Table 1.
Properties of individual Renshaw cells
| Cell identification | B17P | B18P | B22P | B23J |
|---|---|---|---|---|
| Dorsal roots | Intact | Cut | Cut | Cut |
| Segment | T8 | T7 | T7 | T7 |
| Spontaneous discharges | Expiratory | None | Expiratory | Inspiratory |
| Activating nerve | Internal | Dorsal ramus (+ internal) | Internal | Internal |
| Depth of recording, from dorsal surface (mm) | 3.5 | 2.6 | 2.9 | 3.4 |
| Membrane potential (best, mV) | −27 | −40 | −50 | −55 |
| Antidromic from T10 | Yes | Yes | Not tested | Yes |
| Distance to T10 electrodes (mm) | 29.5 | 27.5 | – | 36.5 |
| Conduction velocity (m sec−1) | 29.5 | 27.5 | – | 21.4 |
| Sections | 40 μm parasagittal | 30 μm transverse | 30 μm parasagittal | 30 μm parasagittal |
| Dendritic spread (mm) | ||||
| Rostral | 0.60 | – | 0.55 | 0.64 |
| Caudal | 0.60 | – | 0.69 | 0.40 |
| Collateral spacing (mm) | ||||
| Rostral | 0.65 | 0.41 | 1.2 | 1.4 |
| Caudal | – | 0.78 | 1.65 | – |
| Mean axon diameter (μm) | ||||
| Rostral | 4.0 | 2.79 | 4.0 | 2.11 |
| Caudal | 3.25 | 2.98 | 2.58 | 2.39 |
| Predicted conduction velocity (m sec−1) (caudal axon dia × 8, see text) | 26.0 | 23.8 | 20.6 | 19.1 |