Motor Neurons, Gamma

**Definition:** Motor neurons which activate the contractile regions of intrafusal SKELETAL MUSCLE FIBERS, thus adjusting the sensitivity of the MUSCLE SPINDLES to stretch. Gamma motor neurons may be static or dynamic according to which aspect of responsiveness (or which fiber types) they regulate. The alpha and gamma motor neurons are often activated together (alpha gamma coactivation) which allows the spindles to contribute to the control of movement trajectories despite changes in muscle length.

**Tree numbers:** - A08.675.655.500.525 - A11.671.655.500.525

**Synonyms:** - Motor Neurons, Gamma-Efferent - Neurons, Fusimotor - Neurons, Gamma Motor - Gamma Motorneurons