研究のタイプ: 医学/生物学の研究 (experimental study)

[超低周波磁界ばく露はラットの海馬、嗅内皮質、前頭前皮質のAMPARおよびNMDARサブユニットの発現に多様な影響を与えるが空間学習および記憶には影響しない] med./bio.

The extremely low-frequency magnetic field exposure differently affects the AMPAR and NMDAR subunit expressions in the hippocampus, entorhinal cortex and prefrontal cortex without effects on the rat spatial learning and memory.

掲載誌: Environ Res 2014; 134: 74-80

この研究は、超低周波磁界(50Hz、0.5mT)の慢性ばく露(14および28日間)がラット海馬、嗅内皮質(EC)、前頭前皮質(PFC)のAMPARおよびNMDARサブユニットの発現および空間学習および記憶に与える影響を調べた。その結果、AMPARを形成するサブユニットについては、28日ばく露でECのGluA2発現、14日ばく露でPFCのGluA3発現が有意に低下したが、海馬遺伝子発現はどちらのばく露期間でも影響が見られなかった;NMDARを形成するサブユニットについては14日ばく露海馬のGluN2A、GluN2B発現が有意に増加し、EC、PFCのGluN1、GluN2A発現も増加した、などの所見を報告している。

The detailed summary of this article is not available in your language or incomplete. Would you like to see a complete translation of the summary? Then please contact us →

研究目的(著者による)

To examine the effects of chronic exposure to extremely low frequency magnetic fields on the subunit protein expression of two synaptic receptors in the brain and on spatial learning and memory in rats.

詳細情報

The N-methyl-D-aspartate receptor (NMDA receptor) and the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPA receptor) are glutamate receptors which mediate the fast excitatory neurotransmission in the brain. These receptors play an important role in synaptic plasticity and learning.
60 rats were randomly assigned to one of four groups: 1.) sham exposure for 14 days, 2.) exposure for 14 days, 3.) sham exposure for 28 days and 4.) exposure for 28 days. After the exposure, some animals (5 rats from group 1 and 2, respectively; 6 rats from group 3 and 4, respectively) were immediately used for protein expression analysis, while the others (10 rats from group 1 and 2, respectively; 9 rats from group 3 and 4, respectively) were tested in the Morris water maze.

影響評価項目

ばく露

ばく露 パラメータ
ばく露1: 50 Hz
ばく露時間: 4 h/day for 14 or 28 days

ばく露1

主たる特性
周波数 50 Hz
タイプ
  • magnetic field
波形
  • sinusoidal
ばく露時間 4 h/day for 14 or 28 days
ばく露装置
ばく露の発生源/構造
ばく露装置の詳細 round coil electromagnet with a 1000 turned copper wire constructed on a glass fibre cylinder, the centre of each cage was 15 cm vertical below the poles
パラメータ
測定量 種別 Method Mass 備考
磁束密度 0.5 mT mean 測定値 - in the center of the coils

Reference articles

  • Xiong J et al. (2013): [超低周波磁界ばく露によって誘導される内側嗅内皮質表層での樹状突起棘の密度および形態の変化]

ばく露を受けた生物:

方法 影響評価項目/測定パラメータ/方法

研究対象とした生物試料:
研究対象とした臓器系:
調査の時期:
  • ばく露後

研究の主なアウトカム(著者による)

The magnetic field exposure changed the expression levels of the NMDA receptor and AMPA receptor subunits differently.
Regarding the subunit protein expression of the NMDA receptor, significant increases in the hippocampus were observed after exposure (increased levels of GluN2A and GluN2B after 14 days, increased levels of GluN2B after 28 days) compared to the sham exposure. Additionally in the entorhinal cortex of exposed rats, the NMDA receptor subunit expression was significantly changed (increased levels of GluN1 and GluN2A after 14 days, decreased level of GluN2A after 28 days, increased level of GluN2B after 28 days) in comparison to the sham exposure while in the prefrontal cortex, significant increases were observed (increased levels of GluN1 and GluN2A after 14 days, increased level of GluN1 after 28 days).
Regarding the subunit protein expression of the AMPA receptor, no significant alterations in the hippocampus of exposed rats were observed when compared to the sham exposed rats, while significant decreases were found in the entorhinal cortex (decreased level of GluA2 after 28 days) and in the prefrontal cortex (decreased level of GluA3 after 14 days).
No significant differences occurred regarding spatial learning and memory in the Morris Water maze between the exposed and the sham exposed rats.
The authors conclude that exposure to extremely low frequency magnetic fields could have an influence on the subunit protein expression of synaptic glutamate receptors but does not change the spatial memory and learning abilities of rats.

研究の種別:

研究助成

関連論文