New Mechanism of Pain Control Revealed - norepinephrine. Locus coeruleus.
neurosciencenews.com/lc-neu...
Summary: Stimulating noradrenergic neurons in the locus coeruleus that carry signals from the brain down the spinal dorsal horn activates astrocytes. The astrocyte activation results in hypersensitivity to pain.
Source: Kyushu University