Attenuation during paradoxical sleep of signals from tooth pulp to thalamus

Sleep, pain, fibromyalgia, and chronic fatigue syndrome

“…Cells that are inhibited by morphine, called on cells (i.e., facilitate pain), are active during waking, virtually silent during NREM sleep, and most active during REM sleep. LANDIS reviewed above (Satoh et al, 1980a) and could also reflect reduced descending inhibition of spinal reflexes during sleep (Mason et al, 2001). However, this was not the case.…”

Use of noninvasive dental dolorimetry to evaluate analgesic effects of intravenous and intrathecal administration of morphine in anesthetized dogs

“…9,12 Validity for the use of jaw muscle reflexes as indices of pain in animals is based on the human perception that electrical stimulation of the tooth pulp is predominantly, if not exclusively, a painful stimulus. 13,[23][24][25] The reflex elicited by electrical stimulation of dental nerves can be recorded from the rostral belly of the digastricus muscle by use of electromyography (EMG). [20][21][22] Structural and functional similarity in the intradental innervation of human teeth and that of other animals provides a basis for comparison of the human pain sensations and nerve fiber responses of other animals.…”