Table 1.
Evoked discharge characteristics of cardiorespiratory NTS neurones
| Cardiorespiratory receptor stimulated | Peak firing frequency (Hz) | Firing frequency range (Hz) | Mean duration (s) | Range of duration (s) |
|---|---|---|---|---|
| Cardiac chemo (n= 30) | 14.7 ± 1 | 6–32 | 7.3 ± 0.9 | 1–25 |
| Cardiac mechano (n= 13) | 14.3 ± 2.5 | 4–40 | 4.3 ± 1.2 | 2–5 |
| Baroreceptor (n= 23) | 14.0 ± 2.1 | 4–38 | 2.7 ± 1.1 | 0.2–5 |
| Chemoreceptor (n= 34) | 18.2 ± 1.8 | 8–37 | 7.7 ± 1.2 | 1–10 |
| Right atrial stretch (n= 5) | 14.7 ± 0.7 | 9–28 | 2.8 ± 0.6 | 1–3 |
The mean (±s.e.m.) peak frequency and duration of firing responses of neurones within the NTS during stimulation of cardiac receptors (either chemically with 1–3 μg kg−1 veratridine or by increasing left ventricular pressure by 70–85 mmHg), baroreceptors (by increasing perfusion pressure by 55–70 mmHg), peripheral chemoreceptors (using 1–5 μg sodium cyanide) and right atrial stretch receptors (increasing right atrial pressure by 5–6 mmHg from control levels) are shown. Note that the data are pooled and so any one neurone may be activated by more than one afferent type.