Exposure to 1-bromopropane decreases neuron proliferation in adult rat dentate gyrus

Abstract

Purpose: 1-Bromoprane (1-BP) is used in workplaces as a cleaning and adhesive solvent. Patients intoxicated with 1-BP showed depression, unstable mood and impair of cognitive function. On the other hand, recent studies suggest suppression of neurogenesis (neuron proliferation) in adult hippocampus is involved in depression. Based on the above backgrounds, the present study was designed to investigate effect of exposure to 1-BP on neuron proliferation.
Method: Forty eight male Wistar rats were divided into four groups of twelve and were exposed to 1-BP at 0, 400, 800 and 1000 ppm in inhalation chambers 8 h/day for 7 days. Six rats of each group were perfused for confirming cell proliferation. Cell proliferation was detected with 5-bromo-2'-deoxy-uridine (BrdU) immunostaining. Another six rats of each group were decapitated for measurement of mRNA of brain-derived neurotrophic factor (BDNF) with quantitative real time-polymerase chain reaction.
Result: Cell proliferation didn’t show any change after one-week exposure but decreased at 800ppm after four-week exposure. BDNF mRNA decreased dose-dependently after four-week exposure.
Conclusion: Exposure to 1-BP decreases neuron proliferation. Down-regulation of BDNF might partially contribute to the decrease in neuron proliferation.