ZIKV impairs NSCs proliferation, differentiation, and leads to cell death and small brain cortices during neocortex development. ZIKV (500 PFU) and mock infection were conducted via in utero at E13.5. (A) Sox2 staining and thickness calculation (B, n = 3 per group) of brain sections at E15.5. (C) EdU-labelled NSCs and thickness calculation (D, n = 3 per group) at E15.5. (E) Immature neuron marker Tbr1 staining and thickness calculation (F, n = 5–6 per group) at E17.5. (G) NeuN staining of brain section at E17.5 and thickness calculation of NeuN staining (H), the entire cortex (I), and different layers of the cortex (J, n = 5–6 per group). (K) TUNEL staining and quantification (L, n = 5–6 per group, >500 cells were counted) in brain sections at E17.5. **P < 0.01, ***P < 0.001, calculated by Student’s t-test. NS, not significant. Graphs indicate mean ± SD. Scale bar: A, C, E, G, and K, left panel, 200 µm; enlarged images in the right panel, 20 µm.