Hidenori Yamasue

Publications (79)316.9 Total impact

• Article: Network structure underlying resolution of conflicting nonverbal and verbal social information.

  Takamitsu Watanabe, Noriaki Yahata, Yuki Kawakubo, Hideyuki Inoue, Yosuke Takano, Norichika Iwashiro, Tatsunobu Natsubori, Hidemasa Takao, Hiroki Sasaki, Wataru Gonoi, Mizuho Murakami, Masaki Katsura, Akira Kunimatsu, Osamu Abe, Kiyoto Kasai, Hidenori Yamasue
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  ABSTRACT: Social judgments often require resolution of incongruity in communication contents. Although previous studies revealed that such conflict resolution recruits brain regions including the medial prefrontal cortex (mPFC) and posterior inferior frontal gyrus (pIFG), functional relationships and networks among these regions remain unclear. In this functional magnetic resonance imaging study, we investigated the functional dissociation and networks by measuring human brain activity during resolving incongruity between verbal and nonverbal emotional contents. First, we found that the conflict resolutions biased by the nonverbal contents activated the posterior dorsal mPFC (post-dmPFC), bilateral anterior insula, and right dorsal pIFG, whereas the resolutions biased by the verbal contents activated the bilateral ventral pIFG. In contrast, the anterior dmPFC (ant-dmPFC), bilateral superior temporal sulcus, and fusiform gyrus were commonly involved in both of the resolutions. Second, we found that the post-dmPFC and right ventral pIFG were hub regions in networks underlying the nonverbal- and verbal-content-biased resolutions, respectively. Finally, we revealed that these resolution-type-specific networks were bridged by the ant-dmPFC, which was recruited for the conflict resolutions earlier than the two hub regions. These findings suggest that, in social conflict resolutions, the ant-dmPFC selectively recruits one of the resolution-type-specific networks through its interaction with resolution-type-specific hub regions.
  Social Cognitive and Affective Neuroscience 04/2013; · 6.13 Impact Factor
• Article: Genetic influences on prefrontal activation during a verbal fluency task in adults: A twin study based on multichannel near-infrared spectroscopy.

  Eisuke Sakakibara, Ryu Takizawa, Yukika Nishimura, Shingo Kawasaki, Yoshihiro Satomura, Akihide Kinoshita, Shinsuke Koike, Kohei Marumo, Masaru Kinou, Mamoru Tochigi, [......], Hidenori Yamasue, Junko Matsubayashi, Kenji Kohata, Chie Shimojo, Shiho Okuhata, Toshiaki Kono, Hitoshi Kuwabara, Ayaka Ishii-Takahashi, Yuki Kawakubo, Kiyoto Kasai
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  ABSTRACT: Near-infrared spectroscopy (NIRS) studies have reported that prefrontal hemodynamic dysfunction during executive function tasks may be a promising biomarker of psychiatric disorders, because its portability and noninvasiveness allow easy measurements in clinical settings. Here, we investigated the degree to which prefrontal NIRS signals are genetically determined. Using a 52-channel NIRS system, we monitored the oxy-hemoglobin (oxy-Hb) signal changes in 38 adult pairs of right-handed monozygotic (MZ) twins and 13 pairs of same-sex right-handed dizygotic (DZ) twins during a letter version of the verbal fluency task. Heritability was estimated based on a classical twin paradigm using structured equation modeling. Significant genetic influences were estimated in the right dorsolateral prefrontal cortex and left frontal pole. The degrees of heritability were 66% and 75% in the variances, respectively. This implies that the prefrontal hemodynamic dysfunction observed during an executive function task measured by NIRS may be an efficient endophenotype for large-scale imaging/genetics studies in psychiatric disorders.
  NeuroImage 04/2013; · 5.89 Impact Factor
• Article: Anxiety and Performance: The Disparate Roles of Prefrontal Subregions Under Maintained Psychological Stress.

