Figure 7

The NSC lattice model reproduces the spatiotemporal correlations of NSC fate decisions and shows their impact on long-term neuronal distribution

(A) Top: MC positions at any time t in the lattice model are compared using point pattern statistics with MC positions at t+Δt. Bottom left: Besag’s L functions assessing the spatial interaction of MCs relative to one another at all Δt intervals in 1 representative simulation with aNP-driven LI. L_(simul)(r) (red lines): simulated values; L_(H0,mean)(r) (black dotted lines): means under the random labeling null hypothesis; r: mean NSC cell diameter (distance measured from cell’s center); gray regions: 1-sided 95% confidence envelopes. Bottom right: combined p values (Fisher’s method) of Besag’s L functions for a model with (left) versus without (right) LI (18 simulations each). A significant p = 0.009 is obtained with Δt4. Cutoff for pooled p = 0.01.

(B) Compared L functions (lines) and their 95% confidence intervals (shaded) testing for dispersion between MCs at Δt4 in a model with (pink) and without (blue) LI (18 simulations each). Cutoff for pooled p = 0.01 (see also Figures S6 and S7).

(C) Compared spatial interaction between output neurons in a model with (pink) and without (blue) LI, using a 3D Ripley’s K function on 18 simulations in each model, analyzed during 365 time steps (shaded area: confidence intervals). The positions were evaluated in microns by comparing between the simulated and experimental cell’s mean diameter (lattice plane) and using a neuron’s layer generation rate 30 μm/2 months (time axis) (Than-Trong et al., 2020).

(D) Similar comparison (to C) in 2D, using the L function. At each time step, the neurons are projected on a 2D plane parallel to the lattice surface and accumulated from 365 time steps.

(B)–(D) show centered summary functions, K₃(r) − (4/3)πr³ and L(r) − r, rather than raw functions, to highlight differences. p < 0.001: Studentized permutation tests comparing the values of the K and L functions. Cutoff for p values in (C) and (D) = 0.01.