Acute administration of toluene affects memory retention in novel object recognition test and memory function-related gene expression in mice

Abstract

The present study was designed to investigate the acute effect of a single administration of toluene (300 mg kg(-1), i.p.) on memory retention in the hippocampus-dependent novel object recognition test and N-methyl-D-aspartate (NMDA) receptor subunit expression in the hippocampus of C3H/HeN female mice using real-time RT-PCR. We performed a novel object recognition test including a habituation phase, training phase and test phase in each mouse. Twenty-four hours after the training phase, to determine the effect of acute toluene administration on memory retention, half of the mice (n=10) were injected with toluene 60 min before the test phase. Toluene-injected mice did not prefer novel objects and showed poor discrimination between novel and familiar objects and decreased expression of NMDA receptor subunit NR2B mRNA in the hippocampus. This is the first study to show that acute toluene injection impairs hippocampus-dependent nonspatial memory retention accompanied by selective modulation of NMDA receptor subunit expression.