  Ryu Takizawa, Yukika Nishimura, Hidenori Yamasue, Kiyoto Kasai
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  ABSTRACT: Despite increasing interest in anxiety and psychological stress in daily life, little is known about neural correlates that underlie maintained psychological stress and their relationship with anxiety. In particular, the activation characteristics of lateral prefrontal subregions and their relationship with anxiety and cognitive performance under maintained psychological stress remain unknown. This study used near-infrared spectroscopy (NIRS), a noninvasive and "real-world" functional neuroimaging method, to investigate the hemodynamic responses in wide areas of the prefrontal cortex (PFC) and the influence of anxiety under conditions of maintained stress induced by a continuous arithmetic task (2 sets, 15 min each) performed in a natural sitting posture. Although anxiety and performance are not directly correlated, the hemodynamic response in the medial portion of the lateral PFC (dorsolateral and frontopolar PFC) was significantly associated with anxiety, while hemodynamic responses in the ventrolateral PFC were associated with performance. Additionally, in the same medial region of the lateral PFC, trait and state anxieties were related to changes in deoxy- and oxy-hemoglobin concentrations, respectively. This NIRS finding suggests disparate roles for prefrontal subregions in anxiety and performance under psychological stress and may lead to a better understanding of neural correlates for anxiety in everyday life.
  Cerebral Cortex 02/2013; · 6.54 Impact Factor
• Article: A multimodal approach to investigate biomarkers for psychosis in a clinical setting: The integrative neuroimaging studies in schizophrenia targeting for early intervention and prevention (IN-STEP) project.

  Shinsuke Koike, Yosuke Takano, Norichika Iwashiro, Yoshihiro Satomura, Motomu Suga, Tatsuya Nagai, Tatsunobu Natsubori, Mariko Tada, Yukika Nishimura, Syudo Yamasaki, Ryu Takizawa, Noriaki Yahata, Tsuyoshi Araki, Hidenori Yamasue, Kiyoto Kasai
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  ABSTRACT: Longitudinal clinical investigations and biological measurements have determined not only progressive brain volumetric and functional changes especially around the onset of psychosis but also the abnormality of developmental pathways based on gene-environment interaction model. However, these studies have contributed little to clinical decisions on their diagnosis and therapeutic choices because of subtle differences between patients and healthy controls. A multi-modal approach may resolve this limitation and is favorable to explore the pathophysiology of psychosis. The integrative neuroimaging studies for schizophrenia targeting early intervention and prevention (IN-STEP) is a research project aimed at exploring the pathophysiological features of the onset of psychosis and investigating possible predictive biomarkers for the clinical treatment of psychosis. Since 2008, we have adopted blood sampling, neurocognitive batteries, neurophysiological assessment, structural imaging, and functional imaging longitudinally for help-seeking ultra-high-risk (UHR) individuals and patients with first-episode psychosis (FEP). Here, we intend to introduce the IN-STEP research study protocol and present preliminary clinical findings. Thirty-seven UHR individuals and 30 patients with FEP participated in this study. Six months later, there was no difference in objective and subjective scores between the groups, which suggests that young people having symptoms and functional deficits should be cared for regardless of their history of psychosis according to their clinical stages. The rate of transition to psychosis was 7.1%, 8.0%, and 35.3% (at 6, 12, and 24months, respectively). Through this research project, we expect to clarify the pathophysiological features around the onset of psychosis and improve the prognosis of psychosis through clinical application.
  Biological Psychiatry 12/2012; · 8.28 Impact Factor
• Article: Function and structure in social brain regions can link oxytocin-receptor genes with autistic social behavior.

