EFFECT OF ANESTHETICS ON SYMPATHETIC REFLEX

  • 1 January 1975
    • journal article
    • research article
    • Vol. 46  (2) , 141-150
Abstract
In the awake animal [cat], neither a late response nor a silent period could be evoked from the tibial nerve. Somatic afferentation with impulse trains failed to inhibit efferent sympathetic activity. Vagal afferentation had an inhibitory action, while the excitatory processes were dominant. Urethane anesthesia did not influence the sympathetic nervous processes; the reflex response was practically the same as in the awake animal. Chloralose anesthesia altered the sympathetic reflex observable in the awake animal. Somatic afferentation of low threshold voltage already elicited a late response and a silent period; in addition, a high degree of summation ability of silent periods was apparent. Thus, chloralose anesthesia seems to raise the excitatory level of the sympathetic centers in the direction of inhibition. Combined chloralose plus urethane anesthesia, under which investigations are usually performed, affected the reactivity of the sympathetic centers in the same manner as chloralose anesthesia.