Journal article

Activity patterns of cardiac vagal motoneurons in rat nucleus ambiguus

N Rentero, A Cividjian, D Trevaks, JM Pequignot, L Quintin, RM McAllen

AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY | AMER PHYSIOLOGICAL SOC | Published : 2002

Abstract

Extracellular recordings were made in the right nucleus ambiguus of urethane-anesthetized rats from 33 neurons that were activated at constant latency from the craniovagal cardiac branch. Their calculated conduction velocities were in the B-fiber range (1.6-13.8 m/s, median 4.2), and most (22/33) were silent. Active units were confirmed as cardiac vagal motoneurons (CVM) by the collision test for antidromic activation and by the presence of cardiac rhythmicity in their resting discharge (9/9). Brief arterial pressure rises of 20-50 mmHg increased the activity in five of five CVM by 0.1 +/- 0.02 spikes. s(-1). mmHg(-1) from a resting 3.8 +/- 1.2 spikes/s; they also recruited activity in two o..

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