AFFERENT IMPULSES IN THE DEPRESSOR NERVE

1. Afferent impulses from one more pressure receptor in the depressor nerve of the rabbit have been recorded simultaneously with the arterial blood pressure and ECG.2. There is a discharge of impulses at all pressure levels in the normal living animal.3. The degree of activity of the end-organs varies with the blood pressure and is to a considerable extent dependent upon the variations in pressure during the heart cycle.4. The impulses from a single end-organ are at a maximum frequency during systole.5. As the pressure increases a larger number of end-organs come into play, the impulse frequency in a single nerve fiber increases, and the discharge continues throughout the greater part of the cycle.6. Four types of receptors were found. The first responds rather to the absolute value of the blood pressure, the second rather to the rate of pressure change, the third responds when the blood pressure falls and the fourth is superposed on the QRS-complex of the ECG.