Expression Of Extracellular Matric In The Visual Cortex Of The Developing Rats And The Role Of Extracellular Matrix In The Visual Cortex Plasticity

Purpose :1. Recent studies have demonstrated that astrocytes are able to produce Chondrointin sulfate proteoglycans (CSPGs) which participates in the formation of perineuronal net (PNNs) and the termination of visual plasticity during the critical period. Our study observed the quantity and the distribution of astrocytes in the normal developing visual cortex in order to reveal the underlying role of astrocytes in visual cortex plasticity.2. Extensive investigations have been carried on in the role of CSPGs during the visual cortex plasticity, however, many issues about Hyaluronan (HA) as another essential component of extracellular matrix (ECM) remain to be elucidated. In the present study, we focused on the expression and distribution of HA in the developing visual cortex of the normal and biocularly form-deprived rats, with the purpose of revealing the possible contribution of HA to the visual cortex plasticity.Methods:1. Using Glial Fibrillary Acidic Portein (GFAP) as the mature marker of the astrocytes in the immunohistochemistry analysis, the quantity and the distribution of astrocytes in the normal developing visual cortex were observed in the normal rats at the age of 1, 3, 5, 7 weeks and 3 months.2. The visual cortex of normal rats at the age of 1, 3, 5, 7 weeks and 3 months and biocularly form-deprived rats at the age of 3, 5, 7 weeks and 3 months were analyzed by immunohistochemistry with Neurocan-green flurescent protein (GFP) fusion protein of HA, the expression and distribution of which were investigated.Results:1.GFAP immunopositive astrocytes in the visual cortex of normal rats was scarce at 1- week-old and gradually increased in number from 3-week-old to 5- week-old. The cell...