The goal of the proposed research is to define the underlying mechanisms that control the postnatal critical period for cortical development in kittens. The cat visual system is well suited for the analysis of cortical plasticity as recent studies indicate that environmental input not only directs on-going development, but also plays a role in activating the critical period itself. Specifically, rearing in total darkness prolongs the critical period in cats well beyond the normal age limits. We believe that this preparation provides an ideal experimental model, when compared with age matched normals, for isolating the neurological factors that correlate with functional plasticity. We will compare normal and various types of deprived kittens in studies directed at the following specific aims: 1) To define the role of environmental input in the onset and duration of the critical period: Electrophysiological studies will directly determine how the elimination of input, and the delayed introduction of input alter the normal time course of cortical plasticity. 2) To define the relationship between anatomical and electrophysiological plasticity: Trans-synaptic autoradiography and electrophysiological recordings will be used together to specify how the environment effects afferent input to the cortex. 3) To identify underlying factors that correlate with the developmental state of physiological plasticity. One approach will be to examine the effect of environmental input on the development of specific neurotransmitter systems. A combination of receptor binding, immunohistochemistry and biochemistry will be used to provide a broad range analysis of transmitter systems. A second approach will be to examine whether visual input can affect gene expression. The kitten cortex serves as a well studied and easily manipulated neurological model. Our proposed multidisciplinary approach directly addresses the ways in which the environment controls the physiology, anatomy and biochemistry of the developing nervous system.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS025216-02
Application #
3410435
Study Section
Visual Sciences B Study Section (VISB)
Project Start
1987-07-01
Project End
1992-06-30
Budget Start
1988-07-01
Budget End
1989-06-30
Support Year
2
Fiscal Year
1988
Total Cost
Indirect Cost
Name
Children's Hospital Boston
Department
Type
DUNS #
076593722
City
Boston
State
MA
Country
United States
Zip Code
02115
Kaplan, I V; Guo, Y; Mower, G D (1995) Developmental expression of the immediate early gene EGR-1 mirrors the critical period in cat visual cortex. Brain Res Dev Brain Res 90:174-9
Mower, G D (1994) Differences in the induction of Fos protein in cat visual cortex during and after the critical period. Brain Res Mol Brain Res 21:47-54
Mower, G D; Rosen, K M (1993) Developmental and environmental changes in GAP-43 gene expression in cat visual cortex. Brain Res Mol Brain Res 20:254-8
Jensen, F E; Firkusny, I R; Mower, G D (1993) Differences in c-fos immunoreactivity due to age and mode of seizure induction. Brain Res Mol Brain Res 17:185-93
Rosen, K M; McCormack, M A; Villa-Komaroff, L et al. (1992) Brief visual experience induces immediate early gene expression in the cat visual cortex. Proc Natl Acad Sci U S A 89:5437-41
McCormack, M A; Rosen, K M; Villa-Komaroff, L et al. (1992) Changes in immediate early gene expression during postnatal development of cat cortex and cerebellum. Brain Res Mol Brain Res 12:215-23
Mower, G D (1991) Comparison of serotonin 5-HT1 receptors and innervation in the visual cortex of normal and dark-reared cats. J Comp Neurol 312:223-30
Mower, G D (1991) The effect of dark rearing on the time course of the critical period in cat visual cortex. Brain Res Dev Brain Res 58:151-8
Mower, G D; Christen, W G (1989) Evidence for an enhanced role of GABA inhibition in visual cortical ocular dominance of cats reared with abnormal monocular experience. Brain Res Dev Brain Res 45:211-8
Mower, G D; Rustad, R; White, W F (1988) Quantitative comparisons of gamma-aminobutyric acid neurons and receptors in the visual cortex of normal and dark-reared cats. J Comp Neurol 272:293-302