Glial scar shown to stimulate growth-inhibitory proteoglycans by astrocytes. Experimental reduction of TGFβ-1 and TGFβ-2 has been shown to partially reduce glial scarring. Interleukins are another potential family of scar-inducing cellular messengers. Particularly, interleukin-1, a protein produced by mononuclear phagocytes, helps to initiate the inflammatory response in astrocytes, leading to reactive astrogliosis and the formation of the glial scar. The cytokine family of glial scar inducers include interferon-γ (IFNγ) and fibroblast growth factor 2 (FGF2). IFNγ has been shown to induce astrocyte proliferation and increase the extent of glial scarring in injured brain models. Further, FGF2 production increases after injury to the
Satellite glial cell in the same sheath (reflexive gap junctions). These gap junctions have been identified through the use of electron microscopy and weight tracer markers, such as Lucifer yellow or neurobiotin. The degree to which SGCs are coupled to SGCs of another sheath or to SGCs of the same sheath is dependent on the pH of the cellular environment. From studies on rats and mice, researchers have found that satellite glial cells express many neurotransmitter receptors, such as muscarinic acetylcholine and erythropoietin receptors. In order to differentiate between SGCs and other glial cells researchers have used markers to identify which proteins are