Parallel changes of the spontaneous and stimulus-evoked cortical activity elicited by acute treatment with inorganic mercury in rats

Mercury is known to affect the activity of the nervous system of animals and humans, as indicated by the multitude of neurological signs following e.g. occupational exposure. In animal experiments, heavy metals cause a variety of alterations in the central and peripheral nervous system activity but...

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Bibliographic Details
Main Authors: Pecze László
Papp András
Format: Article
Published: 2002
Series:CENTRAL EUROPEAN JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL MEDICINE 8 No. 2-3
Subjects:
mtmt:1294360
Online Access:http://publicatio.bibl.u-szeged.hu/27604
Description
Summary:Mercury is known to affect the activity of the nervous system of animals and humans, as indicated by the multitude of neurological signs following e.g. occupational exposure. In animal experiments, heavy metals cause a variety of alterations in the central and peripheral nervous system activity but an explanation as to mechanism of action is missing in a number of cases. The aim of the work presented was to find correlation between the changes of spontaneous cortical activity (electrocorticogram, ECoG) and cortical sensory evoked potentials (EPs) recorded from rats acutely treated with mercuric chloride. Adult male Wistar rats were anesthesized with urethane. Silver recording electrodes were placed on the exposed left somatosensory projection area of the whiskers and of the tail. The corresponding peripheral sites were stimulated by electric pulses. During tail stimulation, compound action potentials of the tail nerve were also recorded. After at least 4 control records, mercury (HgCl2, 7 mg/kg) was administered via a peritoneal cannula and the recording was continued for further ca. 2 hours. In the spontaneous activity, increased activity of the low and decreased activity of the high frequency bands was seen Simultaneously, the amplitude of the EPs increased. On the tail nerve potential, Hg caused an amplitude decrease and a latency increase. Latency increase of the cortical EP and the decrease of nerve conduction velocity evolved simultaneously. The alterations are likely due to some specific, and not to a general toxic, effect of Hg.
Physical Description:126-130
ISSN:1219-1221