Brain Power

Helping brain activity to reach other parts of the body bypassing spinal cord and other nervous system injuries is an advancing technology, as Paralyzed Man Walks Using Brain Power and Woman Controls a Fighter Jet Sim Using Only Her Mind illustrates well.

The somewhat reverse path, though, is not so obvious – use brain to override or neutralize nervous systems signaling.  A.M. Youssef, V.G. Macefield, and L.A. Henderson’s paper “Pain inhibits pain; human brainstem mechanisms” is an attempt to bring more light to it:

“Conditioned pain modulation is a powerful analgesic mechanism, occurring when a painful stimulus is inhibited by a second painful stimulus delivered at a different body location.

(…)  Human lesion studies show that the circuitry responsible for conditioned pain modulation lies within the caudal brainstem, although the precise nuclei in humans remain unknown. (…)

The expression of analgesia was associated with reduction in signal intensity increases during each test stimulus in the presence of the conditioning stimulus in three brainstem regions(…) Furthermore, the magnitudes of these signal reductions in all three brainstem regions were significantly correlated to analgesia magnitude.

Defining conditioned pain modulation circuitry provides a framework for the future investigations into the neural mechanisms responsible for the maintenance of persistent pain conditions thought to involve altered analgesic circuitry.”