Research Papers
*
Ferroelectric Tissues
Exotic electrical effect pops up in soft mammalian tissue
07 March 2012 by Maggie McKee, Issue 2855.
http://www.newscientist.com/article/mg21328553.100-exotic-electrical-effect-pops-up-in-soft-mammalian-tissue.htmlPrized for its potential to enhance computer memory, ferroelectricity could soon be the basis for drugs that switch off cholesterol and bio-RAM for implants
AN ELECTRICAL phenomenon called ferroelectricity, used in computer memories, has popped up in the soft tissue of mammals. The discovery raises the possibility of “electrician” drugs that switch off cholesterol’s ability to stick to arteries and, perhaps in the far future, bio-friendly memory for storing programs to run tiny implanted devices.
Electricity plays a vital role in the body, transmitting nerve and muscle impulses, for example. Natural electric fields also appear to aid the development of embryos and the healing of wounds. “We are actually electric,” says Jiangyu Li at the University of Washington in Seattle.
Now he and his colleagues have found a new outlet for bioelectricity. Their experiments show that tissue from pigs’ aortic-artery walls is ferroelectric, meaning that electric fields can control the orientation of at least some of its molecular components (Physical Review Letters, DOI: 10.1103/physrevlett.108.078103). The proteins that make up the tissue are found widely in mammals’ bodies, including in humans, so “it’s entirely possible that this happens in all soft tissues”, says Sergei Kalinin of Oak Ridge National Laboratory in Tennessee, who was not involved in the work.
Ferroelectricity, discovered in 1920, depends on the unequal distribution of positive and negative electric charges in a molecule or solid crystal. Above a threshold temperature, for example, the ions that form the crystal lead zirconate titanate are arranged in a cube, so the charges are symmetrical(see diagram). But below that temperature, the central positive ion moves to a new position, creating more positive charge on one end of the crystal. This “dipole” is akin to a bar magnet’s north and south pole.
Applying a force can move the charges even farther apart in piezoelectric materials, while lowering the temperature further can do so in pyroelectric materials. Both effects also work in reverse, so an electric field can change the shape or temperature of these materials. Ferroelectric materials go one step further: as well as having a dipole below a certain temperature, their polarity can be flipped by turning on an electric field. This makes them good for storing data in binary bits – one dipole alignment encodes a 0, and the opposite a 1. Ferroelectric devices use less power to encode data than some other memory types, and retain their alignment even when the power is turned off.
But what role, if any, does ferroelectricity play in the wall of the aorta? Huajian Gao of Brown University in Providence, Rhode Island, offers several suggestions. Ferroelectricity was recently discovered in proteins in seashells, where it might help provide physical resilience (Acta Materialia, DOI: 10.1016/j.actamat.2011.03.001). When impacts deform the proteins, this can cause their dipole to flip, dissipating energy that might otherwise smash the shells. “Each time the electric dipoles are switched, it dissipates energy as heat,” Gao explains.
Something similar may be at work in the walls of the aorta, which, as the largest artery in the body, is subjected to the highest blood pressures. “We would presumably be protected [from abnormal spikes in pressure] if our body has a way to convert that energy,” says Gao.
However the body uses ferroelectricity, the fact that it is there could lead to new ways of fighting disease. Cholesterol has a dipole. Since like charges repel each other, if you could reverse the charge on your aortic walls, maybe this would prevent the deposition of cholesterol, says Li. “It’s very speculative, but if we can deliver a drug with a certain charge to the artery wall, then that might lead to a different interaction with cholesterol.”
That is a long way off, as it is unclear what is behind the ferroelectricity measured in aortic walls. The researchers suspect it comes from one of the tissue’s component proteins, elastin and collagen. If the latter, the ferroelectricity might come from one of collagen’s building blocks – the amino acid glycine.
In work to appear in Advanced Functional Materials, Andrei Kholkin of the University of Aveiro, Portugal, and his colleagues report that glycine is ferroelectric when its molecules are arranged in a particular kind of crystalline lattice. Whether glycine has this structure in the body is unclear, and even if it does, says Li, “it is too early to say whether this underpins the ferroelectricity we saw”.
