engleski

Prenatal development of human indusium griseum

Aims: This study was performed to analyze growth, formation and differentiation of the indusium griseum (IG), the supracommissural hippocampus, during prenatal human brain development. Methods: We employed immunohistological methods on fixed- paraffin-embedded sections of 24 human fetal brains ranging from the 12th to the 40th postconceptional weeks (PCW). Results: The growth curve of the IG followed the growth of the corpus callosum during its fronto-occipital extension and was most steep between 12th and 24th PCW. The most intensive differentiation processes of IG development were seen between 20th and 28th PCW, as revealed by immunohistochemistry related to synaptic, neuronal, glial and extracellular matrix molecules. The three-layer lamination pattern of the IG in the fetal brains was visible from the 20th PCW onwards, clearly resembling the structural organization of the retrocommissural hippocampus. GFAP-positive cells were visible from the 20th PCW onwards, while fully developed astrocytes could be seen after the 22nd PCW. During this developmental period, neuronal nuclear protein (NeuN) was expressed concomitant with other neuronal markers ; microtubule-associated protein-1b (MAP- 1b), microtubule-associated protein 2 (MAP2), neurofilaments 200kD (NF-200), serotonin transporter (SERT) and the synaptophysin. In the third trimester of gestation, the expression of the molecular markers of differentiation was slightly weaker and the laminar organization of the IG was not clearly discernible anymore. Conclusions: Such a developmental pattern and structural organization of the IG belongs to the earliest corticogenetic processes in the human telencephalon following the development and structural organization of the neighboring retrocommissural hippocampus, which is in correlation with its ontogenetic origin.

Ig

nije evidentirano