  Hidenori Yamasue
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  ABSTRACT: Difficulties in appropriate social and communicative behaviors are the most prevalent and core symptoms of autism spectrum disorders (ASDs). Although recent intensive research has focused on the neurobiological background of these difficulties, many aspects of them were not yet elucidated. Recent studies have employed multimodal magnetic resonance imaging (MRI) indices as intermediate phenotypes of this behavioral phenotype to link candidate genes with the autistic social difficulty. As MRI indices, functional MRI (fMRI), structural MRI, and MR-spectroscopy have been examined in subjects with autism spectrum disorders. As candidate genes, this mini-review has much interest in oxytocin-receptor genes (OXTR), since recent studies have repeatedly reported their associations with normal variations in social cognition and behavior as well as with their extremes, autistic social dysfunction. Through previous increasing studies, medial prefrontal cortex, hypothalamus and amygdala have repeatedly been revealed as neural correlates of autistic social behavior by MRI multimodalities and their relationship to OXTR. For further development of this research area, this mini-review integrates recent accumulating evidence about human behavioral and neural correlates of OXTR.
  Brain & development 09/2012; · 1.74 Impact Factor
• Article: Localized gray matter volume reductions in the pars triangularis of the inferior frontal gyrus in individuals at clinical high-risk for psychosis and first episode for schizophrenia.

  Norichika Iwashiro, Motomu Suga, Yosuke Takano, Hideyuki Inoue, Tatsunobu Natsubori, Yoshihiro Satomura, Shinsuke Koike, Noriaki Yahata, Mizuho Murakami, Masaki Katsura, Wataru Gonoi, Hiroki Sasaki, Hidemasa Takao, Osamu Abe, Kiyoto Kasai, Hidenori Yamasue
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  ABSTRACT: Recent studies have suggested an important role for Broca's region and its right hemisphere counterpart in the pathophysiology of schizophrenia, owing to its roles in language and interpersonal information processing. Broca's region consists of the pars opercularis (PO) and the pars triangularis (PT). Neuroimaging studies have suggested that they have differential functional roles in healthy individuals and contribute differentially to the pathogenesis of schizophrenic symptoms. However, volume changes in these regions in subjects with ultra-high risk for psychosis (UHR) or first-episode schizophrenia (FES) have not been clarified. In the present 3 Tesla magnetic resonance imaging study, we separately measured the gray matter volumes of the PO and PT using a reliable manual-tracing volumetry in 80 participants (20 with UHR, 20 with FES, and 40 matched controls). The controls constituted two groups: the first group was matched for age, sex, parental socioeconomic background, and intelligence quotient to UHR (n=20); the second was matched for those to FES (n=20). Compared with matched controls, the volume of the bilateral PT, but not that of the PO, was significantly reduced in the subjects with UHR and FES. The reduced right PT volume, which showed the largest effect size among regions-of-interest in the both UHR and FES groups, correlated with the severity of the positive symptoms also in the both groups. These results suggest that localized gray matter volume reductions of the bilateral PT represent a vulnerability to schizophrenia in contrast to the PO volume, which was previously found to be reduced in patients with chronic schizophrenia. The right PT might preferentially contribute to the pathogenesis of psychotic symptoms.
  Biological Psychiatry 03/2012; 137(1-3):124-31. · 8.28 Impact Factor
• Article: Tract-specific analysis of white matter integrity disruption in schizophrenia.

