Search results
Results from the WOW.Com Content Network
Axon guidance (also called axon pathfinding) is a subfield of neural development concerning the process by which neurons send out axons to reach their correct targets. Axons often follow very precise paths in the nervous system, and how they manage to find their way so accurately is an area of ongoing research.
Guidance molecules act as cues by carrying information to receptive cells; administering this information which tells the cell and its entities how to properly align. [10] Slit proteins behave as such when working in axonal guidance during the development of the nervous system. Similarly, these proteins help to orchestrate the development of ...
Growth cone receptors detect the presence of axon guidance molecules such as Netrin, Slit, Ephrins, and Semaphorins. It has more recently been shown that cell fate determinants such as Wnt or Shh can also act as guidance cues. The same guidance cue can act as an attractant or a repellent, depending on context.
Netrins establish a gradient to direct commissural axons at a distance; Netrin-2 is expressed broadly in the ventral two thirds of the spinal cord, but not in the floor plate. Mice with netrin-1 loss-of-function exhibit severe disruption in commissural axon migration; this experiment established the importance of Netrin-1 in guidance decisions. [2]
Examples of these molecules include laminin, fibronectin, tenascin, and perlecan. Some of these are surface bound to cells and thus act as short range attractants or repellents. Others are difusible ligands and thus can have long range effects. Cells called guidepost cells assist in the guidance of neuronal axon growth.
Slit-Robo is the name of a cell signaling protein complex with many diverse functions including axon guidance and angiogenesis.. Slit refers to a secreted protein that is most widely known as a repulsive axon guidance cue, and Robo refers to its transmembrane protein receptor.
An important family of adhesion molecules is constituted by the cadherins, whose different combination on targeting cells allow the traction and guidance of the forming axons. A typical example of layers with combinatorial expression of these molecules is the tectal laminae in the chick tectum, where the N-cadherin molecule is present only in ...
Semaphorins are versatile ligands. Their discovery was in regards to axon guidance in the limb buds of grasshoppers in 1992, but since then, it has been discovered that semaphorins have a role in many processes. They not only guide axons in development, but also have major roles in immune function (classes 4, 6, and 7) and the development of bones.