Bioelectric Potentials Research Articles

風速変化に対する植物生体電位応答

風速変化に対する植物生体電位応答

Effect of Respiration on Bioelectric Potential on the Surface of Tomato Eruit Harvested

Effect of Respiration on Bioelectric Potential on the Surface of Tomato Eruit Harvested

Investigation of the Optimum Farming Temperature for Grifola frondosa and Growth Promotion using the Bio-Electric Potential as an Index

The purpose of this study was to investigate the optimum farming conditions for mushrooms from the view point of engineering field. As the bio-electric potential of mushrooms is considered to be closely related to the activation of mushroom cells, this relationship has been used to analyze the dependence of the morphogenetic characteristics of Grifola frondosa on farming temperatures (from 16 to 22 degree C). The experimental results indicated that a maximum response was exhibited, with correspondingly favorable morphogenesis obtained at 18 degree C. Based on the experimental results, including those in a previous study, it was assumed that the larger the bio-electric potential becomes, the higher the growth yield reaches. In order to support this assumption, growth promotion was conducted by intentionally activating the bio-electric potential within the mushrooms by stimulating them with short bursts of illumination. The resulting observation of growth promotion permitted the conclusion that the bio-electric potential can, indeed, be regarded as an index of growth.

Effects of Wavelength of Light Stimuli and Environmental Temperature on the Bio-Electric Potential and the Morphogenetic Properties of Pholiota nameko

In this study, the relationship has been examined between the bio-electric potential and the morphogenetic properties of Pholiota nameko, for investigating the optimum farming conditions for mushrooms from engineering considerations. Initially, the effect of wavelength of light stimuli on the morphogenetic properties was investigated, based on the bio-electric potential under blue light was greater than under red light. The experimental results indicated that progressed morphogenesis obtained under blue light created large bio-electric potentials. This was followed by an investigation of the response characteristics of the bio-electric potential with respect to environmental temperature(from 14℃ to 22℃). This was then used to analyze the dependence of the morphogenetic properties. The experimental results indicated that a maximum response occurred,with correspondingly favorable morphogenesis obtained, at 14℃. Based on the above results, it is concluded that the value of the bio-electric potential is an effective measure for the objective evaluation of farming production.

Bioelectric Potential Characteristic of Potted Plant for Temperature Change in a Residential Space

It becomes obvious that plants are influenced by various kinds of environmental factors, namely temperature, humidity and light intensity. In this study, the influences are examined using the bioelectric potential of the plants. The experiments were carried out in a residential space. One person was living in the residence and a subjective plant was installed in the space. The potential, temperature, humidity, light intensity, atmospheric pressure, sound level and moisture grade in the pot-soil were measured respectively. Some integrated values of the potential characteristics were adopted to derive the influences of the environmental factors. The values were introduced by integrating the characteristic for one hour (vh1), one minute (vm1) or ten minutes (vm10). As for the results, the vh1 became smaller as the atmospheric temperature (tr) became larger, namely negative correlation was recognized among those characteristics. It was also understood that the vh1 characteristic was delayed about one hour than the tr characteristic. The FFT(Fast Fourier Transform) analysis was done to tr and vh1 characteristics and the results for the characteristics were same, namely both characteristics had almost same frequency components. It also became obvious that the vh1 increased as the moisture grade decreased in the pot soil. This result can be applied to the care of plants.

Statistical Analysis of Plant Bioelectric Potential for Communication with Humans

The bioelectric potential of a foliage plant changes according to an occupant’s behavior, for example entering the room in which the plant is installed, as well as watering and touching the plant. The potential shows the impulse responses due to the behaviors. In this study, the integrated values of the bioelectric potential were adopted to identify those behaviors. There are two types of values. Those were derived by integrating the bioelectric potential characteristics for a minute (vm1) and for an hour (vh1) respectively. The histogram of the values vm1 for the steady state perfectly took a normal distribution. The frequencies of vm1 for the behaviors were different compared with the steady state distribution. The system can identify the behaviors by examining the frequency table of vm1. Conversely, it is thought the plant gives us some suggestions using bioelectric potential characteristics. A clue for communication between humans and plants was also obtained. The vh1 becomes higher as the average room temperature (tr) becomes lower. There was a negative correlation between vm1 and tr. There were two groups in the scatter diagram of the variables vm1 and tr.

