Abstract
Characean internodal cells generate receptor potential (ΔEm) at the moment of both compression and decompression ((ΔEm)S and (ΔEm)E, respectively) in long-lasting stimulation. In this report, to verify our hypothesis that the ΔEm depends on the degree of membrane deformation, the ΔEm in internodal cells treated with a potent water channel inhibitor, HgCl2, was investigated.
After the whole-cell treatment with HgCl2, a long-lasting stimulus induced relatively small membrane deformation and ΔEm, compared with those of intact cells. On the other hand, the cell, in which only the stimulated portion had been treated with HgCl2, presented deformation with similar amplitudes of untreated cells but small ΔEm as is the case in the whole-cell, suggesting a possibility that the generation of the ΔEm may be linked to water movement especially across the plasma membrane of the stimulated portion.
