Abstract:

Objective  To study the effects of formaldehyde on memory and the content of neurotransmitter in the cerebral tissue of mice,and explore the effects of formaldehyde on central nervous system and its possible mechanism. Methods  48 Kunming mice were randomly divided into 4 groups：negative control,three experiment groups（low dose group:1/24 LC50,21.0 mg/m³;middle dose group: 1/12 LC50, 42.0 mg/m³;and high dose group:1/6 LC50,84.0 mg/m³）.The mice in experiment groups were exposed to formaldehyd by inspiration in a static total enclosure chamber for 12 weeks.At the first day of the 6th week,8th week and 12th week,the memory of mice was determined,and the neurotransmitters in the cerebral tissue were determined at the end of exposure to toxicants.Results   In  water maze test,at the 8th week,the   swimming time of achieving the goal of the mice in high dose group  was longer than that in control group（P<0.05）.At the  12th week,the swimming time of achieving the goal of the mice in middle dose group and high dose group was increased compared with control group（P<0.01）.And the swimming time of achieving the goal of the mice in high dose gr
oup increased compared with low dose group.（P<0.01）.In high dose  group,the swimming time of achieving the goal at the 12th week was increased compared with the 8th week（P<0.01）.The contents of Ach in cerebral tissue in experiment groups were lower than that in control group(P<0.01）,and the contents of Glu in cerebral tissue were higher than that in control group(P<0.01）.The content of NO in cerebral tissue of mice in each group had no significant difference(P>0.05).Conclusion Long-term exposure to formaldehyde can cause the decreasing of memory,decreasing of the content of Ach and increasing of the content of Glu in the cerebral tissue.It indicates that the change of  neurotransmitter contents  may be one of mechanisms of decreasing of memory in mice.

Key words: formaldehyde;memory;neurotransmitter;nitric oxide;acetylcholine;glutamic acid