Table 1.
Cough parameters after kynurenic acid microinjections in rostral NTS
| Control | 5–15 min | 15–25 min | Recovery | P Value | |
|---|---|---|---|---|---|
| Cough number, motor drive, and mechanics | |||||
| CN (per 20 s) | 10.0 ± 1.2 | 4.1 ± 1.2***+++ | 4.5 ± 0.7***+++ | 9.8 ± 1.1 | <0.001 |
| ABD, % | 100 | 40 ± 9***+++ | 50 ± 7***+++ | 87 ± 8 | <0.001 |
| PS, % | 100 | 89 ± 11 | 90 ± 9 | 110 ± 11 | >0.05 |
| EP E, kPa | 24.1 ± 5.2 | 5.8 ± 1.7***++ | 8.1 ± 1.8***++ | 20.0 ± 4.3 | <0.001 |
| EP I, kPa | −5.6 ± 1.0 | −5.4 ± 0.8 | −5.5 ± 0.9 | −6.5 ± 0.9 | >0.05 |
| Cough phase durations | |||||
| CTI, s | 1.08 ± 0.11 | 3.31 ± 0.68***++ | 3.39 ± 0.52***++ | 1.21 ± 0.10 | <0.001 |
| CTE, s | 1.40 ± 0.14 | 2.76 ± 0.83 | 2.28 ± 0.43 | 1.32 ± 0.19 | >0.05 |
| CTE1, s | 0.63 ± 0.07 | 2.24 ± 0.87 | 1.77 ± 0.42 | 0.75 ± 0.06 | <0.05 |
| CTE2, s | 0.76 ± 0.12 | 0.52 ± 0.21 | 0.52 ± 0.26 | 0.57 ± 0.17 | >0.05 |
| Ttot, s | 2.47 ± 0.24 | 6.07 ± 1.36**++ | 5.47 ± 0.84*++ | 2.53 ± 0.26 | 0.001 |
| Tactive, s | 1.71 ± 0.15 | 5.55 ± 1.43**++ | 4.96 ± 0.88*+ | 1.96 ± 0.13 | <0.01 |
| Other temporal metrics of cough | |||||
| desI, s | 0.14 ± 0.01 | 1.64 ± 0.73*+ | 1.30 ± 0.40 | 0.21 ± 0.02 | <0.05 |
| dif, s | 0.18 ± 0.01 | 1.65 ± 0.70*+ | 1.19 ± 0.41 | 0.25 ± 0.02 | <0.05 |
| over, s | 0.55 ± 0.08 | 3.14 ± 1.16*+ | 2.96 ± 0.88*+ | 0.66 ± 0.12 | <0.01 |
| TPS, s | 1.21 ± 0.12 | 4.95 ± 1.31**++ | 4.44 ± 0.86*++ | 1.42 ± 0.11 | <0.001 |
| TABD, s | 1.04 ± 0.12 | 3.73 ± 1.31*+ | 3.48 ± 0.91*+ | 1.21 ± 0.15 | <0.05 |
| Cardiorespiratory data | |||||
| TI, s | 0.77 ± 0.07 | 2.57 ± 0.57***++ | 2.15 ± 0.32**++ | 0.88 ± 0.11 | <0.001 |
| TE1, s | 0.63 ± 0.09 | 2.64 ± 0.84*+ | 2.30 ± 0.86 | 0.77 ± 0.19 | <0.01 |
| TE2, s | 1.40 ± 0.18 | 0.96 ± 0.14* | 1.13 ± 0.19 | 0.92 ± 0.11* | <0.05 |
| RR, min−1 | 22.6 ± 1.5 | 13.3 ± 2.3***+++ | 14.0 ± 1.8***+++ | 26.6 ± 3.0 | <0.001 |
| PS ampl, % | 13.1 ± 2.2 | 24.3 ± 7.5 | 11.9 ± 2.4 | 18.4 ± 8.3 | >0.05 |
| EP ampl, kPa | 0.33 ± 0.08 | 0.44 ± 0.17 | 0.43 ± 0.16 | 0.26 ± 0.06 | >0.05 |
| ETCO2, mmHg | 31.7 ± 1.8 | 33.4 ± 2.4 | 35.0 ± 2.0 | 32.2 ± 2.1 | >0.05 |
| BP, mmHg | 130 ± 5 | 175 ± 9***+++ | 165 ± 7***+++ | 126 ± 5 | <0.001 |
| HR, min−1 | 188 ± 10 | 213 ± 11*** | 203 ± 11* | 203 ± 11* | <0.01 |
Values are means ± SE (n = 11). Data were pooled for both rNTS microinjection groups. Control, preinjection control; 5–15 min, 15–25 min, data within the time intervals after completion of microinjections; Recovery, data >90 min after microinjections; CN, number of coughs per 20-s stimulus duration (per 1 trial); ABD, amplitudes of abdominal muscle EMG; PS, amplitudes of parasternal muscle EMG; EP E, EP I, expiratory and inspiratory esophageal pressure amplitudes, respectively; CTI, duration of cough inspiratory phase; CTE, duration of cough expiratory phase; CTE1, duration of active cough expiratory phase; CTE2, duration of quiescent period of cough expiration; Ttot, total cough cycle duration; Tactive, duration of cough-related EMG activity; desI, descendent portion of cough parasternal bursting; dif, time interval between the peaks of parasternal and abdominal EMG activity; over, duration of parasternal and abdominal activity overlap; TPS, TABD, durations of cough-related parasternal and abdominal discharge, respectively; TI, inspiratory phase duration; TE1, postinspiratory phase duration; TE2, expiratory phase 2 duration; RR, respiratory rate; PS ampl, amplitudes of parasternal muscle EMG; EP ampl, amplitudes of esophageal pressure; ETCO2, end-tidal CO2 content; BP, mean arterial blood pressure; HR, heart rate. P value is for ANOVA.
P < 0.05,
P < 0.01,
P < 0.001 compared with preinjection control;
P < 0.05,
P < 0.01,
P < 0.001 compared with recovery >90 min after injection.