engleski

Neural crest cell fate in the developing human spinal ganglia

During early human development the neural crest cells separate from the neural tube, undergo epithelial-to-mesenchymal transition and migrate laterally to form the foundation of spinal ganglia (1). Subsequent differentiation of diverse ganglion neuronal cell populations is characterized by morphological and immunohistochemical changes of their pluripotent neural crest cell precursors (2). Material and Methods: We analyze the course of differentiation of specific neuronal populations in histological sections of 10 human spinal ganglia between the 5th-10th developmental week, using immunohistochemical and immunofluorescence methods. Results: At the earliest developmental stages (5th-6th weeks), smaller groups of ganglion cells express neurofilament (NF200) and isolectin-B (IB4)-binding, indicating initial differentiation of mechanoreceptor and nociceptor cell populations. With progression of development their expression and number increase. NF200 positive cells follow ventral to dorsal sequence of appearance within spinal ganglia cell population (p=0, 040 and p=0, 003 respectively), and co-localize with IB4 throughout development. Other nociceptor markers like calcitonin gene- related peptide (CGRP) and vanilloid-receptor-1 (VR1), as well as calretinin marker (calcium signaling) first appear in the 6th week, predominantly in the dorsal parts of ganglia. Conclusion: Our results indicate the high potential of early neuronal differentiation from precursor neural crest cells into mechanoreceptors and nociceptors, and the great diversity of phenotypic expressions of neuronal subtypes at later developmental stages. Understanding the pathway of neural differentiation in the early human spinal ganglia could be important for the studies dealing with process of regeneration of damaged spinal nerves or during repair of pathological changes within affected ganglia.

human embryo; spinal ganglia; IB4; NF200; CGRP; VR1; calretinin

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