Due to a lack of financial resources, we unfortunately have to suspend the import of any new radio frequency and mobile phone-related articles as of now (November 27, 2017). We apologize for this inconvenience and will keep you informed.
Home
Medical/biological study (experimental study)

Effect of 1.8 GHz radiofrequency electromagnetic radiation on novel object associative recognition memory in mice.

Published in: Sci Rep 2017; 7: 44521

Aim of study (acc. to author)

To investigate the effect of exposure to a 1.8 GHz electromagnetic field on the object recognition memory and related brain parameters in mice.
Background/further details: For the novel object recognition test (NORT), mice were exposed to electromagnetic fields with a specific absorption rate of 1.98 W/kg, 2.2 W/kg, 2.42 W/kg, 2.86 W/kg, or 3.3 W/kg (n=8-12 exposed, n=7-12 sham exposed) and examined 3, 4, 5, and 8 days after the exposure. For open field (n=12 exposed, n=10 sham exposed), histological (n=16-18 exposed, n=10-21 sham exposed) and electrophysiological tests (n=12-20 exposed, n=11-16 sham exposed), animals were exposed to 3.3 W/kg and examined three days after the exposure. Every exposure group had its own sham exposure group.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 1.8 GHz
Exposure duration: 30 minutes
object recognition test (NORT)
Exposure 2: 1.8 GHz
Exposure duration: 30 minutes
object recognition test (NORT)
Exposure 3: 1.8 GHz
Exposure duration: 30 minutes
object recognition test (NORT)
Exposure 4: 1.8 GHz
Exposure duration: 30 minutes
object recognition test (NORT)
Exposure 5: 1.8 GHz
Exposure duration: 30 minutes
object recognition test (NORT), open field, histological and electrophysiological tests
Exposure 1
Main characteristics
Frequency 1.8 GHz
Type
Exposure duration 30 minutes
Additional info object recognition test (NORT)
Exposure setup
Exposure source
Chamber two cages of mice for each experimental group (exposed and sham exposed)
Setup exposure system consisted of a computer, a microwave signal source, and a two-dimensional movable loading platform; aperture plane of the horn antenna was 21.4 × 16.3 cm2
Sham exposure A sham exposure was conducted.
Additional info superficial body temperature was measured by an infrared camera and no significant difference was observed between mice exposed to a 3.3 W/kg SAR electromagnetic field and the sham exposure
Parameters
Measurand Value Type Method Mass Remarks
SAR 1.98 W/kg mean calculated brain -
electric field strength 138.8 V/m effective value measured - at a distance of 1.5 m from the antenna
power 90 W - - - -
Exposure 2
Main characteristics
Frequency 1.8 GHz
Type
Exposure duration 30 minutes
Additional info object recognition test (NORT)
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 2.2 W/kg mean calculated brain -
electric field strength 146.4 V/m effective value measured - at a distance of 1.5 m from the antenna
power 100 W - - - -
Exposure 3
Main characteristics
Frequency 1.8 GHz
Type
Exposure duration 30 minutes
Additional info object recognition test (NORT)
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 2.42 W/kg mean calculated brain -
electric field strength 153.5 V/m effective value measured - at a distance of 1.5 m from the antenna
power 110 W - - - -
Exposure 4
Main characteristics
Frequency 1.8 GHz
Type
Exposure duration 30 minutes
Additional info object recognition test (NORT)
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 2.86 W/kg mean calculated brain -
electric field strength 166.9 V/m effective value measured - at a distance of 1.5 m from the antenna
power 130 W - - - -
Exposure 5
Main characteristics
Frequency 1.8 GHz
Type
Exposure duration 30 minutes
Additional info object recognition test (NORT), open field, histological and electrophysiological tests
Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 3.3 W/kg mean calculated brain -
electric field strength 179.3 V/m effective value measured - at a distance of 1.5 m from the antenna
power 150 W - - - -
Exposed system:
  • animal
  • mouse/C57BL
  • whole body

Methods Endpoint/measurement parameters/methodology

Investigated material:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Three days after exposure (SAR of 2.2 W/kg and above), the mice showed significantly enhanced memory abilities in the novel object recognition task compared to sham exposed mice. This effect consisted until the 8th day after exposure. However, no significant exposure effect was found in the motor activity.
The histological examination revealed that in exposed mice, the dendritic spine density in hippocampal pyramidal cells and the dendritic spine length in the prefrontal cortex were significantly increased compared to sham exposed mice. Electrophysiological recordings showed a significantly enhanced excitability in prefrontal cortical and hippocampal slices of exposed mice compared to sham exposed ones.
The authors conclude that a single exposure to a 1.8 GHz electromagnetic field with a SAR of 3.3 W/kg enhanced the object recognition memory in mice, accompanied by histological and electrophysiological alterations, and recommend further studies to examine a potential therapeutic effect.
Study character:

Study funded by

  • National Basic Research Program of China
  • Shanghai Leading Academic Discipline Project, China
  • National Key Research & Development (R&D) Plan, China

Related articles

  • Hussein S et al. (2016): Biochemical and histological studies on adverse effects of mobile phone radiation on rat's brain.
  • Razavinasab M et al. (2016): Maternal mobile phone exposure alters intrinsic electrophysiological properties of CA1 pyramidal neurons in rat offspring.
  • Mugunthan N et al. (2016): Effects of Long Term Exposure of 900-1800 MHz Radiation Emitted from 2G Mobile Phone on Mice Hippocampus- A Histomorphometric Study.
  • Kerimoglu G et al. (2016): Pernicious effects of long-term, continuous 900-MHz electromagnetic field throughout adolescence on hippocampus morphology, biochemistry and pyramidal neuron numbers in 60-day-old Sprague Dawley male rats.
  • Deshmukh PS et al. (2016): Effect of Low Level Subchronic Microwave Radiation on Rat Brain.
  • Sahin A et al. (2015): Deleterious impacts of a 900 MHz electromagnetic field on hippocampal pyramidal neurons of 8-week-old Sprague Dawley male rats.
  • Ikinci A et al. (2013): The Effects of Prenatal Exposure to a 900 Megahertz Electromagnetic Field on Hippocampus Morphology and Learning Behavior in Rat Pups.
  • Hao D et al. (2013): Effects of long-term electromagnetic field exposure on spatial learning and memory in rats.
  • Ntzouni MP et al. (2013): Transient and cumulative memory impairments induced by GSM 1.8 GHz cell phone signal in a mouse model.
  • Narayanan SN et al. (2010): Effect of radio-frequency electromagnetic radiations (RF-EMR) on passive avoidance behaviour and hippocampal morphology in Wistar rats.