Letter | Published:

Production of Membrane Potential Changes in the Frog's Heart by Inhibitory Nerve Impulses



THE observations reported here were made in the course of preliminary experiments concerned with the electrical changes which vagal and sympathetic nerve impulses produce in the pace-maker region of the heart. The preparation was the sinus venosus of the frog together with its nerve supply (one or both vagi; more recently, the intra-cranial roots and sympathetic components of the vagus were prepared for separate stimulation). A micro-electrode was used for intracellular recording of the membrane potential, the electrode being introduced into the sinus through the exposed sino-auricular ostium or through the cut inferior vena cava. Although the nervous control of the heart is not restricted to its pace-maker region, we were especially interested in the mechanism by which nerve impulses regulate the beat frequency, and an attempt was therefore made to place the recording electrode as close as possible to the point of origin of the rhythmic activity. This place can be recognized by the appearance of a slow depolarization preceding each action potential1,2, and the accompanying records were obtained from such regions.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1

    Weidmann, S., J. Physiol., 115, 227 (1951).

  2. 2

    Trautwein, W., and Zink, K., Pflüg. Arch. ges. Physiol., 256, 68 (1952).

  3. 3

    Gaskell, W. H., J. Physiol., 8, 404 (1887).

Download references

Author information

Rights and permissions

To obtain permission to re-use content from this article visit RightsLink.

About this article

Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.