87 - Changes in White Matter of the Human Brain During Fetal Development: A Descriptive Analysis of Coronal and Sagittal Sections with Prussian Blue Staining

Poster Board Number: 87
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Co-authors:

Roberto Rueda-Esteban - Assistant Professor, Anatomy Coordinator, Universidad de los Andes School of Medicine; Juan Sebastián Lopez-McCormick - Clinical Professor of Anatomy, Universidad de los Andes School of Medicine

Abstract Body : Introduction and Objective:


There is scarce literature regarding the preservation and staining of foetal brains, mostly due to the inherent challenges related to its fragility due to its high-water content, hypomyelination, and underdeveloped reticulin structure. To address this dearth of visual resources and enhance comprehension, this study aims to create anatomical specimens of foetal encephalic tissue stained by Prussian Blue method to describe changes in the human brain's white matter during foetal development in coronal and sagittal sections.

Materials and Methods:

After IRB approval was acquired. Coronal and sagittal sections were prepared from the brain of a 39-week-old foetus, followed by Prussian Blue staining according to the modified protocol described by Villegas et al. The myelination of the central nervous system in the embryonic stage was assessed through a descriptive study of grey and white matter distribution in foetal brains treated with Prussian Blue stain.



Results:


Prussian Blue staining revealed a subtle contrast between the thalamus and the posterior limb of the internal capsule, the head of the caudate, the medial segment of the globus pallidus, and the subventricular cortical neuroepithelium, which does not correspond entirely with structures reported in the literature for this stage of foetal development.



Conclusion:


The observed pattern was most likely not attributable to staining artifacts as the protocol was successful in staining grey matter without white matter artifacts. The structures showing subtle contrast in the first brain studied do not correspond to the regions that should exhibit myelination according to the literature. After verifying the integrity of the staining protocol, three possible explanations were considered: the existence of white matter regions different from those previously described, the presence of a compound hindering proper staining, or the absence of specific ferric deposits in certain developmental stages. Additional staining must be conducted to validate or refute these hypotheses. More research in this area is necessary.

Significance:

The proposed research provides a visual resource for facilitating the identification of early traces of white matter, especially for students in neuroanatomy and embryology courses. This resource will enable students to visualize the normal development of white matter in the CNS and facilitate the recognition of embryonic developmental pathologies associated with myelination, such as periventricular leukomalacia.

Funding/Resources:
Anatomy Laboratory, Universidad de los Andes School of Medicine.