Journal ArticleDOI
Enlarged synaptic vesicles as an early sign of secondary degeneration in the optic nerve terminals of the pigeon.
TLDR
The conclusion seems warranted that the ballooning of synaptic vesicles is an early sign of terminal degeneration, it appears to precede vesicular disintegration.Abstract:
The terminal degeneration of retino-tectal fibres was studied electron microscopically in the pigeon Synaptic vesicles seem to undergo systematic changes which can best be observed in aldehyde-fixed material. Initially (i.e. within 12-24 h) the vesicles begin to swell. The enlargement is clearly visible after 4 days (40 % increase in diameter) and reaches a maximum at 14 days (100% increase). At the latter stage, the enlargement is almost invariably associated with the well known opacity of degenerating terminals. In contrast, normal control tissue contains nerve endings with only a few enlarged and no ballooning vesicles. The conclusion seems warranted that the ballooning of synaptic vesicles is an early sign of terminal degeneration, it appears to precede vesicular disintegration.read more
Citations
More filters
Journal ArticleDOI
An autoradiographic and electron microscopic study of retino-hypothalamic connections.
TL;DR: In each of the species examined evidence has been found for a direct projection from the retina to the suprachiasmatic nucleus, but to no other region of the hypothalamus, the possible role of this retinal projection in mediating a variety of light-induced neuroendocrine responses is discussed.
Journal ArticleDOI
An experimental study of the termination of the lateral geniculo-cortical pathway in the cat and monkey.
TL;DR: Electron microscopy shows that degenerating terminals are recognizable in the visual cortex at several stages according to survival period, but that most stages can exist simultaneously in any one site, and that all are associated with asymmetrical membrane thickenings.
Journal ArticleDOI
The site of termination of afferent fibres in the caudate nucleus
TL;DR: Degenerating axon terminals can be recognized after a survival period of 4 days as dark, shrunken profiles with indistinct vesicles, and after shorter survival periods the degenerating terminals contain swollen vesicle and have pale cytoplasm.
Journal ArticleDOI
The distribution of dorsal root axons in laminae I, II and III of the macaque spinal cord: a quantitative electron microscope study.
TL;DR: The projections of dorsalRoot axons to the deeper laminae (IV, V, and VI) of the Macaque spinal cord were examined by the use of experimentally induced degeneration following dorsal rhizotomy or by injection of dorsal root ganglia with tritiated amino acids followed by light and electron mi‐croscopic autoradiography.
References
More filters
Journal ArticleDOI
Distinction of degenerating fibres and boutons of cerebellar and peripheral origin in the deiters' nucleus of the same animal.
Fred Walberg,Enrico Mugnaini +1 more
TL;DR: The present observations indicate that degenerating axons and terminals of both tracts can be distinguished in electron micrographs from the same animal following a double operation and provided that it is sacrificed after a survival time of 3 days.
Related Papers (5)
Two methods for selective silver impregnation of degenerating axons and their synaptic endings in the central nervous system.
Robert P. Fink,Lennart Heimer +1 more
Electron microscopy of experimental degeneration in the avian optic tectum.
E. G. Gray,L. H. Hamlyn +1 more