Physical aspects of biophotons

Ultra weak photon emission-a brief review

Cells emit light at ultra-low intensities: photons which are produced as by-products of cellular metabolism, distinct from other light emission processes such as delayed luminescence, bioluminescence, and chemiluminescence. The phenomenon is known by a large range of names, including, but not limited to, biophotons, biological autoluminescence, metabolic photon emission and ultraweak photon emission (UPE), the latter of which shall be used for the purposes of this review. It is worth noting that the photons when produced are neither 'weak' nor specifically biological in characteristics. Research of UPE has a long yet tattered past, historically hamstrung by a lack of technology sensitive enough to detect it. Today, as technology progresses rapidly, it is becoming easier to detect and image these photons, as well as to describe their function. In this brief review we will examine the history of UPE research, their proposed mechanism, possible biological role, the detection of the phenomenon, and the potential medical applications.

Energetic homeostasis achieved through biophoton energy and accompanying medication treatment resulted in sustained levels of Thyroiditis-Hashimoto's, iron, vitamin D & vitamin B12

We present the case of a 37-year-old premenopausal woman, who presented with fatigue, weakness, pallor, and myalgias. She was on treatment for Hashimoto's Thyroiditis, iron deficiency anemia, deficiency of vitamin D and B12. Further diagnostic workup revealed her anemia was attributed to a long history of menorrhagia, deficiency of vitamin D and B12 which was attributed to Celiac disease. Her overall health improved with daily medication and by being around the biophoton generators, a device-generated biophoton field. Supplemental exposure to biophoton energy stabilized her blood component levels and improved the functional and energetic conditions of all her organs and systems.

Biological autoluminescence as a perturbance-free method for monitoring oxidation in biosystems

Biological oxidation processes are in the core of life energetics, play an important role in cellular biophysics, physiological cell signaling or cellular pathophysiology. Understanding of biooxidation processes is also crucial for biotechnological applications. Therefore, a plethora of methods has been developed for monitoring oxidation so far, each with distinct advantages and disadvantages. We review here the available methods for monitoring oxidation and their basic characteristics and capabilities. Then we focus on a unique method - the only one that does not require input of additional external energy or chemicals - which employs detection of biological autoluminescence (BAL). We highlight the pros and cons of this method and provide an overview of how BAL can be used to report on various aspects of cellular oxidation processes starting from oxygen consumption to the generation of oxidation products such as carbonyls. This review highlights the application potential of this completely non-invasive and label-free biophotonic diagnostic method.

A biophoton method for identifying the quality states of fresh Chinese herbs

Introduction: The quality of Chinese herbs is the basis for ensuring their safety and efficacy. However, the quality evaluation system is imperfect. In particular, there is a lack of quality evaluation methods for fresh Chinese herbs during growth. The biophoton is a common phenomenon and provides complete information about the interior of the living system, which is consistent with the holistic concept of traditional Chinese medicine. Therefore, we aim to correlate the biophoton characteristics with the quality states to find the biophoton parameters that can characterize the quality states of fresh Chinese herbs. Methods: The biophoton characteristics of motherwort and safflower were measured and characterized by the counts per second (CPS) in the steady state and the initial intensity (I₀) and coherent time (T) of delayed luminescence. The active ingredient content was measured by ultra-high-performance liquid chromatography (UPLC). The pigment content of motherwort leaves was measured by UV spectrophotometry. The t-test and correlation analysis were performed on the experimental results. Results: The CPS and I₀ of motherwort and I₀ of safflower showed a significant downward trend during the growth process, and their active ingredient content showed a trend that increased and then decreased. The CPS, I₀, and the content of active ingredients and pigments in a healthy state were significantly higher than those in a poor state, while T showed the opposite results. The CPS and I₀ were all significantly and positively correlated with the content of active ingredients and pigments, while the T of motherwort showed the opposite results. Conclusion: It is feasible to identify the quality states of fresh Chinese herbs by using their biophoton characteristics. Both CPS and I₀ have better correlations with the quality states and can be considered characteristic parameters of the quality of fresh Chinese herbs.

Are Brain-Computer Interfaces Feasible With Integrated Photonic Chips?