光刺激による茸（マイタケ）の生体電位反応（第４報）―子実体および培地内部のリズム変動特性―

In our previous study of measurements of bio-electric potential of Grifola frondosa, a rhythmic fluctuation was often observed in the bio-electric potential reaction, even when light stimuli were applied at regular intervals. If there is any relationship between the duration of light/dark and the rhythmic fluctuation of bio-electric potential, it could be worthwhile to investigate any corresponding relationship to the growth control of mushroom. In this study, the characteristics of rhythmic fluctuations, both for the fruit body and the primordium of Grifola frondosa were investigated, focusing on the reaction of the bio-electric potential when light stimuli were applied to the mushroom on a regular cycle of light/dark conditions for many hours. As a result, rhythmic fluctuation characteristics in the bio-electric potential of the fruit body were confirmed. An approximate cycle was noted between 13 to 64 hours, which tends towards a 1/f2 characteristic fluctuation. On the other hand, although the dependence of bio-electric potential changes on the light stimuli was not observed in the primordium, a bio-rhythm was noted, with an approximate periodic characteristic between 14 to 68 hours, tending towards a 1/f2 fluctuation as in the fruit body.

Problems of Modern Electrocardiography (Dedicated to the Hundredth Anniversary of Electrocardiography, 1903-2003)

Modern electrocardiography provides a wide range of means for system (computer) analysis [1, 3]. Their application to electrocardiographic diagnosis makes it possible to perform digital processing and mapping of the bioelectric potentials of the heart [7, 8]. However, some professional software systems remain of little use by practitioners [1]. Many diagnosticians (especially in municipal polyclinics with a continuous stream of patients) refuse to use auxiliary methods of analysis and automatic interpretation. Experts mention such disadvantages of these methods as operational complexity and unreliability [1]. Meanwhile, the high-technology market is overwhelmed with unclaimed software for electrophysiological equipment. Foreign products of doubtful quality prevail on this market [1, 8]. The demands of physicians are often neglected by ECG software programmers, which complicates the process of development, improvement, and implementation of such methods of system analysis, which could be widely used in everyday medical practice. At present, the preference is given to the empirical methods for interpretation of electrocardiograms (ECG) [1]. However, the routine methods for ECG processing can be effectively used only in institutions with large ECG departments and a limited number of patients.

Bioelectric field potentials of the ventilatory muscles in the crayfish

This study investigated the pattern of the electrical field potentials recorded near the prebranchial chamber of the native crayfish Astacus leptodactylus. Inside the prebranchial chamber, the electrical waves had maximal amplitude and showed 2–4 peaks per cycle. Potentials with the same frequency but smaller amplitude and simpler shape were also recorded outside the chamber, near the edge of the carapace, and at some distance towards the caudal direction. Correlation of these electrical potentials with movements of the scaphognathite in intact Procambarus cubensis with a transparent external wall of the prebranchial chamber has shown a high coincidence both in rate and phase of the two processes. The electrical activity picked up by an electrode located in the prebranchial chamber or near it represents the cumulative electrical field generated by the muscles moving the scaphognathite, and may be termed as the electroscaphognathitegram (ESG). The correlation of the mechanoscaphognatitegram determined optically from the magnified image of the scaphognathite and the ESG allowed us to suggest that the ascending phase of single electrical wave corresponds to the activation of the muscles responsible for downward movement of the scaphognathite, whereas its descending phase reflects its upwards movement.

Bioelectrical potentials of Philodendron cordatum: a new method for investigation of behavior in plants.

We explored the prospect of using the bioelectrical potentiaLs of Philodendron cordatum as a new method for studying the behavior of plants. The bioelectrical potentials were recorded from equipment typically associated with EEG recordings. Plants were exposed to a 6-hr. training period of light only, dark only, or alternating 1-min. periods of light/dark. Following training, all plants were exposed to a 10-min. testing period in darkness during which bioelectrical potentials were recorded. Power of the bioelectric potentials was compared between groups of plants for frequencies between 0.1 and 10.0 Hz. Significant main effects of group and frequency were found, raising questions about the possibility of "learning" in P. cordatum.

