Amplification of olfactory transduction currents implements sparse stimulus encoding.

Area of Science:

• Neuroscience
• Olfactory System Research
• Sensory Biology

Background:

• Sensory systems balance sensitivity to weak stimuli with information processing in complex environments.
• Olfactory sensory neurons (OSNs) exhibit high sensitivity to low odor concentrations and discriminability in complex odor landscapes.
• The mechanisms by which OSNs maintain both sensitivity and sparsity remain unclear.

Purpose of the Study:

• To investigate the role of the calcium-activated chloride channel TMEM16B in supporting dual roles of sensitivity and sparsity in OSNs.
• To determine if TMEM16B influences sensory representations and olfactory-guided behaviors.

Main Methods:

• Utilized multiphoton microscopy to image stimulus-response density of OSNs in the olfactory epithelium.
• Compared OSN responses in wild-type and TMEM16B knockout mice.
• Assessed behavioral responses to odorants, including trimethylamine, and olfactory-guided navigation efficiency.

Main Results:

• TMEM16B knockout mice exhibited denser sensory representations and increased OSN response magnitudes.
• Behaviorally, knockout mice showed increased aversion to trimethylamine, an odorant with concentration-dependent valence switching.
• Olfactory-guided navigation efficiency was decreased in TMEM16B knockout mice.

Conclusions:

• The calcium-activated chloride channel TMEM16B plays a critical role in sparsening sensory representations within the peripheral olfactory system.
• TMEM16B contributes to the efficient integration of olfactory information for complex behaviors.
• Targeting TMEM16B function may offer insights into olfactory processing disorders.