Salford: Blut-Hirn-Schranke bleibt zu ▼ (Allgemein)

H. Lamarr , München, Mittwoch, 10.10.2007, 11:58 (vor 6236 Tagen)

RDW war uns Kritikern eine Nasenlänge voraus und konnte das, was gerüchteweise in Umlauf ist, nämlich dass Leif Salford seine bekannte Studie zur Öffnung der BHS unter Funkfeldeinwirkung nicht erfolgreich wiederholen konnte, mit harten Fakten belegen. Die ursprüngliche Salford-Studie ist eine der Kronjuwelen praktisch aller Fundi-Frontleute und galt bislang als schwerwiegendes Indiz für Gesundheitsgefährdungen durch Mobilfunk. Der folgende Abstract der jüngsten Salford-Studie zur BHS sagt jedoch etwas ganz anderes: Die BHS bleibt geschlossen! Für Fundis ist diese Nachricht betrüblich, für alle anderen erfreulich. Salford wiederholte seine ursprüngliche Studie allerdings nicht 1:1, sondern bestrahlte in der Neueren die Versuchstiere wiederholte male und nicht nur einmal, wie bei der ursprünglichen Studie.

LONG TERM EFFECTS OF MICROWAVES FROM GSM MOBILE PHONES ON THE RAT BRAIN

Jacob Eberhardt, Arne Brun, Gustav Grafstrom, Lars Malmgren, Bertil Persson, Leif G. Salford

Objectives. In a recent study, we found signs of neuronal damage in the rat 28 and 50 days after a 2 hours exposure for GSM microwaves at 900 MHz with SAR < 0.2 W/kg.

The object of the present investigation is to investigate in the rat long term eects on the brain of repeated exposures to GSM mobile phone radiation. For this purpose, the occurrence behavioral changes, leakage of the blood-brain barrier, neuronal damage and signs of premature aging after a one year period of weekly 2 hour exposures to radiation from a GSM mobile phone at dierent intensities is studied.

Methods. 48 male and female Fischer 344 rats were exposed or sham exposed for two hours once a week for 55 weeks in TEM-cells to radiation from a software programmable GSM-900 mobile telephone. The animals were awake during the exposure and could move and turn within the exposure chamber. The peak output power fed into the TEM cells were 5 or 500 mW, resulting into average whole body specific absorption rates of 1 or 100 mW/kg.

A further 8 animals served as cage controls: The latter stayed undisturbed in the animal facility during the whole period of the investigation. 3 weeks after the last exposure, all animals were subjected to two dierent behavioral test: (i) the Open Field test for testing exploratory and motor behavior as well as anxiety, and (ii) the Episodic-like memory task for testing episodic memory and novelty preference [6]. After the behavioral testing period, the animals were anaesthetized and sacrificed by perfusion-fixation with 4% formaldehyde.

Brain slices were stained for RNA/DNA with cresyl violet. Applying albumin antibodies (Dakopatts), albumin in the brain tissue and albumin uptake into neurons is revealed.

Antibodies to glial fibrillary acedic protein reveal fibrils in astrocytes and gliosis. Gallyas silver staining demonstrates silver positive structures such as tangles in degenerated neurons and plaques plus dystrophic neurites. Luxol fast blue stains myelin. Lipofuscin pigment in neurons is shown by Sudan Black B. Synaptic defects can be demonstrated by synaptofysin antibody staining.

Results. The occurrence of blood-brain barrier leakage and damaged (dark) neurons in dierent parts of the brain were judged semi-quantitatively by the neuropathologist. No increased number of albumin foci or dark neurons were found in exposed animals as compared to sham-exposed. Analyses of cytoskeleton changes, gliosis, myelin pathology, aging eects in neurons and synaptic function are in progress. The Open Field test revealed no eect of exposure on exploratory and motor behavior. The episodic memory test revealed worse short-term memory for exposed animals as compared to sham exposed animals.

Conclusions. The fact that no leakage of the blood-brain barrier and occurrence of dark neurons could be demonstrated in the present study, in contrast to earlier studies of our group with in which these parameters were studied 14, 28 and 50 days after one single exposure, might indicate that some adaptation of the CNS to repeated exposures can occur.

However, temporal order memory was a ected in our study, in the same way, but to a lesser extend, as in the group of understimulated "cage controls". This change in cognitive behavior might be caused by premature aging of the CNS of the exposed animals. For that reason, we investigate the possibility of occurrence of morphological signs of premature aging. The results of these analyses will be presented at the meeting.

Acknowledgements. Grants from The Swedish Council forWork Life and Social Research and the Hans and Marit Rausing Charitable foundation are gratefully acknowledged.

Quelle: The Bioelectromagnetics Society 29th Annual Meeting Abstract Collection

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Tags:
Blut-Hirn-Schranke, Kronjuwelen