Table 1.
Stimulus-evoked vasodilation
| Punctate |
10-s stimulus |
30-s stimulus |
||||
| Parameter | Average (0.5–1.5 s after onset) | Peak | Average (0.5–10.5 s after onset) | Peak | Average (0.5–30.5 s after onset) | Peak |
| Surface arteries | ||||||
| Vibrissa (%) | 4.4 ± 4.5 (P < 10−4) | 8.9 ± 6.1 (P < 10−5) | 13.7 ± 7.0 (P < 10−4) | 22.0 ± 8.4 (P < 10−5) | 17.0 ± 9.6 (P < 10−4) | 25.8 ± 12.5; early* (P < 10−5) 27.8 ± 10.7; delayed† (P < 10−5) |
| Control (%) | 1.9 ± 3.0 (P < 3 × 10−3) | 5.0 ± 3.8 (P < 10−5) | 3.2 ± 3.3 (P < 10−3) | 9.6 ± 7.1 (P < 10−5) | 2.9 ± 4 (P < 10−4) | 12.1 ± 8.6; early* (P < 10−5) 9.7 ± 8.4; delayed† (P < 10−5) |
| Sample (n) | 28 | 17 | 39 | |||
| Diameters (μm) | 27.9 ± 13.7 | 16.5 ± 10.4 | 13.1 ± 7.5 | |||
| Surface veins | ||||||
| Vibrissa (%) | −0.7 ± 0.8 (NS) | 1.2 ± 1.2 (NS) | 1.8 ± 3.5 (NS) | 5.6 ± 3.3 (P < 10−5) | 4.1 ± 4.2 (P < 10−4) | 10.2 ± 6.2 (P < 10−5) |
| Control (%) | −0.1 ± 0.1 (NS) | 0.8 ± 0.9 (NS) | 0.8 ± 1.4 (NS) | 5.3 ± 4.1 (P < 3 × 10−3) | 0.5 ± 3.3 (NS) | 6.8 ± 5.7 (P < 10−5) |
| Sample (n) | 7 | 8 | 45 | |||
| Diameters (μm) | 50.7 ± 23.7 | 17.0 ± 16.4 | 13.9 ± 8.3 | |||
| Capillaries | ||||||
| Vibrissa (%) | −0.1 ± 3.0 (NS) | 2.0 ± 5.1 (NS) | ||||
| Control (%) | −0.2 ± 1.7 (NS) | 0.3 ± 2.5 (NS) | ||||
| Sample (n) | 13 | 19 | ||||
| Diameters (μm) | 3.3 ± 0.6 | 2.9 ± 0.5 | ||||
| Depth | 30–50 μm below pia | 20–50 μm below pia | ||||
All numbers are mean ± SD.
*Early peak, which occurs in the 1- to 10-s period after stimulation.
†Delayed peak, which occurs 10–31 s after stimulation.