Behavioral effects of subchronic inorganic manganese exposure in rats.
BACKGROUND
Manganese, an essential micronutrient, is a potential neurotoxicant in prolonged overexposure. Parkinson-like syndrome, motor deficit, disturbed psychomotor development are typical signs of neuropathological alterations due to Mn in humans.


METHODS
Young adult rats, in three groups of 16 each, received 15 and 59 mg/kg b.w. MnCl(2), (control: distilled water) via gavage for 10 weeks, and were kept for further 12 weeks. Correlation of MnCl(2) exposure to body and organ weights, neurobehavioral effects (spatial memory, exploratory activity, psychomotor performance, pre-pulse inhibition), and histopathological changes (gliosis) was sought.


RESULTS
By the end of treatment, Mn accumulated in blood, cortex, hippocampus, and parenchymal tissues. Body and organ weights were reduced in high dose rats. All treated rats showed hypoactivity, decreased memory performance, and diminished sensorimotor reaction. In the dentate gyrus of these, GFAP immunoreactivity increased. During the post-treatment period, body weight of the high dose group remained decreased, locomotor activity returned to control, but the lasting effect of MnCl(2) could be revealed by amphetamine.


CONCLUSIONS
Using complex methodology, new data were obtained regarding the relationship between the long-term effects of MnCl(2) at neuronal and behavioral level.
Vezér
T
T
Department of Public Health, University of Szeged Faculty of Medicine, Dóm toŕ 10, Szeged, Hungary. vezer@puhe.szote.u-szeged.hu
Kurunczi
A
A
Náray
M
M
Papp
A
A
Nagymajtényi
L
L
D000284:Administration, Oral; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D018891:Dentate Gyrus / Q000187:drug effects / Q000378:metabolism; D003913:Dextroamphetamine / Q000008:administration & dosage / Q000009:adverse effects; D020233:Gait Disorders, Neurologic / Q000139:chemically induced; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006814:Hungary; D008297:Male; D008345:Manganese / Q000008:administration & dosage / Q000633:toxicity*; D018782:Maze Learning / Q000187:drug effects; D011597:Psychomotor Performance / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar
D005904:Glial Fibrillary Acidic Protein; D008345:Manganese; D003913:Dextroamphetamine