The effects of lesions of medullary midline and lateral reticular areas on inhibition in the dorsal horn produced by periaqueductal grey stimulation in the cat.
In barbiturate-anaesthetized cats, the excitation of lumbar dorsal horn neurones by impulses in unmyelinated primary afferent fibres was inhibited by electrical stimulation in the periaqueductal grey matter. This inhibition was slightly reduced by extensive electrocoagulation of the medullary midline and para-medial areas including the raphé, but significantly reduced by small bilateral lesions in the region of the caudal lateral reticular nuclei. When the lateral lesions were made subsequent to midline coagulation, the inhibition from periaqueductal grey stimulation was abolished. An important component of spinal inhibition from periaqueductal grey stimulation appears to relay in lateral reticular areas of the medulla.
D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D002415:Cats; D004558:Electric Stimulation; D005727:Ganglia, Spinal / Q000502:physiology*; D008526:Medulla Oblongata / Q000502:physiology*; D009433:Neural Inhibition; D009474:Neurons / Q000502:physiology; D009619:Nociceptors / Q000502:physiology; D010487:Periaqueductal Gray / Q000502:physiology*; D011903:Raphe Nuclei / Q000502:physiology; D012154:Reticular Formation / Q000502:physiology*