Monoamine transporter and enzyme expression in the medial temporal lobe and frontal cortex following chronic bilateral vestibular loss.

Peripheral vestibular damage has been reported to be associated with a high incidence of anxiety disorders and depression. In this study we investigated whether chronic bilateral vestibular deafferentation (BVD) would affect the expression of several biogenic amine enzymes and transporters in the medial temporal lobe (CA1, CA2/3, dentate gyrus (DG), entorhinal (EC) and perirhinal cortices (PRC)) and frontal lobes (FL) of rats. BVD was not associated with any significant differences in dopamine beta-hydroxylase or the dopamine transporter in any brain region studied. There was a significant decrease in tyrosine hydroxylase expression only in the FL and a significant decrease in the expression of the serotonin transporter in the FL and CA1 in BVD rats. Tryptophan hydroxylase showed a significant increase in expression in the FL, CA2/3, and DG and a significant decrease in the EC. These results suggest that biogenic amine pathways in the medial temporal lobe and FL undergo changes following BVD.