光刺激による舞茸の子実体の生体電位反応と形態形成との関係

Mushrooms have recently been attracting increasing attention for their use as part of a healthy diet; because they are rich in nutrients while low in calories, they are effective in preventing modern life-style diseases. Accordingly, mushroom farming has increased. In order to increase the productivity of mushroom farming, it is important to study the optimal farming conditions, such as the temperature, humidity, light stimulus, and the composition of the atmosphere, as well as the ingredients of the culture medium. However, these conditions have generally been chosen according to farmers' experiences at the site and few scientific studies have so far been conducted. We have scientifically investigated the optimum growing conditions of mushrooms focusing on the relationship between the bioelectric potential and the morphogenetic properties. In this study using Grifora Frondosa as a sample, we investigated how the mushroom responds to different wavelengths, luminance, and the irradiation method of the light-stimulus using the bio-electric potential signal as an indicator. The bio-electric potential is estimated to have a close relationship with the activation of the cells. Based on the obtained bio-electric potential data, we experimentally developed a novel light source instrument using a LED for controlling growth, which is effective in forming the fruit-body of the mushroom after development of the primordium at the mushroom growing farm. We report here on the fundamental data concerning the influence of bio-electric potential produced as a result of various light stimuli on the morphogenetic properties of Grifora Frondosa.

Effect of Mentha × piperita essential oil and monoterpenes on cucumber root membrane potential

Peppermint ( Mentha piperita L.) essential oil and its main components were assessed for their ability to interfere with plant plasma membrane potentials. Tests were conducted on root segments isolated from etiolated seedlings of cucumber ( Cucumis sativus L.). Increasing the concentration of peppermint essential oil from 5 to 50 ppm caused a decrease in membrane potential ( V m) hyperpolarization of 10–3 mV, whereas concentrations from 100 up to 900 ppm caused an increasing depolarization of V m (from 5 to 110 mV). When tested at 300 ppm, (+)-menthyl acetate, (−)-limonene and 1,8-cineole did not exert any significant effect on V m, whereas (+)-menthofuran (73 mV), (+)-pulegone (85 mV), (+)-neomenthol (96 mV), (−)-menthol (105 mV) and (−)-menthone (111 mV) showed increased ability to depolarize V m. A plot of log of octanol–water partition coefficient ( K ow) against their depolarizing effect showed a significant negative correlation, suggesting that among all monoterpenoids increased membrane depolarization depends on lower K ow. However, among monoterpene ketones, alcohols and furans, increased membrane depolarization is associated with a decline in water solubility. The possible effect of monoterpenoids on membrane ion fluxes is also discussed, since changes in the bioelectric potential of cells imply changes in the flux of ions across the plasma membrane

Measurement of Bioelectric Potential on Surface of Some Harvested Fruits

The bioelectric potential on plant surface (surface potential) of harvested tomato and banana fruits was measured. Effects of room temperature and respiration rate on the surface potential were investigated. The surface potential clearly changed with temperature. The change in surface potential with temperature depended on respiration-dependent electrogenic potential. It is very likely that the change in respiration at the climacteric stage is able to be distinguished from the change with temperature by detecting the surface potential.