The present paper examines the viability of a radically novel idea for brain-computer interface (BCI), which could lead to novel technological, experimental, and clinical applications. BCIs are computer-based systems that enable either one-way or two-way communication between a living brain and an external machine. BCIs read-out brain signals and transduce them into task commands, which are performed by a machine. In closed loop, the machine can stimulate the brain with appropriate signals. In recent years, it has been shown that there is some ultraweak light emission from neurons within or close to the visible and near-infrared parts of the optical spectrum. Such ultraweak photon emission (UPE) reflects the cellular (and body) oxidative status, and compelling pieces of evidence are beginning to emerge that UPE may well play an informational role in neuronal functions. In fact, several experiments point to a direct correlation between UPE intensity and neural activity, oxidative reactions, EEG activity, cerebral blood flow, cerebral energy metabolism, and release of glutamate. Therefore, we propose a novel skull implant BCI that uses UPE. We suggest that a photonic integrated chip installed on the interior surface of the skull may enable a new form of extraction of the relevant features from the UPE signals. In the current technology landscape, photonic technologies are advancing rapidly and poised to overtake many electrical technologies, due to their unique advantages, such as miniaturization, high speed, low thermal effects, and large integration capacity that allow for high yield, volume manufacturing, and lower cost. For our proposed BCI, we are making some very major conjectures, which need to be experimentally verified, and therefore we discuss the controversial parts, feasibility of technology and limitations, and potential impact of this envisaged technology if successfully implemented in the future.

Influence of far-red light coherence on the functional state of plants

The influence of the coherence of far-red (730 nm) light on the functional activity of plants was studied. Blackberry explants cultivated in vitro on an artificial nutrient medium served as a biological model. The explants were irradiated with light beams with different spatial and temporal coherence. The average cell size D was taken as the discrimination threshold for the coherence length L_{coh} and the correlation radius r_{cor}. The results of irradiation were judged by the length and number of shoots formed on each explant. The greatest photoinduced effect was observed when the conditions L_{coh}, r_{cor}>D were fulfilled, i.e., when the cell fit completely in the coherence volume of the light wave field. Significant differences in growth parameters were also observed in the variants of the experiment with a constant frequency spectrum of radiation (fixed L_{coh}), but different r_{cor}. It is concluded that the correlation properties of radiation affect photoregulatory processes.

Enhancement of the biological autoluminescence by mito-liposomal gold nanoparticle nanocarriers

One of the most important barriers to the detection of the biological autoluminescence (BAL) from biosystems using a non-invasive monitoring approach, in both the in vivo and the in vitro applications, is its very low signal intensity (< 1000 photons/s/cm²). Experimental studies have revealed that the formation of electron excited species, as a result of reactions of biomolecules with reactive oxygen species (ROS), is the principal biochemical source of the BAL which occurs during the cell metabolism. Mitochondria, as the most important organelles involved in oxidative metabolism, are considered to be the main intracellular BAL source. Hence, in order to achieve the BAL enhancement via affecting the mitochondria, we prepared a novel mitochondrial-liposomal nanocarrier with two attractive features including the intra-liposomal gold nanoparticle synthesizing ability and the mitochondria penetration capability. The results indicate that these nanocarriers (with the average size of 131.1 ± 20.1 nm) are not only able to synthesize the gold nanoparticles within them (with the average size of 15 nm) and penetrate into the U2OS cell mitochondria, but they are also able to amplify the BAL signals. Our results open new possibilities for the use of biological autoluminescence as a non-invasive and label-free monitoring method in nanomedicine and biotechnology.

An Experimental Investigation of Ultraweak Photon Emission from Adult Murine Neural Stem Cells