Ferroelectricity – or hints of it – have been found in biological molecules before, says retired biophysicist Richard Leuchtag. Proteins called microtubules, which help cells divide, have been reported to be ferroelectric, and he thinks the molecules that allow ions to pass through cell membranes, carrying impulses along nerve and muscle fibres, are too. “I would say ferroelectricity is present in most cells of the body,” he says. He adds that getting these smaller components to display ferroelectricity at the tissue level probably requires their dipoles to be at least partially aligned.
Regardless of the cause, says Kholkin, the discovery paves the way for building memory devices made of molecules that already exist in the body. “Glycine is completely safe,” he says. It might form the basis for a memory that could be slipped into the body to program tiny implants that deliver drugs, say. “Imagine if we could make a fully biocompatible memory chip,” says Kholkin.
Such devices might store data highly efficiently. Applying an electric field to a molecular lattice could in theory flip only one molecule, whereas doing so to a solid crystal tends to flip about a dozen single crystals. “This gives you a much higher density of information,” says Kholkin.
For now, Gao says the discovery of ferroelectricity in soft tissue is humbling. “Sometimes we discover in nature something that we thought was a human invention,” he says. “Evolution is a powerful force – it has found many engineering solutions in our body.”
07 March 2012 by Maggie McKee, Issue 2855.
http://www.newscientist.com/article/mg21328553.100-exotic-electrical-effect-pops-up-in-soft-mammalian-tissue.htmlPrized for its potential to enhance computer memory, ferroelectricity could soon be the basis for drugs that switch off cholesterol and bio-RAM for implants
AN ELECTRICAL phenomenon called ferroelectricity, used in computer memories, has popped up in the soft tissue of mammals. The discovery raises the possibility of “electrician” drugs that switch off cholesterol’s ability to stick to arteries and, perhaps in the far future, bio-friendly memory for storing programs to run tiny implanted devices.
Electricity plays a vital role in the body, transmitting nerve and muscle impulses, for example. Natural electric fields also appear to aid the development of embryos and the healing of wounds. “We are actually electric,” says Jiangyu Li at the University of Washington in Seattle.
Now he and his colleagues have found a new outlet for bioelectricity. Their experiments show that tissue from pigs’ aortic-artery walls is ferroelectric, meaning that electric fields can control the orientation of at least some of its molecular components (Physical Review Letters, DOI: 10.1103/physrevlett.108.078103). The proteins that make up the tissue are found widely in mammals’ bodies, including in humans, so “it’s entirely possible that this happens in all soft tissues”, says Sergei Kalinin of Oak Ridge National Laboratory in Tennessee, who was not involved in the work.
Ferroelectricity, discovered in 1920, depends on the unequal distribution of positive and negative electric charges in a molecule or solid crystal. Above a threshold temperature, for example, the ions that form the crystal lead zirconate titanate are arranged in a cube, so the charges are symmetrical(see diagram). But below that temperature, the central positive ion moves to a new position, creating more positive charge on one end of the crystal. This “dipole” is akin to a bar magnet’s north and south pole.
Applying a force can move the charges even farther apart in piezoelectric materials, while lowering the temperature further can do so in pyroelectric materials. Both effects also work in reverse, so an electric field can change the shape or temperature of these materials. Ferroelectric materials go one step further: as well as having a dipole below a certain temperature, their polarity can be flipped by turning on an electric field. This makes them good for storing data in binary bits – one dipole alignment encodes a 0, and the opposite a 1. Ferroelectric devices use less power to encode data than some other memory types, and retain their alignment even when the power is turned off.
But what role, if any, does ferroelectricity play in the wall of the aorta? Huajian Gao of Brown University in Providence, Rhode Island, offers several suggestions. Ferroelectricity was recently discovered in proteins in seashells, where it might help provide physical resilience (Acta Materialia, DOI: 10.1016/j.actamat.2011.03.001). When impacts deform the proteins, this can cause their dipole to flip, dissipating energy that might otherwise smash the shells. “Each time the electric dipoles are switched, it dissipates energy as heat,” Gao explains.