Auxin-Induced Electrophysiological Gradients in Plant Axial Organs

Indole-3-acetic acid (IAA) is known to induce slow oscillations of the bioelectric potential (BEP) in plant tissues, which can be measured with extracellular and intracellular electrodes. Oscillations on the cell surface correspond to those of the membrane potential in auxin-treated cells [3]. Newman concluded that auxindependent BEP oscillations were related to the mechanism of the auxin polar transport [8, 9], which occurs through the living phloem and xylem tissues in stems and roots [6, 7]. However, it is only one aspect of the phytohormone action. The IAA effects on plant growth, movements, and other processes of vital activity, including the auxin transport, are mediated by the same mechanism of the hormonal signal perception and transduction with participation of membranes [3]. The objective of this work was to investigate the influence of the local treatment of conducting and peripheral tissues with IAA on BEP generation. The segments excised from burdock ( Arctium lappa L.) petioles and dandelion ( Taraxacum officinale L.) roots were used. Surface BEP were measured using EVL-1MZ AgCl electrodes with a micropipette filled with 3% agar and 0.1 M KCl and a pH-340 amplifier of the constant current. Two-cm-long segments were excised from basal parts of burdock petioles. They were incubated in 10 - 3 M CaCl 2 at room temperature and illumination for 2 h, rinsed with distilled water, and fixed vertically (with apical cut upward) in petri dishes filled with 10 - 3 M CaCl 2 so that the solution covered the 0.5-cm basal parts of the segments. On the cut surface, two symmetrical conducting bundles or parenchymal regions were selected, and small cotton clumps (1.5 mm in diameter) moistened with distilled water were placed on. They exerted a contact between plant tissues and electrodes. The difference of potentials between two bundles or parenchymal zones was measured three times at intervals of 10 min to obtain stable values. Thereafter, the cotton clump under the measuring electrode was replaced by that moistened with IAA (10 or 100 mg/l) and cotton clumps moistened with distilled water under the reference electrodes and under both electrodes of control segments were refreshed. The difference of potentials was monitored for 2 h. Periodically, drying cotton clumps were moistened with distilled water or auxin solutions. Five experiments were carried out with five replicates in each. The control values were subtracted, and the means with their confidence intervals at p = 0.05 are presented.

Effect of artificial electric fields on plants grown under microgravity conditions.

Ionic and structural hetorogeneity of cells, tissues, and organs of plants are associated with a spectrum of electric characteristics such as bioelectric potentials, electrical conductance, and bioelectric permeability. An important determinant for the plant function is electric properties of the cell membranes and organelles which maintain energy and substance exchange with the environment. Enzymes and other biologically active substances have a powerful charge at the molecular level. Finally, all molecules, including those of water, represent dipoles, and this determines their reactive capacity. A major determinant is the bioelectric polarity of a plant is genetically predetermined and cannot be modified. It is an intrinsic structural feature of the organism whose evolution advent was mediated by gravity. An illustrative presentation of polarity is the downward growth of the roots and upward growth of stems in the Earth's gravitation field. However, gravity is a critical, but not the sole determinant of the plant organism polarization. Potent polarizing effects are exerted by light, the electromagnetic field, moisture, and other factors. It is known that plant cultivation in an upturned position is associated with impairment of water and nutrient uptake, resulting in dyscoordination of physiological processes, growth and developmental retardation. These abnormalities were characteristic when early attempts were made to grow plants in weightlessness conditions.

Non‐invasive recording of heart rate and ventilation rate in rainbow trout during rest and swimming. Fish go wireless!

Resting heart rates and ventilation rates in rainbow trout Oncorhynchus mykiss at 15°C are 31·8±1·8 beat min−1 and 53·1±3·7 breaths min−1, respectively. The non‐invasive recording system picked up the bioelectric potentials generated by the fish in the water and was based on an array of six silver‐silver chloride electrodes covered with agar‐gel, which provided a better signal‐to‐noise ratio than in previously described systems, and allowed the determination of heart rate and ventilation rates at different swimming speeds up to 21 s−1. In concert with the lower rates, the scope for changes in heart rate and ventilation rate during swimming was also considerably larger than in earlier studies (2·4‐ and 2·0‐fold, respectively). Two main conclusions result from this work: (i) short recovery times under 48 h after anaesthesia and surgery are unlikely to provide truly resting heart rates and ventilation rates in trout at 15°C; (ii) heart rate regulation during exercise is more important than previously thought and might account for a larger proportion of the increase in cardiac output observed in swimming trout.

