Effects of unilateral visual deprivation on the developing avian brain

Brain Research Bulletin

Harrington

Anderson

1978

[411][412][413] 19711.-The effects of unilateral extirpation of the right optic cup of the three-day incubated chick embryo upon the rate of synthesis and the stability of DNA in the non-innervated optic lobe, have been studied. This surgical procedure prevents innervation of the optic lobe contralateral to the removed eye, while the other optic lobe is normally innervated by retinal ganglion cells of the remaining eye. At the 20th day of incubation, the DNA content of the non-innervated lobe was below that of the paired lobe receiving normal innervation. This deficiency of cell number was caused by two events; death of an excess number of neurons formed early in embryogenesis and a reduced rate of glial proliferation in the later stages of incubation. Non-innervationEnucleation Chick embryo

Section: Discussionmentioning

confidence: 99%

Section: Dna Determinationmentioning

confidence: 99%

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Effects of prevention of afferentation of the development of the chick optic lobe

Brain Research Bulletin

Harrington

Anderson

1978

“…This has been shown to cause major developmental failure of the tectum and lesser metabolic effects in the corresponding cerehral hemispheres (2,3). It is difficult to determine the relat;on between such impaired metabolism and reduced vascular supply, as both effects appear very rapidly after eye removal.…”

Section: Discussionmentioning

confidence: 99%

“…An experimental model was employed utilizing chicks that had been monocularly visually deprived by unilateral eye enucleation or by eyelid suture. These procedures have been described ( 2). In brief, the advantages of such a system are: (a) The complete decussation of the avian optic tract, in conjunction with the absence of major interhemispheric commissures such as a corpus callosum reduces interactions between the two symmetrical halves of the brain (8).…”

Section: Introductionmentioning

confidence: 99%

Stimulus deprivation and cerebral blood flow

Morelos

1971

Experimental Neurology

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The effect of unilateral visual deprivation on the vascular system of brain regions has been studied in the chick where the visual pathways are totally crossed. We injected 1251-iodantipyrine or 1251-iodinated albumin into the hearts of chicks at various times after monocular eyelid suture or unilateral eye extirpation. Radioactivity within optic lobes and cerebral hemispheres was assayed, to estimate the velocity of blood flow or the plasma volume. As early as I hr after monocular deprivation by eyelid suture or by enucleation, significant deficits in the velocity of the circulation through the contralateral brain regions were observed. These effects were maintained for at least 6 days and were of similar magnitude in contralateral optic lobes (which are directly innervated by the optic nerve) and the contralateral cerebral hemispheres (which receive no primary innervation from the optic nerve). After I hr of either form of monocular deprivation, a reduced plasma volume was found in contralateral optic lobes but not in cerebral hemispheres. These data suggest that maintenance of optimal cerebral vascular supply may be dependent on a patterned sensory input to the btain. A deficiency in the complexity of cerebral afferentation in the young animal may impair adequate vascularity and thus retard maturation.

Rapid changes in cerebral blood flow and initial visual experience in the developing chick

Developmental Psychobiology

Purdy

1976

Self Cite

A single eye of young chicks was sewed shut for various times. Regions contralateral to and primarily or secondarily innervated by the sutured eye had a reduced rate of cerebral blood flow in comparison to the corresponding ipsilateral regions. However, upon reopening the sutured eye after 2 days, these contralateral regions (optic lobes and cerebral hemispheres) exhibited a rapid increase in cerebral blood flow to a level significantly above that in control ipsilateral areas. The duration of this effect was considerably prolonged in chicks that were monocularly sutured immediately after hatching without prior exposure to light. Chicks that had 1 week of normal vision before monocular suture did not show this overcompensatory effect. If the period of monocular suture was extended to 7 days before restoration of vision to the occluded eye, the overcompensatory vascular effect was delayed. The maximal effect was apparent only upon the 1st exposure of an eye to major visual input. A possible relation exists between this rapid increase in regional blood flow and the period when visual imprinting could normally be expected to be maximal.