Something similar may be at work in the walls of the aorta, which, as the largest artery in the body, is subjected to the highest blood pressures. “We would presumably be protected [from abnormal spikes in pressure] if our body has a way to convert that energy,” says Gao.
However the body uses ferroelectricity, the fact that it is there could lead to new ways of fighting disease. Cholesterol has a dipole. Since like charges repel each other, if you could reverse the charge on your aortic walls, maybe this would prevent the deposition of cholesterol, says Li. “It’s very speculative, but if we can deliver a drug with a certain charge to the artery wall, then that might lead to a different interaction with cholesterol.”
That is a long way off, as it is unclear what is behind the ferroelectricity measured in aortic walls. The researchers suspect it comes from one of the tissue’s component proteins, elastin and collagen. If the latter, the ferroelectricity might come from one of collagen’s building blocks – the amino acid glycine.
In work to appear in Advanced Functional Materials, Andrei Kholkin of the University of Aveiro, Portugal, and his colleagues report that glycine is ferroelectric when its molecules are arranged in a particular kind of crystalline lattice. Whether glycine has this structure in the body is unclear, and even if it does, says Li, “it is too early to say whether this underpins the ferroelectricity we saw”.
Ferroelectricity – or hints of it – have been found in biological molecules before, says retired biophysicist Richard Leuchtag. Proteins called microtubules, which help cells divide, have been reported to be ferroelectric, and he thinks the molecules that allow ions to pass through cell membranes, carrying impulses along nerve and muscle fibres, are too. “I would say ferroelectricity is present in most cells of the body,” he says. He adds that getting these smaller components to display ferroelectricity at the tissue level probably requires their dipoles to be at least partially aligned.
Regardless of the cause, says Kholkin, the discovery paves the way for building memory devices made of molecules that already exist in the body. “Glycine is completely safe,” he says. It might form the basis for a memory that could be slipped into the body to program tiny implants that deliver drugs, say. “Imagine if we could make a fully biocompatible memory chip,” says Kholkin.
Such devices might store data highly efficiently. Applying an electric field to a molecular lattice could in theory flip only one molecule, whereas doing so to a solid crystal tends to flip about a dozen single crystals. “This gives you a much higher density of information,” says Kholkin.
For now, Gao says the discovery of ferroelectricity in soft tissue is humbling. “Sometimes we discover in nature something that we thought was a human invention,” he says. “Evolution is a powerful force – it has found many engineering solutions in our body.”
Geomagnetics Correlates Positively with ESP
Magnetite in the Inner Ear & Brain
Some thoughts on the paper:
Bioelectromagnetics 23:488495 (2002)
Calcite Microcrystals in the Pineal Gland of the Human Brain
First Physical and Chemical Studies byBaconnier, Lang et al.
It should be noted that these are initial findings of an ongoing study. Given the proper opportunity this study may yield results that are of great significance in the area of mobile phones and health. One thing that could adversely affect the impact of any such results would be the exaggeration or misrepresentation of the findings so far, or premature claims relating to studies still under way. This could discredit the research and make it difficult to have genuine findings taken seriously.
The researchers have isolated and studied calcite microcrystals which they have found in human pineal glands.
Quotes from the paper:
"The pineal gland converts a neuronal signal into an endocrine output. [It] is located close to the anatomical centre of the human brain. A total of 20 glands from [human] subjects ranging in age from 15 to 68 years were studied. Microcrystals were found in every gland in quantities ranging from 100 to 300 crystals per cubic millimetre of gland. No attempt was made to correlate the quantity of crystals with either the age of the subject or pathological details. Length dimensions of the crystals varied from 2-3 to about 20 micrometres. These results (referring to various forms of analysis described in detail) and the electron diffraction measurements definitely prove that the microcrystals are calcite. These calcite crystals bear a striking resemblance to the otoconia of the inner ear. The calcite in otoconia has been shown to exhibit piezoelectricity. If piezoelectricity were to exist [in the pineal calcite microcrystals], an electromechanical coupling mechanism to external electromagnetic fields may be possible."
