Relationship between olfactory function and olfactory neuronal population in C57BL6 mice injected intraperitoneally...

Area of Science:

• Neuroscience
• Sensory Biology
• Toxicology

Background:

• Olfactory receptor neuron (ORN) integrity is crucial for olfaction.
• 3-methylindole is a known neurotoxin that can induce olfactory dysfunction.
• Quantifying the relationship between olfactory test outcomes and neuronal populations is essential for understanding olfactory impairment.

Purpose of the Study:

• To investigate the correlation between a simple olfactory test and the olfactory neuronal population in mice exposed to 3-methylindole.
• To determine the minimum number of intact olfactory neurons required to maintain olfaction.

Main Methods:

• A mouse model (C57BL6) was used, with olfactory dysfunction induced by 3-methylindole injection.
• Olfactory function was assessed using a food-finding test after 72-hour starvation.
• Olfactory neuronal population was quantified by measuring olfactory marker protein (OMP) expression in the olfactory neuroepithelium and olfactory bulb.

Main Results:

• Food-finding time significantly increased with higher doses of 3-methylindole.
• A significant decrease in OMP expression was observed in the olfactory neuroepithelium and olfactory bulb at higher 3-methylindole doses.
• Food-finding time showed a significant inverse correlation with OMP density in both the olfactory bulb and neuroepithelium.

Conclusions:

• Olfactory impairment in mice treated with 3-methylindole is directly correlated with the olfactory neuronal population.
• The food-finding test is a practical and easily administered tool for evaluating olfactory dysfunction in this mouse model.