giovedì 29 marzo 2012

Iperattività riscontrata su topi dopo esposizione nell'utero

La sperimentazione è stata fatta su topi in gradivanza esposte a radiazione da cellulare.
I risultati evidenziano delle alterazioni neurologiche dei neonati, con iperattivià , disturbi di memoria; si è ipotizzato - da controlli sul alcuni livelli ormonali - danni sulla trasmissione nelle sinapsi.

Gli autori portano ad un parallelismo sulla iperattività dei bambini che è diventato negli ultimi decenni una malattia sempre più riconosciuta.

Study finds indication of effects on neurodevelopment and behavior in mice after in utero cell phone exposure

Researchers at the Yale University, New Haven, USA, investigated the offspring of 39 pregnant mice that had been exposed to the electromagnetic field of a commercial mobile phone (800-1900 MHz, SAR according to manufacturer’s data: 1.6 W/kg) round the clock throughout gestation (days 1-17). The distance of the mobile phone, operated in muted, uninterrupted active call mode, to the dams was 4.5 to 22.3 cm, depending on the location of the animal within the cage. As a control group, further 42 dams were sham exposed.
Tests performed: (1) On the twelfth day of gestation the level of the stress hormone corticosterone in the blood of the dams was measured. (2) After birth, the young mice had to perform three different behavioral tests (47 - 82 exposed and 51 - 79 sham-exposed animals, depending on the type of test): memory test, anxiety/hyperactivity test and anxious behavior test. (3) Electrophysiological measurements of coronal cortical slices prepared from the brain of 3-4 week old mice to assess the effectiveness of transmission of the neurotransmitter glutamate at synapses in the brain (glutamatergic synaptic transmission in the pyramidal cells in a specific layer of the prefrontal cortex).

Results: The behavioral tests showed that mice exposed in utero were hyperactive, had impaired memory and decreased anxiety. The electrophysiological measurements showed that these behavioral changes were caused by changes in neuronal programming due to impaired effectiveness of synaptic glutamate transmission. This effect was not restricted to the cerebral cortex, but also occurred in another brain area. Stress of exposed dams could be excluded as a possible reason for the behavioral and electro-physiological differences in the offspring, because stress hormone levels were not significantly increased as compared to the sham-exposed dams.

The authors comment that their results are the first experimental evidence of neuropathological effects of in utero cell phone exposure which persist into adult age. According to the authors, the observed behavioral symptoms would resemble those of human children with ADHD (attention deficit hyperactivity disorder). They conclude that further experiments would be needed in humans or non-human primates to determine the risks of mobile phone exposure during pregnancy.

Note: This interesting research should first be replicated under more defined exposure conditions using exact dosimetric models to determine the real SAR values in the exposed animals.

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