"The possibility of nonthermal coupling of electromagnetic radiation to biological systems has been considered recently [Kirschvink, 1992]. Reiter [1993] has reviewed the literature on the possible effects of static and low frequency electromagnetic fields on the production of melatonin by the pineal gland. A study by de Seze, [1998,1999] showed no influence of microwave frequency radiation on melatonin secretion. However, Kirschvink et al. [1992] and Kirschvink [1996] have shown the presence of minute crystals of magnetite in the human brain and have suggested a mechanism for coupling of microwave radiation to them. Additional research onthe nonthermal effects of microwave radiation is definitely warranted."
"In conclusion, we believe that even a very small risk of possible nonthermal coupling of radiation to microcrystals in the pineal gland merits further detailed study. Our future research will address these questions."
To my mind, the significant features that can be used in the current debate are:
The human pineal gland, in the centre of the brain, has been found to contain large numbers of calcite micro-crystals that 'bear a striking resemblance' to calcite crystals found in the inner ear. The ones found in the inner ear have been shown to exhibit the quality of piezoelectricity. If those found in the pineal gland also have this quality then this would provide a means whereby an external electromagnetic field might directly influence the brain.
Both the Stewart Report and the NRPB Report consider at some length how it might be possible for non-thermal levels of microwave radiation to affect a living organism.
In the Stewart Report, Section 5 paragraphs 12 through to 26 detail the sort of requirements that might have to apply in order for an electromagnetic field to directly affect biological tissue -- living cells. Nowhere in these paragraphs is the possibility considered of any form of crystalline deposit which might provide the 'missing link' between electromagnetic radiation and biological effects. It's interesting to note, though, that paragraph 18 does refer to a suggestion by Frohlich that a biological system might behave in some way like a radio receiver, amplifying a very small signal through a process of resonance; this idea is dismissed due to the unlikelihood of biological material resonating in this way -- but of course one of the earliest types of radio was the 'crystal set', in which a mineralcrystal was made to resonate (by tuning with a 'cats whisker') with an incoming radio wave, which is simply an electromagnetic wave of rather lower frequency than microwaves. The conclusion of this section was that there is little evidence to support resonant behaviour. The existence in the pineal gland of crystals which may prove to exhibit piezoelectric properties puts the whole issue in a totally different light-- particularly in a scenario where the absolute requirement is to 'play it safe' (Stewart's 'Precautionary Principle').
(It's worth noting that paragraph 5.6 of this report considers the possibility of the magnetite crystals (see above) providing a causal link, and discounts this on scientific grounds. It goes on to say: "Indeed, it seems to be generally agreed that any biological effects from mobile phones are much more likely to result from electric rather than from magnetic fields." Note that piezoelectric qualities do link electric fields to mechanical effects.)
In the NRPB Report on TETRA, paragraphs 78 to 102 consider the effect of radiation, amplitude modulated (pulsed) at around 16Hz (cycles/second), on calcium efflux in the brain -- the basis of the Stewart Report warning against using this pulsing frequency. Paragraphs 92-96, a substantial proportion of the latter half of this section, are devoted almost entirely to highlighting the fact that no clear mechanism has yet been identified to explain the effects observed by some researchers. The obvious inference that readers are expected to draw is that, because no clear explanation is apparent, these effects are highly questionable -- indeed, one sentence in paragraph 95 almost says as much. Again, with the sort of causal link that may be provided by microcrystals interspersed among the organic matter of the brain, the perspective on this aspect of the issue is dramatically altered.
In brief, then:
Two things can be definitively stated from this research so far:
1. Calcite microcrystals have been positively identified, in substantial quantities, in every one of 20 human pineal glands studied;
2. These crystals bear a striking resemblance to those found in the human inner ear, which have been shown to exhibit piezoelectric qualities.
