Neurogenesis relies on a delicate balance between progenitor maintenance and neuronal production. Progenitors divide symmetrically to increase the pool of dividing cells. Subsequently, they divide asymmetrically to self-renew and produce new neurons or, in some brain regions, intermediate progenitor cells (IPCs).
View Article and Find Full Text PDFDeveloping axons must control their growth rate to follow the appropriate pathways and establish specific connections. However, the regulatory mechanisms involved remain elusive. By combining live imaging with transplantation studies in mice, we found that spontaneous calcium activity in the thalamocortical system and the growth rate of thalamocortical axons were developmentally and intrinsically regulated.
View Article and Find Full Text PDFDuring embryonic development, the oligodendrocyte precursors (OPCs) are generated in specific oligodendrogliogenic sites within the neural tube and migrate to colonize the entire CNS. Different factors have been shown to influence the OPC migration and differentiation, including morphogens, growth factors, chemotropic molecules, and extracellular matrix proteins. Neuregulins have been shown to influence the migration of neuronal precursors as well as the movement and differentiation of Schwann cells for peripheral myelination, but their role in the motility of OPCs has not been explored.
View Article and Find Full Text PDFThe assembly of neural circuits is dependent upon the generation of specific neuronal subtypes, each subtype displaying unique properties that direct the formation of selective connections with appropriate target cells. Actions of transcription factors in neural progenitors and postmitotic cells are key regulators in this process. LIM-homeodomain transcription factors control crucial aspects of neuronal differentiation, including subtype identity and axon guidance.
View Article and Find Full Text PDFp38 Mitogen-activated protein kinases (MAPK) are a family of Ser/Thr kinases that regulate important cellular processes such as stress responses, differentiation, and cell-cycle control . Activation of MAPK is achieved through a linear signaling cascade in which upstream kinases (MAPKKs) dually phosphorylate MAPKs at a conserved 3-amino-acid motif (Thr-X-Tyr) . G-protein-coupled receptor kinases (GRKs) are known to selectively phosphorylate G-protein-coupled receptors (GPCRs) and thus trigger desensitization .
View Article and Find Full Text PDFThe G protein-coupled receptor kinases (GRKs) participate with arrestins in the regulation and signal propagation of multiple G protein-coupled receptors (GPCR) of key physiological and pharmacological relevance in the cardiovascular system. The complex mechanisms of regulation of GRK expression, degradation and function are being unveiled gradually. The levels of these kinases are known to change in pathological situations such as heart failure, hypertrophy and hypertension, and in animal models of these diseases.
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