When warned their breathing was about to be restricted, the most resilient participants — SEALs and adventure racers,
among others — showed a
burst of blood - flow
activity in an area
of the brain that registers sensations in the body, called the insular cortex.
Among these systems, hypothalamo - neurohypophyseal magnocellular neurons have been early - considered models, as they typically display an electrical
activity consisting
of bursts of action potentials that is optimal for the release
of boluses
of the neurohormones oxytocin and vasopressin.