Effect of environmental factor influencing the development of mouse cerebral cortex.

The cerebral cortex is organized into six cell layers, each of which contains neurons with similar morphology, functions, gene-expression profiles, and projection patterns. These layer-specific neuronal phenotypes are sequentially generated from common cortical progenitor cells in the ventricular zone of dorsal telencephalon. Although recent investigations have clarified important roles of intrinsic factors such as transcription factors and regulators of the cell cycle for the maturation of cortical progenitors, growth factors and neurotrophic factors environmentally supplied by the cerebral cortex are thought to regulate proliferation and neural development and determine neuronal differentiation in the cerebral cortex. In this review, I focus on the function of neurotrophin-family neurotrophic factor, including nerve growth factor, brain-derived neurotrophic factor (BDNF), neurotropin-3 (NT-3) and neurotrophin-4 in the formation of the neuronal layer of the cerebral cortex. Especially, BDNF and NT-3 are expressed in the proliferating cortical progenitors and influence the biological properties of cortical progenitors prior to neurogenesis and play distinct roles in generation of cortical neuronal subtypes.