ABSTRACT
In this work an ultrastructural analysis of the nuclear inclusions of neurons of chick (Gallus gallus) dorsomedial cerebral cortex during different perinatal stages has been made. Two types of nuclear inclusions could be identified: a) membranous nuclear inclusions and b) nuclear bodies. Into the type of membranous nuclear inclusions we distinguish compact and pleomorphic membranous inclusions. Compact membranous nuclear inclusions are located close to the nuclear envelope and they are circularly shaped; the largest inclusions of this type frequently contain a fine granular material. Pleomorphic membranous inclusions are irregularly shaped and do not contain any electrondense material; this type of membranous inclusions can be mainly seen in newborn and rarely at later stages. These features suggest a transport mechanism cytoplasm-nucleus and nucleus-cytoplasm which coincides with the hyperactivity of these neurons during these perinatal stages. The nuclear bodies can be exclusively seen in the newborn stage and they possibly have an important role related to the cellular hyperactivity of these stages of the development.
