Strain Differences in Extracellular Amino Acid Neurotransmitter Levels in the Hippocampi of Major Histocompatibility Complex Congenic Mice in Response to Toluene Exposure

Objective: The aim of the present study was to investigate the possible role of the major histocompatibility complex locus in neurotransmitter systems in the mouse hippocampus following toluene exposure. Methods: We compared the changes in toluene-induced extracellular amino acid neurotransmitter levels in the hippocampi of 2 strains of male congenic mice, C57BL/10 (H-2(b)) and B10.BR/Sg (H-2(k)). In vivo microdialysis was performed in each freely moving mouse after a single intraperitoneal injection of toluene (300 mg/kg), and neurotransmitters in the hippocampal microdialysates were measured using high-performance liquid chromatography. Results: The basal extracelluar glutamate and glycine levels in the hippocampi of the C57BL mice were significantly higher than those in the B10. BR mice. However, the basal extracellular taurine levels in the hippocampi of the C57BL mice were significantly lower than those in the B10. BR mice. Although no changes in the glutamate levels were observed after toluene injection in either strain, the glycine levels increased significantly after toluene injection in the C57BL mice. On the other hand, significantly lower taurine levels were observed after toluene injection in both strains of mice. Conclusions: Our data demonstrate the existence of a relationship between H-2 haplotypes and hippocampal neurotransmitter levels in mice. Copyright (C) 2009 S. Karger AG, Basel