Effect of inhaled formaldehyde on learning and memory of mice.
In this study, we investigated the effect of inhaled formaldehyde on learning and memory capacity. After exposure to 0 (control), 1 and 3 mg/m(3) of gaseous formaldehyde respectively, the behavior of mice in a Morris water maze, the expression of NR1, NR2B mRNA and oxidative damage levels in mice brain were analyzed. The water maze performance, the activities of dismutase superoxide (SOD) and levels of glutathione (GSH) decreased significantly in 3 mg/m(3) group (P < 0.01, compared with control group); while malondialdehyde (MDA) contents and expression of NR1 and NR2B genes increased significantly after exposure to 3 mg/m(3) of gaseous formaldehyde (P < 0.05, <0.01, <0.01, compared with control group). These findings indicate that inhaled formaldehyde negatively affects learning and memory at 3 mg/m(3) of gaseous formaldehyde but not at lower levels. Oxidative stress-induced neuron damages in the brain may be the possible mechanism for these effects.


CONCLUSIONS
This study indicates that inhaled formaldehyde starts to negatively affect learning and memory at a middle concentration of formaldehyde without interference of other indoor air pollutants. Oxidative damage, and the alteration of NMDA receptor expression, which were induced by formaldehyde inhalation, may be the possible mechanism for gaseous formaldehyde-induced neurotoxicity.
Lu
Z
Z
College of Life Science, Central China Normal University, Wuhan, China.
Li
C M
CM
Qiao
Y
Y
Yan
Y
Y
Yang
X
X
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D002493:Central Nervous System Diseases / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004587:Electrophoresis, Agar Gel; D005557:Formaldehyde / Q000008:administration & dosage / Q000633:toxicity*; D019570:Inhalation Exposure / Q000009:adverse effects; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D018782:Maze Learning / Q000187:drug effects*; D008568:Memory / Q000187:drug effects*; D051379:Mice; D018384:Oxidative Stress; D016194:Receptors, N-Methyl-D-Aspartate / Q000096:biosynthesis / Q000235:genetics
C409466:NR1 NMDA receptor; C121001:NR2B NMDA receptor; D016194:Receptors, N-Methyl-D-Aspartate; D005557:Formaldehyde; D008315:Malondialdehyde