Abstract

Introduction

Materials & Methods

Results

Discussion & Conclusion

References

Discussion
Board

Fig. 1. Area Under the Beam Walk Curve for 6 Hours Post-Injury and Post-Injection. After surgery, all contused (SX) animals were equivalent and all sham-operated (SH) animals were equivalent in their ability to traverse the beam. After full recovery on this task prazosin (PRAZ), but not propranolol (PROP) or saline (SAL). reinstated hemiplegia in injured animals. Any effects in other groups were bilateral (data not shown). The effects of a single dose of PRAZ were dose-dependent and did not differ over time. A short movie illustrating reinstatement in a recovered rat given PRAZ 4 months after injury is on the Internet at http://www.unm.edu/~feeney/index.html

Fig. 2. Recovery of Vibrissae-Evoked and Forelimb-Evoked Tactile Placing After a Unilateral Sensorimotor Cortex Contusion. Injured animals showed severe unilateral deficits on both tactile placing tasks. Vibrissae-evoked placing was slower to recover than forelimb-evoked placing. No drug produced a reinstatement of placing deficits after recovery on these tasks, thus these tasks were discontinued after the first month of testing.

Fig. 3 Enduring Reinstatement of Deficits on the Beam Walk Task by Multiple Doses of Prazosin. The contused (SX) group receiving PRAZ was significantly more impaired than the sham-operated (SH) group at three hours after the 3rd injection (p<.01). The SX-PRAZ group showed a significant positive correlation between initial deficit scores and the mean reinstated deficit scores (r=.71, p<.05). In addition, SX-PRAZ showed a significant positive correlation between initial deficits scores and the maximum reinstated deficit scores (r=.84, p<.05).

Fig. 4. Enduring Reinstatement of Deficits on the Beam Walk Task by Multiple Doses of Clonidine. The SX-CLON group was significantly different from the SH-CLON group at 3 hours after the 3rd injection (p<.01). The SX-CLON approached significance for a positive correlation between initial deficit scores and the mean reinstated deficit scores (r=.69, p>.05). There was a significant positive correlation between score and time for the SX-CLON group (r=.87, p<.01).

Histology:

There were no significant differences between contused groups on any histological measure. The cyst volume mean (33.95 mm3 +/- 4.32) was consistent with those previously reported [2]. This indicates this rodent model of TBI is quite reliability as it is reproducible by different investigators, with different apparatus at a 15 year interval.

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