FIGURE 7.

Photomicrographs of the periventricular white matter (PVWM) region adjacent to the caudal ganglionic eminence (CGE; outlined in Figure 2) demonstrating the growth cone proteins (anti-drebrin), synaptic connections (anti-synaptophysin and anti-SNAP-25) and interneuronal proteins (anti-calretinin and anti-parvalbumin). In the control case (A) anti-drebin expression is seen on growth cones as long bipolar extensions. In contrast, the case with ACTG1 variant, heterotopia are identified with neurons expressing dense drebrin protein with blunt and short extensions (B). The immunoreactivity of synaptophysin densely surrounds the outer regions of the neuronal heterotopia (C). Detection of glutamatergic cells inside the neuronal heterotopia is seen with anti-SNAP-25 staining (D,Di). Of interest, the PVWM region surrounding the neuronal heterotopia have SNAP-25 positive axons (Dii). Additionally, rabbit anti-calretinin neurons seen in the neuronal heterotopia (E) however, the neuronal heterotopia were negative for rabbit anti-parvalbumin (F).