Neurons like other living cells may have ultraweak photon emission (UPE) during neuronal activity. This study is aimed to evaluate UPE from neural stem cells (NSC) during their serial passaging and differentiation. We also investigate whether the addition of silver nanoparticles (AgNPs) or enhancement of UPE (by AgNPs or mirror) affect the differentiation of NSC. In our method, neural stem and progenitor cells of subventricular zone (SVZ) are isolated and expanded using the neurosphere assay. The obtained dissociated cells allocated and cultivated into three groups: groups: I: cell (control), II: cell + mirror, and III: cell + AgNPs. After seven days, the primary neurospheres were counted and their mean number was obtained. Serial passages continuous up to sixth passages in the control group. Differentiation capacity of the resulting neurospheres were evaluated in vitro by immunocytochemistry techniques. Measurement of UPE was carried out by photomultiplier tube (PMT) in the following steps: at the end of primary culture, six serial cell passages of the control group, before and after of the differentiation for 5 minutes. The results show that neither mirror nor AgNPs affect on the neurosphere number. The UPE of the NSC in the sixth subculturing passage was significantly higher than in the primary passage (P < 0.05). AgNPs significantly increased the UPE of the NSC compared to the control group before and after the differentiation (P < 0.05). Also, the treatment with AgNPs increased 44% neuronal differentiation of the harvested NSCs. UPE of NSC after the differentiation was significantly lower than that before the differentiation in each groups, which is in appropriate to the cell numbers (P < 0.0001). The mirror did not significantly increase UPE, neither before nor after the differentiation of NSC. As a conclusion, NSC have UPE-properties and the intensity is increased by serial passaging that are significant in the sixth passage. The AgNPs increases the UPE intensity of NSC that pushes more differentiation of NSC to the neurons. The mirror was not effective in enhancement of UPE. As a result, UPE measurement may be suitable for assessing and studying the effects of nanoparticles in living cells and neurons.

Characterization of the hot and cold medicinal properties of traditional Chinese herbs by spontaneous photon emission ratio of mice

ETHNOPHARMACOLOGICAL RELEVANCE

One important therapeutic characteristic of traditional Chinese medicine (TCM) for its properly-guided clinical prescription is considering the cold and hot medicinal properties of traditional Chinese herbs. According to the TCM theory, the hot and cold medicinal properties are defined by the general responses of a human body to a given herbal medicine. This definition is subjective and ambiguous which attenuates the modernization of TCM. Biological spontaneous photon emission (SE) is a normal phenomenon reflecting the transition of the quantum state of molecules inside an organism. The alteration of its level can indicate the changes of many aspects of the organism including metabolism. Thus, we can exploit this feature to develop a novel and scientific approach to quantitively and objectively characterize the hot and cold medicinal properties of traditional Chinese herbs.

OBJECTIVE

To determine whether SE can be used to characterize the hot and cold medicinal properties of traditional Chinese herbs, this study took advantage of the ultra-weak luminescence detection technology to examine the effects of traditional Chinese herbs with hot or cold medicinal property to the level of SE in mice.

MATERIALS AND METHODS

Mice were intragastrically administered with twenty traditional Chinese herbs harboring cold or hot property for ten consecutive days respectively. During the course of treatment, SE intensity of the abdomen and the back of each individual mouse were measured and recorded. At the end of the treatment, the total antioxidant capacity, superoxide dismutase activity, Na⁺-K⁺-ATPase activity and Ca²⁺-Mg²⁺-ATPase activity in the liver of all mice were examined.

RESULTS

Ratio between the SE intensity of the abdomen and back of mice (defined as SE ratio) was able to distinguish the cold and hot medicinal properties of traditional Chinese herbs. Mice treated with hot herbs and cold herbs have higher and lower SE ratios respectively compared with control mice. Furthermore, levels of selected biochemical indexes in the liver were correlated with most of the SE ratio changes induced by herbal treatment.

CONCLUSIONS

We have developed a novel and promising approach to quantitatively investigate herbal properties and we propose that SE ratio defined in this study can serve as a sensitive parameter to characterize the cold and hot medicinal properties of traditional Chinese herbs.

BIOPHOTONS IN RADIOBIOLOGY: INHIBITORS, COMMUNICATORS AND REACTORS

Radiation-induced bystander effects refer to the production of signals from irradiated cells which induce responses in unirradiated, or bystander, cells. There has been a recent resurgence of interest in low-energy photon biology. This is due to concerns about health effects, increased use of biophoton imaging techniques, and the fact that biophotons can act as a bystander signal. This review discusses the history of light signaling in biology and potential mechanisms involved in the generation and transduction of signaling mechanisms. The role of photons in signaling in the animal and plant kingdoms is also reviewed. Finally, the potential to harness these mechanisms in radiation protection or therapy is discussed with emphasis on promising future directions for research.

