Actions of morphine on the segmental reflex of the decerebrate‐spinal cat

Abstract

1 The actions of morphine were studied on the segmental reflex of the decerebrate-spinal cat. Morphine decreased arterial blood pressure. 2 Morphine inhibited mono- and polysynaptic reflexes. The influence of morphine on monosynaptic reflexes was more obvious at stimulation of the dorsal root at a frequency of 12·5 Hz than at 05 or 2·5 Hz. 3 The total amount of activity recorded from the ventral root after morphine depended on whether or not the evoked reflex was maximal or submaximal. 4 These actions of morphine were antagonized by naloxone.