A 30-year-old textbook assumption about how the brain selects its first neurons has been debunked.
April 1, 2026
Original Paper
Positional cues, not Notch, direct Neuroblast selection during early neurogenesis in the Drosophila embryo
bioRxiv · 10.64898/2026.03.30.715196
The Takeaway
It was long believed that 'Notch signaling' acted like a lottery to pick which cells become neurons. This study reveals that cells are actually pre-destined by their physical coordinates in the embryo, and the Notch pathway only arrives later to stabilize a decision that was already made.
From the abstract
Notch-mediated lateral inhibition is a conserved patterning process that controls alternative cell fate decisions and produces regular cell fate patterns. Prevailing models posit that lateral inhibition singles-out cells from fields of initially equipotent cells by amplifying stochastic fluctuations of Notch or pre-existing fate biases. Here, we revisited the role of Notch in early Drosophila neurogenesis, studying the dynamics of Neuroblast specification by live imaging the transcription of two