Non-destructive evaluation of watermelon seeds germination by using Delayed Luminescence

The evaluation of optical properties of biological samples is gaining increasing interests both in scientific and commercial fields concerning agriculture and food processing. The optical techniques can indeed be able to provide information on quality assessment in a fast and non-destructive way. This feature makes them suitable for automatic management of control processes. In this paper, we propose to use the Delayed Luminescence, a ultra-weak and photo-induced emission of optical photons, as a tool for a rapid evaluation of germination performance, the principal index reflecting seed quality. Two lots of 'Mirella' F₁ watermelon dried seeds, of 96 seeds each, were considered. The seeds were analyzed in the conditions as provided by seed/breeding company. Characteristics of Delayed Luminescence emission from each single seed were correlated to the different germination levels as assessed by International Seed Testing Procedures. Parametric differences in the two lots were determined, based on the relaxation kinetics of some spectral components. A control test, with the aim to construct a calibration model, was conceived and successfully tested. Time decays of Delayed Luminescence spectral components at central wavelengths 450 nm, 550 nm and 650 nm, corresponding to spectrum region where natural biomarkers as NADH, flavins and lipopigments, protoporphyrin and ROS respectively emit, have been evaluated. The results show that such time decays are strictly connected to the biological state of the system under analysis and allow also proposing Delayed Luminescence measurement as a quick, cheap and non-destructive test for seed viability analysis.

Some elements of homœopathy

The extremely high sensitivity of biological systems provides the key to understanding homœopathic ‘effects’. According to the classical analogon of a pendulum, the ‘coherent state’ in quantum physics are able to explain the simile principle as well as the potency rule as interrelated phenomena. The basic effect is always delocalization of the energy to such an extent that the physical proof gets more and more complicated the higher the efficacy becomes.

Leaf wound induced ultraweak photon emission is suppressed under anoxic stress: Observations of Spathiphyllum under aerobic and anaerobic conditions using novel in vivo methodology

Plants have evolved a variety of means to energetically sense and respond to abiotic and biotic environmental stress. Two typical photochemical signaling responses involve the emission of volatile organic compounds and light. The emission of certain leaf wound volatiles and light are mutually dependent upon oxygen which is subsequently required for the wound-induced lipoxygenase reactions that trigger the formation of fatty acids and hydroperoxides; ultimately leading to photon emission by chlorophyll molecules. A low noise photomultiplier with sensitivity in the visible spectrum (300–720 nm) is used to continuously measure long duration ultraweak photon emission of dark-adapting whole Spathiphyllum leaves (in vivo). Leaves were mechanically wounded after two hours of dark adaptation in aerobic and anaerobic conditions. It was found that (1) nitrogen incubation did not affect the pre-wound basal photocounts; (2) wound induced leaf biophoton emission was significantly suppressed when under anoxic stress; and (3) the aerobic wound induced emission spectra observed was > 650 nm, implicating chlorophyll as the likely emitter. Limitations of the PMT photocathode’s radiant sensitivity, however, prevented accurate analysis from 700–720 nm. Further examination of leaf wounding profile photon counts revealed that the pre-wounding basal state (aerobic and anoxic), the anoxic wounding state, and the post-wounding aerobic state statistics all approximate a Poisson distribution. It is additionally observed that aerobic wounding induces two distinct exponential decay events. These observations contribute to the body of plant wound-induced luminescence research and provide a novel methodology to measure this phenomenon in vivo.

Speculations about Bystander and Biophotons

Mothersill and many others during the last hundred years have shown that cells and now whole animals may communicate with each other by electromagnetic waves called biophotons. This would explain the source of the bystander phenomena. These ultra-weak photons are coherent, appear to originate and concentrate in DNA of the cell nucleus and rapidly carry large amounts of data to each cell and to the trillions of other cells in the human body. The implications of such a possibility can be wonderfully important.

Enhanced coherence within the theta band between pairs of brains engaging in experienced versus naïve Reiki procedures

OBJECTIVES

The study objective was to discern whether the coherence between brain activities of the "patient" and practitioner differ between Reiki experts and novices.

