Stem cells nervous system

The chromaffin cells of the adrenal medulla may be considered to be modified sympathetic neurons that are able to synthesize E from NE by /V-methylation. In this case the amine is Hberated into the circulation, where it exerts effects similar to those of NE in addition, E exhibits effects different from those of NE, such as relaxation of lung muscle (hence its use in asthma). Small amounts of E are also found in the central nervous system, particularly in the brain stem where it may be involved in blood pressure regulation. DA, the precursor of NE, has biological activity in peripheral tissues such as the kidney, and serves as a neurotransmitter in several important pathways in the brain (1,2). 

Beyond roles of chemokine receptors in hematopoiesis and innate immunity, roles for chemokines in adaptive immunity emerged. Moreover, other nonleukocyte migration properties of chemokine receptors have been identified. These include roles in the biology of endothelial cells (Chapter 15), cancer (Chapter 16), smooth muscle (Chapter 11), fibroblasts (Chapter 14), stem cells (Chapter 8), and all cell types associated with nervous system tissues (Chapter 17). In many instances, broad functional overlap is evident as chemokines can direct the migration of these cells just as they do with leukocytes. In certain instances, the ability of chemokines to retain cell populations within a specific microenvironment is as important as their migration-promoting properties. However, it is also clear that migration and retention are not the sole end points. 

Anderson, D. I. Stem cells and pattern formation in the nervous system the possible versus the actual. Neuron 1 19-35, 2001. 

STEM CELLS CONTRIBUTE TO THE DEVELOPING NERVOUS SYSTEM 507... 

Central nervous system stem cells maintain an undifferentiated state and the capacity to self-renew in response to epidermal growth factor and fibroblast growth factor 507 Cell lineage studies reveal close associations between distinct neural cell types 508... 

Bone morphogenetic proteins stimulate astrogenesis 508 Neural crest stem cells give rise to neuronal or glial derivatives in the peripheral nervous system 509... 

STEM CELLS OFFER THE POTENTIAL FOR REPAIR IN THE ADULT NERVOUS SYSTEM 510... 

A central role for neural stem cells in the development of the nervous system is becoming clear. During embryo-logical development, the nervous system originates from... 

Some aspects of multiple sclerosis are reflected in the animal model experimental autoimmune encephalomyelitis, which is induced by immunization of susceptible animals with appropriate encephalogenic proteins or peptides. In these animals, if cultured adult stem cell neurospheres are injected into the bloodstream, injected cells can find their way to damaged portions of the nervous system and improve function in mice. How the injected cells augmented the recovery process is unclear. One possibility is that cells recruited to the lesions differentiated into oligodendrocytes and generated new myelin sheaths, but this seems unlikely in the face of ongoing cellular destruction. 

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