the cell bodies of efferent motor neurons are found in cerebral cortex.
where are the cell bodies of efferent motor neurons found?
cerebral cortex
the basic route of nerve signals within the efferent somatic nervous system involves a sequence that begins in the upper cell bodies of motor neurons (upper motor neurons) within the precentral gyrus (which approximates the primary motor cortex). stimuli from the precentral gyrus are transmitted from upper motor neurons and down the corticospinal tract, via axons to control skeletal (voluntary) muscles. these stimuli are conveyed from upper motor neurons through the ventral horn of the spinal cord, and across synapses to be received by the sensory receptors of alpha motor neurons (large lower motor neurons) of the brainstem and spinal cord.
somatic nervous system
another distinguishing molecular marker of gamma motor neurons is transcription factor err3. it is expressed at high levels in gamma motor neurons, but very little in alpha motor neurons. on the other hand, neuronal dna binding protein neun, are present in significantly greater quantities in alpha motor neurons. osteopontin, a protein also expressed in bones, hence the "osteo-" prefix, is a marker for alpha motor neurons. this in turn can provide scientists a way of eliminating gamma motor neurons if alpha motor neurons are of interest. one study in particular made this conclusion based on the fact that osteopontin was present in larger cell bodies, indicating the alpha motor neurons as they have larger cell bodies than gamma motor neurons.
gamma motor neuron