Superior temporal gyrus in schizophrenia: a volumetric magnetic resonance imaging study

The left superior temporal gyrus (STG) has been reported to be smaller in patients with schizophrenia. The volume of the STG has been found to correlate negatively with severity of hallucinations and thought disorder. In this study, we measured the STG volume of 20 normal controls and 20 patients with schizophrenia using 3 mm contiguous coronal T1 magnetic resonance images. We found that patients had a significantly smaller left anterior STG, and that the volume of this region negatively correlated with the severity of hallucinations. The left posterior STG was not significantly smaller in patients than in controls, but its volume negatively correlated with severity of thought disorder. We also found that the left anterior STG was smaller than the right STG in patients but not in controls. The STG has at least three histologically distinct areas, each with different connections to the rest of the brain. These data are consistent with the proposition that dysfunction of the primary auditory cortex in the anterior and middle STG and auditory association cortex in the posterior STG may play a role in the production of auditory perceptual abnormalities and poor organization of thought respectively.     

Morphologic alterations of the parcellated superior temporal gyrus in schizophrenia spectrum

Morphologic abnormalities of the superior temporal gyrus (STG) as well as its sub-regions such as Heschl's gyrus (HG) or planum temporale (PT) have been reported in schizophrenia patients, but have not been extensively studied in schizotypal subjects. In the present study, magnetic resonance images were acquired from 65 schizophrenia patients, 39 schizotypal disorder patients, and 72 healthy controls. Volumetric analyses were performed using consecutive 1-mm coronal slices on the temporal pole (TP) and superior temporal sub-regions [planum polare (PP), HG, PT, rostral STG, and caudal STG]. The HG was significantly smaller in schizophrenia patients compared with controls but not in schizotypal patients, while volume reductions of the left PT and bilateral caudal STG were common to both disorders. The TP gray matter was larger in female schizotypal patients compared with female schizophrenia patients. There were no significant group differences in the PP and rostral STG volume. In the subgroup of early phase schizophrenia patients (illness duration <1.0 year), smaller volumes for the left PP and rostral STG were correlated with hallucinations and delusions. Our findings suggest that morphologic changes in the posterior regions of the STG are common to the schizophrenia spectrum, whereas less involvement of the HG, and possibly the PP and rostral STG might be related to the sparing of schizotypal patients from developing overt psychosis.     

Telomere quantification in frontal and temporal brain tissue of patients with schizophrenia

Recent imaging studies have suggested that accelerated aging occurs in schizophrenia. However, the exact cause of these findings is still unclear. In this study we measured telomere length, a marker for cell senescence, in gray and white matter brain tissue from the medial frontal gyrus (MFG) and superior temporal gyrus (STG) of 9 patients with schizophrenia and 11 controls. No alterations in telomere length were found in MFG gray and white matter and in STG gray matter. A significant reduction in telomere length was observed in STG white matter of patients with schizophrenia as compared to controls (fold change of −0.42, U = 5, P = 0.008). Our results support previous findings that telomere length in gray matter is not affected, whereas they suggest that increased cell senescence may affect white matter temporal brain tissue.     

Sylvian fissure and medial temporal lobe structures in patients with schizophrenia: a magnetic resonance imaging study

Volumes of the medial temporal lobe structures (i.e. the amygdala, hippocampus, and parahippocampal gyrus), Sylvian fissure, and inferior horn of the lateral ventricle relative to the cerebral hemisphere were measured in 24 patients with schizophrenia and 23 normal controls using magnetic resonance imaging. The patients had significantly larger Sylvian fissures and inferior horns bilaterally than the controls. In the patients the right Sylvian fissure size showed a significant positive correlation with the duration of illness. Moreover, earlier onset of illness was significantly correlated with decreased volume of the left medial temporal lobe structures. These results replicate previous finding of inferior horn enlargement and suggest the significance of the Sylvian fissure and the medial temporal lobe structures in pathophysiology of schizophrenia.     

Association between smaller left posterior superior temporal gyrus volume on magnetic resonance imaging and smaller left temporal P300 amplitude in first-episode schizophrenia

BACKGROUND: In chronic schizophrenia, the P300 is broadly reduced and shows a localized left temporal deficit specifically associated with reduced gray matter volume of the left posterior superior temporal gyrus (STG). In first-episode patients, a similar left temporal P300 deficit is present in schizophrenia, but not in affective psychosis. The present study investigated whether the left temporal P300-left posterior STG volume association is selectively present in first-episode schizophrenia. METHOD: P300 was recorded as first-episode subjects with schizophrenia (n = 15) or affective psychosis (n = 18) or control subjects (n = 18) silently counted infrequent target tones amid standard tones. High-resolution spoiled gradient-recalled acquisition magnetic resonance images provided quantitative measures of temporal lobe gray matter regions of interest. RESULTS: Patients with first-episode schizophrenia displayed a reversed P300 temporal area asymmetry (smaller on the left), while magnetic resonance imaging showed smaller gray matter volumes of left posterior STG relative to control subjects and patients with affective psychosis (15.4% and 11.0%, respectively), smaller gray matter volumes of left planum temporale (21.0% relative to both), and a smaller total Heschl's gyrus volume (14.6% and 21.1%, respectively). Left posterior STG and the left planum temporale, but not other regions of interest, were specifically and positively correlated (r>0.5) with left temporal P300 voltage in patients with schizophrenia but not in patients with affective psychosis or in control subjects. CONCLUSION: These results suggest that the left temporal P300 abnormality specifically associated with left posterior STG gray matter volume reduction is present at the first hospitalization for schizophrenia but is not present at the first hospitalization for affective psychosis.     

