Measurement of respiratory times in freely moving rats.
A catheter was threaded beneath the skin from the trachea to an opening on the top of the skull. It conducted a small fraction of the ventilatory flow to an external miniaturized transducer, which was composed of a heating element surrounded by two thermocouples. During inspiration, the heating element heated the inner thermocouple, whereas during expiration it heated the outer one. A square signal synchronous with breathing was obtained from the difference in temperature at the two probing sites. Inspiratory and expiratory times were calculated from this signal. This device has been tested with calibrated flows, and compared with head-out plethysmography. It may be easily adapted for ventilatory measurements in any small mammal.
Miramand
J L
JL
Laboratoire de Physiologie, Faculté de Médecine de Paris-Sud, Le Kremlin-Bicêtre, France.
Vardon
G
G
Pacteau
C
C
el-Massioui
N
N
Gallego
J
J
D000818:Animals; D011603:Psychophysiology / Q000295:instrumentation*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012119:Respiration / Q000502:physiology*; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D014159:Transducers