Morphine enhances the activity of thermoreceptive cold-specific lamina I spinothalamic neurons in the cat.
The possibility that morphine might differentially affect spinal neurons responsive to small-diameter thermoreceptive-specific afferents was tested. Systemic morphine enhanced a portion or all of the stimulus-response function of 7 of 9 lamina I spinothalamic tract cells specifically sensitive to cold applied to the glabrous hindpaw in the cat. This result contrasts strongly with the predominant inhibition of nociceptive lamina I neurons by morphine.
Division of Neurobiology, Barrow Neurological Institute, Phoenix, AZ 85013.
A D
AD
Craig
S J
SJ
Hunsley
D000704:Analysis of Variance; D000818:Animals; D002415:Cats; D003080:Cold Temperature; D005528:Foot / Q000294:innervation; D009020:Morphine / Q000494:pharmacology*; D009433:Neural Inhibition; D009474:Neurons / Q000502:physiology*; D009619:Nociceptors / Q000187:drug effects; D011984:Sensory Receptor Cells / Q000502:physiology*; D013133:Spinothalamic Tracts / Q000166:cytology / Q000502:physiology*; D013697:Thermosensing / Q000502:physiology*
D009020:Morphine