Decreasing auditory input induces neurogenesis impairment in the hippocampus.
Sci Rep
; 11(1): 423, 2021 01 11.
Article
in En
| MEDLINE
| ID: mdl-33432038
ABSTRACT
Hearing loss is associated with cognitive decline and dementia risk. Sensorineural hearing loss suppresses hippocampal neurogenesis, resulting in cognitive decline. However, the underlying mechanism of impaired neurogenesis and the role of microglial activation and stress responses related to hearing loss in the hippocampus remains unknown. Using a conductive hearing loss (CHL) model, we investigated whether a decrease in sound level could induce impairment of hippocampal neurogenesis and examined the differences between unilateral CHL (uCHL) and bilateral CHL (bCHL). To establish the CHL mouse model, ears were unilaterally or bilaterally occluded for five weeks by auditory canal ligation. Although hearing thresholds were significantly increased following CHL, CHL mice exhibited no significant loss of spiral ganglion or hippocampal neurons. Hippocampal neurogenesis was significantly and equally decreased in both sides following uCHL. More severe decreases in hippocampal neurogenesis were observed in both sides in bCHL mice compared with that in uCHL mice. Furthermore, microglial invasion significantly increased following CHL. Serum cortisol levels, which indicate stress response, significantly increased following bCHL. Therefore, auditory deprivation could lead to increased microglial invasion and stress responses and might be a risk factor for hippocampal neurogenesis impairment.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Neurogenesis
/
Hearing Loss, Conductive
/
Hippocampus
Type of study:
Prognostic_studies
/
Risk_factors_studies
Limits:
Animals
Language:
En
Journal:
Sci Rep
Year:
2021
Document type:
Article
Affiliation country: