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Does exposure to a radiofrequency electromagnetic field modify thermal preference in juvenile rats?

Pelletier A, Delanaud S, de Seze R, Bach V, Libert JP, Loos N - PLoS ONE (2014)

Bottom Line: Our results indicated that relative to control group, exposure to RF-EMF at 31°C was associated with a significantly lower tail skin temperature (-1.6°C) which confirmed previous data.The PS did not differ significantly between the two groups.We conclude that RF-EMF exposure induced a shift in thermal preference towards higher temperatures.

View Article: PubMed Central - PubMed

Affiliation: PériTox Laboratory, UMR-I 01 INERIS, Faculty of Medicine, Jules Verne University of Picardy, Amiens, France.

ABSTRACT
Some studies have shown that people living near a mobile phone base station may report sleep disturbances and discomfort. Using a rat model, we have previously shown that chronic exposure to a low-intensity radiofrequency electromagnetic field (RF-EMF) was associated with paradoxical sleep (PS) fragmentation and greater vasomotor tone in the tail. Here, we sought to establish whether sleep disturbances might result from the disturbance of thermoregulatory processes by a RF-EMF. We recorded thermal preference and sleep stage distribution in 18 young male Wistar rats. Nine animals were exposed to a low-intensity RF-EMF (900 MHz, 1 V x m(-1)) for five weeks and nine served as non-exposed controls. Thermal preference was assessed in an experimental chamber comprising three interconnected compartments, in which the air temperatures (Ta) were set to 24°C, 28°C and 31°C. Sleep and tail skin temperature were also recorded. Our results indicated that relative to control group, exposure to RF-EMF at 31°C was associated with a significantly lower tail skin temperature (-1.6°C) which confirmed previous data. During the light period, the exposed group preferred to sleep at Ta = 31°C and the controls preferred Ta = 28°C. The mean sleep duration in exposed group was significantly greater (by 15.5%) than in control group (due in turn to a significantly greater amount of slow wave sleep (SWS, +14.6%). Similarly, frequency of SWS was greater in exposed group (by 4.9 episodes.h-1). The PS did not differ significantly between the two groups. During the dark period, there were no significant intergroup differences. We conclude that RF-EMF exposure induced a shift in thermal preference towards higher temperatures. The shift in preferred temperature might result from a cold thermal sensation. The change in sleep stage distribution may involve signals from thermoreceptors in the skin. Modulation of SWS may be a protective adaptation in response to RF-EMF exposure.

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Thermal preference for controls (A) and RF-EMF exposed rats (B) over a 24 h period.The mean ± SEM time (in minutes, averaged over two-hour periods) spent in each of the three air temperatures zones (24°C (•), 28°C (□) and 31°C (▴), indicating the preferred temperature) during the dark and light periods.
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pone-0099007-g002: Thermal preference for controls (A) and RF-EMF exposed rats (B) over a 24 h period.The mean ± SEM time (in minutes, averaged over two-hour periods) spent in each of the three air temperatures zones (24°C (•), 28°C (□) and 31°C (▴), indicating the preferred temperature) during the dark and light periods.

Mentions: We observed circadian variation in the animal’s thermal preference (Figure 2). During the light period, the thermal preference in the control group (top panel) was 28°C (with an acrophase between 3 pm and 5 pm). In the exposed group (bottom panel), the animals preferred 31°C during the light period (with an acrophase between 1 pm and 3 pm). The effect of RF-EMF exposure was significant during the light period only. During the dark period, the animals in both the control group and the exposed group preferred a Ta of 24°C, and the circadian variation in thermal preference tended to disappear (i.e. the curves reached a plateau) at 28°C and 31°C.


Does exposure to a radiofrequency electromagnetic field modify thermal preference in juvenile rats?

Pelletier A, Delanaud S, de Seze R, Bach V, Libert JP, Loos N - PLoS ONE (2014)

Thermal preference for controls (A) and RF-EMF exposed rats (B) over a 24 h period.The mean ± SEM time (in minutes, averaged over two-hour periods) spent in each of the three air temperatures zones (24°C (•), 28°C (□) and 31°C (▴), indicating the preferred temperature) during the dark and light periods.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4048227&req=5

pone-0099007-g002: Thermal preference for controls (A) and RF-EMF exposed rats (B) over a 24 h period.The mean ± SEM time (in minutes, averaged over two-hour periods) spent in each of the three air temperatures zones (24°C (•), 28°C (□) and 31°C (▴), indicating the preferred temperature) during the dark and light periods.
Mentions: We observed circadian variation in the animal’s thermal preference (Figure 2). During the light period, the thermal preference in the control group (top panel) was 28°C (with an acrophase between 3 pm and 5 pm). In the exposed group (bottom panel), the animals preferred 31°C during the light period (with an acrophase between 1 pm and 3 pm). The effect of RF-EMF exposure was significant during the light period only. During the dark period, the animals in both the control group and the exposed group preferred a Ta of 24°C, and the circadian variation in thermal preference tended to disappear (i.e. the curves reached a plateau) at 28°C and 31°C.

Bottom Line: Our results indicated that relative to control group, exposure to RF-EMF at 31°C was associated with a significantly lower tail skin temperature (-1.6°C) which confirmed previous data.The PS did not differ significantly between the two groups.We conclude that RF-EMF exposure induced a shift in thermal preference towards higher temperatures.

View Article: PubMed Central - PubMed

Affiliation: PériTox Laboratory, UMR-I 01 INERIS, Faculty of Medicine, Jules Verne University of Picardy, Amiens, France.

ABSTRACT
Some studies have shown that people living near a mobile phone base station may report sleep disturbances and discomfort. Using a rat model, we have previously shown that chronic exposure to a low-intensity radiofrequency electromagnetic field (RF-EMF) was associated with paradoxical sleep (PS) fragmentation and greater vasomotor tone in the tail. Here, we sought to establish whether sleep disturbances might result from the disturbance of thermoregulatory processes by a RF-EMF. We recorded thermal preference and sleep stage distribution in 18 young male Wistar rats. Nine animals were exposed to a low-intensity RF-EMF (900 MHz, 1 V x m(-1)) for five weeks and nine served as non-exposed controls. Thermal preference was assessed in an experimental chamber comprising three interconnected compartments, in which the air temperatures (Ta) were set to 24°C, 28°C and 31°C. Sleep and tail skin temperature were also recorded. Our results indicated that relative to control group, exposure to RF-EMF at 31°C was associated with a significantly lower tail skin temperature (-1.6°C) which confirmed previous data. During the light period, the exposed group preferred to sleep at Ta = 31°C and the controls preferred Ta = 28°C. The mean sleep duration in exposed group was significantly greater (by 15.5%) than in control group (due in turn to a significantly greater amount of slow wave sleep (SWS, +14.6%). Similarly, frequency of SWS was greater in exposed group (by 4.9 episodes.h-1). The PS did not differ significantly between the two groups. During the dark period, there were no significant intergroup differences. We conclude that RF-EMF exposure induced a shift in thermal preference towards higher temperatures. The shift in preferred temperature might result from a cold thermal sensation. The change in sleep stage distribution may involve signals from thermoreceptors in the skin. Modulation of SWS may be a protective adaptation in response to RF-EMF exposure.

Show MeSH
Related in: MedlinePlus