Determination of carbon dioxide detection thresholds in trained rats.
Concentration-response functions for the detection of CO2 were established for six rats. The animals were tested in a wind tunnel apparatus and trained using standard operant techniques and a discrete trials, go, no-go successive discrimination paradigm. The primary conclusion to be drawn from the performance measurements is that, at least under carefully controlled conditions, rats can detect physiologic concentrations of CO2 (0-4%). Minimum detectable concentrations fell within the range of 0.04-1.7% CO2. The concentration-response function describing the detectability of CO2 for the six rats was divided into an upper and lower limb at a concentration (5%) that was approximately equal to the end expiratory CO2 levels for the rat (4.88%). High levels of performance were observed for concentrations above this point, while those below it (0.02-2.5%) represented the dynamic range of detectability. Based on a 65% performance criterion, the average threshold performance for six rats was 0.52%. Possible interpretations of these data are discussed.
Youngentob
S L
SL
Department of Physiology, SUNY Health Science Center, Syracuse 13210.
Hornung
D E
DE
Mozell
M M
MM
D000818:Animals; D001143:Arousal / Q000502:physiology; D002245:Carbon Dioxide; D002628:Chemoreceptor Cells / Q000502:physiology*; D003216:Conditioning, Operant / Q000502:physiology; D008297:Male; D051381:Rats; D012684:Sensory Thresholds / Q000502:physiology; D012903:Smell / Q000502:physiology*; D014276:Trigeminal Nerve / Q000502:physiology
D002245:Carbon Dioxide