Descending neuron

As the sole conduits of information between the brain and the body, descending neurons play a key role in behavior.

[5][6][7][8] Work in the fruit fly Drosophila melanogaster suggests that they are organized into three broad pathways (see schematic).

[8] Two direct pathways link specific regions in the brain to motor circuits in the ventral nerve cord controlling the legs and wings, respectively.

Descending neurons play an important role in initiating, maintaining, modulating, and terminating behaviors.

[23][24] Some descending pathways form direct connections with motor neurons and premotor interneurons,[25] including central pattern generators.

Schematic of major descending pathways in mammals. The corticospinal and corticobulbar tracts are pyramidal tracts controlling voluntary movement. The tectospinal , rubrospinal , vestibulospinal , and reticulospinal tracts are extrapyramidal tracts controlling involuntary movement.
Side-view schematic of major descending pathways in Drosophila melanogaster . In the ventral nerve chord, the major pathways target the dorsal wing, neck, and haltere neuropils, the ventral leg neuropils, and the intermediate tectulum, an integrative region. Adapted from Namiki et al. (2018) [ 4 ] .