  Natsuko Kunimatsu, Shigeki Aoki, Akira Kunimatsu, Osamu Abe, Haruyasu Yamada, Yoshitaka Masutani, Kiyoto Kasai, Hidenori Yamasue, Kuni Ohtomo
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  ABSTRACT: Several studies have suggested that white matter integrity is disrupted in some brain regions in patients with schizophrenia. The purpose of this study was to assess the white matter integrity of the cingulum, uncinate fasciculus, fornix, and corpus callosum using diffusion tensor imaging (DTI). Participants comprised 39 patients with schizophrenia (19 males and 20 females) and 40 age-matched normal controls (20 males and 20 females). We quantitatively assessed the fractional anisotropy (FA) and apparent diffusion coefficient (ADC) of the anterior cingulum, body of the cingulum, uncinate fasciculus, fornix, and corpus callosum on a tract-specific basis using diffusion tensor tractography (DTT). Group differences in FA and ADC between the patients and normal controls were sought. Additional exploratory analyses of the relationship between the FA or ADC and four clinical parameters (i.e., illness duration, positive symptom scores, negative symptom scores, and medication dosage) were performed. Results were analyzed in gender-combined and gender-separated group comparisons. FA was significantly lower on both sides of the anterior cingulum, uncinate fasciculus, and fornix in the schizophrenia patients irrespective of gender group separation. In the gender-combined analyses, significantly higher ADC values were demonstrated in the schizophrenia patients in both sides of the anterior cingulum, body of the cingulum and uncinate fasciculus, the left fornix, and the corpus callosum, compared with those of the normal controls. In the gender-separated analyses, the male patients showed higher ADC in the left anterior cingulum, the bilateral cingulum bodies, and the bilateral uncinate fasciculi. The female patients showed higher ADC in the right anterior cingulum, the left fornix, and the bilateral uncinate fasciculus. In correlation analyses, a significant negative correlation was found between illness duration and ADC in the right anterior cingulum in the gender-combined analyses. The gender-separated analyses found that the male patients had a significant negative correlation between negative symptom scores and FA in the right fornix, a positive correlation between illness duration and FA in the right anterior cingulum, and a negative correlation between illness duration and FA in the left uncinate fasciculus. Our DTI study showed that the integrity of white matter is disrupted in patients with schizophrenia. The results of our sub-analyses suggest that changes in FA and ADC may be related to negative symptom scores or illness duration.
  Psychiatry Research 03/2012; 201(2):136-43. · 2.52 Impact Factor
• Source

  Available from: Osamu Abe

  Article: Diminished medial prefrontal activity behind autistic social judgments of incongruent information.

  Takamitsu Watanabe, Noriaki Yahata, Osamu Abe, Hitoshi Kuwabara, Hideyuki Inoue, Yosuke Takano, Norichika Iwashiro, Tatsunobu Natsubori, Yuta Aoki, Hidemasa Takao, [......], Masaki Katsura, Akira Kunimatsu, Yuki Kawakubo, Hideo Matsuzaki, Kenji J Tsuchiya, Nobumasa Kato, Yukiko Kano, Yasushi Miyashita, Kiyoto Kasai, Hidenori Yamasue
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  ABSTRACT: Individuals with autism spectrum disorders (ASD) tend to make inadequate social judgments, particularly when the nonverbal and verbal emotional expressions of other people are incongruent. Although previous behavioral studies have suggested that ASD individuals have difficulty in using nonverbal cues when presented with incongruent verbal-nonverbal information, the neural mechanisms underlying this symptom of ASD remain unclear. In the present functional magnetic resonance imaging study, we compared brain activity in 15 non-medicated adult males with high-functioning ASD to that of 17 age-, parental-background-, socioeconomic-, and intelligence-quotient-matched typically-developed (TD) male participants. Brain activity was measured while each participant made friend or foe judgments of realistic movies in which professional actors spoke with conflicting nonverbal facial expressions and voice prosody. We found that the ASD group made significantly less judgments primarily based on the nonverbal information than the TD group, and they exhibited significantly less brain activity in the right inferior frontal gyrus, bilateral anterior insula, anterior cingulate cortex/ventral medial prefrontal cortex (ACC/vmPFC), and dorsal medial prefrontal cortex (dmPFC) than the TD group. Among these five regions, the ACC/vmPFC and dmPFC were most involved in nonverbal-information-biased judgments in the TD group. Furthermore, the degree of decrease of the brain activity in these two brain regions predicted the severity of autistic communication deficits. The findings indicate that diminished activity in the ACC/vmPFC and dmPFC underlies the impaired abilities of individuals with ASD to use nonverbal content when making judgments regarding other people based on incongruent social information.
  PLoS ONE 01/2012; 7(6):e39561. · 4.09 Impact Factor
• Article: Reply to: Neurogenetic Effects of OXTR rs2254298 in the Extended Limbic System of Healthy Caucasian Adults.

  Hidenori Yamasue, Motomu Suga, Noriaki Yahata, Hideyuki Inoue, Mamoru Tochigi, Osamu Abe, Xiaoxi Liu, Yoshiya Kawamura, Mark A Rogers, Kunio Takei, Haruyasu Yamada, Shigeki Aoki, Tsukasa Sasaki, Kiyoto Kasai
  Biological psychiatry 08/2011; · 8.93 Impact Factor
• Article: Case of alfacalcidol-induced hypercalcemia presenting as bipolar disorder.

