We hypothesized that male patients with schizophrenia spectrum disorders who have prodromal sympt... more We hypothesized that male patients with schizophrenia spectrum disorders who have prodromal symptoms of obsessive-compulsive disorder (OCD) have ventricular enlargement compared with non-psychotic OCD patients, and that the difference in the ventricular size would offer a clue to the early detection of schizophrenia spectrum disorders. The ventricle-brain ratios (VBRs) in eight male patients with schizophrenia or schizotypal personality disorder (SPD) who had prodromal symptoms of OCD were compared with eight male patients with non-psychotic OCD and 14 normal male comparison subjects using three-dimensional magnetic resonance imaging (MRI). The VBR of the schizophrenia spectrum group was significantly larger than those of the OCD group or comparison subjects. Even the minimum VBR in the schizophrenia spectrum group was larger than the maximum VBR in the OCD group. These results may suggest the usefulness of three-dimensional MRI for early detection of patients with schizophrenia spe...
Sleep can integrate information into existing memory networks, look for common patterns and disti... more Sleep can integrate information into existing memory networks, look for common patterns and distil overarching rules, or simply stabilize and strengthen the memory exactly as it was learned. Recent research has shown that sleep facilitates abstraction of gist information as well as integration across multiple memories, insight into hidden solutions, and even the ability to make creative connections between distantly related ideas and concepts. To investigate the effect of sleep on memory organization, 35 normal volunteers were randomly assigned either to the sleep (n = 17) or wake group (n = 18). The sleep subjects performed the Japanese Verbal Learning Test (JVLT), a measure of learning and memory, three times in the evening, and slept. On the following morning (9 h later), they were asked to recall the words on the list. The wake subjects took the same test in the morning, and were asked to recall the words in the same time interval as in the sleep group. The semantic clustering r...
Progress in neuro-psychopharmacology & biological psychiatry, 2011
While longitudinal magnetic resonance imaging (MRI) studies have demonstrated progressive gray ma... more While longitudinal magnetic resonance imaging (MRI) studies have demonstrated progressive gray matter reduction of the superior temporal gyrus (STG) during the early phases of schizophrenia, it remains largely unknown whether other temporal lobe structures also exhibit similar progressive changes and whether these changes, if present, are specific to schizophrenia among the spectrum disorders. In this longitudinal MRI study, the gray matter volumes of the fusiform, middle temporal, and inferior temporal gyri were measured at baseline and follow-up scans (mean inter-scan interval=2.7 years) in 18 patients with first-episode schizophrenia, 13 patients with schizotypal disorder, and 20 healthy controls. Both schizophrenia and schizotypal patients had a smaller fusiform gyrus than controls bilaterally at both time points, whereas no group difference was found in the middle and inferior temporal gyri. In the longitudinal comparison, the schizophrenia patients showed significant fusiform ...
The similarity between psychotic symptoms in patients with schizophrenia such as hallucinations a... more 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 ...
Progress in neuro-psychopharmacology & biological psychiatry, Jan 15, 2011
An enlarged volume of the pituitary gland has been reported in the schizophrenia spectrum, possib... more An enlarged volume of the pituitary gland has been reported in the schizophrenia spectrum, possibly reflecting the hypothalamic-pituitary-adrenal (HPA) hyperactivity. However, it remains largely unknown whether the pituitary size longitudinally changes in the course of the spectrum disorders. In the present study, longitudinal magnetic resonance imaging (MRI) data were obtained from 18 patients with first-episode schizophrenia, 13 patients with schizotypal disorder, and 20 healthy controls. The pituitary volume was measured at baseline and follow-up (mean, 2.7 years) scans and was compared across groups. The pituitary volume was larger in the schizophrenia patients than controls at baseline, and both patient groups had significantly larger pituitary volume than controls at follow-up. In a longitudinal comparison, both schizophrenia (3.6%/year) and schizotypal (2.7%/year) patients showed significant pituitary enlargement compared with controls (-1.8%/year). In the schizophrenia patie...
Abnormal fatty acid composition in neural membranes, that is, the balance between essential polyu... more Abnormal fatty acid composition in neural membranes, that is, the balance between essential polyunsaturated fatty acids (EPUFAs) and saturated fatty acids, has been suggested to be related to the psychotic symptoms and cognitive impairment of schizophrenia. This study was conducted to test the hypothesis that the ability of atypical antipsychotic drugs to ameliorate positive symptoms and cognitive function relevant to daily living would be predicted by baseline EPUFAs concentrations in the erythrocyte membrane in subjects with schizophrenia. A total of 24 actively psychotic patients with schizophrenia participated in the study. After blood drawing, they were treated with olanzapine or perospirone. The Scale for the Assessment of Positive Symptoms (SAPS) and the Scale for Assessment of Negative symptoms (SANS), as well as the script tasks, a measure of event schema recognition, were administered at baseline and 3months after the start of treatment. Erythrocyte membrane fatty acid lev...
