Cross-talk between glial cells and neurons: Relationship in Multiple Sclerosis.

Abstract

In medicine, the search for the cause of a disease has been critical to understanding the nature of the disorder, and an important step towards the discovery of effective therapies and prevention. The search for a cause is more difficult than it may seem at first. For example, even if we find the mechanism by which the disease progresses, the questions would be: what started the process; then, if we have found the factors that initiated the process that will lead to questions as to what happened to this person, and at this very moment. The answer to research questions often raises more questions, and that is how research progresses. Communication between the immune system and the Central nervous system (CNS), essential for maintaining homeostasis, is exemplified by cross-talk between glia and neurons. While actively microglia cells are modulated by neurons in the healthy brain, little is known about the cross-talk between oligodendrocytes and neurons. Oligodendrocytes, the myelin-forming cells in the CNS, are essential for the propagation of action potentials along axons, and additionally they serve to support neurons by neurotropic factors. In demyelinating diseases, such as multiple sclerosis, oligodendrocytes are thought to be the victims. Also they have strong immune functions, express a wide variety of innate immune receptors, produces and respond to the chemokines and cytokines and modulate immune responses. In Addition, they elicit responses that cause progressive neuro degeneration. Under certain ccircumstances some cells cross the blood brain barrier and reach the parenchyma, activating a cascade of events culminating in an inflammatory lesion and demyelization. The main participants of these attacks are the CD4+ T cells, antigen presenting glia (microglia and astrocytes), macrophages and B cells. On the other hand further evidence support that the beginning of auto immune response is initiated within the CNS; we should consider other theories to explain not only multiple sclerosis as an autoimmune disease and that starts outside the central nervous system. There is an intimate relationship that we must pay more attention in our research: the dialogue neuron-glia; the cross-talk between microglia and neuron help us to uncover novel pathways in the brain.