account for the potential challenges that the
histological data may present. For example,
pathological conditions accompanied by microg-
lial response may also be accompanied by an
alternation to the spatial distribution of glial
cells ( 40 ). Development, especially at prenatal
stages, poses an additional challenge for Nissl-
ST: On one hand, Nissl-ST provides a potentialmeans to study the initial development of
myelin, as some studies in rats found that at
birth, oligodendroglial progenitor cells were
already assembled in short rows resembling766 5 NOVEMBER 2021¥VOL 374 ISSUE 6568 science.orgSCIENCE
Fig. 4. Applicability of Nissl-based structure tensor across datasets.(A) In-plane orientation maps in coronal slices of four independent datasets, demonstrating
the applicability of Nissl-ST to existing histological datasets of humans and nonhuman primates (rhesus macaque and vervet monkey), establishing the existence
of the whole-brain glial framework across species. (B) Magnified view of tile from EdingerÕs comb in each specimen [white arrowheads in (A)]. The characteristic
axonal crossing in this region is preserved across species.
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