Developmental qualitative and quantitative aspects of the subependymal layer from the caudato-pallial angel of the rat lateral ventricles.

We have studied by both qualitative and quantitative methods the subependymal cells in the caudato-pallial angle (CPA) of the lateral ventricle from 1, 2, 6 and 18 month-old rats. We have chosen the CPA, among other zones, because it is an easily delimited glial proliferative zone. The qualitative analysis was carried out using both Klüver-Barrera and Luxol-Fast-Blue stains. The quantitative study was carried out by a semiautomatized image analysis system. Three types of subependymal nuclei were classified by Klüver-Barrera stain, according to the following parameters: staining intensity, morphology and size. Each of the three type groups was found at different frequency depending of rat age. Luxol-Fast-Blue stained mitotic images in metaphase or anaphase: n = 38 in the 1 month, n = 49 in 2 months, n = 12 in the 6 months, and n = 5 in the 18 month-old rats. The quantitative analysis (length, areas and volume of CPA) were in agreement with the above data, showing a more subependymal activity in the 2 month-old animals than in the 1, 6 and 18 month-old rats.