RATIONALE

If the physical process associated with Reiki involves "convergence" between the practitioner and subject, then this congruence should be evident in time-dependent shared power within specific and meaningful frequency electroencephalographic bands.

DESIGN

Simultaneous quantitative electroencephalogram measures (19 channels) were recorded from 9 pairs of subjects when 1 of the pairs was an experienced Reiki practitioner or had just been shown the procedure. Pairs recorded their experiences and images.

SETTING/LOCATION

The "practitioner" and "patient" pairs were measured within a quiet, comfortable acoustic chamber.

OUTCOME MEASURES

Real-time correlations and coherence between pairs of brains for power (μV(2)·Hz(-1)) within the various frequency bands over the 10-min sessions were recorded and analyzed for each pair. Descriptors of experiences were analyzed for word meanings.

RESULTS

Only the coherence within the theta range increased over time between the brains of the Reiki pairs relative to the Sham pairs, particularly over the left hemisphere. The pleasantness-unpleasantness rating for the words employed to describe experiences written after the experiment were more congruent for the Reiki pairs compared to the reference pairs.

CONCLUSIONS

The increased synchronization of the cerebral activity of the participant and the practitioner during proximal therapies involving touch such as Reiki may be an important component of any subsequent beneficial effects.

Role of reactive oxygen species in ultra-weak photon emission in biological systems

Ultra-weak photon emission originates from the relaxation of electronically excited species formed in the biological systems such as microorganisms, plants and animals including humans. Electronically excited species are formed during the oxidative metabolic processes and the oxidative stress reactions that are associated with the production of reactive oxygen species (ROS). The review attempts to overview experimental evidence on the involvement of superoxide anion radical, hydrogen peroxide, hydroxyl radical and singlet oxygen in both the spontaneous and the stress-induced ultra-weak photon emission. The oxidation of biomolecules comprising either the hydrogen abstraction by superoxide anion and hydroxyl radicals or the cycloaddition of singlet oxygen initiate a cascade of oxidative reactions that lead to the formation of electronically excited species such as triplet excited carbonyl, excited pigments and singlet oxygen. The photon emission of these electronically excited species is in the following regions of the spectrum (1) triplet excited carbonyl in the near UVA and blue-green areas (350-550nm), (2) singlet and triplet excited pigments in the green-red (550-750nm) and red-near IR (750-1000nm) areas, respectively and (3) singlet oxygen in the red (634 and 703nm) and near IR (1270nm) areas. The understanding of the role of ROS in photon emission allows us to use the spontaneous and stress-induced ultra-weak photon emission as a non-invasive tool for monitoring of the oxidative metabolic processes and the oxidative stress reactions in biological systems in vivo, respectively.

Enhancement of biophoton emission of prostate cancer cells by Ag nanoparticles

Ultraweak intrinsic bioluminescence of cancer cell is a noninvasive method of assessing bioenergetic status of the investigated cells. This weak biophoton emission generated by prostate cancer cells (PC₃) was measured in the presence of Ag nanoparticles and its correlation with singlet oxygen production was investigated. The comparison between nanoparticles concentration, bioluminescence intensity, and cell survival showed that Ag nanoparticles do not significantly affect cell survival at used concentration but they increase cell bioluminescent processes. It was also confirmed that singlet oxygen contributes to biophoton emission, that Ag nanoparticles increase this contribution, and that there are secondary mechanisms independent of singlet oxygen by which Ag nanoparticles contribute to increased cellular bioluminescence, possibly through plasmon resonance enhancement of intrinsic fluorescence.

Photon emissions from human brain and cell culture exposed to distally rotating magnetic fields shared by separate light-stimulated brains and cells

Light flashes delivered to one aggregate of cells evoked increased photon emission in another aggregate of cells maintained in the dark in another room if both aggregates shared the same temporospatial configuration of changing rate, circular magnetic fields. During the presentation of the same shared circumcerebral magnetic fields increases in photon emission occurred beside the heads of human volunteers if others in another room saw light flashes. Both cellular and human photon emissions during the light flashes did not occur when the shared magnetic fields were not present. The summed energy emissions from the dark location during light stimulation to others was about 10(-11) W/m(2) and calculated to be in the order of 10(-20) J per cell which is coupled to membrane function. These results support accumulating data that under specific conditions changes in photon emissions may reflect intercellular and interbrain communications with potential quantum-like properties.

