Interpretation by theoretical model of dynamic and steady components in frog gustatory response

The behavior of dynamic component (slow component) and steady component of the frog glossopharyngeal nerve response to CaCl2, measured in number of impulses firing per second, was examined under various conditions. 1) The magnitude of the dynamic component increased with the flow rate below about 0.3 ml/s, whereas that of the steady component was independent of the flow rate. 2) The magnitude of the dynamic component increased with a rise of temperature between 2.5 and 20 degrees C, whereas that of the steady component was practically independent of temperature. Removal of Ca2+ from the receptor membrane yielded a large dynamic component even at 2.5 degrees C. 3) The treatment of the tongue with procaine led to a large reduction in the magnitude of the dynamic component, whereas the effect of procaine on the steady component was not pronounced. 4) The magnitude of the dynamic component varied with the pH of the stimulating solution, whereas that of steady component was practically independent of a pH between 4.5 and 7.5. The above results were well interpreted by the following reaction scheme: S (stimulus + A (receptor domain) in equilibrium (SA)active in equilibrium (SA) inactive where (SA) active and (SA) inactive are active and inactive complexes.