Citation

Kim J, Lim J, Moon SH, Liu KH, Choi HJ. Biomol. Ther. (Seoul) 2020; ePub(ePub): ePub.

Affiliation

College of Pharmacy and Institute of Pharmaceutical Sciences, CHA University, Seongnam 13488, Republic of Korea.

Copyright

(Copyright © 2020, Korean Society of Applied Pharmacology)

DOI

10.4062/biomolther.2020.055

PMID

32336053

Abstract

Inhaled solvents such as toluene are of particular concern due to their abuse potential that is easily exposed to the environment. The inhalation of toluene causes various behavioral problems, but, the effect of short-term exposure of toluene on changes in emotional behaviors over time after exposure and the accompanying pathological characteristics have not been fully identified. Here, we evaluated the behavioral and neurochemical changes observed over time in mice that inhaled toluene. The mice were exposed to toluene for 30 min at a concentration of either 500 or 2,000 ppm. Toluene did not cause social or motor dysfunction in mice. However, increased anxiety-like behavior was detected in the short-term after exposure, and depression-like behavior appeared as delayed effects. The amount of striatal dopamine metabolites was significantly decreased by toluene, which continued to be seen for up to almost two weeks after inhalation. Additionally, an upregulation of serotonin 1A (5-HT_1A) receptor in the hippocampus and the substantia nigra, as well as reduced immunoreactivity of neurogenesis markers in the dentate gyrus, was observed in the mice after two weeks. These results suggest that toluene inhalation, even single exposure, mimics early anxiety- and delayed depression-like emotional disturbances, underpinned by pathological changes in the brain.

Language: en

Keywords

Anxiety; Depression; Dopamine; Neurogenesis; Serotonin 5-HT1A receptor; Toluene