Cerebral oxygenated hemoglobin changes during olfactory stimulations using near-infrared spectroscopy

• Published in: OTOLOGIA FUKUOKA Vol. 52; no. 4; pp. 229 - 236
• Main Authors: RIKIMARU, Fumihide, KATO, Toshihiko, HARADA, Hirofumi, TANAKA, Masahiro
• Format: Journal Article
• Language: Japanese
• Published: JIBI TO RINSHO KAI 20.07.2006
• Subjects: 嗅覚検査; 脳内酸化ヘモグロビン濃度; 近赤外線分光法
• ISSN: 0447-7227; 2185-1034
• DOI: 10.11334/jibi1954.52.4_229

In the present study, the purpose was to investigate whether it is feasible to evaluate the cerebral activity to olfactory sensation by measuring the relevant changes in the concentration of cerebral oxygenated hemoglobin during exposure to various types of smell stimuli in adult subjects, using nearinfrared spectroscopy. Regarding the near-infrared oxygen monitor unit, the NIRO-300 (Hammamatsu Photonics K. K., Japan) device was employed. The study subjects consisted of a total of 13 adults with normal olfaction, and as smell stimuli, vanilla essence, strawberry essence, and E5 of the T & T Olfactometer were used. A statistical evaluation was carried out using the t-test, with a p value of p<0.05 considered to indicate a statistically significant difference. In all of the odorant sources, the concentration of oxyhemoglobin showed a transient decrease after the initiation of the olfactory stimulation and thereafter exhibited an increase. Smell stimulus-evoked fluctuations in the concentration of oxyhemoglobin were though to reflect the cerebral activity of the orbital gyri of the frontal lobe that is said to be implicated in olfactory perception.