Fig. 4: Gestational HTX impairs embryonic cortical development and increases microglial pool
Embryonic brains from EUT (gestated in euthyroidism), HTX (offspring gestated under hypothyroxinemia), and HTX + T4 (offspring gestated undeer MMI+T4 treatment)dams euthanized at E14 were fixed, cryosectioned, and analyzed by immunofluorescence to evaluate neuronal progenitor cells (NPCs) and microglia. (a) Representative images of Pax6⁺ radial glial cells in embryonic cortices from each maternal condition. (b) Quantification of Pax6⁺ cells. (c) Representative images of Tbr2⁺ intermediate progenitor cells in embryonic cortices. (d) Quantification of Tbr2⁺ cells. (e) Representative images of Tbr1⁺ deep-layer neurons. (f) Quantification of Tbr1⁺ neurons. (g) Representative images of Iba1⁺ microglia. (h) Quantification of Iba1⁺ cells. Pax6⁺, Tbr2⁺, and Tbr1⁺ cells were quantified within a rectangular region (200 μm wide x 400 μm long) extending from the ventricular zone to the meninges. Iba1⁺ cells were quantified within a defined area along the cortical wall. For each fetal brain, quantification was performed on three consecutive coronal sections, and the average value was used per animal. Images were acquired at 20x magnification. Scale bar: 200 μm. n = 6–7 per group. CP: cortical plate; VZ: ventricular zone. Data are presented as means ± SEM. Statistical significance was determined using one-way ANOVA followed by Tukey’s post hoc test or Kruskal–Wallis with Dunn’s post hoc test, depending on normality. Mann–Whitney U test was also applied where appropriate. *p ≤ 0.05, **p ≤ 0.01. EUT: white box; HTX: red box; HTX + T4: green box.
