5HTR3A-driven GFP labels immature olfactory sensory neurons

Area of Science:

• Neuroscience
• Cell Biology
• Developmental Biology

Background:

• The ionotropic serotonin receptor, 5-HT3, is present in developing central nervous system neurons.
• The adult olfactory epithelium continuously generates new olfactory sensory neurons (OSNs).

Purpose of the Study:

• To investigate the expression of the 5-HT3 receptor in the adult olfactory epithelium.
• To utilize a transgenic mouse model to track 5-HT3a subunit expression and its role in neurogenesis.

Main Methods:

• Employing a transgenic mouse model where 5-HT3a subunit promoter drives green fluorescent protein (GFP) expression.
• Assessing co-localization of native 5-HT3a mRNA and GFP in adult mouse olfactory and vomeronasal epithelium.
• Analyzing cellular markers of differentiation in GFP-labeled cells.

Main Results:

• Both 5-HT3a mRNA and GFP were detected in globose basal cells of the adult olfactory and vomeronasal epithelium.
• GFP labeling persisted for approximately 5 days post-division, marking immature OSNs.
• Immature OSNs displayed differentiation markers (GAP43, PGP9.5) and some showed signs of further maturation (cilia, NaV1.5 expression).

Conclusions:

• 5-HT3a expression indicates a proliferative or developmental state in olfactory epithelium, irrespective of age.
• The 5-HT3A GFP mouse model is a valuable tool for studying adult olfactory neurogenesis.