Open AccessChronic anosmia induces depressive behavior and reduced anxiety via dysregulation of glucocorticoid receptor and corticotropin-releasing hormone in a mouse model
Author(s) -
Sang Ho Ahn,
HyunWoo Shin,
Usman Mahmood,
Roza Khalmuratova,
SeaYuong Jeon,
Hong Jin,
Jung-Seok Choi,
HyeSun Kim,
Dae Woo Kim
Publication year - 2016
Publication title -
rhinology (amsterdam. online)/rhinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.275
H-Index - 57
eISSN - 1996-8604
pISSN - 0300-0729
DOI - 10.4193/rhino15.209
Subject(s) - anosmia , glucocorticoid receptor , endocrinology , behavioural despair test , medicine , elevated plus maze , open field , olfactory epithelium , olfaction , anxiety , mineralocorticoid receptor , olfactory system , olfactory mucosa , glucocorticoid , hippocampus , receptor , psychology , neuroscience , psychiatry , antidepressant , disease , covid-19 , infectious disease (medical specialty)
Background: Olfactory loss is highly prevalent, and comorbid mood disorders are common. Considering olfactory input is highly interconnected with the limbic system, and that the limbic system manages mood, it is predictable that impairments in the sense of smell may result in mood changes. Methodology: Chronic olfactory deficits were induced by repeated intranasal irrigation of ZnSO4 for 12 weeks in BALB/c mice. H&E staining, OMP staining, and potato chip finding test were performed to confirm olfactory loss. Tail suspension, forced swim, and splash tests were performed to evaluate depression, as well as open field, elevated plus maze tests were applied to assess anxiety. The mRNA levels of glucocorticoid receptor (GR) and corticotropin releasing hormone (CRH) were measured by real-time PCR to confirm relevant molecular changes. Results: Disruption of the olfactory epithelium and olfactory loss was confirmed in histological studies and potato chip finding test. Behavioral tests show that the chronic anosmic state caused increased depression and reduced anxiety. PCR data showed that mRNA levels of GR in the hypothalamus and CRH in the amygdala were significantly decreased. Conclusions: These results propose that ZnSO4-induced chronic anosmia can cause a depressive and anxiolytic state via decreased hypothalamic GR and amygdalar CRH.