Hypothesis: The Role of Sterols in Autism Spectrum Disorder

Figure 2

The sonic hedgehog gradient in embryonic neural patterning. SHH-regulated gradient defines neuronal subtypes during embryonic patterning. Sonic hedgehog (SHH) (yellow) is secreted from cells of notochord (Nc) and ventral floor plate to create a ventral-dorsal concentration gradient along the neural tube (Nt). Spatial organization of six progenitor-cell domains is established by the SHH gradient restricting the expression of various protein-marker profiles. The initiation of these markers at successive developmental time periods results in V0–V3 and motor neuron (MN) subtype patterning along the ventral midline in the neural tube.