Annual Meeting of the Society for Neuroscience edition:32 location:Orlando, Florida, U.S.A. date:November 2-7, 2002
The visual cortex, within a critical period, has the remarkable capability to adapt to changes in visual input, by modifying its connections, while in adulthood this cortical plasticity is greatly reduced. The molecular basis underlying this age-dependent difference in modifiability of the visual cortex is not yet known in great detail. Using fluorescent 2D differential gel electrophoresis (2D-DIGE) and mass spectrometry, an attempt was made to identify the proteins that characterize this critical period for cortical plasticity. Therefore, protein expression levels in visual area 17 were compared between 30-day old kittens and adult cats. This let us to identify 32 proteins with differential expression levels, of which 18 were more abundantly expressed in kitten and 14 were more abundant in adult cat striate cortex. Moreover, HPLC prefractionation of the samples prior to 2D-DIGE resulted in the identification of 8 additional differential proteins. Next to several metabolic enzymes, proteins involved in the outgrowth of axons (collapsin response mediator proteins) and the formation of new cytoskeletal filaments (cofilin, T-complex proteins) were isolated from kitten visual cortex, probably enabling the rapid growth of new connections upon sensory changes. In adult cats, as before, the higher expression level of glial fibrillary acidic protein (GFAP) could be related to the termination of the critical period.