Table 2.
Postnatal physiological changes in AMH and AM nociceptors
| Factor | AMH |
AM |
||
|---|---|---|---|---|
| P2–P5 | P6–P10 | P2–P5 | P6–P10 | |
| Average postnatal age, days | 3.6–1.0; 40 | 8.2–1.6; 25 | 3.8–1.1; 19 | 8.3–1.5; 45 |
| Conduction velocity, m/s | 0.8 ± 0.2‡‡‡* (0.6–3.2; 40) | 1.3 ± 0.6 (0.6–3.2; 25) | 1.0 ± 0.4‡‡‡ (0.7–2.5; 19) | 1.6 ± 0.8 (0.6–4.9; 45) |
| Mechanical threshold, mN# | 0.71* (0.08–3.9; 36) | 0.71 (0.08–5.7; 23) | 1.13 (0.4–13.7; 16) | 1.56 (0.08–19.5; 42) |
| Heat threshold, °C | 49.7 ± 3.6 (42.2–55.2; 40) | 48.8 ± 3.7 (38.0–53.3; 25) | ||
| Spike amplitude, mV | 70.0 ± 10.1 (45.5–88.4; 25) | 69.2 ± 8.2 (54.5–86.4; 20) | 63.7 ± 12.0 (46.4–84.1; 11) | 70.8 ± 10.4 (40.8–93.6; 35) |
| Spike overshoot, mV | 16.5 ± 11.4* (−7.9–35.9; 25) | 13.2 ± 12.8 (−8.4–37.3; 20) | 7.2 ± 13.0‡ (−13.5–26.5; 11) | 15.2 ± 11.1 (−10.3–32.6; 35) |
| Spike duration (D50), ms | 1.7 ± 0.6‡ (0.8–3.0; 25) | 1.3 ± 0.5 (0.6–2.1; 20) | 1.5 ± 0.5 (1.0–2.3; 11) | 1.5 ± 0.5 (0.5–3.0; 35) |
| AHP duration (AHP50), ms | 5.9 ± 2.6‡ (2.1–12.5; 25) | 4.3 ± 2.5 (1.3–10.1; 20) | 5.6 ± 2.2 (3.1–9.2; 11) | 6.7 ± 6.2 (2.2–35.1; 35) |
Values represent means ± SD (range; n), except
#
(median, Mann–Whitney U test.
‡
Difference (P < 0.05) within the same cell types (e.g., AMH or AM) across different age groups; ‡‡P < 0.01;
‡‡‡
P < 0.001.
*
Difference (P < 0.05) across different cell types within the same age group.