These two facts alone are sufficient to call into question the basis of conclusions in both the Stewart Report and the NRPB Report on TETRA. Neither of these reports considered the possibility of the sort of coupling that might be provided through crystals of this type. The reassurances given in both of these reports are thus based on a false premise, that any coupling of microwave radiation to cellular activity in a living organism must be direct, acting through the medium of biological material. It is of course entirely possible that other similar phenomena exist elsewhere in the brain (and/or other parts of the body), as yet undiscovered.
Whilst the means by which microwaves might directly affect living cells are rather obscure, the interaction between electromagnetic radiation and certain types of crystal structures is well understood; the possibility of this then affecting living cells is very real.
The ICNIRP guidelines must therefore be considered inadequate, since they take no account of such a possible causal mechanism. The fact that such a mechanism has not yet been proved to operate in no way lessens the responsibility of those setting or implementing guidelines to allow for its possibility � a precautionary approach.
(Dr.) Grahame Blackwell.
Bioelectromagnetics 23:488495 (2002)
Calcite Microcrystals in the Pineal Gland of the Human Brain
First Physical and Chemical Studies byBaconnier, Lang et al.
It should be noted that these are initial findings of an ongoing study. Given the proper opportunity this study may yield results that are of great significance in the area of mobile phones and health. One thing that could adversely affect the impact of any such results would be the exaggeration or misrepresentation of the findings so far, or premature claims relating to studies still under way. This could discredit the research and make it difficult to have genuine findings taken seriously.
The researchers have isolated and studied calcite microcrystals which they have found in human pineal glands.
Quotes from the paper:
"The pineal gland converts a neuronal signal into an endocrine output. [It] is located close to the anatomical centre of the human brain. A total of 20 glands from [human] subjects ranging in age from 15 to 68 years were studied. Microcrystals were found in every gland in quantities ranging from 100 to 300 crystals per cubic millimetre of gland. No attempt was made to correlate the quantity of crystals with either the age of the subject or pathological details. Length dimensions of the crystals varied from 2-3 to about 20 micrometres. These results (referring to various forms of analysis described in detail) and the electron diffraction measurements definitely prove that the microcrystals are calcite. These calcite crystals bear a striking resemblance to the otoconia of the inner ear. The calcite in otoconia has been shown to exhibit piezoelectricity. If piezoelectricity were to exist [in the pineal calcite microcrystals], an electromechanical coupling mechanism to external electromagnetic fields may be possible."
"The possibility of nonthermal coupling of electromagnetic radiation to biological systems has been considered recently [Kirschvink, 1992]. Reiter [1993] has reviewed the literature on the possible effects of static and low frequency electromagnetic fields on the production of melatonin by the pineal gland. A study by de Seze, [1998,1999] showed no influence of microwave frequency radiation on melatonin secretion. However, Kirschvink et al. [1992] and Kirschvink [1996] have shown the presence of minute crystals of magnetite in the human brain and have suggested a mechanism for coupling of microwave radiation to them. Additional research onthe nonthermal effects of microwave radiation is definitely warranted."
"In conclusion, we believe that even a very small risk of possible nonthermal coupling of radiation to microcrystals in the pineal gland merits further detailed study. Our future research will address these questions."
To my mind, the significant features that can be used in the current debate are:
The human pineal gland, in the centre of the brain, has been found to contain large numbers of calcite micro-crystals that 'bear a striking resemblance' to calcite crystals found in the inner ear. The ones found in the inner ear have been shown to exhibit the quality of piezoelectricity. If those found in the pineal gland also have this quality then this would provide a means whereby an external electromagnetic field might directly influence the brain.
Both the Stewart Report and the NRPB Report consider at some length how it might be possible for non-thermal levels of microwave radiation to affect a living organism.
In the Stewart Report, Section 5 paragraphs 12 through to 26 detail the sort of requirements that might have to apply in order for an electromagnetic field to directly affect biological tissue -- living cells. Nowhere in these paragraphs is the possibility considered of any form of crystalline deposit which might provide the 'missing link' between electromagnetic radiation and biological effects. It's interesting to note, though, that paragraph 18 does refer to a suggestion by Frohlich that a biological system might behave in some way like a radio receiver, amplifying a very small signal through a process of resonance; this idea is dismissed due to the unlikelihood of biological material resonating in this way -- but of course one of the earliest types of radio was the 'crystal set', in which a mineralcrystal was made to resonate (by tuning with a 'cats whisker') with an incoming radio wave, which is simply an electromagnetic wave of rather lower frequency than microwaves. The conclusion of this section was that there is little evidence to support resonant behaviour. The existence in the pineal gland of crystals which may prove to exhibit piezoelectric properties puts the whole issue in a totally different light-- particularly in a scenario where the absolute requirement is to 'play it safe' (Stewart's 'Precautionary Principle').
