COOPERATIVE BEHAVIOR OF K+ CHANNELS IN THE TONOPLAST OF CHARA-CORALLINA

Spontaneous cooperativity of K+ channels is studied in excised patches of Chara corallina tonoplasts. Bar histograms (dwell time versus number of open channels) are constructed from the time series of current by means of the high-order Hinkley detector (R. Schultze and S. Draber. 1993. J. Membr. Biol. 132:41-52). A statistical test, based on these bar histograms, shows that the channels are not independent. Further analysis reveals that the channels are cooperatively changing their open probability, which leads to the idea of cooperative mode shifting.