Neurodegenerative changes have been suggested to provide a basis for the pathophysiology of schiz... more Neurodegenerative changes have been suggested to provide a basis for the pathophysiology of schizophrenia. T-817MA (1-{3-[2-(1-benzothiophen-5-yl) ethoxy] propyl} azetidin-3-ol maleate) is a novel compound with neuroprotective and neurite-outgrowth effects, as elicited in rat primary cultured neurons. We examined the effect of T-817MA on phencyclidine (PCP)-induced disruption of prepulse inhibition (PPI), a measure of sensorimotor gating, in male Wistar rats. In chronic experiments, male Wistar rats were injected intermittently with PCP (2.0 mg/kg, i.p., three times per week) or vehicle (saline, 2.0 ml/kg) for 1 month. T-817MA (0.21 or 0.07 mg/ml, p.o.) or distilled water was administered throughout the study period. In an acute experiment, T-817MA (8.4 mg/kg, p.o.) or distilled water was administered, followed by treatment with PCP (2.0 mg/kg, i.p.) or vehicle (saline, 2.0 ml/kg), before PPI measurements. Intermittent administration of PCP for 1 month induced persistent disruption ...
It has been reported that long-term memory function, including the semantic structure of category... more It has been reported that long-term memory function, including the semantic structure of category, is impaired in patients with schizophrenia. The present study was performed to determine: (1) whether the deficit in semantic structure in schizophrenia is independent of cultural backgrounds, and (2) the effect of age of onset and verbal intelligence on the degradation of semantic structure in these patients. Fifty-seven Japanese patients with schizophrenia and 33 normal control subjects entered the study. The semantic structure was derived by Multidimensional Scaling (MDS) analysis based on data from the ANIMAL category fluency test. The semantic structure was compared between: (1) schizophrenic patients as a whole vs. normal control subjects; (2) earlier onset (age of onset <20 years) vs. later-onset groups of patients; and (3) high Vocabulary score (score of the Vocabulary subtest from the WAIS-R>7) vs. low Vocabulary score patient groups. Normal control subjects demonstrated...
The Wechsler Adult Intelligence Scale was examined in 39 patients with schizophrenia, the visual ... more The Wechsler Adult Intelligence Scale was examined in 39 patients with schizophrenia, the visual cognitive task of Picture Completion showing the most impairment. In order to clarify the role of eye movements in Picture Completion, searching eye movements in 12 schizophrenic patients and 12 normal controls were recorded using an infrared eye-mark recorder. Schizophrenic patients as a group showed fewer eye fixations, and shorter total length of scan path than normal controls during the last 10 s of exposure to the picture. However, the patients who responded correctly, did so with a similar number of fixations and similar length of total scan path to those of normal controls. The patients who failed in the task took a significantly longer time for the first survey of the picture than the successful patients and normal controls. The less efficient strategy of visual search seen in the patients who failed might be a manifestation of poor reality testing and be related to frontal lobe ...
Eye movements during the Benton Visual Retention Test were examined using an eye-mark recorder in... more Eye movements during the Benton Visual Retention Test were examined using an eye-mark recorder in 32 schizophrenic patients and 32 normal controls. The patients had significantly fewer eye fixations, longer mean duration of fixation and shorter length of mean scan path than the controls. In the patients, these eye movement parameters were significantly correlated with the negative symptom score but not with the positive symptom score on the Positive and Negative Syndrome Scale. These parameters had a significant correlation with the composite score on the Scale for the Assessment of Negative Symptoms (SANS). In particular, they were highly correlated with avolition-apathy and affective flattening or blunting scores on SANS subscales. Thus, examination of scanning eye movements seemed to be a good objective index of negative symptoms. Secondly, regional cerebral blood flow (rCBF) was examined using N-isopropyl-p-[123I]iodoamphetamine (123I-IMP) and single photon emission computer tom...
BackgroundThe anterior limb of the internal capsule (ALIC) contains the anterior thalamic peduncl... more BackgroundThe anterior limb of the internal capsule (ALIC) contains the anterior thalamic peduncle connecting the medial and anterior thalamic nuclei with the prefrontal cortex and the cingulate gyrus. The purpose of this study was to detect the volumetric changes in the ALIC in view of the putative abnormal frontothalamic connectivity in schizophrenia.
