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Dysmyelinogenesis in caprine β‐mannosidosis: Ultrastructural and morphometric studies in fetal optic nerve
Author(s) -
Lovell Kathryn L.,
Boyer Philip J.
Publication year - 1987
Publication title -
international journal of developmental neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.761
H-Index - 88
eISSN - 1873-474X
pISSN - 0736-5748
DOI - 10.1016/0736-5748(87)90035-9
Subject(s) - fetus , myelin , oligodendrocyte , myelinogenesis , ultrastructure , optic nerve , biology , pathology , anatomy , prenatal development , central nervous system , neuroscience , medicine , pregnancy , genetics
The optic nerves from a goat fetus affected with β‐mannosidosis and a control fetus were analysed morphologically in order to investigate developmental aspects of β‐mannosidosis‐associated myelin deficits. In the affected fetus, the number of myelinated axons per unit area was about 25% of the control values. Histograms of axonal diameter indicated that a greater percentage of the myelinated and unmyelinated axons were of larger caliber in the affected fetus than in the control fetus and that very few small axons were myelinated in the affected animal. The mean values of myelin sheath thickness in the affected and control animals did not differ significantly. Ultrastructural analysis revealed a decreased proportion of oligodendrocytes and an increased proportion of astrocytes in the affected fetus. These results indicate that the pathogenetic process leading to cellular abnormalities and myelin deficits in β‐mannosidosis has been initiated prior to 124 days gestation, during an early stage of myelination in the goat optic nerve. The decrease in number of oligodendrocytes suggests that early cell death and/or change in oligodendrocyte proliferation contribute to the myelin deficit. Analysis of the prenatal development of lesions will help clarify the pathogenesis of dysmyelinogenesis in β‐mannosidosis.