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.
Guidepost cells set of guidepost cells present for TCA guidance. These GABAergic neurons migrate to the medial ganaglionic eminence (MGE) region to form a "corridor" between proliferation zones of the MGE and globus pallidus (GP). Corridor cells provide TCA growth through MGE-derived regions. However, the Neurgulin1 signaling pathway needs to be activated, with the expression of ErbB4 receptors on the surface of TCAs, for the connection to occur between corridor cells and TCAs. There are subpopulations of glial cells that provide guidance cues for axonal growth. The first set of cells, called the "mid-line glial zipper", regulate the midline fusion and guidance