title: Familial Influences on Mismatch Negativity and Its Association with Plasma Glutamate Level: A Magnetoencephalographic Study in Twins.
abstract: Mismatch negativity (MMN) or its magnetic counterpart (magnetic mismatch negativity; MMNm) is regarded as a promising biomarker for schizophrenia. Previous electroencephalographic studies of MMN have demonstrated a moderate-to-high heritability for MMN amplitudes.N-methyl-D-aspartate receptor-dependent glutamatergic neurotransmission is implicated in MMN generation. We hypothesized that the differences between identical twins in MMNm variables might be associated with differences in plasma levels of amino acids involved in glutamatergic neurotransmission. Thirty-three pairs of monozygotic (MZ) and 10 pairs of dizygotic (DZ) twins underwent MMNm recording. The MMNm in response to tone duration changes, tone frequency changes, and phonemic changes was recorded using 204-channel magnetoencephalography. Of these, 26 MZ and 7 DZ twin pairs underwent blood sampling for determination of plasma amino acid levels. MMNm peak strength showed relatively high correlations in both MZ and DZ twin pairs. The differences in MMNm latencies tended to correlate with the differences in plasma amino acid levels within MZ pairs, while no significant correlation was observed after the Bonferroni correction. We observed a familial trait in MMNm strength. The differences in MMN latency in MZ twins might be influenced by changes in glutamate levels and glutamate-glutamine cycling; however, the results need to be replicated.
authors.affiliation: Department of Neuropsychiatry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Yukika
authors.initials: Y
authors.lastname: Nishimura
authors.affiliation: Department of Child Neuropsychiatry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Kawakubo
authors.affiliation: Department of Rehabilitation, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Motomu
authors.initials: M
authors.lastname: Suga
authors.affiliation: Department of Division of Clinical Neuroscience, Chiba University Centre for Forensic Mental Health, Chiba, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Hashimoto
authors.affiliation: Department of Psychiatry and Neuroscience, Graduate School of Medicine, Gunma University, Maebashi, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Takei
authors.affiliation: Department of Office for Mental Health Support, Division for Counselling and Support, The University of Tokyo, Tokyo, Japan.
authors.forename: Kunio
authors.initials: K
authors.lastname: Takei
authors.affiliation: Department of Neuropsychiatry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Inoue
authors.affiliation: Department of Department of Clinical Laboratory, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Yumoto
authors.affiliation: Department of Neuropsychiatry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Ryu
authors.initials: R
authors.lastname: Takizawa
authors.affiliation: Department of Neuropsychiatry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Kiyoto
authors.initials: K
authors.lastname: Kasai
keywords: Glutamate; Magnetoencephalography; Mismatch negativity; Monozygotic twins