An MRI study of the superior temporal subregions in first-episode patients with various psychotic disorders

Morphologic abnormalities of the superior temporal gyrus (STG) have been reported in schizophrenia, but have not been extensively studied in other psychotic disorders such as affective psychosis. In the present study, magnetic resonance imaging was used to examine the volumes of the STG and its subregions [planum polare (PP), Heschl gyrus (HG), planum temporale (PT), rostral STG, and caudal STG] in 162 first-episode patients with various psychotic disorders [46 schizophrenia (31 schizophrenia and 15 schizoaffective disorder), 57 schizophreniform disorder, 34 affective psychosis, and 25 other psychoses] and 62 age- and sex-matched healthy controls. The first-episode schizophrenia patients had significantly less gray matter in HG, PT, and caudal STG bilaterally compared with all other groups, but there was no difference between the controls and affective psychosis, schizophreniform disorder, or other psychoses for any STG subregion. The STG white matter volume did not differ between groups. Our findings indicate that morphologic abnormalities of the STG gray matter are specific to schizophrenia among various psychotic disorders, implicating its role in the underlying pathophysiology of schizophrenia.     

A SPECT study of apathy in Alzheimer's disease

BACKGROUND/AIMS: To assess the association between regional cerebral blood flow (rCBF) and apathy in Alzheimer's Disease (AD). METHODS: SPECT and MRI scans were obtained from 51 nondepressed outpatients meeting criteria for probable AD (age 77.6 +/- 6.6 years; MMSE 22.3 +/- 5.1; 23 apathetic, 28 nonapathetic) and 23 healthy elderly (75.6 +/- 3.8 years) controls. The following regions of interest (ROIs) were compared between apathetic and nonapathetic AD patients and then referenced against aged controls: anterior cingulate, orbitofrontal cortex, middle medial temporal cortex, hippocampus, medial superior temporal cortex, thalamus/hypothalamus and pons. RESULTS: Apathetic and nonapathetic patients had significant differences in rCBF. Relative to nonapathetic AD patients, apathetic AD patients had lower perfusion in 2 ROIs (right orbitofrontal cortex and left anterior cingulate) and higher perfusion in 5 ROIs (right and left hippocampi, left medial superior temporal gyrus, and right and left middle medial temporal cortex). Comparison of rCBF in these 7 ROIs to healthy elderly controls confirmed hypoperfusion in the left anterior cingulate and right orbitofrontal cortex and suggested a relative sparing of perfusion among apathetic AD patients in the remaining 5 ROIs. CONCLUSIONS: In this group of nondepressed patients with AD, apathetic subjects displayed significant perfusion differences compared to nonapathetic subjects.     

Gaze-triggered orienting is reduced in chronic schizophrenia

Patients with schizophrenia have been reported to demonstrate subtle impairment in gaze processing, which in some cases indicates hypersensitivity to gaze, while in others, hyposensitivity. The neural correlate of gaze processing is situated in the superior temporal sulcus (STS), a major portion of which is constituted by the superior temporal gyrus (STG), and may be the underlying dysfunctional neural basis to the abnormal gaze sensitivity in schizophrenia. To identify the characteristics of gaze behavior in patients with chronic schizophrenia, in whom the STG has been reported to be smaller in volume, we tested 22 patients (mean duration of illness 29 years) in a spatial cueing paradigm using two central pictorial gaze cues, both of which effectively triggered attentional orienting in 22 age-matched normal controls. Arrow cues were also employed to determine whether any compromise in schizophrenia, if present, was gaze-specific. Results demonstrated that schizophrenic subjects benefit significantly less from congruent cues than normal subjects, which was evident for gaze cues but not for arrow cues. This finding is suggestive of a relatively gaze-specific hyposensitivity in patients with chronic schizophrenia, a finding that is in line with their clinical symptomatology and that may be associated with a hypoactive STS.     

