Intracellular Axial Current in Chara corallina Reflects the Altered Kinetics of Ions in Cytoplasm under the Influence of Light

Abstract

Recent experiments demonstrate that the concentration of Ca2+ in cytoplasm of Chara corallina internodal cells plays important role in electrical excitation of the plasma membrane. The concentration of free Ca2+ in the cytoplasm -[Ca2+]c is also sensitive to visible light. Both phenomena were simultaneously studied by noninvasive measuring action potential (AP) and magnetic field with a superconducting quantum interference device magnetometer in very close vicinity of electrically excited internodal C. corallina cells. A temporal shift in the depolarization maximum, which progressively occurred after transferring cells from the dark into the light, can be explained by the extended Othmer model. Assuming that the change in membrane voltage during the depolarization part of AP is the direct consequence of an activation of [Ca2+]c sensitive Cl- channels, the model simulations compare well with the experimental data. We can say that we have an example of electrically elicited AP that is of biochemical nature. Electric and magnetic measurements are in good agreement.

Broadening the definition of a nervous system to better understand the evolution of plants and animals

“…For example, in Chara corallina , the action potential is not based only on voltage-dependent ion channels; the exposure to light causes a progressive shift in the depolarization maximum. 132 But this complexity does not signify a difference between plants and animals because some neurons in animals also have action potentials that are not entirely based on time- and voltage-dependent ion channels. 133 A recent study in Nitellopsis obtusa and Marchantia polymorpha has shown that inhibitors of human two-pore channels alter resting potential, action potential amplitudes and the duration of action potential repolarization by affecting channels.…”

High-resolution room-temperature sample scanning superconducting quantum interference device microscope configurable for geological and biomagnetic applications

“…1,2 In addition to the SQUID's unsurpassed field sensitivity, this technique is completely non-invasive and can be implemented to study a great variety of samples. RT sample SSM is continuing to play an important role in biomagnetism, [3][4][5][6][7][8] nondestructive evaluation, [9][10][11][12][13][14] and geomagnetism. 15,16 Since the field and spatial resolution are highly diminished as the distance between the sample and the sensor increases, the key to this technique is to bring the sensor, held at cryogenic temperatures, as close as possible to the sample.…”

Action potentials induce biomagnetic fields in Venus flytrap plants

“…Although human and animal biomagnetism are well-developed areas of research 2,20,21,24,25,26 , very little analogous work has been conducted in the plant kingdom 9,12,22,27 , largely because biomagnetic signals are typically much smaller in amplitude and frequency than their animal counterparts. Previously reported detection of plant biomagnetism, which established the existence of measurable magnetic activity in the plant kingdom, was carried out using superconducting-quantum-interference-device (SQUID) magnetometers 9,12,22 . Atomic magnetometers are arguably more attractive for biological applications, since, unlike SQUIDs 28,29 , they are non-cryogenic and can be miniaturized to optimize spatial resolution of measured biological features 20,26,30 .…”