Inhibition of spinal nociceptive transmission accompanies cardiovascular changes from stimulation in diencephalic 'defence' regions of cats.
In anaesthetized cats, diencephalic regions were electrically stimulated while recording evoked responses from lumbar dorsal horn neurones and cardiovascular parameters. Neuronal responses to impulses evoked electrically in unmyelinated primary afferents were inhibited by stimulation in many diencephalic regions. Responses to non-noxious cutaneous stimulation (hair deflection) were inhibited at relatively few sites. Indirect circulatory measurements showed that this selective spinal inhibition was accompanied by increases in cardiac output and muscle blood flow but reduced cutaneous perfusion. This association between selective inhibition of nociceptive spinal neuronal responses and a cardiovascular response pattern associated with the defence reaction supports the proposal that analgesia could be an important component of defensive behaviour.
D000818:Animals; D001794:Blood Pressure; D001931:Brain Mapping; D002302:Cardiac Output; D002320:Cardiovascular Physiological Phenomena; D002415:Cats; D004027:Diencephalon / Q000502:physiology*; D004558:Electric Stimulation; D009132:Muscles / Q000098:blood supply; D009433:Neural Inhibition; D010146:Pain / Q000503:physiopathology*; D012867:Skin / Q000098:blood supply; D013116:Spinal Cord / Q000503:physiopathology*