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THE REFRACTORY PHASE ASSOCIATED WITH ONE SINGLE EXCITATORY PROCESS IN YOHIMBINISED NERVE
Author(s) -
Tait John
Publication year - 1909
Publication title -
quarterly journal of experimental physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0370-2901
DOI - 10.1113/expphysiol.1909.sp000033
Subject(s) - yohimbine , excitatory postsynaptic potential , refractory (planetary science) , refractory period , anesthesia , medicine , endocrinology , chemistry , inhibitory postsynaptic potential , biology , antagonist , receptor , astrobiology
1. In the refractory phase associated with one excitatory process in yohimbinised nerve two distinct stages are present. In the first or absolutely refractory stage conductivity is suspended. In the second relatively refractory stage conductivity, while present, is diminished in amount. Throughout this stage, however, it gradually and progressively increases from zero right up to the extent to which it was present before the excitatory process occurred. 2. Both these stages are present in the recovery of normal nerve after activity. 3. Yohimbine prolongs both the absolutely refractory phase and the relatively refractory phase of nerve. By much the greatest absolute prolongation is in the relatively refractory phase. 4. The total refractory phase of deeply yohimbinised nerve corresponding to one single excitatory process may be as long as 2·2 seconds. The greatest previously recorded prolongation (Trait and Gunn) was ·25 second. 5. Although yohimbine gradually depresses the function of a nerve, and although the immediate effect of activity during yohimbine anaesthesia is to exaggerate this depression of function, yet as regards the repair after activity yohimbine affects merely its rate and not its amount. The expenses of this research have been defrayed by a grant from the Carnegie Trust. For my supply of yohimbine I am indebted to Drs Hillringhaus and Heilmann, Chemische Fabrik, Güstrow.