Dynamics of Central and Peripheral Evoked Electrical Activity in the Nervous System of Rats
Exposed to Xenobiotics
András Papp, László Pecze, and Tünde Vezér
Department of Public Health, University of Szeged Faculty of Medicine, Szeged, Hungary
Corresponding author: András Papp
Department of Public Health
University of Szeged Faculty of Medicine
Dóm tér 10.
H-6720 Szeged, Hungary
Telephone: +36-62-545-119
Fax number: +36-62-545-120
E-mail: ppp@puhe.szote.u-szeged.hu
CEJOEM 2004, Vol.10. No.1.: 52–59
Key words:
Cortical evoked potential, nerve action potential, heavy metals, rat
Abstract:
The complex chemical pollution of our environment results in mass human exposure to a number
of proved or supposed neurotoxicants. In most cases, there are no overt symptoms of nervous system
damage, thus new sensitive indicators of the resulting functional alterations still need to be
worked out. Various forms of evoked electrical activity of the central and peripheral nervous
system are routinely recorded in experimental animals and in humans, and are known to be sensitive
to damaging influences. In the present work, male Wistar rats (300–350 g body weight) were acutely
or subchronically treated with various neurotoxic heavy metals and dynamic alterations in
different forms of evoked activity (somatosensory cortical evoked potentials and peripheral nerve
action potential) were observed.
A series of 50 stimuli was applied and the first and last five
evoked responses were averaged. The changes in the amplitude and latency of the responses over the
series (last 5 vs. first 5) and the dependence of this difference on the frequency of stimulation
were calculated. It was found that several of these variables, e.g., the amplitude of the cortical
evoked response, were sensitive and dose-dependent indicators of the nervous system damage caused
by the heavy metal exposure. On the basis of our results, new, easy to use functional tests for
detection and follow-up of nervous system damage of environmental origin could be developed.
Received: 19 September 2003
Accepted: 1 December 2003
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