Beiträge zur Physiologie des Hirnstammes

In this monograph Hess presents the results of stimulation of the diencephalon in animals, chiefly cats. The technic employed was described in detail in a monograph published in 1932. In the place of faradic stimulation there was used a direct current interrupted about eight times a second and dampened by the presence of condensers and choke coils in the circuit. Hess believes that this type of current selectively stimulates autonomic paths and centers and makes it possible to activate these without influencing somatic functions. It may be doubted whether this is true in the central nervous system; the selection of the interrupted and dampened direct current as a means of stimulation was unfortunate. Many points in the thalamus, hypothalamus and adjacent structures were stimulated, the effects on blood pressure and respiration were recorded and the location of the stimulated points plotted on a series of photographs through horizontal sections of