  Hiroyuki Tamiya, Tsuyoshi Okamura, Norichika Iwashiro, Kazuma Ishiki, Hidenori Yamasue, Kiyoto Kasai
  Psychiatry and Clinical Neurosciences 08/2011; 65(5):536-7. · 2.13 Impact Factor
• Article: Reduced amygdala and hippocampal volumes in patients with methamphetamine psychosis.

  Lina Orikabe, Hidenori Yamasue, Hideyuki Inoue, Yoichiro Takayanagi, Yuriko Mozue, Yasuhiko Sudo, Tatsuji Ishii, Masanari Itokawa, Michio Suzuki, Masayoshi Kurachi, Yuji Okazaki, Kiyoto Kasai
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  ABSTRACT: The similarity between psychotic symptoms in patients with schizophrenia such as hallucinations and delusions and those caused by administration of methamphetamine has been accepted. While the etiology of schizophrenia remains unclear, methamphetamine induced psychosis, which is obviously occurred by methamphetamine administration, had been widely considered as a human pharmaceutical model of exogenous psychosis. Although volume reductions in medial temporal lobe structure in patients with schizophrenia have repeatedly been reported, those in patients with methamphetamine psychosis have not yet been clarified. Magnetic resonance images (MRI) were obtained from 20 patients with methamphetamine psychosis and 20 age, sex, parental socio-economic background, and IQ matched healthy controls. A reliable manual tracing methodology was employed to measure the gray matter volume of the amygdala and the hippocampus from MRIs. Significant gray matter volume reductions of both the amygdala and hippocampus were found bilaterally in the subjects with methamphetamine psychosis compared with the controls. The degree of volume reduction was significantly greater in the amygdala than in hippocampus. While the total gray, white matter and intracranial volumes were also significantly smaller-than-normal in the patients; the regional gray matter volume reductions in these medial temporal structures remained statistically significant even after these global brain volumes being controlled. The prominent volume reduction in amygdala rather than that in hippocampus could be relatively specific characteristics of methamphetamine psychosis, since previous studies have shown significant volume reductions less frequently in amygdala than in hippocampus of the other psychosis such as schizophrenia.
  Biological Psychiatry 07/2011; 132(2-3):183-9. · 8.28 Impact Factor
• Source

  Available from: Tsutomu Takahashi

  Article: Classification of first-episode schizophrenia patients and healthy subjects by automated MRI measures of regional brain volume and cortical thickness.

  Yoichiro Takayanagi, Tsutomu Takahashi, Lina Orikabe, Yuriko Mozue, Yasuhiro Kawasaki, Kazue Nakamura, Yoko Sato, Masanari Itokawa, Hidenori Yamasue, Kiyoto Kasai, Masayoshi Kurachi, Yuji Okazaki, Michio Suzuki
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  ABSTRACT: Although structural magnetic resonance imaging (MRI) studies have repeatedly demonstrated regional brain structural abnormalities in patients with schizophrenia, relatively few MRI-based studies have attempted to distinguish between patients with first-episode schizophrenia and healthy controls. Three-dimensional MR images were acquired from 52 (29 males, 23 females) first-episode schizophrenia patients and 40 (22 males, 18 females) healthy subjects. Multiple brain measures (regional brain volume and cortical thickness) were calculated by a fully automated procedure and were used for group comparison and classification by linear discriminant function analysis. Schizophrenia patients showed gray matter volume reductions and cortical thinning in various brain regions predominantly in prefrontal and temporal cortices compared with controls. The classifiers obtained from 66 subjects of the first group successfully assigned 26 subjects of the second group with accuracy above 80%. Our results showed that combinations of automated brain measures successfully differentiated first-episode schizophrenia patients from healthy controls. Such neuroimaging approaches may provide objective biological information adjunct to clinical diagnosis of early schizophrenia.
  PLoS ONE 01/2011; 6(6):e21047. · 4.09 Impact Factor
• Article: Cortical thickness, gray matter volume, and white matter anisotropy and diffusivity in schizophrenia.

