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 SchulzDepartment of Public Health, Albert Szent-Györgyi Medical UniversityDóm tér 10, H-6720Szeged, 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.