Primary motor cortex

Definition: It is a brain region that is located in the dorsal portion of the frontal lobe adjacent to the central sulcus. It has a strong somatotopic organization. It mediates voluntary movements of the limbs and trunk; it is called primary because it contains neurons that directly activate somatic motor neurons in the spinal cord. Complex sensory information is also sent to higher-order motor areas, located rostral to the primary motor cortex, where programs for movement, or potential movements, are calculated and conveyed to the primary motor cortex for implementation. Some of the motor areas in the frontal lobe also send commands directly to the spinal cord. Cells in the primary motor cortex influence neurons in the ventral horn of the spinal cord responsible for muscle movements, and thus the primary motor cortex is intimately associated with the motor system of the spinal cord.

Alternative definition:

Synonym: primary motor

References: E. Kandel. Principles of Neural Science, Fifth Edition. Principles of Neural Science. McGraw-Hill Education, 2013.

https://doi.org/10.1038/s41598-023-33780-1 https://doi.org/10.1016/j.jneumeth.2020.108790

Related terms: Brodmann area 4