Quantitative study of cellular and volumetric growth of magnocellular and laminar auditory nuclei in developing chick brainstem

摘要

Development of the second and third order auditory nuclei-nucleus magnocel- lularis (NM) and nucleus laminaris (NL) respectively-was studied using Nissl stained serial sections from brain specimens between 8 day of incubation and posthatch day 1, at every two day interval. Reconstruction of these nuclei from three incubation ages showed progressive growth of both nuclei in a rostrocaudal direction. The volume, total neuron, dead cell and glial cell numbers were estimated using stereological quantitation methods. Both nuclei, while undergoing an overall gradual increase in volume up to 20 days registered a transient drop in volume; earlier for NM at 10 days and later for NL at 18 days. From day 20 the two nuclei showed accelerated growth in volume.