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Magnetobiology & Magnetoreception [Resources]
#1
Extremely weak simple oscillating magnetic fields (MF), when added to the local geomagnetic field have been observed to disrupt the European Robin's orientation (Ritz et. al. 2009), this disruption has been shown to operate at MF intensities as low 15 nanotesla. To put that intensity in perspective, that's 3000 times weaker than the Earth's local geomagnetic field of 46 microtelsa.

Trying to reproduce biological effects of these hyperweak MF is proving very very difficult. In this study, only very specific MF oscillating frequencies and intensities, when combined with very specific static MF intensity, and specific frequencies of light could produce the effect. Even then, the addition of these hyperweak oscillating MF's could do nothing more than produce a blunt 'disruption' of some unknown mechanism which is used by the Robin to orientate itself.

It's a great example of simple patterned hyperweak external MF's affecting a biological organisms behavior, whilst in the presence of other stronger MF's.
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#2
Kavokin et al 2014 has now replicated Ritz's work (above), but with garden warblers, at a different time of year, and using different equipment.

Their results indicate that garden warblers can select and maintain broadly correct migratory orientation on the basis of magnetic cues alone, and that this ability can be transiently damaged by weak 190 nanoTesla oscillating (1.4MHz) magnetic fields (MF) - these are hundreds of times weaker than the earths local geomagnetic field.

It now seems certain that organics can detect hyperweak MF's despite the presence of stronger MF's, and that nature has evolved some way of doing so, that we as yet do not understand.
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#3
Engals et al 2014 has now shown hyper-weak magnetic field (MF) effects on the European Robin's navigation at a broader range of frequencies, and at an even lower MF intensity of 1 nanoTesla. To put that intensity in perspective that's 40,000 times lower than the earth's local geomagnetic field, and is at least an order of magnitude lower than previous studies.

Although this intensity is still approximately two orders of magnitude above the average MF of the brain, it's really quite close now.
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#4
A very exciting study on the spontaneous alignment of snapping turtles exposed to hyper-weak magnetic fields (MF) between about 30 - 50 nanoTesla. I think its incredibly exciting...

Quote:Quote: "...What is arguably the most important finding from these experiments, however, is that in addition to the well-studied use in goal-directed orientation, the magnetic field appears to play an important, and as yet poorly understood role, in encoding spatial information in the animal’s immediate surroundings..."


Landler et al 2015 "Spontaneous Magnetic Alignment by Yearling Snapping Turtles: Rapid Association of Radio Frequency Dependent Pattern of Magnetic Input with Novel Surroundings"

Quote:Abstract
We investigated spontaneous magnetic alignment (SMA) by juvenile snapping turtles using exposure to low-level radio frequency (RF) fields at the Larmor frequency to help characterize the underlying sensory mechanism.

Turtles, first introduced to the testing environment without the presence of RF aligned consistently towards magnetic north when subsequent magnetic testing conditions were also free of RF ( ‘ RF off ! RF off ’ ), but were disoriented when subsequently exposed to RF ( ‘ RF off ! RF on ’ ). In contrast, animals initially introduced to the testing environment with RF present were disoriented when tested without RF ( ‘ RF on ! RF off ’ ), but aligned towards magnetic south when tested with RF (‘ RF on ! RF on ’).

Sensitivity of the SMA response of yearling turtles to RF is consistent with the involvement of a radical pair mechanism. Furthermore, the effect of RF appears to result from a change in the pattern of magnetic input, rather than elimination of magnetic input altogether, as proposed to explain similar effects in other systems/organisms. The findings show that turtles first exposed to a novel environment form a lasting association between the pattern of magnetic input and their surroundings. However, under natural conditions turtles would never experience a change in the pattern of magnetic input. Therefore, if turtles form a similar association of magnetic cues with the surroundings each time they encounter unfamiliar habitat, as seems likely, the same pattern of magnetic input would be associated with multiple sites/localities. This would be expected from a sensory input that functions as a global reference frame, helping to place multiple locales (i.e., multiple local landmark arrays) into register to form a global map of familiar space.
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#5
Tomanova et. al. 2016 show disruption to magnetic orientation of Antarctic Krill by hyper-weak radiofrequency fields at 2 nano Tesla (nT), that's about 20,000 times weaker than the earths local geomagnetic field. It's not quite as thorough as some of the studies above, but I think it's still a solid result, even if the 2nT observation (originally intended as a control) also ended up disrupting the Krill's orientation.