  Mizuho Murakami, Hidemasa Takao, Osamu Abe, Hidenori Yamasue, Hiroki Sasaki, Wataru Gonoi, Yosuke Takano, Kunio Takei, Kiyoto Kasai, Kuni Ohtomo
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  ABSTRACT: The study was conducted to evaluate simultaneously gray matter changes and white matter changes in patients with schizophrenia. Cortical thickness, gray matter volume, and white matter anisotropy and diffusivity changes in schizophrenic patients (n = 21) were assessed relative to age-, gender-, and parental socioeconomic status-matched healthy controls (n = 21). We used a newly described semi-automated method (FreeSurfer version 4.5) to determine cortical thickness and gray matter volume and used the tract-based spatial statistics method to evaluate white matter anisotropy and diffusivity. Schizophrenic patients showed a significant decrease in hippocampal volume compared with healthy controls. No significant thickness deficits or anisotropy and diffusivity changes were found in schizophrenic patients compared with healthy controls. Stepwise multivariate analysis revealed that hippocampal volume was positively related to duration of illness in schizophrenic patients. Our results suggest that hippocampal volume is smaller in schizophrenic patients compared with healthy controls and that progressive hippocampal volume loss occurs in the early course of illness in schizophrenic patients but not in the more chronic stages.
  Neuroradiology 01/2011; 53(11):859-66. · 2.82 Impact Factor
• Article: Reduced gray matter volume of pars opercularis is associated with impaired social communication in high-functioning autism spectrum disorders.

  Syudo Yamasaki, Hidenori Yamasue, Osamu Abe, Motomu Suga, Haruyasu Yamada, Hideyuki Inoue, Hitoshi Kuwabara, Yuki Kawakubo, Noriaki Yahata, Shigeki Aoki, Yukiko Kano, Nobumasa Kato, Kiyoto Kasai
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  ABSTRACT: Recent literature suggests that the inferior frontal gyrus, especially its posterior portion, has an important role in imitation and social reciprocity and in the pathophysiology of their disturbance in autism spectrum disorders (ASD). However, the structural abnormality of this region has not fully been clarified in subjects with ASD. Here we obtained magnetic resonance images from 13 right-handed men with high-functioning ASD (Asperger disorder [n = 10] or autism [n = 3]) and from 11 age-, parental socioeconomic background-, and intelligence quotient-matched right-handed typical men. A reliable manual tracing methodology was employed to measure the gray matter volume of the pars opercularis, corresponding to Brodmann area 44, and the pars triangularis, corresponding to Brodmann area 45. A significant gray matter volume reduction of both the pars opercularis and triangularis was found bilaterally in the subjects with ASD compared with the typical control subjects. The effect size seemed to be larger for pars opercularis (1.25) than for pars triangularis (.90). The reduced volume of right as well as total pars opercularis showed a significant association with the increased severity of social communication problems in the ASD group. The current findings support an important role of pars opercularis, a center of the mirror neuron system, in the pathophysiology of ASD.
  Biological psychiatry 12/2010; 68(12):1141-7. · 8.93 Impact Factor
• Article: Continuous positive airway pressure for obstructive sleep apnea improved negative symptoms in a patient with schizophrenia.

  Kazuyuki Sugishita, Hidenori Yamasue, Kiyoto Kasai
  Psychiatry and Clinical Neurosciences 12/2010; 64(6):665. · 2.13 Impact Factor
• Article: A case of adult-onset type II citrullinemia with comorbid epilepsy even after liver transplantation.

