抄録
Circulatory and respiratory function of the thalamus was studied in 25 dogs and the following results were obtained.
(1) Marked elevation of arterial blood pressure was observed by the stimulation of the midline nuclei group and medial nuclei group. Stimulating the anterior nuclei group, slight vasopressor responses were found. But the stimulation of the ventral and lateral nuclei group caused little change in blood pressure.
(2) The standard and intraatrial lead of electrocardiogram showed marked acceleration of cardiac rate and various arrhythmias such as nodal extrasystole or escape and ventricular extrasystole etc. by the stimulation of the midline and medial nuclei group and some portions of the anterior nuclei group. These ventricular extrasystoles were divided into 2 groups according to their characteristics in EKG and the regions causing each of them were also discussed. The stimulation of the ventral and lateral nuclei group scarcely resulted in any disturbances of the cardiac rhythm.
(3) Acceleration of breathing was shown on the stimulation of the midline, medial and ventral nuclei group. All cases of the anterior nuclei stimulation elicited marked inhibition of respiration.
(4) Other visceral and somatic changes such as pupillodilatation, erection of hair, urinary or fecal incontinence and convulsion were observed upon the stimulation of various regions in the thalamus, but they occurred most prominently on the midline and medial nuclei stimulation.
From the data above-mentioned, it can be concluded that the stimulation of the medial part of the thalamus-midline and medial nuclei group-results in marked changes in circulation, respiration and other autonomic functions. Furthermore, considering the anatomical relationship between the thalamic nuclei and the higher autonomic centers, it seems that the autonomic representation in the thalmus locates in this portion.