(It's worth noting that paragraph 5.6 of this report considers the possibility of the magnetite crystals (see above) providing a causal link, and discounts this on scientific grounds. It goes on to say: "Indeed, it seems to be generally agreed that any biological effects from mobile phones are much more likely to result from electric rather than from magnetic fields." Note that piezoelectric qualities do link electric fields to mechanical effects.)
In the NRPB Report on TETRA, paragraphs 78 to 102 consider the effect of radiation, amplitude modulated (pulsed) at around 16Hz (cycles/second), on calcium efflux in the brain -- the basis of the Stewart Report warning against using this pulsing frequency. Paragraphs 92-96, a substantial proportion of the latter half of this section, are devoted almost entirely to highlighting the fact that no clear mechanism has yet been identified to explain the effects observed by some researchers. The obvious inference that readers are expected to draw is that, because no clear explanation is apparent, these effects are highly questionable -- indeed, one sentence in paragraph 95 almost says as much. Again, with the sort of causal link that may be provided by microcrystals interspersed among the organic matter of the brain, the perspective on this aspect of the issue is dramatically altered.
In brief, then:
Two things can be definitively stated from this research so far:
1. Calcite microcrystals have been positively identified, in substantial quantities, in every one of 20 human pineal glands studied;
2. These crystals bear a striking resemblance to those found in the human inner ear, which have been shown to exhibit piezoelectric qualities.
These two facts alone are sufficient to call into question the basis of conclusions in both the Stewart Report and the NRPB Report on TETRA. Neither of these reports considered the possibility of the sort of coupling that might be provided through crystals of this type. The reassurances given in both of these reports are thus based on a false premise, that any coupling of microwave radiation to cellular activity in a living organism must be direct, acting through the medium of biological material. It is of course entirely possible that other similar phenomena exist elsewhere in the brain (and/or other parts of the body), as yet undiscovered.
Whilst the means by which microwaves might directly affect living cells are rather obscure, the interaction between electromagnetic radiation and certain types of crystal structures is well understood; the possibility of this then affecting living cells is very real.
The ICNIRP guidelines must therefore be considered inadequate, since they take no account of such a possible causal mechanism. The fact that such a mechanism has not yet been proved to operate in no way lessens the responsibility of those setting or implementing guidelines to allow for its possibility � a precautionary approach.
(Dr.) Grahame Blackwell.
THREE ABSTRACTS Brain Res. Bull. (1996) vol. 39: 255-259
Magnetic Properties of Human Hippocampal Tissue: Evaluation of Artefact and Contamination Sources Jon Dobson and Paola Grassi
DOBSON, J. and GRASSI, P. Magnetic properties of human hippocampal tissue - evaluation of artefact and contamination sources BRAIN RES. BULL. - In order to investigate the possibility that post mortem chemical alteration or contamination is responsible for recent results indicating the presence of magnetite in human brain tissue and to determine whether magnetite is present in living brain tissue, we examined tissue samples resected from six patients during amygdalo-hippocampectomy operations. The tissue samples were sealed in sterilized vials in the operating theater and placed into liquid nitrogen directly after removal to prevent changes in tissue chemistry after the death of the brain cells. The low temperature magnetic properties of the tissue were measured in order to determine the presence of ferro- or ferrimagnetic material in the tissue. The results of these experiments indicate that magnetite is present in the tissue. In addition, results of experiments designed to control for airborne contamination and contamination during cauterization of vessels during surgery indicate that these are not significant sources of magnetite contamination in the tissue.
