Response characteristics of primary afferent fibers
| Fiber type | Number of fibers | Mean (±SE) CV (m/sec) | Median mechanical threshold (mN) | |||
|---|---|---|---|---|---|---|
| Control | Tumor | Control | Tumor | Control | Tumor | |
| Aβ | 33 | 30 | 20.8 ± 1.2 | 19.8 ± 1.4 | 4.4 | 1.2 |
| RA | 23 | 24 | 19.5 ± 1.5 | 19.1 ± 1.5 | 2.1 | 1.2 |
| SA | 10 | 6 | 23.9 ± 1.8 | 22.1 ± 4.1 | 6.1 | 2.8 |
| Aδ | 21 | 26 | 6.2 ± 0.6 | 5.9 ± 0.6 | 10.3 | 5.2 |
| C | 30 | 50 | 0.6 ± 0.04 | 0.5 ± 0.03 | 24.4 | 24.4 |
| Excited by heat | Mean (±SEM) heat threshold (°C) | |||||
|---|---|---|---|---|---|---|
| Control | Tumor | Control | Tumor | |||
| Aδ | 2/16 (12.5%) | 2/16 (12.5%) | 49.0 ± 0 | 45.0 ± 2.0 | ||
| C | 17/27 (63%) | 18/35 (51%) | 41.8 ± 1.0 | 38.3 ± 0.7 | ||
| Excited by cold | Mean (±SEM) cold threshold (°C) | |||||
|---|---|---|---|---|---|---|
| Control | Tumor | Control | Tumor | |||
| Aδ | 4/14 (29%) | 5/14 (36%) | 3.0 ± 5.7 | 11.2 ± 6.1 | ||
| C | 34/44 (77%) | 15/31 (48%) | 10.2 ± 2.6 | 11.2 ± 2.4 | ||
| Functional subclassification of fibers according to temperature sensitivity1-a | ||||||
|---|---|---|---|---|---|---|
| Aδ fibers (n) | C fibers (n) | |||||
| Control | Tumor | Control | Tumor | |||
| AM | 67% (10) | 41% (7) | CM | 20% (5) | 24% (8) | |
| AMC | 20% (3) | 35% (6) | CMC | 16% (4) | 18% (6) | |
| AMH-I | 6.5% (1) | 12% (2) | CMH | 24% (6) | 30% (10) | |
| AMH-II | 12% (2) | CMHC | 40% (10) | 21% (7) | ||
| AMHC-I | 6.5% (1) | |||||
↵F1-a Only units tested for both heat and cold stimulus trials were classed.