Cyclic voltammetry of apple fruits: Memristors in vivo.

A memristor is a resistor with memory that exhibits a pinched hysteretic relationship in cyclic voltammetry. Recently, we have found memristors in the electrical circuitry of plants and seeds. There are no publications in literature about the possible existence of memristors and electrical differentiators in fruits. Here we found that the electrostimulation of Golden Delicious or Arkansas Black apple fruits by bipolar periodic waves induces hysteresis loops with pinched points in cyclic voltammograms at low frequencies between 0.1MHz and 1MHz. At high frequencies of 1kHz, the pinched hysteresis loop transforms to a non-pinched hysteresis loop instead of a single line I=V/R for ideal memristors because the amplitude of electrical current depends on capacitance of a fruit's tissue and electrodes, frequency and direction of scanning. Electrostimulation of electrical circuits in apple fruits by periodic voltage waves also induces electrotonic potential propagation due to cell-to-cell electrical coupling with electrical differentiators. A differentiator is an electrical circuit in which the output of the circuit is approximately directly proportional to the rate of change of the input. The information gained from electrostimulation can be used to elucidate and to observe electrochemical and electrophysiological properties of electrical circuits in fruits.

Memristors: Memory elements in potato tubers.

A memristor is a nonlinear element because its current-voltage characteristic is similar to that of a Lissajous pattern for nonlinear systems. This element was postulated recently and researchers are looking for it in different biosystems. We investigated electrical circuitry of red Irish potato tubers (Solanum tuberosum L.). The goal was to discover if potato tubers might have a new electrical component - a resistor with memory. The analysis was based on a cyclic current-voltage characteristic where the resistor with memory should manifest itself. We found that the electrostimulation by bipolar sinusoidal or triangle periodic waves induces electrical responses in the potato tubers with fingerprints of memristors. Tetraethylammonium chloride, an inhibitor of voltage gated K(+) channels, transforms a memristor to a resistor in potato tubers. Our results demonstrate that a voltage gated K(+) channel in the excitable tissue of potato tubers has properties of a memristor. Uncoupler carbonylcyanide-4-trifluoromethoxy-phenyl hydrazone decreases the amplitude of electrical responses at low and high frequencies of bipolar periodic sinusoidal or triangle electrostimulating waves. The discovery of memristors in plants creates a new direction in the understanding of electrical phenomena in plants.

Memory elements in the electrical network of Mimosa pudica L.

The fourth basic circuit element, a memristor, is a resistor with memory that was postulated by Chua in 1971. Here we found that memristors exist in vivo. The electrostimulation of the Mimosa pudica by bipolar sinusoidal or triangle periodic waves induce electrical responses with fingerprints of memristors. Uncouplers carbonylcyanide-3-chlorophenylhydrazone and carbonylcyanide-4-trifluoromethoxy-phenyl hydrazone decrease the amplitude of electrical responses at low and high frequencies of bipolar sinusoidal or triangle periodic electrostimulating waves. Memristive behavior of an electrical network in the Mimosa pudica is linked to the properties of voltage gated ion channels: the channel blocker TEACl reduces the electric response to a conventional resistor. Our results demonstrate that a voltage gated K(+) channel in the excitable tissue of plants has properties of a memristor. The discovery of memristors in plants creates a new direction in the modeling and understanding of electrical phenomena in plants.

Morphing structures of the Dionaea muscipula Ellis during the trap opening and closing.

The Venus flytrap is a marvelous plant that has intrigued scientists since the times of Charles Darwin. This carnivorous plant is capable of very fast movements to catch a prey. We found that the maximal speed of the trap closing in the Dionaea muscipula Ellis is about 130,000 times faster than the maximal speed of the trap opening. The mechanism and kinetics of this movement was debated for a long time. Here, the most recent Hydroelastic Curvature Model is applied to the analysis of this movement during closing and opening of the trap with or without a prey. Equations describing the trap movement were derived and verified with experimental data. Chloroform and ether, both anesthetic agents, induce action potentials and close the trap without the mechanical stimulation of trigger hairs. We tested this by dropping 10 µL of ether on the midrib inside the trap without touching any of the mechanosensitive trigger hairs. The trap closed slowly in 10 s. This is at least 20 times slower than the closing of the trap mechanically or electrically. The similar effect can be induced by placing 10 µL of chloroform on the midrib inside the trap, however, the lobes closing time in this case is as fast as closing after mechanical stimulation of the trigger hairs.

Memristors in plants.

We investigated electrical circuitry of the Venus flytrap, Mimosa pudica and Aloe vera. The goal was to discover if these plants might have a new electrical component--a resistor with memory. This element was postulated recently and the researchers were looking for its presence in different systems. The analysis was based on cyclic current-voltage characteristic where the resistor with memory should manifest itself. We found that the electrostimulation of plants by bipolar sinusoidal or triangle periodic waves induces electrical responses in the Venus flytrap, Mimosa pudica and Aloe vera with fingerprints of memristors. Tetraethylammonium chloride, an inhibitor of voltage gated K(+) channels, transforms a memristor to a resistor in plant tissue. Our results demonstrate that a voltage gated K(+) channel in the excitable tissue of plants has properties of a memristor. This study can be a starting point for understanding mechanisms of memory, learning, circadian rhythms, and biological clocks.

Memristors in the electrical network of Aloe vera L.

A memristor is a resistor with memory, which is a non-linear passive two-terminal electrical element relating magnetic flux linkage and electrical charge. Here we found that memristors exist in vivo. The electrostimulation of the Aloe vera by bipolar sinusoidal or triangle periodic waves induce electrical responses with fingerprints of memristors. Uncouplers carbonylcyanide-3-chlorophenylhydrazone and carbonylcyanide-4-trifluoromethoxy-phenyl hydrazone decrease the amplitude of electrical responses at low and high frequencies of bipolar periodic sinusoidal or triangle electrostimulating waves. Memristive behavior of an electrical network in the Aloe vera is linked to the properties of voltage gated ion channels: the K(+) channel blocker TEACl reduces the electric response to a conventional resistor. Our results demonstrate that a voltage gated K(+) channel in the excitable tissue of plants has properties of a memristor. The discovery of memristors in plants creates a new direction in the modeling and understanding of electrical phenomena in plants.

Memristors in the Venus flytrap.

A memristor is a nonlinear element because its current-voltage characteristic is similar to that of a Lissajous pattern for nonlinear systems. We investigated the possible presence of memristors in the electrical circuitry of the Venus flytrap's upper and lower leaves. The electrostimulation of this plant by bipolar sinusoidal or triangle periodic waves induces electrical responses in the upper and lower leaves of the Venus flytrap with fingerprints of memristors. The analysis was based on cyclic voltammetric characteristics where the memristor, a resistor with memory, should manifest itself. Tetraethylammonium chloride, an inhibitor of voltage gated K(+) channels, or NPPB, a blocker of voltage gated Cl(-) and K(+) channels, transform a memristor to a resistor in plant tissue. Uncouplers carbonylcyanide-3-chlorophenylhydrazone (CCCP) and carbonylcyanide-4-trifluoromethoxy-phenyl hydrazone (FCCP) decrease the amplitude of electrical responses at low and high frequencies of bipolar periodic electrostimulating waves. Our results demonstrate that voltage gated K(+) channels in the Venus flytrap have properties of memristors of type 1 and type 2. The discovery of memristors in plants creates a new direction in the modeling and understanding of electrical phenomena in plants.