Biochem. Biophys. Res. Comm. (1996) 227(3):718-723
Application of the Ferromagnetic Transduction Model to D.C. and Pulsed Magnetic Fields: Effects on Epileptogenic Tissue & Implications for Cellular Phone Safety Jon Dobson and Tim St. Pierre
The ferromagnetic transduction model proposed by Kirschvink (1) suggests that the coupling of biogenic magnetite particles in the human brain to mechanosensitive membrane ion gates may provide a mechanism for interactions of environmental magnetic fields with humans. Extremely low frequency alternating magnetic fields primarily were considered, and in the model A.C. fields with frequencies below 10 Hz should have minimal effect. We show that pulsed fields, square waves and D.C. fields also could force open the membrane gates long enough to disrupt normal neurophysiological processes. The model may therefore be extended to explain results obtained in studies of epileptic patients which show effects on the central nervous system from low frequency square wave and D.C. magnetic fields. In addition, the model also may provide a plausible mechanism linking exposure to magnetic fields from discontinuous transmission cellular telephones and disruption of normal cellular processes in the human brain.
Brain Res. Bull. (1995) 36/2: 149-153
Magnetic Material in the Human Hippocampus J.R. Dunn, M. Fuller, J. Zoeger, J. Dobson, F. Heller, J. Hammann, E. Caine and B.M. Moskowitz
DUNN, J.R., M. FULLER, J. ZOEGER, J. DOBSON, F. HELLER, J. HAMMANN, E. CAINE, and B.M. MOSKOWITZ, Magnetic material in the Human Hippocampus, BRAIN RES. BULL. Magnetic analyses of hippocampal material from deceased normal and epileptic subjects, and from the surgically removed epileptogenic zone of a living patient have been carried out. All had magnetic characteristics similar to those reported for other parts of the brain (6). These characteristics along with low temperature analysis indicate that the magnetic material is present in a wide range of grain sizes. The low temperature analysis also revealed the presence of magnetite through manifestation of its low temperature transition. The wide range of grain sizes is similar to magnetite produced extracellularly by the GS-15 strain of bacteria and unlike that found in magnetotactic bacteria MV-1, which has a restricted grain size range. Optical microscopy of slices revealed rare 5 to 10 micron clusters of finer opaque particles, which were demonstrated with Magnetic Force Microscopy to be magnetic. One of these was shown with EDAX to contain Al, Ca, Fe, and K, with approximate weight percentages of 55, 19, 19, and 5 respectively.
Magnetic Properties of Human Hippocampal Tissue: Evaluation of Artefact and Contamination Sources Jon Dobson and Paola Grassi
DOBSON, J. and GRASSI, P. Magnetic properties of human hippocampal tissue - evaluation of artefact and contamination sources BRAIN RES. BULL. - In order to investigate the possibility that post mortem chemical alteration or contamination is responsible for recent results indicating the presence of magnetite in human brain tissue and to determine whether magnetite is present in living brain tissue, we examined tissue samples resected from six patients during amygdalo-hippocampectomy operations. The tissue samples were sealed in sterilized vials in the operating theater and placed into liquid nitrogen directly after removal to prevent changes in tissue chemistry after the death of the brain cells. The low temperature magnetic properties of the tissue were measured in order to determine the presence of ferro- or ferrimagnetic material in the tissue. The results of these experiments indicate that magnetite is present in the tissue. In addition, results of experiments designed to control for airborne contamination and contamination during cauterization of vessels during surgery indicate that these are not significant sources of magnetite contamination in the tissue.
Biochem. Biophys. Res. Comm. (1996) 227(3):718-723
Application of the Ferromagnetic Transduction Model to D.C. and Pulsed Magnetic Fields: Effects on Epileptogenic Tissue & Implications for Cellular Phone Safety Jon Dobson and Tim St. Pierre
The ferromagnetic transduction model proposed by Kirschvink (1) suggests that the coupling of biogenic magnetite particles in the human brain to mechanosensitive membrane ion gates may provide a mechanism for interactions of environmental magnetic fields with humans. Extremely low frequency alternating magnetic fields primarily were considered, and in the model A.C. fields with frequencies below 10 Hz should have minimal effect. We show that pulsed fields, square waves and D.C. fields also could force open the membrane gates long enough to disrupt normal neurophysiological processes. The model may therefore be extended to explain results obtained in studies of epileptic patients which show effects on the central nervous system from low frequency square wave and D.C. magnetic fields. In addition, the model also may provide a plausible mechanism linking exposure to magnetic fields from discontinuous transmission cellular telephones and disruption of normal cellular processes in the human brain.
