OBJECTIVE: Near-infrared spectroscopy (NIRS) is a non-invasive method for investigating activation of the human cortex. The applicability of NIRS to the olfactory cortex was investigated. MATERIAL AND METHODS: The relative oxy- and deoxy-hemoglobin levels of the orbito-frontal cortex during olfactory stimulation in healthy subjects were measured using NIRS. RESULTS: When perfumed strips containing the odorants beta-phenyl ethyl alcohol, iso-valeric acid and gamma-undecalactone were presented, the oxy-hemoglobin level increased but the deoxy-hemoglobin level did not change. The increase in the oxy-hemoglobin level was observed bilaterally. A placebo perfumed strip did not elicit a change in the hemoglobin level. It was also observed that the odorant intensity affected the oxy-hemoglobin level. Although the orbito-frontal cortices seemed to be activated bilaterally during olfaction, the right cortex was activated to a greater extent than the left. CONCLUSION: NIRS appears to be an adequate method for investigating the human olfactory cortex.
OBJECTIVE: Near-infrared spectroscopy (NIRS) is a non-invasive method for investigating activation of the human cortex. The applicability of NIRS to the olfactory cortex was investigated. MATERIAL AND METHODS: The relative oxy- and deoxy-hemoglobin levels of the orbito-frontal cortex during olfactory stimulation in healthy subjects were measured using NIRS. RESULTS: When perfumed strips containing the odorants beta-phenyl ethyl alcohol, iso-valeric acid and gamma-undecalactone were presented, the oxy-hemoglobin level increased but the deoxy-hemoglobin level did not change. The increase in the oxy-hemoglobin level was observed bilaterally. A placebo perfumed strip did not elicit a change in the hemoglobin level. It was also observed that the odorant intensity affected the oxy-hemoglobin level. Although the orbito-frontal cortices seemed to be activated bilaterally during olfaction, the right cortex was activated to a greater extent than the left. CONCLUSION: NIRS appears to be an adequate method for investigating the human olfactory cortex.
Authors: D Val-Laillet; E Aarts; B Weber; M Ferrari; V Quaresima; L E Stoeckel; M Alonso-Alonso; M Audette; C H Malbert; E Stice Journal: Neuroimage Clin Date: 2015-03-24 Impact factor: 4.881