  Yosuke Eriguchi, Hidenori Yamasue, Nagafumi Doi, Takuji Nishida, Osamu Abe, Haruyasu Yamada, Shigeki Aoki, Motomu Suga, Hideyuki Inoue, Hiroi Nonaka, Takayuki Obata, Hiroo Ikehira, Keiko Kobayashi, Kiyoto Kasai
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  ABSTRACT: The current study using single case voxel-based morphometry (VBM) of magnetic resonance imaging (MRI) and ¹H-MR-spectroscopy (¹H-MRS) explores the neural background of unexplained seizure attacks and electroencephalography (EEG) abnormalities persisting even after liver transplantation in a patient with adult-onset type II citrullinemia (CTLN2). Although the MRI had shown no gross abnormality, the VBM revealed significantly smaller-than-normal regional volume in the left hippocampus of the patient as compared with 111 age-matched controls. ¹H-MRS further indicated reduction of all metabolite concentrations in the left hippocampus compared with those in the right homolog region, with the single exception of elevated glutamate concentration. These results are similar to those of patients with mesial temporal lobe epilepsy (TLE), although CTLN2-complicated mesial TLE has rarely been reported. In contrast to TLE, periictal asterixis and interictal slow activities on EEG support another possibility that the patient might have slight metabolic encephalopathy even after the liver transplantation.
  Epilepsia 12/2010; 51(12):2484-7. · 3.96 Impact Factor
• Article: Association between the oxytocin receptor gene and amygdalar volume in healthy adults.

  Hideyuki Inoue, Hidenori Yamasue, Mamoru Tochigi, Osamu Abe, Xiaoxi Liu, Yoshiya Kawamura, Kunio Takei, Motomu Suga, Haruyasu Yamada, Mark A Rogers, Shigeki Aoki, Tsukasa Sasaki, Kiyoto Kasai
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  ABSTRACT: Recent studies have suggested that oxytocin affects social cognition and behavior mediated by the oxytocin receptor (OXTR) in amygdala in humans as well as in experimental animals. Genetic studies have revealed a link between the OXTR gene and the susceptibility to autism spectrum disorders (ASD), especially in the social dysfunctional feature of ASD. We examined the relationship between amygdala volume measured with manual tracing methodology and seven single nucleotide polymorphisms and one haplotype-block in OXTR, which were previously reported to be associated with ASD, in 208 socially intact Japanese adults with no neuropsychiatric history or current diagnosis. The rs2254298A allele of OXTR was significantly associated with larger bilateral amygdala volume. The rs2254298A allele effect on amygdala volume varied in proportion to the dose of this allele. The larger the number of rs2254298A alleles an individual had, the larger their amygdala volume. Such an association was not observed with hippocampal volume or with global brain volumes, including whole gray, white matter, and cerebrospinal-fluid space. Furthermore, two three-single nucleotide polymorphism haplotypes, including rs2254298G allele, showed significant associations with the smaller bilateral amygdala volume. The present results suggest that OXTR might be associated with the susceptibility to ASD, especially in its aspects of social interaction and communication mediated by a modulation of amygdala development, one of the most distributed brain regions with high density of OXTR. Furthermore, amygdala volume measured with magnetic resonance imaging could be a useful intermediate phenotype to uncover the complex link between OXTR and social dysfunction in ASD.
  Biological psychiatry 12/2010; 68(11):1066-72. · 8.93 Impact Factor
• Article: Age-related changes in regional brain volume evaluated by atlas-based method.

