Figure 5.

Cortical impact does not reduce the number of neuroblasts in the claustrum. We observed large chains of neuroblasts traveling from the SVZ through the external capsule and entering the claustrum in sham piglets. We compared the density of neuroblasts in the external capsule and claustrum in piglets injured or receiving sham surgery at PND 7 and brains collected at PND 14. (A) Neuroblasts were quantified in the white matter (yellow) ventral to the SVZ and in the white matter adjacent to the claustrum (Cl, blue). (B) The maximum density of neuroblasts in the external capsule and claustrum in injured piglets were not different from sham piglets. In injured piglets, the density of neuroblasts in the claustrum was nearly three-fold greater than in the injured gray matter of the rostral gyrus indicating that postnatal population of this region is still prioritized after TBI in the gyrencephalic brain. (C) When piglets were binned according to lesion type, the neuroblast density was greater in the external capsule in piglets with “cavity⁺ lesions” than shams or “cavity⁻ lesions” (^{a, b}Means ± SEM with different letters differ, P < 0.05). (D) Low power view of the SVZ, ventral white matter, external capsule, and claustrum (Cl, indicated with broken line) with neuroblasts detected with DCX (green) with the red star corresponding to the sulci marked with a red star in (A). (D1) In the dorsal claustrum, long and thick chains of neuroblasts are observed in a migratory morphology. (D2,D3) In the ventral claustrum, neuroblasts are extremely dense with individual neuroblasts and various sizes of clusters. (D4) A large cluster of neuroblasts approximately 1000 μm in length appears to migrate through the external capsule. Scale bars: (A) = 1 cm; (D) = 200 μm; (D4) = 100 μm; (D1–D3) = 20 μm.