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Abstract:
We explored the novel concept that electrical stimulation of certain midbrain areas (the dorsal and median raphe nuclei) for one week improves recovery from acute traumatic brain injury. We designed and manufactured a wireless implantable stimulator for rats, with embedded stimulating electrode. A fluid percussion injury was created over the rat?s right motor cortex. After 4-6 hours, we implanted the electrode in one of the target areas; the stimulator was attached to the skull. Stimulation was given 12 hours daily in 5-minute alternating periods at 8 Hz. Comparisons were made with injured, non-stimulated rats and with uninjured rats (stimulated and non-stimulated). Behavioral testing at 6 weeks, after either dorsal or median raphe stimulations, improved learning in a water maze test and normalized sensorimotor performance (movements in a transparent cylinder). Higher rates of stimulation (20 Hz) or one-week delay in starting treatment proved less efficacious. Histological inspection at 8 weeks showed an enlarged fiber tract (corpus callosum) after early 8-Hz median raphe stimulation, but no changes in cell counts or hippocampal or cortical volume with any treatment. Overall, the median raphe performed better. Its early stimulation with a temporary implant should be considered for enhancing recovery after certain traumatic brain injuries.
| Limitations: |
APPROVED FOR PUBLIC RELEASE |
| Description: |
Final rept. 7 Apr 2008-6 Apr 2010 |
| Pages: |
20 |
| Report Date: |
MAY 2010 |
| Contract Number: |
W81XWH-08-1-0288 |
| Report Number: |
A259145 |
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