Nonlinear enhancement of spontaneous biophoton emission of sweet potato by silver nanoparticles

Ultraweak biophoton emission of cutting-injured sweet potato is enhanced by the incubation with Ag nanoparticles in a nonlinear way. The late peak of the emission after the cutting injury is amplified as much as 15 times, while only little amplification was identified for the emission measured immediately after the cutting. The effect requires the presence of nutritive media to support the active metabolic processes and is also affected by the timing of the addition of the Ag nanoparticles. Proposed mechanisms of reactive oxygen species generation and energy resonance transfer are discussed.

Spontaneous photon emission and delayed luminescence of two types of human lung cancer tissues: adenocarcinoma and squamous cell carcinoma

We measured spontaneous photon emission and delayed luminescence from human cancerous lung tissue and compared with those from adjacent normal lung tissue. For the detection of extremely weak photon emission from tissue we used a sensitive photomultiplier tube attached to a dark chamber. The samples were illuminated with a metal halide lamp for measurement of delayed luminescence. Extracted samples from surgery were measured within an hour. We found that the delayed luminescence showed salient aspects in making discrimination between tumor and adjacent normal tissue. Squamous cell carcinoma had more prominent character in delayed luminescence than adenocarcinoma.

Spontaneous Ultraweak Photon Emission from Biological Systems and the Endogenous Light Field

Still one of the most astonishing biological electromagnetic phenomena is the ultraweak photon emission (UPE) from living systems. Organisms and tissues spontaneously emit measurable intensities of light, i.e. photons in the visible part of the electromagnetic spectrum (380-780 nm), in the range from 1 to 1,000 photons x s-1 x cm-2, depending on their condition and vitality. It is important not to confuse UPE from living systems with other biogenic light emitting processes such as bioluminescence or chemiluminescence. This article examines with basic considerations from physics on the quantum nature of photons the empirical phenomenon of UPE. This leads to the description of the non-thermal origin of this radiation. This is in good correspondence with the modern understanding of life phenomena as dissipative processes far from thermodynamic equilibrium. UPE also supports the understanding of life sustaining processes as basically driven by electromagnetic fields. The basic features of UPE, like intensity and spectral distribution, are known in principle for many experimental situations. The UPE of human leukocytes contributes to an endogenous light field of about 1011 photons x s-1 which can be influenced by certain factors. Further research is needed to reveal the statistical properties of UPE and in consequence to answer questions about the underlying mechanics of the biological system. In principle, statistical properties of UPE allow to reconstruct phase-space dynamics of the light emitting structures. Many open questions remain until a proper understanding of the electromagnetic interaction of the human organism can be achieved: which structures act as receptors and emitters for electromagnetic radiation? How is electromagnetic information received and processed within cells?

Is there a biology of quantum information?

This paper briefly considers the notion of a biology of quantum information from a number of complementary points of view. We begin with a very brief look at some of the biomolecular systems that are thought to exploit quantum mechanical effects and then turn to the issue of measurement in these systems and the concomitant generation of information. This leads us to look at the internalist stance and the exchange interaction of quantum particles. We suggest that exchange interaction can also be viewed using ecological ideas related to apparatus-object. This can also help develop the important notion of complementarity in biosystems in relation to the nature and generation of information at the microphysical scale.

Two-dimensional photon counting imaging and spatiotemporal characterization of ultraweak photon emission from a rat's brain in vivo

The process of metabolic reactions within living cells leads to spontaneous ultraweak light emission. The development of a system for highly sensitive imaging and spatiotemporal analysis of ultraweak photon emission from a rat's brain is reported in this paper. The equipment used in this experiment consists of a two-dimensional photon-counting tube with a photocathode measuring 40 mm in diameter, a highly efficient lens system, and an electronic device to record time series of a photoelectron train with spatial information. The sensitivity and ability to extract spatiotemporal information from sequential data of a single photoelectron train were examined. The minimum detectable radiant flux density of the system was experimentally estimated to be 9.9 x 10(-17) W/cm2 with a 1-s observation time. Spontaneous photon emission was demonstrated from an exposed rat's cortex in vivo without adding any chemical agent or employing external excitation. An image of ultraweak photon emission was compared with one obtained after cardiac arrest. The intensity after cardiac arrest was depressed to approximately 60% of before that. The regional properties of time courses of emission intensity were also demonstrated, indicating the potential usefulness for spatiotemporal characterization of photon emission with mapping of physiological information such as oxidative stress. This technology constitutes a novel method, with the potential to extract pathophysiological information from the central nervous system.

