Cellular dynamics and tissue interactions of the dura mater during head development.

During development and growth of the neurocranium, the dura mater regulates events in the underlying brain and overlying skull by the release of soluble factors and cellular activity. Morphogenesis of the cranial bones and sutures is dependent on tissue interactions with the dura mater, which control the size and shape of bones as well as sutural patency. Development of the brain also involves interactions with dura mater: secretion of stromal derived factor 1 (SDF-1) is a critical event in directing migration of the external granular layer precursors of the cerebellar cortex and the Cajal-Retzius (CR) cells of the cerebral cortex. The dura mater is also required for growth of the hippocampal dentate gyrus. Wnt1Cre/R26R transgenic reporter mice were used to study the origin and fates of the cells of dura mater during head development. The dura mater of mammals is derived entirely from the cranial neural crest. Beginning around neonatal day 10 (N 10), the dura mater is infiltrated by cells derived from paraxial mesoderm, which later come to predominate. Over the course of infancy, the neural crest-derived cells of the dura mater become sequestered in niche-like distribution characteristic of stem cells. Simultaneously, dura mater cells underlying the sagittal suture migrate upward into the mesodermally-derived mesenchyme separating the parietal bones. Although initially the parietal bones are formed entirely from paraxial mesoderm, the cellular composition gradually becomes chimeric and is populated mainly by neural crest-derived cells by N 30. This occurs as a consequence of osteoblastic differentiation at the dura mater interface and intravasation of neural crest-derived osteoclastic and other hematopoietic precursors. The isolated cells of the dura mater are multipotent in vitro, giving rise to osteoblasts, neuronal cells and other derivatives characteristic of cranial neural crest, possibly reflecting the multipotent nature of dura mater cells in vivo. Copyright 2008 Wiley-Liss, Inc.