title: Neuronal differentiation in the developing human spinal ganglia.
abstract: The spatiotemporal developmental pattern of the neural crest cells differentiation toward the first appearance of the neuronal subtypes was investigated in developing human spinal ganglia (SG) between the fifth and tenth developmental week using immunohistochemistry and immunofluorescence methods. First neurofilament-200- (NF200, likely myelinated mechanoreceptors) and isolectin-B4-positive neurons (likely unmyelinated nociceptors) appeared already in the 5/6th developmental week and their number subsequently increased during the progression of development. Proportion of NF200-positive cells was higher in the ventral parts of the SG than in the dorsal parts, particularly during the 5/6th and 9/10th developmental weeks (Mann-Whitney, P = 0.040 and P = 0.003). NF200 and IB4 colocalized during the whole investigated period. calcitonin gene-related peptide (CGRP; nociceptive responses), vanilloid receptor-1 (VR1; polymodal nociceptors), and calretinin (calcium signaling) cell immunoreactivity first appeared in the sixth week and eighth week, respectively, especially in the dorsal parts of the SG. VR1 and CGRP colocalized with NF00 during the whole investigated period. Our results indicate the high potential of early differentiated neuronal cells, which slightly decreased with the progression of SG differentiation. On the contrary, the number of neuronal subtypes displayed increasing differentiation at later developmental stage. The great diversity of phenotypic expression found in the SG neurons is the result of a wide variety of influences, occurring at different stages of development in a large potential repertory of these neurons. Understanding the pathway of neural differentiation in the human, SG could be important for the studies dealing with the process of regeneration of damaged spinal nerves or during the repair of pathological changes within the affected ganglia. Anat Rec, 299:1060-1072, 2016. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Laboratory for Early Human Development, Department of Anatomy, Histology and Embryology, School of Medicine, University of Split, Split, Croatia.
authors.forename: Katarina
authors.initials: K
authors.lastname: Vukojevic
authors.affiliation: Laboratory for Early Human Development, Department of Anatomy, Histology and Embryology, School of Medicine, University of Split, Split, Croatia.
authors.forename: Natalija
authors.initials: N
authors.lastname: Filipovic
authors.affiliation: Laboratory for Early Human Development, Department of Anatomy, Histology and Embryology, School of Medicine, University of Split, Split, Croatia.|Department of Oncology, University Hospital Mostar, Bosnia and Herzegovina, Mostar, Bosnia and Herzegovina.
authors.forename: Ivana
authors.initials: I
authors.lastname: Tica Sedlar
authors.affiliation: Educational Department, Faculty of Philosophy, University of Split, Split, Croatia.
authors.forename: Ivana
authors.initials: I
authors.lastname: Restovic
authors.affiliation: Department of Biology, Faculty of Science, University of Split, Split, Croatia.
authors.forename: Ivana
authors.initials: I
authors.lastname: Bocina
authors.affiliation: Laboratory for Early Human Development, Department of Anatomy, Histology and Embryology, School of Medicine, University of Split, Split, Croatia.
authors.forename: Irena
authors.initials: I
authors.lastname: Pintaric
authors.affiliation: Laboratory for Early Human Development, Department of Anatomy, Histology and Embryology, School of Medicine, University of Split, Split, Croatia.
authors.forename: Mirna
authors.initials: M
authors.lastname: Saraga-Babic
mesh_terms: D002454:Cell Differentiation; D002478:Cells, Cultured; D005727:Ganglia, Spinal / Q000166:cytology* / Q000378:metabolism; D006801:Humans; D008465:Mechanoreceptors / Q000378:metabolism*; D009474:Neurons / Q000166:cytology* / Q000378:metabolism; D009619:Nociceptors / Q000378:metabolism*
keywords: CGRP; IB4; NF200; VR1; human embryo; spinal ganglia