Changes in expression of brain derived neurotrohic factor in the nuclues accumbens, caudate putamen, ventral tegmental area and prefrontal cortex of adolescent rats following acute toluene exposure

Abstract

The objective of this study was to determine the effects of repeated acute toluene exposure in adolescent rats on the protein expression of brain-derived neurotrophic factor (BDNF) in brain regions associated with addictive behavior. The brain regions examined included the nucleus accumbens, caudate putamen, the ventral tegmental area and prefrontal cortex. Six adolescent rats were placed in inhalation chambers and exposed to 6000 parts per million toluene vapors for a period of 20 minutes per day for 10 days. Six addition rats were exposed only to air. Twenty-four hours after the last exposure, rats were euthanized, the brains extracted, and the nucleus accumbens, caudate putamen, ventral tegmental area and prefrontal cortex dissected. Protein was extracted and BDNF quantified by way of immunoblot analysis. Results indicate that although there were no significant changes in brain-derived neurotrophic factor expression levels between the experimental and control groups, several trends were apparent. The prefrontal cortex and nucleus accumbens showed an increased brain-derived neurotrophic factor level in toluene-exposed subjects when compared to control. The ventral tegmental area showed a decrease in brain-derived neurotrophic factor in toluene-exposed rats. BDNF levels in the caudate putamen were almost identical between control and toluene-exposed subjects. These data suggest that toluene exposure may alter BDNF levels but additional testing either including a greater subject size or altered toluene exposure paradigm may be necessary to produce significant changes.