Temperature sensitivity of afferent receptors of the isolated rabbit brain

compressed and distended their abdomen with the aid of the diaphragm and abdominal muscles. As a result of these exercises, after only 1 week both volunteers were able to reduce their heart rate appreciably without any particular effect (Fig. 2)~ Injections of atropine into the volunteers in a dose of 1 mg subcutaneously completely prevented this "voluntary ~ control of their heart beat~ The facts described above thus confirmed once again the validity of the classical view that purely voluntary control of the cardiac rhythm is impossible, but at the same time, they showed how it can be successfully imitated over a wide range of fre~ quencies. This procedure can evidently be used in clinical practice to explain and correct types of cardiac arhythmia, and also to produce conditioned-reflex inhibition of cardiac activity.