The Postnatal Development of the Visual Corticopontine Projection in the Hamster
Loading...
Authors
Graf, Ethan R.
Issue Date
1999
Type
Thesis
Language
en_US
Keywords
Alternative Title
Abstract
The adult mammalian cortex is divided into a number of different
functionally distinct areas, each forming very specific connections with other
areas of the brain. But exactly how hardwired are these connections? A major
concern in the study of cortical development is how such distinct areas, including
the specificity of their connections, develop. Some studies show that the
developing cortex is just as differentiated as the adult while other studies reveal
that early cortex is fairly uniform and becomes transformed and differentiated
throughout development by the input it receives.
By removing the lateral geniculate nucleus (LON) in the thalamus, visual
cortical axons are forced to develop without thalamic input. A study of the visual
corticopontine projection in the hamster in this situation shows a dramatic
increase in the extent of arborization within the pons as compared to the normally
developing corticopontine tract (M. Kingsbury, personal communication). In
order to discover the role thalamic input plays in cortical development, the normal
development of this tract in the hamster was studied. It was discovered that while
there seems to be a period of exuberance during development, it is not as great as
that observed in the thalamic lesioned brains. It appears as though developing
cortex void of thalamic input fails to undergo the process of refinement while at
the same time increases the amount of secondary sprouting. The exuberance in
these brains, which is not found at any time during development, proves how
plastic connections may be, while at the same time is likely to profoundly affect
the functional capabilities of other areas.
With honors.
With honors.
Description
v, 47 p.
Citation
Publisher
Kalamazoo College
License
U.S. copyright laws protect this material. Commercial use or distribution of this material is not permitted without prior written permission of the copyright holder.