Spatial learning in deer mice: sex differences and the effects of endogenous opioids and 60 Hz magnetic fields

Kavaliers, Martin; Ossenkopp, Klaus‐Peter; Prato, Frank S.; Innes, Duncan; Galea, Liisa A.M.; Kinsella, D. M.; Perrot-Sinal, Tara S.

doi:10.1007/bf00216135

Cited by 77 publications

(42 citation statements)

References 74 publications

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“…Previous reports have not found gender differences [7,9], but there is some evidence for such differences in the effects of various types of magnetic field [26][27][28][29][30][31]. Our results do not agree with some studies in which suicide numbers were found to be inversely related to geomagnetic activity [12,13].…”

Section: Discussioncontrasting

confidence: 99%

Association of geomagnetic disturbances and suicides in Japan, 1999–2010

Tada

Nishimura

Nakatani

et al. 2013

Environ Health Prev Med

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Objectives Previous studies have shown a positive relationship between geomagnetic disturbances and an increased incidence of suicide. The Japanese suicide rate is the ninth highest in the world, but there have been no reports examining the relationship between geomagnetic disturbance and the number of suicides, and, therefore, this paper examines this relationship. Methods The number of Japanese suicides per month from January 1999 to December 2010 was obtained, and it was found that a total of 262,596 males and 102,539 females committed suicide during this period. To adjust the other factors which affect the number of suicides, a multiple linear regression analysis with backward elimination was carried out, with the monthly number of suicides as the response variable and the monthly mean K index value, monthly mean number of sunspots, monthly mean unemployment rate, proportion of elderly people (%), monthly mean air pressure (hPa), monthly mean air temperature (°C), monthly mean humidity (%), and monthly mean day length (h) as the explanatory variables. ResultsIn the multiple linear regression analysis for males, the monthly mean K index value was associated with the monthly number of suicides, but in females, the monthly mean K index value was not associated with the monthly number of suicides. Conclusion In this study, we generated a hypothesis that geomagnetic disturbances may trigger male suicides.

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Section: Discussioncontrasting

confidence: 99%

Association of geomagnetic disturbances and suicides in Japan, 1999–2010

Tada

Nishimura

Nakatani

et al. 2013

Environ Health Prev Med

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“…As well, ELF magnetic ®eld exposures are reported to modify homing pigeon behavior [Papi et al, 1992] and spatial learning in rodents [Kavaliers et al, 1996] in a manner consistent with alterations in opioid function. These results, from a number of different laboratories, strongly suggest that ELF magnetic ®elds affect opioid systems and their behavioral actions.…”

Section: Introductionmentioning

confidence: 95%

Extremely low frequency magnetic fields can either increase or decrease analgaesia in the land snail depending on field and light conditions

Prato

Kavaliers

Thomas

2000

Bioelectromagnetics

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Results of prior investigations with opioid peptide mediated antinociception or analgaesia have suggested that these extremely low frequency (ELF) magnetic field effects are described by a resonance mechanism rather than mechanisms based on either induced currents or magnetite. Here we show that ELF magnetic fields (141–414 μT peak) can, in a manner consistent with the predictions of Lednev's parametric resonance model (PRM) for the calcium ion, either (i) reduce, (ii) have no effect on, or (iii) increase endogenous opioid mediated analgaesia in the land snail, Cepaea nemoralis. When the magnetic fields were set to parameters for the predictions of the PRM for the potassium ion, opioid‐peptide mediated analgaesia increased and there was evidence of antagonism by the K+ channel blocker, glibenclamide. Furthermore, these effects were dependent on the presence of light; the effects were absent in the absence of light. These observed increases and decreases in opioid analgaesia are largely consistent with the predictions of Lednev's PRM. Bioelectromagnetics 21:287–301, 2000. © 2000 Wiley‐Liss, Inc.

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“…enkephalin, endorphin) peptide-mediated antinociception (`analgaesia') in a variety of species, including humans (Kavaliers & Ossenkopp 1988, 1991Prato et al 1995;Betancur et al 1994;Del Seppia et al 1995;Papi et al 1995). Also, extremely low frequency (ELF) magnetic ¢eld exposures are reported to modify homing pigeon behaviour (Papi et al 1992), and spatial learning in rodents (Kavaliers et al 1996), in a manner consistent with alterations in opioid activity. Together, these results, from a number of di¡erent laboratories and species, indicate that ELF magnetic ¢elds can a¡ect opioid systems and their behavioural actions.…”

Section: Introductionmentioning

confidence: 99%

Modulatory actions of light on the behavioural responses to magnetic fields by land snails probably occur at the magnetic field detection stage

Prato

Kavaliers

Thomas

et al. 1998

Proc. R. Soc. Lond. B

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The attenuation of opioid peptide-mediated antinociception or analgaesia is a well-established e¡ect of extremely low frequency (ELF) magnetic ¢elds. Results of prior studies indicated a modulatory role for light such that when the ELF exposures were carried out in the absence of light, the inhibitory e¡ect on analgaesia was reduced. Here, we investigated whether this modulatory e¡ect of light occurs at either the magnetic ¢eld detection stage or is associated with a post-detection mechanism. We compared the e¡ects of the presence and absence of light on the attenuation of opioid-induced analgaesia in the land snail, Cepaea nemoralis, by (i) an ELF magnetic ¢eld (15 min, 60 Hz, 141 mT peak), and (ii) the prototypic opiate antagonist, naloxone. Determinations were performed during the subjective`day' and`night' in the presence (1.9 W m À2 and 1.0 mW m À2 , respectively) and absence of light (less than 10 À6 W m À2 ). The inhibitory e¡ects of the ELF magnetic ¢elds and naloxone on opioid-induced analgaesia were similar in the presence of light; whereas in the absence of light the inhibitory e¡ects of the ELF magnetic ¢elds as a percentage of sham were markedly reduced, while those of naloxone were una¡ected. This indicates that the modulatory e¡ects of light on the actions of the ELF magnetic ¢elds probably a¡ect the detection mechanism prior to its coupling to the opioid system.

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Spatial learning in deer mice: sex differences and the effects of endogenous opioids and 60 Hz magnetic fields

Cited by 77 publications

References 74 publications

Association of geomagnetic disturbances and suicides in Japan, 1999–2010

Association of geomagnetic disturbances and suicides in Japan, 1999–2010

Extremely low frequency magnetic fields can either increase or decrease analgaesia in the land snail depending on field and light conditions

Modulatory actions of light on the behavioural responses to magnetic fields by land snails probably occur at the magnetic field detection stage

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