Behavioural and Neurophysiological Consequences of Subchronic Mercury Exposure in Rats

Horst Schulz, László Nagymajtényi, András Papp, and Illés Dési

Department of Public Health, Albert Szent-Györgyi Medical University, and
WHO Collaborating Centre for Chemical Safety, Szeged, Hungary
 
Corresponding author: Dr. Horst Schulz
Department of Public Health, Albert Szent-Györgyi Medical University
Dóm tér 10, H-6720 Szeged, Hungary
Tel: 66-62-455-119
Fax: 36-62-455-120
E-mail: sch@puhe.szote.u-szeged.hu

CEJOEM 1997, 3:210-223


Key words:
Mercuric chloride, open field behaviour, electrocorticogram, cortical evoked potential, conduction velocity, refractory period, rat
Abstract:
Mercury and mercury compounds are neurotoxic and cause behavioural and neurological disorders as reported in a number of human and animal experimental studies. In the present study, the effect of subchronic (4, 8, and 12 weeks) relatively low-level (0.4, 0.8, and 1.6 mg/kg mercury in form of HgCl2, per os by gavage) treatment on spontaneous open field exploration of male Wistar rats, as well as on their spontaneous and evoked bioelectric activity in anaesthetized state was investigated. Certain behavioural characteristics, like horizontal and vertical ambulation (as an expression of hypo- or hyperactivity), grooming, and electrophysiological parameters (electrocorticogram, sensory evoked potentials, conduction velocity and refractory periods of peripheral nerve) were recorded. The results showed that mercury had dose and treatment-time related hypoactivating effects. It was also found that mercury dose- and time-dependently changed each of the examined behavioural and electrophysiological parameters. Most of these changes became more expressed – and, partly, significant – by the end of the experiment at week 12.
Received: 25 July 1997
Accepted: 11 August 1997

Posted: 25 November 1998

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