Table 1.
Schwann cell bridge formation during denervation, reinnervation, and partial denervation
| Experiment | Number of endplates examined | Percentage of endplates w/bridges* | Percentage of bridges w/sprouts | |
|---|---|---|---|---|
| Innervated | Denervated | |||
| Reinnervation (7–8 d) | 291 ± 27 | 20 ± 6 | 11 ± 2 | 88 |
| Reinnervation (12 d) | 358 ± 35 | 1 ± 1 | 24 ± 1 | 98 |
| Full denervation (12 d) | 0 | 192 ± 13 | 6 ± 2 | 0 |
| Partial denervation (PD) in 10-wk-old rats | ||||
| PD & botox for 3 d | 94 ± 32 | 387 ± 13 | 2 ± 1 | 89 |
| PD & vehicle for 3 d | 165 ± 67 | 269 ± 18 | 10 ± 1 | 94 |
| PD & botox for 7 d | 77 ± 22 | 310 ± 23 | 6 ± 1 | 93 |
| PD & vehicle for 7 d | 86 ± 17 | 362 ± 39 | 30 ± 3 | 100 |
| PD in 5-wk-old rats; muscles examined 3 d later | ||||
| Btx initiated 48 hr after PD | 199 ± 101 | 557 ± 95 | 9 ± 3 | 100 |
| Vehicle initiated 48 hr after PD | 155 ± 27 | 391 ± 38 | 21 ± 1 | 100 |
| Botox initiated 44 hr after PD | 124 ± 17 | 455 ± 25 | 14 ± 2 | 100 |
| Vehicle initiated 44 hr after PD | 143 ± 28 | 596 ± 82 | 25 ± 2 | 100 |
Data are expressed as mean ± SEM. Three muscles were examined in all sets of experiments except those evaluated 7–8 d after reinnervation (five muscles were examined) and muscles treated with botox 44 hr after PD (four muscles were examined).
*Percentage of bridges is of all endplates (denervated and innervated) in reinnervation experiments and of innervated endplates in PD experiments.