Quote:ABSTRACT

Studies on weak man-made radiofrequency (RF) electromagnetic fields affecting animal magnetoreception aim for a better understanding of the reception mechanism and also point to a new phenomenon having possible consequences in ecology and environmental protection. RF impacts on magnetic compasses have recently been demonstrated in migratory birds and other vertebrates. We set out to investigate the effect of RF on the magnetic orientation of the Antarctic krill species Gondogeneia antarctica, a small marine crustacean widespread along the Antarctic littoral line. Here, we show that upon release, G. antarctica (held under laboratory conditions) escaped in the magnetically seaward direction along the magnetic sea–land axis (y-axis) of the home beach. However, the animals were disoriented after being exposed to RF. Orientation was lost not only in an RF field with a magnetic flux density of 20 nT, as expected according to the literature, but even under the 2 nT originally intended as a control. Our results extend recent findings of the extraordinary sensitivity of animal magnetoreception to weak RF fields in marine invertebrates.
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#6
OK, this behavioral study ( Prato et. al. 2013 ) which shows an extremely robust effect, deals with hyper-weak (33 nT) magnetic field (MF) effects on mice. These hyper-weak magnetic fields reduce a strange analgesic effect on mice previously discovered by the authors. This analgesic effect is caused by 1 hour of shielding from ambient MF's inside a Mu Metal box. The study sort of falls outside of the usual Magnetoreception studies to do with animal navigation. I only stumbled across it yesterday. It's one of the most thorough studies I've ever read, but I still don't know what to make of it. It's very detailed and somewhat difficult to understand so I will try to simplify, and briefly explain the main issues as I see it...

Over 5 days, separate groups of mice were individually placed on a hot plate to cause pain to their feet (pre-exposure - open circles fig 2), and the length of time in seconds was recorded before they lifted a foot to lick it (latency). Immediately following foot shock, these groups of mice were placed inside various light shielded boxes, (because photons somehow alter the observed analgesic effect)...

From left to right... they were individually placed for 1 hour inside a sham control fibreglass box (not expected to affect EM fields), a steel box (expected to reduce EF, but not MF), a mu-Metal box (expected to substantially reduce both EF and MF), and a series of other identical mu-Metal boxes which had been fitted with coils that could produce the targeted MF's shown in figure 2.

Immediately following release from the box, the mice were again individually placed on a hot plate to cause pain to their feet (post-exposure - filled circles fig 2), and the length of time in seconds was recorded before they lifted a foot to lick it (latency).

[Image: mice_mu_metal_box1.jpg]

250 mice were tested in this double-blinded study*, which replicates an earlier study, by bizarrely showing that the group of mice which we're shielded from the earths local geomagnetic field within the positive control mu-Metal box for 1 hour, had increasing latency to footshock after they left the box and were tested again. This behavior was in the opposite direction to groups of mice placed in the sham fibreglass, and stainless steel control boxes for 1 hour, as they had reduced latency to footshock after they left their box and were tested again.

By adding other mu-Metal boxes fitted with coils that could produce specific MF's, the authors now bizzarely show that these specific MF strengths and frequencies also allow an increasing latency in mice to footshock after they left their box and were tested again... however this time the effect only becomes visible on day 4 and 5, and is reduced by some 60%...

This is really interesting, because it shows that being temporarily removed from the earths magnetic field, causes some type of behavioral reinforcing effect (because footshock latency time increases further each day). And that this effect is inversely related to what one would normally expect to see. But really bizzarely, this inverse reinforcing effect only appears on post-exposure, and not on pre-exposure to the mu-Metal box over the 5 days. Before the mice go into the mu-Metal box, this group of mice have a similar response to pre-exposure footshock as all the other mice, but a completely different reinforcing effect to post-exposure footshock... which gets stronger every day!

...that hyper-weak magnetic fields in the frequencies shown, reduce (but not eliminate) this effect, makes things even more complicated.

At 33 nT, these fields are really too weak to have any known chemical effect, that could partially reverse the analgesic effect the authors describe.

Notes:

* The main purpose of a double-blinded study (compared to single-blinding) is to also prevent the experimenters knowing the conditions. In this experiment, the experimenters were all double-blinded regarding exposure conditions, D.D.H. carried out the experiments, and A.W.T. completed the analysis prior to L.D.K. disclosing the exposure conditions. Only L.D.K. (a technical manager separate from the actual experiments) knew the conditions.
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#7
I've been looking around for other other papers which may help shed light on Prato's study (post above this one)... I came across a paper in which the authors produce a very similar response using combat-related stimuli in combat-related PTSD suffers....

Pitman et. al. (1990) "Naloxone-reversible analgesic response to combat-related stimuli in posttraumatic stress disorder. A pilot study."

http://www.ncbi.nlm.nih.gov/pubmed/2350206

It's all a bit speculative... but I like where it's going (so felt like sharing my thoughts...)

Mice study
-------------
Footshock event ---> 1 hour shielding from ambient geomagnetic field ---> Analgesic response produced upon re-exposure to original footshook event.

PTSD suffers study
-------------------------
Combat-related traumatic event ---> elapse of time since event ---> Analgesic response shown upon re-exposure to stimulus resembling the original traumatic event.


The PTSD study seems to show a distinct memory effect, and the basic similarity between both of these studies, suggests to me that the results produced in the mice study, might also be related to memory. The results from both studies seems to show something rather like an inability to process/consolidate memory.

