Abstract: | The effects of 20 mM tetraethylammonium (TEA) and 5 mM 4-aminopyridine (4-AP) on mechanically and electrically excitable membranes of Pacinian corpuscles were investigated using the air gap technique for producing constant superfusion and recording electrical response at the receptor. The effects of TEA led to a 150% rise in the duration of receptor potential, the amplitude of which declined by 40%. No statistically significant changes in response to mechanical stimulation could be detected after applying 4-AP to the receptor membrane. The two blockers mentioned did modify the membrane of the first nodes of Ranvier, producing a 2–3-fold increase in the duration of action potentials. Computations based on the Dodge model would indicate that the observed effects may be explained by inhibition of voltage-dependent potassium channels which help to transform receptor current into spike response in the intact receptor.I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. Translated from Neirofiziologiya, Vol. 20, No. 5, pp. 623–630, September–October, 1988. |