Teneurin trans-axonal signaling prunes topographically missorted axons.

Area of Science:

• Neuroscience
• Developmental Biology
• Cell Biology

Background:

• Precise neural circuit formation requires eliminating aberrant axonal projections during development.
• The mechanisms initiating and controlling axonal pruning in vivo are not fully understood.

Purpose of the Study:

• To elucidate the molecular mechanisms underlying axonal pruning of misrouted retinal axons in the visual system.
• To identify the cell surface molecules involved in trans-axonal signaling for topographic tract organization.

Main Methods:

• Retinotopic neuron transplantation experiments in vivo.
• Analysis of cell surface molecule expression patterns (Glypican-3, Teneurin-3, Latrophilin-3).
• Investigating signaling pathways involved in axonal guidance and pruning.

Main Results:

• Glypican-3 and Teneurin-3, expressed by ventral retinal ganglion cells, cooperate to prune misrouted dorsal axons.
• Latrophilin-3, an adhesion G-protein-coupled receptor, signals along dorsal axons to initiate the elimination of topographic errors.
• Pioneer ventral axons instruct the pruning of missorted dorsal axons through trans-axonal signaling.

Conclusions:

• Glypican-3, Teneurin-3, and Latrophilin-3 are essential for organizing topographic tracts in the visual system.
• Axonal pruning can be initiated by signaling interactions between axons themselves.
• This study reveals a novel mechanism for correcting developmental wiring errors in the nervous system.