Gamma Motoneuron

Gamma Motoneuron

Gamma motoneurons (γ-motoneurons), also called gamma motor neurons, are a type of lower motor neuron used in the process of muscle contraction, and represents about 30% of fibers going to the muscle. Like alpha motor neurons, another type of motor neuron, its cell bodies are located in the anterior horn of the spinal cord. Their axons originate from the bulboreticular facilitatory region of the pons in the brainstem with a diameter of only 5 um. The presence of myelination allows a conduction velocity of 4–24 meters per second, significantly faster than nonmyelinated axons. The typical conduction velocity for a γ-motoneuron axon is in the region of 4 to 24 m/s. However, the conduction velocity is slower than the alpha motor neurons. Unlike the alpha neurons, gamma motor neurons do not directly adjust the lengthening or shortening of muscles. However, their role is important in keeping muscle spindles taut, thereby allowing firing of alpha neurons to continue to discharge leading to muscle contraction. These neurons also play a role in adjusting the sensitivity of muscle spindles.

Read more about Gamma Motoneuron:  Alpha Gamma Co-Activation, Fusimotor System, Gamma Bias, Gamma Motor Neuron Development, Muscle Tone, Abnormal Gamma Motor Neuron Activity