The amygdala is known to be involved in the pathology of schizophrenia. While only a limited numb... more The amygdala is known to be involved in the pathology of schizophrenia. While only a limited number of studies in schizophrenia have measured the amygdala as a single structure. The aim of this study was to examine the hypothesis that patients with schizophrenia would show reduced volumes in the amygdala compared with normal controls. We investigated amygdala volume in 40
We hypothesized that male patients with schizophrenia spectrum disorders who have prodromal sympt... more We hypothesized that male patients with schizophrenia spectrum disorders who have prodromal symptoms of obsessive-compulsive disorder (OCD) have ventricular enlargement compared with non-psychotic OCD patients, and that the difference in the ventricular size would offer a clue to the early detection of schizophrenia spectrum disorders. The ventricle-brain ratios (VBRs) in eight male patients with schizophrenia or schizotypal personality disorder (SPD) who had prodromal symptoms of OCD were compared with eight male patients with non-psychotic OCD and 14 normal male comparison subjects using three-dimensional magnetic resonance imaging (MRI). The VBR of the schizophrenia spectrum group was significantly larger than those of the OCD group or comparison subjects. Even the minimum VBR in the schizophrenia spectrum group was larger than the maximum VBR in the OCD group. These results may suggest the usefulness of three-dimensional MRI for early detection of patients with schizophrenia spe...
Sleep can integrate information into existing memory networks, look for common patterns and disti... more Sleep can integrate information into existing memory networks, look for common patterns and distil overarching rules, or simply stabilize and strengthen the memory exactly as it was learned. Recent research has shown that sleep facilitates abstraction of gist information as well as integration across multiple memories, insight into hidden solutions, and even the ability to make creative connections between distantly related ideas and concepts. To investigate the effect of sleep on memory organization, 35 normal volunteers were randomly assigned either to the sleep (n = 17) or wake group (n = 18). The sleep subjects performed the Japanese Verbal Learning Test (JVLT), a measure of learning and memory, three times in the evening, and slept. On the following morning (9 h later), they were asked to recall the words on the list. The wake subjects took the same test in the morning, and were asked to recall the words in the same time interval as in the sleep group. The semantic clustering r...
Progress in neuro-psychopharmacology & biological psychiatry, 2011
While longitudinal magnetic resonance imaging (MRI) studies have demonstrated progressive gray ma... more While longitudinal magnetic resonance imaging (MRI) studies have demonstrated progressive gray matter reduction of the superior temporal gyrus (STG) during the early phases of schizophrenia, it remains largely unknown whether other temporal lobe structures also exhibit similar progressive changes and whether these changes, if present, are specific to schizophrenia among the spectrum disorders. In this longitudinal MRI study, the gray matter volumes of the fusiform, middle temporal, and inferior temporal gyri were measured at baseline and follow-up scans (mean inter-scan interval=2.7 years) in 18 patients with first-episode schizophrenia, 13 patients with schizotypal disorder, and 20 healthy controls. Both schizophrenia and schizotypal patients had a smaller fusiform gyrus than controls bilaterally at both time points, whereas no group difference was found in the middle and inferior temporal gyri. In the longitudinal comparison, the schizophrenia patients showed significant fusiform ...
The similarity between psychotic symptoms in patients with schizophrenia such as hallucinations a... more 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 ...
Progress in neuro-psychopharmacology & biological psychiatry, Jan 15, 2011
An enlarged volume of the pituitary gland has been reported in the schizophrenia spectrum, possib... more An enlarged volume of the pituitary gland has been reported in the schizophrenia spectrum, possibly reflecting the hypothalamic-pituitary-adrenal (HPA) hyperactivity. However, it remains largely unknown whether the pituitary size longitudinally changes in the course of the spectrum disorders. In the present study, longitudinal magnetic resonance imaging (MRI) data were obtained from 18 patients with first-episode schizophrenia, 13 patients with schizotypal disorder, and 20 healthy controls. The pituitary volume was measured at baseline and follow-up (mean, 2.7 years) scans and was compared across groups. The pituitary volume was larger in the schizophrenia patients than controls at baseline, and both patient groups had significantly larger pituitary volume than controls at follow-up. In a longitudinal comparison, both schizophrenia (3.6%/year) and schizotypal (2.7%/year) patients showed significant pituitary enlargement compared with controls (-1.8%/year). In the schizophrenia patie...
Abnormal fatty acid composition in neural membranes, that is, the balance between essential polyu... more Abnormal fatty acid composition in neural membranes, that is, the balance between essential polyunsaturated fatty acids (EPUFAs) and saturated fatty acids, has been suggested to be related to the psychotic symptoms and cognitive impairment of schizophrenia. This study was conducted to test the hypothesis that the ability of atypical antipsychotic drugs to ameliorate positive symptoms and cognitive function relevant to daily living would be predicted by baseline EPUFAs concentrations in the erythrocyte membrane in subjects with schizophrenia. A total of 24 actively psychotic patients with schizophrenia participated in the study. After blood drawing, they were treated with olanzapine or perospirone. The Scale for the Assessment of Positive Symptoms (SAPS) and the Scale for Assessment of Negative symptoms (SANS), as well as the script tasks, a measure of event schema recognition, were administered at baseline and 3months after the start of treatment. Erythrocyte membrane fatty acid lev...
