Effects of coronary artery occlusion on thoracic spinal neurons receiving viscerosomatic inputs.
Action potentials of single cells in the gray matter of the T2 to T4 spinal segments of chloralose-anesthetized cats were recorded during occlusion of the anterior descending branch of the left coronary artery. Only cells responding both to visceral and somatic afferent inputs were examined. In 53% of the cells the discharge frequency was unaffected by coronary artery occlusion (CAO). The remaining 47% could be classified by four response patterns: 1) in 18% frequency increased immediately following the onset of CAO; 2) in 22%, frequency increased 13.6 +/- 3.3 (SE) s after CAO and the increased frequency usually was associated with changes in the configuration of the electrocardiogram; 3) in 3%, frequency increased at the onset of CAO and then increased more approximately 11 s later; 4) in 4%, inhibition of spontaneous activity occurred during CAO. A noxious pinch applied to the somatic receptive field maximally excited 94% and inhibited 6% of the cells. Since viscerosomatic convergence provides a basis for referred pain, these cells could potentially be involved with transmission of nociceptive information to regions of the brain that integrate pain sensations.
D000200:Action Potentials; D000818:Animals; D001931:Brain Mapping; D002415:Cats; D003327:Coronary Disease / Q000503:physiopathology; D003331:Coronary Vessels / Q000502:physiology*; D004558:Electric Stimulation; D009475:Neurons, Afferent / Q000502:physiology; D010146:Pain / Q000503:physiopathology; D011311:Pressoreceptors / Q000502:physiology; D012867:Skin / Q000294:innervation; D013564:Sympathetic Nervous System / Q000502:physiology*; D009435:Synaptic Transmission; D013900:Thoracic Nerves / Q000502:physiology*