Brain Activations in Response to Prolonged Citral Inhalation Detected by Manganese-Enhanced Magnetic Resonance Imaging (MEMRI)

Abstract

In this study, an olfactory inhalation instrument was devised to allow the rats to inhale volatile citral or odorless air. Manganese-enhanced magnetic resonance imaging (MEMRI) was used to reveal changes of accumulative brain activities after a 24 h inhalation of volatile citral. Compared with the control group, the rats in the citral group showed increased functional activities in the core of nucleus accumbens (AcbC) and olfactory glomerular layer (GL), and decreased Mn2+ accumulation in the brain regions of visual cortex (VC), auditory cortex (AC) and retrosplenial cortex (RSC). Functional correlations between the GL and associated brain regions increased after citral inhalation. These results suggested that MEMRI might be used to detect brain activation associated with sustained olfactory stimulation.

Keywords

• manganese-enhanced magnetic resonance imaging (memri)
• citral
• olfactory inhalation
• functional brain activation