Brain Res. Bull. (1995) 36/2: 149-153
Magnetic Material in the Human Hippocampus J.R. Dunn, M. Fuller, J. Zoeger, J. Dobson, F. Heller, J. Hammann, E. Caine and B.M. Moskowitz
DUNN, J.R., M. FULLER, J. ZOEGER, J. DOBSON, F. HELLER, J. HAMMANN, E. CAINE, and B.M. MOSKOWITZ, Magnetic material in the Human Hippocampus, BRAIN RES. BULL. Magnetic analyses of hippocampal material from deceased normal and epileptic subjects, and from the surgically removed epileptogenic zone of a living patient have been carried out. All had magnetic characteristics similar to those reported for other parts of the brain (6). These characteristics along with low temperature analysis indicate that the magnetic material is present in a wide range of grain sizes. The low temperature analysis also revealed the presence of magnetite through manifestation of its low temperature transition. The wide range of grain sizes is similar to magnetite produced extracellularly by the GS-15 strain of bacteria and unlike that found in magnetotactic bacteria MV-1, which has a restricted grain size range. Optical microscopy of slices revealed rare 5 to 10 micron clusters of finer opaque particles, which were demonstrated with Magnetic Force Microscopy to be magnetic. One of these was shown with EDAX to contain Al, Ca, Fe, and K, with approximate weight percentages of 55, 19, 19, and 5 respectively.
REFERENCES:
[1] Kirschvink, JL, DS Jones, BJ MacFadden (1985) Magnetite biomineralization and magnetoreception in organisms: a new biomagnetism. New York: R.P. Plenum Publishing Corp.
[2] Kirschvink, JL, A Kobayashi-Kirschivink, BJ Woodford (1992) Magnetite biomineralization in the human brain. Proc. Natl. Acad. Sci., USA, 89: 7683-7687.
[3] Dunn, JR, M Fuller, J Zoeger, JP Dobson, F Heller, E Caine and BM Moskowitz (1995) Magnetic material in the human hippocampus. Brain Res. Bull., 36: 149-153.
[4] Dobson, JP, M Fuller, S Moser, HG Wieser, JR Dunn and J Zoeger (1995) Evocation of epileptiform activity by weak D.C. magnetic fields and iron biomineralization in the human brain. In: Biomagnetism: Fundamental Research and Applications, eds. C Baumgartner, L Deecke, G Stroink, SJ Williamson. Elsevier, Amsterdam: 16-19.
[5] Dobson, JP and P Grassi (1996) Magnetic Properties of Human Hippocampal Tissue - Evaluation of Artefact and Contamination Sources. Brain Res. Bull., vol. 39: 255-259.
[6] Dobson, JP and T St. Pierre (1996) Application of the Ferromagnetic Transduction Model to D.C. and Pulsed Magnetic Fields: Effects on Epileptogenic Tissue and Implications for Cellular Phone Safety. Biochem. Biophys. Res. Comm., 227: 718-723.
[7] Kirschvink, JL (1996) Microwave absorption by magnetite: A possible mechanism for coupling of non-thermal levels of radiation to biological systems. Bioelectromag., 17: 187-194.
[1] Kirschvink, JL, DS Jones, BJ MacFadden (1985) Magnetite biomineralization and magnetoreception in organisms: a new biomagnetism. New York: R.P. Plenum Publishing Corp.
[2] Kirschvink, JL, A Kobayashi-Kirschivink, BJ Woodford (1992) Magnetite biomineralization in the human brain. Proc. Natl. Acad. Sci., USA, 89: 7683-7687.
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