Table 3. Sensitivity of firing frequency to different chemical stimuli.
| Stimulus | pHo | pHi | %CO2 | FRs | SI (%) |
|---|---|---|---|---|---|
| N | 7.45 | 7.25 | 5 | 1.43 | 0 |
| IH | 7.45 | 7.25 | 15 | 1.26 | 11.9 |
| IA | 7.10 | 7.00 | 5 | 3.03 | 111.9 |
| HA | 7.10 | 7.00 | 15 | 2.85 | 99.3 |
| HA* | 7.10 | 7.25 | 15 | 2.68 | 87.4 |
The sensitivity (SI) is relative to the stimulus and is calculated for different chemical conditions. As in Eq (1), it is defined as the percentage of control firing rate (FRc = 1.43 Hz) to which the firing rate changes (FRs) in response to a specific chemical stimulus. Stimuli: normocapnia (N), isohydric hypercapnia (IH), isocapnic acidosis (IA), hypercapnic acidosis (HA), hypercapnic acidosis with no change in intracellular pH (HA*).