茸（なめこ）における光刺激と生体電位反応 （第１報） 刺激波長と生体電位との関係

茸（なめこ）における光刺激と生体電位反応 （第１報） 刺激波長と生体電位との関係

トマトの葉面電位の特徴と栄養診断への適用

A foliar potential shift is a micropotential that is released from the surface of plant leaves. We have been investigating the relationship between foliar potential and the nutritional status of plants. In foliar potential attributable to different measurement sites were investigated.In experiments on the relationship between foliar potentials and the nutritional status of plants, three test groups were established (complete nutrition, N-deficient, and Mg-deficient groups), and changes in potential were measured at the upper and lower leaves of plants in each group. Measurements were converted into logarithmic values, and were studied statistically by a discriminant analysis. The results showed that potentials at 14 and 16 Hz on upper leaves were greater for the N-deficient group than those for the complete nutrition group. Furthermore, the potential at 19 Hz on the upper leaves was greater for the Mg-deficient plants than that for the complete nutrition group.Experiments on the nycterohemeral characteristics of foliar potential were conducted to identify differences in foliar potentials between night and day. In the past, foliar potentials have only even when measurements are taken during the day, it is difficult to evaluate the effect of conducting experiments in daylight. In the present study, a shield box made using a transparent conductive film was used to allow foliar potentials to be measured during the day. We found that potentials at the same frequencies (11, 13-14 Hz) were greater at night for both upper and lower leaves.Experiments on the differences in foliar potential attributable to different measurement sites were conducted to clarify the effect of electrode location on test data. Two sets of experiments were performed. In one, an electrode was placed at two different locations on the upper-most leaf. In the other, an electrode was placed on an upper leaf and a lower leaf of the same plant to evaluate differences in data. Data from the same leaf showed a high degree of similarity. Identifiable characteristics in the frequency composition between upper and lower leaves in plants in the N-deficient or Mg-deficient groups. Nevertheless, potential shifts that could distinguish upper and lower leaves could not be confirmed in plants in the complete nutrition group.

Optical monitoring of PO 2 changes and simultaneous recording of bioelectric activity in human and animal brain slices

For investigations of hypoxic effects in nervous tissue, brain slices are often used as a model system. This provides the advantage that parameters of the micromilieu, e.g. pH and temperature can easily be controlled and measurements of different data, e.g. bioelectric potentials, ion activities etc. can be performed. It is of special importance that the PO 2 the slice preparation is exposed to is equally controlled under these conditions. Therefore, a PO 2 monitoring system is needed which provides representative values for the tissue environment. This requirement is fulfilled by an optical PO 2 sensing method based on phosphorescence quenching as a function of PO 2. Here, the application of this method as adapted for use in in vitro models is described and compared to the polarographic oxygen-sensing method. Both the optical and polarographic methods are comparable regarding accuracy and response time of measurements. Furthermore, both the optical method and electrophysiological measurements can be combined. Lastly, under experimental conditions, neither the phosphorescent dye Palladium-meso-tetra-4-carboxyphenyl-porphine nor the illumination necessary for excitation of the dye influence bioelectric activity of neuronal tissue in vitro. In conclusion, the optical PO 2 sensing method presented here provides a tool for reliable and continuous monitoring of PO 2 in the immediate environment of brain slice preparations.

Measurements of the bioelectrical potential of a Japanese oak (Quercus crispula Blume) sapling: Effect of the radial distribution of inorganic ingredients within a tree stem on the diurnal change in resting potential

This study investigated the relation between the resting potential of a 2-year-old Japanese oak (Quercus crispula Blume) sapling and its physiology, especially the radial transport of water containing inorganic ingredients in the stem using the scanning electron microscope-energy dispersive X-ray microanalyzer (SEM-EDXA) method. The resting potential of a sapling could be monitored continuously with our measuring apparatus. Changes in resting potential were due to the light. The hyperpolarization and depolarization peaks of the resting potential, whose absolute voltage was about 10mV, occurred right after lights-off and lights-on, respectively. The resting potential was found to show periodic responses for each day unit. At night (lights-off), the resting potential tended to depolarize with an increase in tangential strain. On the other hand, during the daytime (lights-on) the resting potential tended to hyperpolarize, depolarize, or show a nearly constant value for the tangential strain. The water containing inorganic ingredients was transported, via transpiration, in both directions between the mature xylem zone and the phloem zone through differentiating xylem cells. This water transport within a tree stem had a significant effect on the diurnal changes in resting potential.