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
Perisynaptic schwann cells cells of which Perisynaptic Schwann cells are a subset. Neural crest cells are found in the dorsal neural tube from which nerves and glia alike grow and Neural crest cells are the precursors to many various tissue types including enteric neurons and glia. Schwann cell precursors (a first derivative of Neural crest cells) are present as the nerve axon grows from the dorsal neural tube, but it has been shown that these glial precursors are not essential to axonal growth. The transition from neural crest cells to Schwann cell precursors is characterized by Sox10 and generally occurs around embryonic day