FIGURE 3 | Corpus callosum development.

Midline structures support the development of the corpus callosum in the human brain. Panels a–c depict coronal sections of human fetal brains at 17 weeks gestation. Panel a is labelled with an anti-glial fibrillary acidic protein antibody, panel b with an anti-neuropilin 1 (NPN1) antibody and panel c with an anti-nuclear factor 1a (NFIA) antibody. Several midline glial structures are present at the cortical midline, including the glial wedge (GW; a), the indusium griseum glia (IGG; a) and the midline zipper glia (MZG; d,e). Pioneer axons, which form an additional potential guidance mechanism, express the guidance receptor NPN1 (b,d,e) and arise from the cingulate gyrus (b). In addition, the developing human brain contains subcallosal sling neurons, stained here with an antibody to NFIA (c). Developing human and mouse brains differ in two significant ways at the midline. First, in humans, differentiating astrocytes are found across the entire width of the midline (a,d,e). These cells can either be part of the subcallosal sling or an extension of the MZG. Second, a population of NFIA/ neuronal-specific nuclear protein (NeuN)/calretinin positive cells is present above the corpus callosum in humans (c), but not in mice. It is unclear whether these cells are similar to the subcallosal sling neurons or whether they might form neurons in the IGG (e). Scale bars: a and b, 3 mm; c, 400 mm. Panels a and b modified, with permission, from Ref. 9 © (2006) Wiley and Sons.

Download file

If the slide opens in your browser, select "File > Save As" to save it.

• Download Power Point slide (266 KB)