Glial scar brain and spinal cord. FGF2 has also been shown to increase astrocyte proliferation "in vitro". Ciliary neurotrophic factor (CNTF) is a cytosolic protein that is not secreted. CNTF has been shown to promote the survival of neuronal cultures "in vitro", and it can also act as a differentiator and trophic factor on glial cells. Further, CNTF has been previously shown to affect the differentiation of glial precursor cells "in vitro"; however, the influence of CNTF in the "in vivo" setting has only recently been determined. Winter "et al." used CNTF over-expressing transgenic mice as well as wildtype controls that had
Effect of spaceflight on the human body lymphocytes. As these cells are central to the immune system, any damage weakens the immune system, which means that in addition to increased vulnerability to new exposures, viruses already present in the body—which would normally be suppressed—become active. In space, T-cells (a form of lymphocyte) are less able to reproduce properly, and the T-cells that do reproduce are less able to fight off infection. Over time immunodeficiency results in the rapid spread of infection among crew members, especially in the confined areas of space flight systems. On 31 May 2013, The NASA scientists reported that a possible manned mission to