Rewiring the taste system.

Area of Science:

• Neuroscience
• Sensory Biology
• Molecular Biology

Background:

• Mammalian taste buds contain 50-100 taste receptor cells (TRCs) representing five basic tastes.
• Mature TRCs have short lifespans (5-20 days) and are replenished by stem cells.
• Maintaining precise connections between TRCs and neurons is crucial for taste signal fidelity.

Purpose of the Study:

• To investigate the mechanisms ensuring accurate wiring of taste receptor cells to their corresponding neurons.
• To understand how signal transmission integrity is maintained despite rapid cell turnover.

Main Methods:

• Examined instructive signals provided by bitter and sweet TRCs to target neurons.
• Utilized guidance molecules SEMA3A and SEMA7A.
• Engineered mice with targeted expression of guidance molecules in specific TRC classes.

Main Results:

• Bitter and sweet TRCs use distinct guidance molecules (SEMA3A and SEMA7A) to instruct target neurons.
• Targeted expression of SEMA3A or SEMA7A resulted in miswired sweet and bitter cells.
• Engineered mice exhibited altered neuronal responses to sweet, bitter, and sour stimuli.

Conclusions:

• Uncovered the peripheral wiring logic of the mammalian taste system.
• Demonstrated how guidance molecules ensure labelled-line sensory circuit integrity.
• Highlighted the role of molecular cues in maintaining sensory pathway fidelity during cell turnover.