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Using the liquid microelectrode technique, the electrical potentials of nodal cells and the with them internodal cells neighbouring, of Nitellopsis obtusa plants of the Characeae family were determined. A specific variation in the potential of nodal cells in the form of cacophony-type irregular disturbances was also found, indicating that the node is not a passive mechanical element controlled by internodal cells, but is a complex system of coupled-, and different metabolic oscillators.

By means of the techniques of external electrodes and microelectrodes, it was found that evanescent flow of an alternating current through plasmalemma of Characeae cells neutralises oscillatory change in their electrical resistance and reversibly diminishes its value. This effect is particularly significant in the case of "high resistance cells", but it weakens with increasing temperature. The value of the estimated activation energy indicates that, after flow of the alternating current through the membrane, a rapid increase in the conductivity may be caused by an increase in conductivity of potassium channels. This result seems to support the hypothesis of electroconformational feedback.

Characteristics of changes in ultraweak luminescence of Nitella internodal cells under physiological conditions and after exposure to the action of biologically active substances are determined. The results presented here supplement the picture of oscillatory behaviour of Nitella cells worked out by us regarding changes in the electrical and transport properties.

The amplitudes of oscillation changes of potential and electrical resistance of Nitellopsis obtusa cell membranes differing from each other in their individual evolution stages were determined. The first, third and fifth cells from the tops of the plants were collected for measurements and only those characterised by rhythmical changes in potential and electrical conductivity of membranes (which revealed one or simultaneously 2-3 types of oscillations) were selected. Visible dependence of the amplitude of investigated changes on developmental stages of the cells, correlating with the intensity of metabolic transformations, was established.

The dependence of the amplitude of oscillatory changes in the electrical resistance of Nitellopsis obtusa cell membranes on the vegetation season of these plants is determined. The measurements were made on third cells from the tips of the plants which showed at least one type of oscillation in the resistance. A clear dependence of the amplitude of the studied changes on the vegetation season, especially on the maturity and rest stages of the plants, was found. These results as well as the observed changes in the characteristics of oscillations in the resistance, caused by sudden changes in the temperature of the cell surrounding, indicate a relationship between the oscillatory behaviour and the intensity of metabolic changes in the cells.