  Wataru Gonoi, Osamu Abe, Hidenori Yamasue, Haruyasu Yamada, Yoshitaka Masutani, Hidemasa Takao, Kiyoto Kasai, Shigeki Aoki, Kuni Ohtomo
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  ABSTRACT: The effects of aging on brain volume are generally investigated using voxel-based morphometry (VBM) or the manually traced region-of-interest (ROI) method. We introduce an atlas-based method as a methodological alternative that calculates absolute volume as a non-biased and semi-automatic whole-brain technique. We enrolled 115 healthy females (mean age, 36.7 years) and 130 healthy males (mean age, 37.1 years). Volume data were acquired using a 1.5 tesla magnetic resonance scanner. After spatial normalization, a lobar-based atlas template was applied, and the absolute volumes of the frontal, temporal, parietal, and occipital lobes and the sublobar and limbic areas were calculated bilaterally. The effects of age on regional brain volume were evaluated statistically. The volume of all ROIs declined linearly with increasing age. The bilateral frontal lobes showed the steepest involution. Analysis of variance revealed significant laterality and interaction of gender and age. The atlas-based method introduced in the present study has advantages over the manually traced ROI method in its objectivity, coverage, and time requirement and has an advantage over the VBM method in its computability of absolute volume. The results are largely in agreement with those reported previously, thereby reconfirming the importance of matching gender and age in analyzing brain disorders.
  Neuroradiology 10/2010; 52(10):865-73. · 2.82 Impact Factor
• Article: Gray and white matter asymmetries in healthy individuals aged 21-29 years: a voxel-based morphometry and diffusion tensor imaging study.

  Hidemasa Takao, Osamu Abe, Hidenori Yamasue, Shigeki Aoki, Hiroki Sasaki, Kiyoto Kasai, Naoki Yoshioka, Kuni Ohtomo
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  ABSTRACT: The hemispheres of the human brain are functionally and structurally asymmetric. The study of structural asymmetries provides important clues to the neuroanatomical basis of lateralized brain functions. Previous studies have demonstrated age-related changes in morphology and diffusion properties of brain tissue. In this study, we simultaneously explored gray and white matter asymmetry using voxel-based morphometry (VBM) and diffusion tensor imaging (DTI) in 109 young healthy individuals (58 females and 51 males). To eliminate the potential confounding effects of aging and handedness, we restricted the study to right-handed subjects aged 21-29 years. VBM and voxel-based analysis of fractional anisotropy (FA) maps derived from DTI revealed a number of gray matter volume asymmetries (including the right frontal and left occipital petalias and leftward asymmetry of the planum temporale) and white matter FA asymmetries (including leftward asymmetry of the arcuate fasciculus, cingulum, and corticospinal tract). There was no significant effect of sex on gray and white matter asymmetry. Leftward volume asymmetry of the planum temporale and leftward FA asymmetry of the arcuate fasciculus were simultaneously demonstrated. Post hoc analysis showed that the gray matter volume of the planum temporale and FA of the arcuate fasciculus were positively related (Pearson correlation coefficient, 0.43; P < 0.0001). The results of our study demonstrate gray and white matter asymmetry in right-handed healthy young adults and suggest that leftward volume asymmetry of the planum temporale and leftward FA asymmetry of the arcuate fasciculus may be related.
  Human Brain Mapping 09/2010; 32(10):1762-73. · 5.88 Impact Factor
• Article: [Autism spectrum disorders--recent advances in the research on the impairment in social communication].

  Nobumasa Kato, Hidenori Yamasue, Keiichiro Watanabe, Seiichiro Jinde, Miyuki Sadamatsu
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  ABSTRACT: Since the discovery of early infantile autism (1943), the etiology of the disease has for long been a matter of dispute-from a form of innate schizophrenia, maltreatment by 'refrigerator mother', to dysfunction of speech development. After the re-discovery of Asperger syndrome by Wing (1981), the concept of this diverse syndrome complex has merged to pervasive developmental disorders (PDD) or autism spectrum disorders (ASD). People suffering from Asperger syndrome do not show impairments in speech development, in fact, they have good linguistic abilities. They can explain their own psychopathology, which helps in the understanding of classical autism with profound mental retardation. Currently, ASD is prevalent in 1 of 150 births with strong genetic inheritance. ASD is therefore thought a psychiatric common disease. Asperger syndrome has frequently been the subject of neuroimaging studies,since social communication is an important characteristic of human behavior. This review encompasses a historical and clinical overview of ASD and puts force the current perspectives on the researches in animal models,genetic studies of animal and human samples,and neuroimaging studies. Our current focus is the possible role of oxytocin,which was recently found to have an effect on empathy,in the etiology of ASD.
  Brain and nerve = Shinkei kenkyū no shinpo 09/2010; 62(9):975-86.