In vivo imaging of spontaneous ultraweak photon emission from a rat's brain correlated with cerebral energy metabolism and oxidative stress

Living cells spontaneously emit ultraweak light during the process of metabolic reactions associated with the physiological state. The first demonstration of two-dimensional in vivo imaging of ultraweak photon emission from a rat's brain, using a highly sensitive photon counting apparatus, is reported in this paper. It was found that the emission intensity correlates with the electroencephalographic activity that was measured on the cortical surface and this intensity is associated with the cerebral blood flow and hyperoxia. To clarify the mechanism of photon emission, intensity changes from whole brain slices were examined under various conditions. The removal of glucose from the incubation medium suppressed the photon emission, and adding 50 mM potassium ions led to temporal enhancement of emission and subsequent depression. Rotenone (20 microM), an inhibitor of the mitochondrial electron transport chain, increased photon emission, indicating electron leakage from the respiratory chain. These results suggest that the photon emission from the brain slices originates from the energy metabolism of the inner mitochondrial respiratory chain through the production of reactive oxygen. Imaging of ultraweak photon emission from a brain constitutes a novel method, with the potential to extract pathophysiological information associated with neural metabolism and oxidative dysfunction of the neural cells.

Nonlinear response of biophoton emission to external perturbations

By considering an exciplex system consisting of collective molecules in interaction with both the 'pumping' fields and the biophoton fields, the two-level exciplex model and the three-level exciplex model are presented. They are useful for the investigation of the quasi-stationary behaviour of biophoton emission, and biophoton emission as a dynamic process in the presence of external perturbations. Our theoretical results predict a series of nonlinear effects, such as chaos, fractal behaviour, and non-equilibrium phase transition. These effects characterize the coherence nature of living systems. In our approaches, there are two important quantities f and x, which can be used to mark the working points of the two-level and three-level exciplex systems. All the influences of external perturbations on the exciplex systems, e.g. change of temperature, the addition of agents, exposure to light, etc., can be interpreted as shifts of the working points of the systems, leading to a diversity of nonlinear response of biophoton emission. In addition, the agreements of the theoretical results and the corresponding experimental observations on biophoton emission from biological systems in the presence of external perturbations are demonstrated.

Photon emission in tumor biology

Photon emission from mammalian cells has been subject of study for many years. Growing research activity is directed on the photon emission within the field of tumor biology. These studies, applying high-sensitivity photon counting methods, have paid attention to several aspects, including photon emission from serum of tumor-bearing animals, photon emission of tumors and of isolated tumor cells. In addition, research activity is increased with respect to the photon emission induced by white light from cultured tumor cells. In this review we report on the different aspects of spontaneous and induced photon emission of tumor cells as compared to normal cells. Throughout these studies the question of a functional biological role of this spontaneous and light-induced photon emission has been raised and some different points of view will be discussed.

Light-induced photon emission by rat hepatocytes and hepatoma cells

We have investigated spontaneous and light-induced photon emission of suspensions of rat hepatocytes and of HTC hepatoma cells. Rat hepatocytes exhibit spontaneous biophoton emission, but from hepatoma cells this was not detectable. In contrast, after irradiation with white light, the reemission intensity was found to be lower for hepatocytes than for the tumor cell line. Induced photon emission was neither influenced by anaerobiosis nor by the intactness of the cells. Cell-fractionation studies demonstrate that the induced photon emission was caused by the nuclear fraction and by isolated chromatin. Phenol-extracted DNA, however, has lost this capacity. Our data suggest that differences in the chromatin structure may explain the cell-specific induced photon emission.