| Abstract: | Odor and trigeminal pain thresholds were studied four timeseach at 24:00, 04:00, 08:00, 12:00, 16:00 and 20:00 h in randomizedorder on different days in five healthy male volunteers. Nocircadian rhythm of olfactory or trigeminal thresholds wereobserved. However, the variability of odor, but not pain thresholds,increased from 04:00 h (thresholds between 0.4 and 1.2 p.p.m.)to 16:00 h (thresholds between 0.1 and 2 p.p.m.). It is hypothesizedthat environmental influences contribute to this increase invariance. Chem. Senses 22: 593–598, 1997. |
