Periventricular nodular heterotopia results from neurons failing to migrate from which region?

Periventricular nodular heterotopia results from neurons failing to migrate from which region?

• A. Ventricular zone
• B. Subventricular zone
• C. Cortical plate
• D. Midline germinal zone

Answer: (A)

Neurons destined to form the cortex originate in the ventricular zone, the lining of the neural ventricles. From there, they migrate outward along radial glia to reach the cortical plate. In periventricular nodular heterotopia, the problem is a failure of these neurons to exit the ventricular zone and continue their journey to the cortex, so they remain as nodules clustered near the ventricles. The subventricular zone is part of the migratory pathway, but the source of the migrating neurons is the ventricular zone, not a different region. The cortical plate is the destination, not the origin, and the midline germinal zone isn’t the typical site implicated here.

Neurons destined to form the cortex originate in the ventricular zone, the lining of the neural ventricles. From there, they migrate outward along radial glia to reach the cortical plate. In periventricular nodular heterotopia, the problem is a failure of these neurons to exit the ventricular zone and continue their journey to the cortex, so they remain as nodules clustered near the ventricles. The subventricular zone is part of the migratory pathway, but the source of the migrating neurons is the ventricular zone, not a different region. The cortical plate is the destination, not the origin, and the midline germinal zone isn’t the typical site implicated here.