Table 1.
Temporal cough parameters
| Control | Unilateral | Bilateral | Recovery | P Value | |
|---|---|---|---|---|---|
| CTi, s | |||||
| DLH | 1.00 ± 0.07 | 1.06 ± 0.11 | 0.97 ± 0.09 | NS | |
| KYN | 1.13 ± 0.13 | 0.66 ± 0.06**‡ | 0.90 ± 0.04* | <0.01 | |
| GAB | 0.99 ± 0.09 | 1.80 ± 0.17* | 2.12 ± 0.39**‡ | 1.28 ± 0.16 | <0.01 |
| CTe, s | |||||
| DLH | 1.36 ± 0.21 | 1.62 ± 0.43 | 1.59 ± 0.24 | NS | |
| KYN | 1.81 ± 0.27 | 1.41 ± 0.30* | 1.34 ± 0.14* | <0.05 | |
| GAB | 2.00 ± 0.66 | 4.35 ± 1.59*‡ | 5.61 ± 1.38**‡‡ | 2.18 ± 0.69 | <0.01 |
| CTe1, s | |||||
| DLH | 0.80 ± 0.09 | 0.68 ± 0.09*‡ | 0.81 ± 0.09 | <0.05 | |
| KYN | 0.96 ± 0.11 | 0.83 ± 0.04 | 0.85 ± 0.03 | NS | |
| GAB | 0.88 ± 0.05 | 1.46 ± 0.23 | 1.83 ± 0.27*‡ | 0.97 ± 0.06 | <0.05 |
| CTe2, s | |||||
| DLH | 0.57 ± 0.14 | 0.94 ± 0.37 | 0.77 ± 0.17 | NS | |
| KYN | 0.86 ± 0.19 | 0.58 ± 0.27 | 0.50 ± 0.16* | <0.05 | |
| GAB | 1.11 ± 0.70 | 2.89 ± 1.73 | 3.79 ± 1.50 | 1.21 ± 0.67 | =0.05 |
| CTtot, s | |||||
| DLH | 2.36 ± 0.26 | 2.68 ± 0.52 | 2.55 ± 0.29 | NS | |
| KYN | 2.95 ± 0.38 | 2.07 ± 0.34** | 2.25 ± 0.16** | <0.01 | |
| GAB | 2.99 ± 0.74 | 6.15 ± 1.65*‡ | 7.73 ± 1.41***‡‡ | 3.45 ± 0.80 | <0.001 |
| CTma, s | |||||
| DLH | 1.80 ± 0.15 | 1.74 ± 0.19 | 1.78 ± 0.16 | NS | |
| KYN | 2.09 ± 0.23 | 1.48 ± 0.08* | 1.75 ± 0.04 | <0.05 | |
| GAB | 1.88 ± 0.08 | 3.26 ± 0.26* | 3.94 ± 0.65**‡ | 2.24 ± 0.16 | <0.01 |
| dif, s | |||||
| DLH | 0.23 ± 0.02 | 0.27 ± 0.01 | 0.25 ± 0.01 | NS | |
| KYN | 0.28 ± 0.02 | 0.26 ± 0.02 | 0.25 ± 0.01 | NS | |
| GAB | 0.27 ± 0.03 | 0.40 ± 0.04††† | 0.64 ± 0.05***‡‡‡ | 0.28 ± 0.03 | <0.001 |
| over, s | |||||
| DLH | 0.43 ± 0.06 | 0.34 ± 0.04 | 0.45 ± 0.05 | NS | |
| KYN | 0.57 ± 0.09 | 0.31 ± 0.07**‡ | 0.47 ± 0.10 | <0.05 | |
| GAB | 0.51 ± 0.10 | 0.87 ± 0.22 | 0.80 ± 0.34 | 0.57 ± 0.16 | NS |
Values are means ± SE. Bilateral, pooled data for 1–8 and 20–30 min for gabazine (GAB), pooled data for 5–15 and 20–35 min post last microinjection for kynurenic acid (KYN); control, preinjection control; recovery, 5–35 min for DLH, >120 min for KYN and GAB after the last microinjection; unilateral, within 120 s postmicroinjection for d,l-homocysteic acid (DLH), 1–8 min for GAB. CTe, duration of the cough expiratory phase; CTe1, duration of active cough expiratory phase; CTe2, quiescent period of cough expiration; CTi, duration of cough inspiratory phase; CTtot, total cough cycle duration; dif, time interval between the peaks of parasternal/diaphragm and abdominal EMG activity; over, duration of parasternal/diaphragm and abdominal EMG activities overlap. Sample size: 8 for DLH, 6 for KYN, 5 for GAB; P values in the table are that of the repeated-measures ANOVA, P values from the Student–Newman–Keuls posttest; *, **, ***P < 0.05, <0.01, <0.001 compared with preinjection control, respectively; †††P < 0.001 compared with bilateral data; ‡, ‡‡, ‡‡‡P < 0.05, <0.01, <0.001 compared with recovery, respectively; not significant (NS): P > 0.05.