Table 1.

Physiological data

			C3H	p ≤ 0.05	Tg8	C3H (n)	Tg8 (n)
Breathing parameters
Pneumotachography, deep  anesthesia	TTOT	Milliseconds	493  ± 33	NS	467  ± 20
	TE	Milliseconds	333  ± 30	NS	336  ± 20	19	17
	TI	Milliseconds	160  ± 10	*	131  ± 6
	VT	Milliseconds	197  ± 11	*	157  ± 11
Plethysmography, slight  anesthesia	TTOT	Milliseconds	357  ± 21	NS	391  ± 59
	TE	Milliseconds	242  ± 24	NS	296  ± 59	20	25
	TI	Milliseconds	114  ± 9	*	96  ± 4
	VT	Microliters	219  ± 21	*	156  ± 16	8	9
Firing activity
Diaphragm, deep anesthesia	Early motor units	Hertz	56  ± 2	*	63  ± 1	16	18
	Late motor units	Hertz	41  ± 2	*	47  ± 2	20	18
Intercostal, deep anesthesia	Early motor units	Hertz	70  ± 6	NS	57  ± 4	9	6
	Late motor units	Hertz	50  ± 2	NS	45  ± 2	37	41
MIN, deep anesthesia		Hertz	44  ± 3	*	65  ± 5	12	18
Respiratory regulations
Mild hypoxia, slight  anesthesia	ΔVE	% of normoxia	+47  ± 141-160	*	+18  ± 71-160
	ΔVT	% of normoxia	+31  ± 71-160	*	+11  ± 41-160	17	19
Tracheal occlusion, deep  anesthesia	ΔTE	% of control	+55  ± 141-160	*	−2  ± 3 NS	6	8
Lung inflation, deep  anesthesia	VTthreshold	Microliters	200  ± 18	*	316  ± 25	5	6
Vagal stimulation, deep  anesthesia			+		+	4	4

The breathing parameters (T_TOT, total respiratory cycle; T_E, expiratory time;T_I, inspiratory time; V_T, tidal volume) in two experimental conditions (pneumotachography and plethysmography), and the firing activity of the early and late motor units of the diaphgram and of the intercostal muscles as well as that of the medullary inspiratory neurons (MIN) is given as mean ± SEM for the C3H and Tg8 mice. For the respiratory regulations in the C3H and Tg8 mice, respiratory variations of breathing parameters (ΔV_E, minute ventilation; ΔV_T, tidal volume; Δf_R, respiratory frequency) during mild hypoxia are given as mean ± SEM of the percentage of normoxic values of the same mouse tested in two conditions (normoxia being the control condition); during tracheal occlusions the variations ofT_E (ΔT_E) are given as mean ± SEM of the percentage of control values of the same mouse tested in two conditions (before and after tracheal occlusions).V_T thresholds to obtain a response to lung inflation and the responses to vagal stimulation are also given. The state of anesthesia is given. Statistically significant differences between the values of C3H and Tg8 mice are given in the fifth column (

^*for p ≤ 0.05; NS for a nonsignificant difference).

F1-160: represents a statistically significant difference between the values obtained in different conditions in the same strain of mice. In the last two columns, n gives the number of neurons or animals studied.