Nerve Impulse Conduction and Cutaneous Receptor Responses During General Anesthesia

Abstract

The effects of ether, methoxyflurane, halothane and nitrous oxide on impulse generation and impulse conduction in the peripheral nervous system were studied in 16 cats. The compound action potential, generated by electrical stimulation of the femoral nerve, was recorded from the nerve''s intact saphenous branch. Spike amplitude and integrated output of cutaneous touch receptors likewise were recorded from the saphenous nerve. General anesthetics had no significant effect on conduction in myelinated (alpha and delta) fibers. Output from cutaneous receptors also was not greatly altered by inhalation anesthetics. Amplitude of non-myelinated (C-fiber) responses decreased slightly during halothane and nitrous oxide administration, and increased slightly when ether or methoxyflurane were given. However, the changes produced in C-fibers were insignificant, and probably of little practical consequence. Thus, inhalation anesthetics[long dash]in usual anesthetic concentrations[long dash]have no important effect on conduction in the peripheral nerve or on generation of impulses in cutaneous receptors.