Cortical Inhibition

When cortical inhibition is strong, the body can stand upright, recover from stress quickly, maintain balanced muscle tone, and react quickly to instability. The cortex, the outer wrinkled portion of the brain, is the key structure providing inhibitory control over body systems. The brain's primary output is inhibitory, functioning by turning systems off and restraining activity rather than exciting them. Most brain cells are inhibitory rather than excitatory because neurons are naturally designed to fire and require mechanisms to keep that firing in check. The inhibitory control of the sympathetic response runs on the same side of the brain as the body side it governs, unlike many other brain functions that cross over. Greater sweating on one side of the body is linked to weaker cortical inhibition on that same side of the brain. More sweating on the left side specifically suggests weaker inhibitory capacity from the left hemisphere of the brain. When cortical inhibition is weak, flexor postures emerge, stress remains active longer, and muscle tone and reaction time decline. Cortical inhibitory control is essential for upright posture, normal movement, stress regulation, muscle t…