How do the Notch and Delta molecules regulate cell differentiation in the developing nervous system?

In the developing central nervous system, the Notch and Delta molecules regulate cell differentiation through a process known as lateral inhibition.1

This mechanism functions as follows:

• Interaction: Cells in the neuroepithelium express a surface receptor called Notch and a signaling molecule called Delta. Delta on one cell binds to and activates Notch on adjacent cells.1
• Signal Cascade: When Notch is activated, it triggers intracellular events that suppress the production of Delta and inhibit neuronal differentiation within that specific cell.1
• Differentiation Outcome: This feedback loop amplifies minor initial differences in Delta expression among neighboring cells.1
  • Cells with high Delta production and low Notch activation differentiate into neurons.1
  • Cells with low Delta production and high Notch activation remain as precursor cells or differentiate into glial (supporting) cells.1

By repressing similar differentiation in neighbors, this system ensures that the tissue generates a balanced distribution of specialized cell types.1