The time of origin and the pattern of survival of neurons in the isthmo-optic nucleus of the chick.
Details
Serval ID
serval:BIB_6CDBC05BE19D
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
The time of origin and the pattern of survival of neurons in the isthmo-optic nucleus of the chick.
Journal
Journal of Comparative Neurology
ISSN
0021-9967[print], 0021-9967[linking]
Publication state
Published
Issued date
1976
Volume
167
Number
2
Pages
125-142
Language
english
Notes
Journal Article Research Support, U.S. Gov't, P.H.S. --- Old month value: May 15
Abstract
The time of origin of the cells in the isthmo-optic nucleus (ION--the nucleus of origin of centrifugal fibers to the avian retina) has been determined in the chick by a variant of the cumulative labeling method, using 3H-thymidine autoradiography. All the neurons of the ION are generated (i.e., pass through their last phase of DNA synthesis) over a 50-hour period between the latter part of the fifth and the seventh days of incubation (stages 28--31 of the Hamburger and Hamilton ['51] series) but the cells come to be assembled within the nucleus along a distinct temporo-spatial gradient. The earliest-formed cells occupy the ventrolateral part of the nucleus while the last neurons to be generated come to lie along its dorsomedial margin. When the nucleus is numerically complete, around the eleventh day of incubation, it contains about 22,000 neurons, but between the thirteenth and seventeenth days (stages 39 through 43) this number is produced by nearly 60% to about 9,500 cells. Following the radical extirpation of the one optic cup or the circumscribed removal of the neural retina early on the third day of incubation, the cell loss in the contralateral ION is greatly accentuated, so that by the eighteenth day of incubation no cells remain in the nucleus. Serial counts of the numbers of cells in the nucleus on the side of the eye (or retinal) removals show that it, too, undergoes additional cell degeneration, so that by the end of the phase of naturally occurring neuronal loss, only about half the normal number of cells persist in these experimental animals.
Keywords
Age Factors, Animals, Cell Count, Cell Survival, Chick Embryo, Eye/embryology, Neurons/physiology, Optic Nerve/cytology, Optic Nerve/embryology, Retina/embryology, Retina/physiology, Superior Colliculi/physiology
Pubmed
Web of science
Create date
20/01/2008 18:49
Last modification date
20/08/2019 15:26