PMID: 3766766Oct 1, 1986Paper

Cardiac input to medullary reticular formation: neuronal responses to CAO

The American Journal of Physiology
R W Blair

Abstract

Responses of 46 medullary reticular neurons to coronary arterial occlusions (CAO) of the left anterior descending (LAD) and left circumflex (CX) coronary arteries were determined in chloralose-anesthetized cats paralyzed with pancuronium. Extracellular potentials were recorded from individual neurons, in the medial reticular formation, responsive to electrical stimulation of cardiopulmonary sympathetic afferents. CAO responses were characterized by one of three patterns. Cell activity changed during myocardial ischemia (IS response). Fifteen neurons were excited during ischemia (9 +/- 2.8 to 15 +/- 3.2 spikes/s for CX occlusion and 10 +/- 3.0 to 17 +/- 4.7 spikes/s for LAD occlusion), and two were inhibited (8 +/- 3.0 to 4 +/- 3.0 spikes/s). Cell activity changed at the onset or release of occlusion and rapidly adapted (ON response). Four cells were excited at the onset of LAD occlusion (2 +/- 1.4 to 10 +/- 6.0 spikes/s), 9 cells were excited at onset of CX occlusion (5 +/- 2.5 to 16 +/- 5.6 spikes/s), and 1 cell decreased its rate at onset of CX occlusion. A combination of ON and IS responses occurred in five cells (ON-IS response). Overall, 24 neurons exhibited at least one of these responses, and 22 cells were unaffected by ...Continue Reading

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