Figure 1.

Overview of the major events in murine SVZ development and the role of thyroid hormones therein.

While the SVZ-NSCs are generated during embryonic development, they postnatally reactivate under the influence of genes and extracellular factors. We found that when postnatal TH serum levels peak, intracellular TH action in NSCs increases, coinciding with the onset of SVZ-neurogenesis. Consequently, this window represents a phase when SVZ-NSCs are particularly sensitive to exposure to endocrine disruptors. Indeed, developmental exposure to the TH-synthesis blocker PTU dysregulated TH-target genes, and permanently disrupted the neuron/oligodendroglia output in the SVZ. As a consequence, young adult mice developmentally exposed but fed a normal diet thereafter, underperformed on olfactory behavior tests that normally depend on proper SVZ-neurogenesis. Scale bar: 50 µm. E: Embryonic day; EDC: endocrine disrupting chemical; NSC: neural stem cell; P: postnatal day; PTU: propylthiouracil; SVZ: subventricular zone; TH: thyroid hormone. Data source: Vancamp et al. (2022) combined with unpublished figures from the authors.