Neurones ocytocinergiques envoyant leurs projections axonales vers le tronc cérébral

Oxytocin-producing neurons sending their axon projections to the brainstem (in white) in the brain of a rat made transparent, observed using a fluorescence confocal microscope. Oxytocin is a hormone that alleviates inflammatory pain. Research scientists have discovered that when a pain message is received from the neurons in the spinal cord, around 30 neurons in the hypothalamus activate a family of magnocellular neurons. These then release oxytocin into the bloodstream, numbing the peripheral neurons that are sending the pain message to the brain. At the same time, the hormone goes directly to the spinal cord, to the precise place where the intensity of the sensory message is encoded, via the axon, which acts as an extension of the oxytocin-producing neurons. This discovery could make it possible to target this handful of neurons to treat pathological pain and thereby limit the side effects of certain treatments. Research scientists also think that the malfunction of this system could be what causes chronic pain to become long-term.