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Terminal degeneration and glial reactions in the lateral geniculate nucleus of the squirrel monkey after eye removal
Author(s) -
WongRiley Margaret T. T.
Publication year - 1972
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.901440104
Subject(s) - enucleation , biology , gliosis , squirrel monkey , phagocytosis , neuroglia , degeneration (medical) , astrocyte , anatomy , neuroscience , retina , pathology , microbiology and biotechnology , central nervous system , medicine , genetics
Young adult squirrel monkeys were subjected to unilateral or bilateral enucleation, and allowed to survive for varying periods of time. Transneuronal degeneration confirms previous studies that the homogeneous parvocellular mass actually has four hidden laminae. Electron microscopic studies show that the retinal (RL) terminals undergo three stages of degenerative changes after enucleation: neurofilamentous hyperplasia; increased electron density; and phagocytosis by glial elements. The time course of these changes is correlated with those of the Glees and the Nauta preparations. The other types of axons remain normal. Three types of neuroglial cells are found in the normal and degenerating LGN: Oligodendrocytes, astrocytes and a phagocytic glial cell type. The oligodendrocytes do not appear to participate actively in phagocytosis. The astrocytes undergo a filamentous hyperplasia during degeneration; they may engulf some degenerating terminals, and contribute to the formation of gliosis. The phagocytic glial cells proliferate during the degenerative process, and actively phagocytose both the dense terminals and the degenerating myelinated axons.