Frizzled3 Controls Axonal Polarity and Intermediate Target Entry during Striatal Pathway Development

Area of Science:

• Neuroscience
• Developmental Biology
• Molecular Biology

Background:

• The striatum is crucial for movement and emotion.
• Medium spiny neurons (MSNs) form key output pathways.
• Striatal axon development is poorly understood.

Purpose of the Study:

• Investigate Frizzled3's role in MSN axon pathway formation.
• Identify molecular mechanisms of anterior-posterior axon guidance.
• Determine Frizzled3's function in axon entry into the globus pallidus.

Main Methods:

• Utilized Frizzled3 and Wnt5a knockout mouse models.
• Performed in vitro axon guidance assays.
• Examined embryonic striatal pathway development.

Main Results:

• Frizzled3 knockout mice show defects in MSN axon anterior-posterior guidance and globus pallidus entry.
• Wnt5a acts as an attractant and shows an anterior-posterior gradient.
• Wnt5a knockout mice phenocopy Frizzled3 mutant axon guidance defects.
• Frizzled3 is required non-cell-autonomously for MSN axon entry into the globus pallidus.
• Frizzled3 influences corridor guidepost cell development.

Conclusions:

• Frizzled3 and Wnt5a are critical for striatal axon guidance.
• Frizzled3 has both cell-autonomous and non-cell-autonomous roles in pathway formation.
• Frizzled3 is linked to guidepost cell development, impacting multiple axon tracts.