The mice study implicates very weak ambient geomagnetic fields as being the important factor, and I'm therefore speculating that ambient magnetic fields might be important to a memory consolidation, such that blocking the ambient magnetic fields produces a PTSD-like response within the mice, and a subsequent analgesic effect upon re-exposure to the stimuli - just like with the PTSD sufferers.

In mice who were also shielded from the ambient geomagnetic field within a Mu-metal chamber, but had a 33nT hyper-weak magnetic field reintroduced from a magnetic coil within the mu-metal chambers (much much weaker than the earths ambient field), the subsequent PTSD-like response is much reduced.

This difference between the mice groups sham control test, Mu-metal/33nT field test, and the Mu-metal positive control test, suggest to me something like a logarithmic effect from ambient magnetic fields on memory encoding. This would mean that the stronger the ambient magnetic field is, the smaller the contributory effect it has on memory consolidation, so that the weaker the magnetic field the dis-proportionally larger effect they contribute to memory consolidation.

Now that's nice... because it seems to tie up with something we generally see from studies... that the weaker fields seems to be having some effect... where as the stronger fields don't... that is the weaker the field, the greater the effect (disproportionately speaking).

It's worthwhile reconsidering the Landler study (mentioned in a previous post), which also implicates the particular pattern of magnetic input as having importance. Whereby the particular ambient magnetic field pattern present at any particular moment in time, seems to play a role in encoding spatial information in the animal’s immediate surroundings.

Fascinating stuff... no doubt these will become important issues to our understanding of the NDE.
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#8
A nice review on magnetoreception...

The Effect of Extremely Low Frequency Alternating Magnetic Field on the Behavior of Animals in the Presence of the Geomagnetic Field

with a focus on Russian theories, that we often don't get to hear much about... also a brief mention of correlations found with picoTesla (pT) fields (these are really weak), and myocardial infarction rates. But there is no way of me knowing if the research is solid, as it's all in Russian.
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#9
Short and informative 10 minute video explaining Engles et al 2014, which demonstrated that very weak general environmental electromagnetic noise from human activities can disrupt robins behaviour...



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#10
Big news!! A testable theory...!!

Very interesting new Magnetic Field theory proposed by Vladimir Binhi & Frank Prato. Binhi appears to have simplified his previous quantum theory which he proposed to explain the behavioral effects observed in organisms exposed to very weak magnetic fields. As the paper has been co-authored with Prato, it looks like this simplification and generalisation has been done so the theory can be tested classically (and I guess Prato is already underway doing that).

Link to the paper...

https://thinkingdeeper.files.wordpress.c...anisms.pdf

Binhi has generalised his theory, and looks only at the magnetic field (MF) effects on the magnetic moment of 'stuff' in the body. He seems to have driven a coach and horses through the idea of looking for individual mechanisms to explain the weak MF effects observed in organisms, instead concentrates on the point where MF field first interacts with the magnetic moment of 'anything' in the organism. Which it must surely do, because everything in the body has a magnetic moment. It's a really interesting perspective.

Binhi simplifies the theory, which basically says that Direct Current MF's (DC MF's) such as the earths geomagnetic field, cause a natural ongoing precession in the magnetic of moment of stuff in the body. That precession can get altered, by interactions with Alternating Current MF's (AC MF's). He further suggests that the AC MF effect becomes much stronger when the DC MF has been cut to 'zero' - with limited or no natural precession of the magnetic moment (i.e. you've put the organism in a Mu Metal box to shield it from the earths magnetic field). This idea is obviously related to Prato's work (above) showing a strong Post Traumatic Stress-like effect in rodents placed in a Mu Metal chamber between footshocks.

The theory seems to put some limits on the effect, small MF field effects getting swamped by all the other thermal electrochemical stuff going on in the brain. Hence the effects get clearly exposed when the whole organism is hidden from the earths DC MF using Mu Metal chambers (as Prato's work shows), but it means that to explain the navigation effect on birds and reptiles he suggests that the effect may be getting amplifed by great numbers of the same of mechanism in the organisms eye. Amplified to a level whereby we can expose a behavioral effect caused by weak MF effects.

I can see issues with it, but it's damn interesting, because following Binhi's ideas it seems to suggest that during the cardiac arrest NDE/OBE, the reduction in power of the brains own EM field would expose it, and turn it into one humongous sized weak MF amplifier. (the like of which even god has never seen Usul... lol)

[I've got no formal training, so if I've got anything wrong in how I'm interpreting this paper, then let me know]

On a side issue, if this is correct, I guess they will have to provide an artificial source of DC MF for astronauts in deep space (Mars Mission), otherwise as they move away from the earths influence they are likely to go mad, or suffer from some sort of PTSD like symptoms, or worse...

UPDATE

Letter from by Dr. Frank Barnes and Dr. Ben Greenebaum in response to the Binhi & Prato (2017)...

https://thinkingdeeper.files.wordpress. ... ments2.pdf

Response to letter by Binhi & Prato...

https://thinkingdeeper.files.wordpress. ... ments3.pdf
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