Primary Cilia in Cerebral Cortex: Growth and Functions on Neuronal and Non-neuronal Cells

Abstract

The prevailing view until very recently was that primary neuronal cilia, which were first described in electron microscopic studies of the central nervous system (CNS) approximately 50 years ago, were likely vestigial. This was due in large part to their lost motility during the course of evolution. For decades, further investigation into these structures was hampered by the lack of methods to specifically label cilia and the paucity of information about their growth and function in the CNS. In this chapter, we review the unexpected roles that primary cilia have in shaping the CNS and in particular the generation and maturation of cells in the postnatal cerebral cortex. We discuss newly available research tools for detecting cilia and manipulating ciliogenesis. Focusing on the mammalian cerebral cortex, this chapter reviews the patterns of growth of neuronal cilia, signaling profiles and putative functions of neuronal and non-neuronal cilia, and potential consequences of abnormal ciliogenesis in these cell types.