Phylogenetic Disorder of Neocortex

development and diversification of a species or group of organisms
It is evolutionary history of a kind of organism

.
It is also termed as Neopallium or Isocortex .
In human brain it is the largest part of cerebral cortex.

This gave rise to first mammals about 200 million years ago.
These creatures already had NEOCORTEX i.e. extra layers of neural tissue on the surface of brain responsible for the complexity and flexibility of mammalian behaviour .

developmental process, beginning with production of neuronal and glial precursors in the germinal zones lining the lateral and third ventricles, followed by migration of the neurons from the germinal zone to their eventual destinations. The neurons differentiate into several cell types (ie, pyramidal cells, stellate cells) and organize into horizontal laminar aggregates and vertical columns, resulting in the production of normal cortical cytoarchitectonic patterns. Any disruption of the normal processes of neuronal generation and migration result in brain malformations, which can cause variable degrees of neurologic dysfunction. An understanding of the normal processes of gray matter development is essential to understanding the disorders of this development. Although this manuscript deals only with gray matter development, neuronal development is coordinated with, and dependent upon, the generation and development of nonneural cells, such as astrocytes and oligodendrocytes.

by brain cell death.
Caused by Degeneration of neocortex