Neurodegenerative changes have been suggested to provide a basis for the pathophysiology of schiz... more Neurodegenerative changes have been suggested to provide a basis for the pathophysiology of schizophrenia. T-817MA (1-{3-[2-(1-benzothiophen-5-yl) ethoxy] propyl} azetidin-3-ol maleate) is a novel compound with neuroprotective and neurite-outgrowth effects, as elicited in rat primary cultured neurons. We examined the effect of T-817MA on phencyclidine (PCP)-induced disruption of prepulse inhibition (PPI), a measure of sensorimotor gating, in male Wistar rats. In chronic experiments, male Wistar rats were injected intermittently with PCP (2.0 mg/kg, i.p., three times per week) or vehicle (saline, 2.0 ml/kg) for 1 month. T-817MA (0.21 or 0.07 mg/ml, p.o.) or distilled water was administered throughout the study period. In an acute experiment, T-817MA (8.4 mg/kg, p.o.) or distilled water was administered, followed by treatment with PCP (2.0 mg/kg, i.p.) or vehicle (saline, 2.0 ml/kg), before PPI measurements. Intermittent administration of PCP for 1 month induced persistent disruption ...
It has been reported that long-term memory function, including the semantic structure of category... more It has been reported that long-term memory function, including the semantic structure of category, is impaired in patients with schizophrenia. The present study was performed to determine: (1) whether the deficit in semantic structure in schizophrenia is independent of cultural backgrounds, and (2) the effect of age of onset and verbal intelligence on the degradation of semantic structure in these patients. Fifty-seven Japanese patients with schizophrenia and 33 normal control subjects entered the study. The semantic structure was derived by Multidimensional Scaling (MDS) analysis based on data from the ANIMAL category fluency test. The semantic structure was compared between: (1) schizophrenic patients as a whole vs. normal control subjects; (2) earlier onset (age of onset <20 years) vs. later-onset groups of patients; and (3) high Vocabulary score (score of the Vocabulary subtest from the WAIS-R>7) vs. low Vocabulary score patient groups. Normal control subjects demonstrated...
The Wechsler Adult Intelligence Scale was examined in 39 patients with schizophrenia, the visual ... more The Wechsler Adult Intelligence Scale was examined in 39 patients with schizophrenia, the visual cognitive task of Picture Completion showing the most impairment. In order to clarify the role of eye movements in Picture Completion, searching eye movements in 12 schizophrenic patients and 12 normal controls were recorded using an infrared eye-mark recorder. Schizophrenic patients as a group showed fewer eye fixations, and shorter total length of scan path than normal controls during the last 10 s of exposure to the picture. However, the patients who responded correctly, did so with a similar number of fixations and similar length of total scan path to those of normal controls. The patients who failed in the task took a significantly longer time for the first survey of the picture than the successful patients and normal controls. The less efficient strategy of visual search seen in the patients who failed might be a manifestation of poor reality testing and be related to frontal lobe ...
Eye movements during the Benton Visual Retention Test were examined using an eye-mark recorder in... more Eye movements during the Benton Visual Retention Test were examined using an eye-mark recorder in 32 schizophrenic patients and 32 normal controls. The patients had significantly fewer eye fixations, longer mean duration of fixation and shorter length of mean scan path than the controls. In the patients, these eye movement parameters were significantly correlated with the negative symptom score but not with the positive symptom score on the Positive and Negative Syndrome Scale. These parameters had a significant correlation with the composite score on the Scale for the Assessment of Negative Symptoms (SANS). In particular, they were highly correlated with avolition-apathy and affective flattening or blunting scores on SANS subscales. Thus, examination of scanning eye movements seemed to be a good objective index of negative symptoms. Secondly, regional cerebral blood flow (rCBF) was examined using N-isopropyl-p-[123I]iodoamphetamine (123I-IMP) and single photon emission computer tom...
BackgroundThe anterior limb of the internal capsule (ALIC) contains the anterior thalamic peduncl... more BackgroundThe anterior limb of the internal capsule (ALIC) contains the anterior thalamic peduncle connecting the medial and anterior thalamic nuclei with the prefrontal cortex and the cingulate gyrus. The purpose of this study was to detect the volumetric changes in the ALIC in view of the putative abnormal frontothalamic connectivity in schizophrenia.
The amygdala is known to be involved in the pathology of schizophrenia. While only a limited numb... more The amygdala is known to be involved in the pathology of schizophrenia. While only a limited number of studies in schizophrenia have measured the amygdala as a single structure. The aim of this study was to examine the hypothesis that patients with schizophrenia would show reduced volumes in the amygdala compared with normal controls. We investigated amygdala volume in 40
Uploads
Papers by Masayoshi Kurachi