Figure 7.10: Gate control of pain Pain transmission neurons in the spinal cord or brainstem, which receive input from pain sensory neurons coming from the body, can be made more or less excitable by descending connections from the brain. In the figure, + indicates excitatory connections and − indicates inhibitory connections. The excitatory and inhibiting effects on the pain transmission neurons constitute the metaphorical “gate” in the gate-control theory of pain.
(Adapted from Watkins & Maier, 2000.)