Signals from the caudal diencephalon are required for the projection of the Interstitial Nuclei of Cajal.

Autor: Solís-S JC; Department of Biomedical Research, School of Medicine, Autonomous University of Queretaro, Qro., Mexico., García-Solís P; Department of Biomedical Research, School of Medicine, Autonomous University of Queretaro, Qro., Mexico., Hernández-Chan NG; Department of Biomedical Research, School of Medicine, Autonomous University of Queretaro, Qro., Mexico., Zamorano-Martínez DA; Department of Biomedical Research, School of Medicine, Autonomous University of Queretaro, Qro., Mexico., Villagrán-Herrera ME; Department of Biomedical Research, School of Medicine, Autonomous University of Queretaro, Qro., Mexico., Hernández-Puga G; Department of Biomedical Research, School of Medicine, Autonomous University of Queretaro, Qro., Mexico., Vergara-Castañeda HA; Department of Biomedical Research, School of Medicine, Autonomous University of Queretaro, Qro., Mexico., Sánchez-Tusie AA; Department of Biomedical Research, School of Medicine, Autonomous University of Queretaro, Qro., Mexico., Varela-Echavarría A; Institute of Neurobiology, National Autonomous University of Mexico, Qro., Mexico., Hernández-Montiel HL; Department of Biomedical Research, School of Medicine, Autonomous University of Queretaro, Qro., Mexico. Electronic address: hebert@uaq.mx.
Jazyk: angličtina
Zdroj: International journal of developmental neuroscience : the official journal of the International Society for Developmental Neuroscience [Int J Dev Neurosci] 2018 Oct; Vol. 69, pp. 10-16. Date of Electronic Publication: 2018 Jun 13.
DOI: 10.1016/j.ijdevneu.2018.06.002
Abstrakt: Axonal projection is controlled by discrete regions localized at the neuroepithelium, guiding the neurite growth during embryonic development. These regions exert their effect through the expression of a family of chemotropic molecules, which actively participate in the formation of neuronal connections of the central nervous system in vertebrates. Previous studies describe prosomere 1 (P1) as a possible organizer of axonal growth of the rostral rhombencephalon, contributing to the caudal projection of reticulospinal rhombencephalic neurons. This work studies the contribution of chemotropic signals from P1 or pretectal medial longitudinal fascicle (MLF) neurons upon the caudal projection of the interstitial nuclei of Cajal (INC). By using in ovo surgeries, retrograde axonal labeling, and immunohistochemical techniques, we were able to determine that the absence of P1 generates a failure in the INC caudal projection, while drastically diminishing the reticulospinal rhombencephalic neurons projections. The lack of INC projection significantly decreases the number of reticulospinal neurons projecting to the MLF. We found a 48.6% decrease in the projections to the MLF from the rostral and bulbar areas. Similarly, the observed decrease at prosomere 2 was 51.5%, with 61.8% and 32.4% for prosomeres 3 and 4, respectively; thus, constituting the most affected rostral regions. These results suggest the following possibilities: i, that the axons of the reticulospinal neurons employ the INC projection as a scaffold, fasciculating with this pioneer projection; and ii, that the P1 region, including pretectal MLF neurons, exerts a chemotropic effect upon the INC caudal projection. Nonetheless the identification of these chemotropic signals is still a pending task.
(Copyright © 2018 ISDN. Published by Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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