A comparative neuroimaging perspective of olfaction and higher-order olfactory processing: on health and disease. (September 2022)

• Record Type: Journal Article
• Authors: Kulason, Sue; Ratnanather, J.Tilak; Miller, Michael I.; Kamath, Vidyulata; Hua, Jun; Yang, Kun; Ma, Minghong; Ishizuka, Koko; Sawa, Akira
• Is Part Of: Seminars in cell & developmental biology. Volume 129(2022)
• Page Start: 22
• Page End: 30
• Publication Date: 2022-09
• Subjects: ACC Anterior cingulate cortex -- AD Alzheimer's disease -- aIns Anterior insula -- AON Anterior olfactory nucleus -- aPir Anterior piriform -- dACC dorsal anterior cingulate cortex -- fMRI Functional magnetic resonance imaging -- Ins Insula -- MCC Midcingulate cortex -- MeA Medial nucleus of the amygdala -- mPFC Medial prefrontal cortex -- MRI Magnetic resonance imaging -- OB Olfactory bulb -- OE Olfactory epithelium -- OFC Orbitofrontal cortex -- OT Olfactory tubercle -- PAC Periamygdaloid complex -- PD Parkinson's disease -- PET Positron emission tomography -- Pir Piriform cortex -- PirF Frontal portion of the piriform cortex -- PirT Temporal portion of the piriform cortex -- pPir Posterior piriform -- SZ Schizophrenia -- TT Tenia tecta; Neuroimaging -- Olfactory bulb -- Primary olfactory cortex -- Medial prefrontal cortex -- Orbitofrontal cortex -- Insula; Cytology -- Periodicals; Developmental biology -- Periodicals; 571.6
• DOI: 10.1016/j.semcdb.2021.08.009
• Languages: English
• ISSNs: 1084-9521

Abstract

Abstract: Olfactory dysfunction is often the earliest indicator of disease in a range of neurological and psychiatric disorders. One tempting working hypothesis is that pathological changes in the peripheral olfactory system where the body is exposed to many adverse environmental stressors may have a causal role for the brain alteration. Whether and how the peripheral pathology spreads to more central brain regions may be effectively studied in rodent models, and there is successful precedence in experimental models for Parkinson's disease. It is of interest to study whether a similar mechanism may underlie the pathology of psychiatric illnesses, such as schizophrenia. However, direct comparison between rodent models and humans includes challenges under light of comparative neuroanatomy and experimental methodologies used in these two distinct species. We believe that neuroimaging modality that has been the main methodology of human brain studies may be a useful viewpoint to address and fill the knowledge gap between rodents and humans in this scientific question. Accordingly, in the present review article, we focus on brain imaging studies associated with olfaction in healthy humans and patients with neurological and psychiatric disorders, and if available those in rodents. We organize this review article at three levels: 1) olfactory bulb (OB) and peripheral structures of the olfactory system, 2) primary olfactory cortical and subcortical regions, and 3) associated higher-order cortical regions. This research area is still underdeveloped, and we acknowledge that further validation with independent cohorts may be needed for many studies presented here, in particular those with human subjects. Nevertheless, whether and how peripheral olfactory disturbance impacts brain function is becoming even a hotter topic in the ongoing COVID-19 pandemic, given the risk of long-term changes of mental status associated with olfactory infection of SARS-CoV-2. Together, in this review article, we introduce this underdeveloped but important research area focusing on its implications in neurological and psychiatric disorders, with several pioneered publications.