Formation and growth of the cerebral convolutions. II. Cell death in the gyrus suprasylvius and adjoining sulci in the cat

Abstract

Cell death, calculated by counting pyknotic nuclei to assess the number of dying cells, in the gyrus suprasylvius (GS-Syl) and adjoining sulci sulcus lateralis (SL) and sulcus suprasylvius (SS-Syl) was studied in cats aged 5, 15, 25 days and 6 months. Three patterns of cell death were characterized: (1) an ascending gradient from the inner to the upper cortical layers; (2) a lateromedial gradient from the SS-Syl towards the SL; and (3) a predominance of cell death in the sulcal zones. These patterns are in accordance with the sequence of cortical neurogenesis, the lateromedial pattern of the whole formation and growth of the GS-Syl and adjoining sulci, and the differences in the cortical thickness between the sulci and the gyral crown.