000502:physiology; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D011814:Quipazine / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017366:Serotonin Receptor Agonists / Q000627:therapeutic use*; D013119:Spinal Cord Injuries / Q000188:drug therapy / Q000473:pathology / Q000534:rehabilitation
D017366:Serotonin Receptor Agonists; D011814:Quipazine
cortical reorganization; electrophysiology; physical therapy; serotonin; somatosensory cortex; spinal cord transection