Modulation of cerebral haemodynamic response to olfactory stimuli by emotional valence detected by functional magnetic resonance imaging.

Autor:	Caous CA; Instituto do Cérebro, Instituto Israelita de Ensino e Pesquisa Albert Einstein, São Paulo SP, Brazil., Tobo PR; Natura Inovação Tecnologia Produto Ltda, Cajamar SP, Brazil., Talarico VH; Natura Inovação Tecnologia Produto Ltda, Cajamar SP, Brazil., Gonçales LRL; Natura Inovação Tecnologia Produto Ltda, Cajamar SP, Brazil., Yoshimine E; Natura Inovação Tecnologia Produto Ltda, Cajamar SP, Brazil., da Cruz AC Jr; NIF/LIM44, Department of Radiology, Hospital das Clínicas, University of São Paulo SP, Brazil., Albuquerque C; Natura Inovação Tecnologia Produto Ltda, Cajamar SP, Brazil., Amaro E Jr; Instituto do Cérebro, Instituto Israelita de Ensino e Pesquisa Albert Einstein, São Paulo SP, Brazil.; NIF/LIM44, Department of Radiology, Hospital das Clínicas, University of São Paulo SP, Brazil.
Jazyk:	angličtina
Zdroj:	Dementia & neuropsychologia [Dement Neuropsychol] 2015 Oct-Dec; Vol. 9 (4), pp. 405-412.
DOI:	10.1590/1980-57642015DN94000405
Abstrakt:	Olfactory perception, although restricted to just a few contexts in everyday life, is key in medicine. Several dementia conditions have been associated with early loss of olfactory discrimination. Despite the fact that several brain areas have been associated with olfaction in functional magnetic resonance imaging (fMRI), the mechanisms by which emotional valence is conveyed to the brain are not fully understood. Methods: In this study, we compared cerebral activations by olfactory stimuli using different emotional valence stimuli on event-related fMRI. We used three standard olfactory odorants with different valence (positive, neutral and negative). Forty-three healthy subjects (22 males) were scanned on a 3.0T MR system. Olfactory stimulation was attained through a delivery system synchronized with image acquisition and subjects´ breathing instructions. fMRI data analysis was performed by the FSL package (Oxford University) including head movement correction, GLM modeling of the neurovascular (BOLD) response and group activation maps produced at p<0.05and corrected for multiple comparison. Results: Increased cerebral responses within the anterior cingulate, amygdaloid nuclei, as well as the dorsolateral prefrontal, occipital and orbitofrontal cortices were observed in positive and negative valence conditions, while response to neutral valence arousal was less intense and not observed in the amygdaloid complex. The most significant statistical response aroused from the stimuli clusters was observed in the negative condition. Conclusion: The results of the present study support the hypothesis that neutral stimuli may be more sensitive to early losses in pathological conditions, particularly dementia. Competing Interests: Disclosure: Patricia Renovato Tobo, Vania Hercilia Talarico, Luciana Ribeiro Lopes Gonçales, Elise Youshimine and Cristovão Albuquerque were working for Natura Inovação Tecnologia Produto Ltda. during the execution of this study.
Databáze:	MEDLINE
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