The CNS does have some capacity for 'remembering' pain. During high g
manoeuvres pilots sometimes experience pain in the lower face and teeth.
Looking into this it was established that those pilots who had recent dental
work reported pain in the teeth far more often than the face in general.
Pain receptors may retain some sensitivity after a prolonged bout of firing
(LTP?). This form of sensory memory probably finds its origin at the sensory
receptor sites, possibly the brainstem, probably not higher. It makes sense,
an area once injured should be 'watched' more carefully by the CNS, although
there do seem to be circumstances where the mechanism goes overboard. Is
this a conscious remembering?