Glial cell line-derived neurotrophic factor and is the first member of the GDNF family of ligands (GFL) found. Glial cell line-derived neurotrophic factor has been shown to interact with GFRA2 and GDNF family receptor alpha 1. GDNF has regenerative properties for brain cells and showed potential as treatment for Parkinson's disease - monkeys with an induced form of Parkinson's disease showed less trembling when treated with the drug, and neuronal fibres grew in part of the human brain exposed to the drug. However progress to a treatment is hampered by the problem of delivering the drug to brain cells through the blood-brain barrier in human.
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