| Name: | primary motor neuron |
|---|---|
| Synonyms: | primary motoneuron |
| Definition: | Motor neurons that arise during the first day of development. Primary motoneurons have larger diameter cell bodies and axons than secondary motoneurons and are positioned more dorsally and medially than secondary motoneurons. Primary motoneurons are present in a single bilateral pair of clusters in each spinal segment and innervate axial muscle fibers in the corresponding pair of myotomes. Axons make a conspicuous loop around the Mauthner axon before entering the ventral root. |
| Ontology: | Anatomy Ontology [ZFA:0009244] |
| Name: | axon guidance |
|---|---|
| Synonyms: | axon chemotaxis, axon growth cone guidance, axon pathfinding |
| Definition: | The chemotaxis process that directs the migration of an axon growth cone to a specific target site in response to a combination of attractive and repulsive cues. |
| Ontology: | GO: Biological Process [GO:0007411] QuickGO AmiGO |