[Excitatory effect of low dose of manganese on spontaneous discharges of dorsal root ganglion neurons].
OBJECTIVE
To investigate the toxicity of low dose of manganese on peripheral nervous system.


METHODS
With methods of the perfusion of dorsal root ganglion (DRG) in vitro and single fiber recording of the spontaneous discharges, the effect of manganese chloride (MnCl2 1, 2, 5, 10, 50, 100 micromol/L) on neurons were observed.


RESULTS
MnCl2 enhanced spontaneous discharges of DRG neurons in dose-dependent manner, but failed to affect the discharges of silent fibers. Different patterns of effects were observed in study. 1 micromol/L MnCl2 persistent enhanced the spontaneous discharges. The frequency of discharges reversed after a transient excitatory effect when 5 micromol/L MnCl2 was applied. However, 50 micromol/L MnCl2 gradually decreased the frequency of discharges followed a transient excitatory effect.


CONCLUSIONS
These results suggest that low dose of manganese enhanced the spontaneous discharges of DRG neurons. This may partially explain the mechanism of paraesthesia in slight poison of manganese.
Yang
Rui-Hua
RH
Department of Occupational and Environmental Health, Fourth Military Medical University, Xi'an 710033, China.
Chen
Jing-Yuan
JY
Hu
San-Jue
SJ
D000200:Action Potentials / Q000187:drug effects* / Q000502:physiology; D000818:Animals; D002712:Chlorides / Q000633:toxicity; D004305:Dose-Response Relationship, Drug; D004594:Electrophysiology; D004785:Environmental Pollutants / Q000633:toxicity*; D005260:Female; D005727:Ganglia, Spinal / Q000166:cytology / Q000502:physiology*; D008297:Male; D008345:Manganese / Q000633:toxicity*; D017895:Manganese Compounds; D009431:Neural Conduction / Q000187:drug effects; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012584:Sciatic Nerve / Q000187:drug effects / Q000502:physiology
D002712:Chlorides; D004785:Environmental Pollutants; D017895:Manganese Compounds; D008345:Manganese; C025340:manganese chloride