Topographical patterns of lobar atrophy in frontotemporal dementia and Alzheimer's disease

BACKGROUND/AIMS: Fronto-temporal dementia (FTD) designates a group of relatively common neurodegenerative disorders. The aim of this study was to characterize the patterns of brain atrophy in FTD compared to Alzheimer's disease (AD). METHODS: A novel semiautomatic volumetric MRI analysis method was applied to measure regional brain volumes in FTD (n = 15; behavioural variant n = 9, language variant n = 6) in contrast with AD patients (n = 15) and age-matched controls (NC) (n = 15). FTD and AD patients were matched on demographic measures and Mini Mental State Examination scores. RESULTS: Significant atrophy was present in the frontal and anterior temporal lobes of subjects with FTD compared to AD (p = 0.02; effect size = 1.11) and compared to NC (p < 0.001; effect size = 1.86). Severe atrophy of the left anterior temporal region distinguished the language variant. AD patients, by contrast, did not differ from NC for frontal lobe volume but had smaller anterior temporal lobes (p = 0.03). Both dementia groups had medial temporal lobe atrophy of similar magnitude. A logistic regression model including 4 regional measures correctly classified 100% of subjects. CONCLUSION: FTD can be reliably differentiated from AD by virtue of a topographical pattern of atrophy involving the frontal lobes and anterior temporal regions. Medial temporal lobe volumes do not distinguish FTD from AD.     

Association between absence of the adhesio interthalamica and amygdala volume in schizophrenia

Abnormal neurodevelopment in midline structures such as the adhesio interthalamica (AI) has been reported in schizophrenia, but not consistently replicated. We investigated the prevalence and anterior-posterior length of the AI in 62 schizophrenia patients (32 males, 30 females) and 63 healthy controls (35 males, 28 females) using magnetic resonance imaging. We also explored the relation between the AI and volumetric measurements for the third ventricle, medial temporal structures (amygdala, hippocampus, and parahippocampal gyrus), superior temporal sub-regions, and frontal lobe regions (prefrontal area and anterior cingulate gyrus). The AI was absent in 24.2% (15/62) of the schizophrenia patients and in 9.5% (6/63) of the controls, showing a significant group difference. For the length of the AI, schizophrenia patients had a shorter AI than controls, and males had a shorter AI than females. The subjects without an AI had a significantly larger third ventricle and smaller parahippocampal gyrus than the subjects with an AI for both groups. We found a significant diagnosis-by-AI interaction for the amygdala. The schizophrenia patients without an AI had a smaller bilateral amygdala than those with an AI, whereas the AI was not associated with the volume of the amygdala in the control subjects. These findings suggest that the absence of AI in schizophrenia could be a marker of developmental abnormalities in the neural network including the thalamus and connected amygdaloid regions, which may play an important role in the pathogenesis of schizophrenia.     

Distinct MRI atrophy patterns in autopsy-proven Alzheimer's disease and frontotemporal lobar degeneration

To better define the anatomic distinctions between Alzheimer's disease (AD) and frontotemporal lobar degeneration (FTLD), we retrospectively applied voxel-based morphometry to the earliest magnetic resonance imaging scans of autopsy-proven AD (N = 11), FTLD (N = 18), and controls (N = 40). Compared with controls, AD patients showed gray matter reductions in posterior temporoparietal and occipital cortex; FTLD patients showed atrophy in medial prefrontal and medial temporal cortex, insula, hippocampus, and amygdala; and patients with both disorders showed atrophy in dorsolateral and orbital prefrontal cortex and lateral temporal cortex (P(FWE-corr) < .05). Compared with FTLD, AD patients had decreased gray matter in posterior parietal and occipital cortex, whereas FTLD patients had selective atrophy in anterior cingulate, frontal insula, subcallosal gyrus, and striatum (P < .001, uncorrected). These findings suggest that AD and FTLD are anatomically distinct, with degeneration of a posterior parietal network in AD and degeneration of a paralimbic fronto-insular-striatal network in FTLD.     

Reduced auditory M100 asymmetry in schizophrenia and dyslexia: applying a developmental instability approach to assess atypical brain asymmetry

Although atypical structural and functional superior temporal gyrus (STG) asymmetries are frequently observed in patients with schizophrenia and individuals with dyslexia, their significance is unclear. One possibility is that atypical asymmetries reflect a general risk factor that can be seen across multiple neurodevelopmental conditions--a risk factor whose origins are best understood in the context of Developmental Instability (DI) theory. DI measures (minor physical anomalies (MPAs) and fluctuating asymmetries (FAs)) reflect perturbation of the genetic plan. The present study sought to assess whether the presence of peripheral indices of DI predicts anomalous functional auditory cortex asymmetry in schizophrenia patients and dyslexia subjects. The location of the auditory M100 response was used as a measure of functional STG asymmetry, as it has been reported that in controls (but not in subjects with schizophrenia or dyslexia) the M100 source location in the right hemisphere is shifted anterior to that seen for the left hemisphere. Whole-brain auditory evoked magnetic field data were successfully recorded from 14 male schizophrenia patients, 21 male subjects with dyslexia, and 16 normal male control subjects. MPA and FA measures were also obtained. Replicating previous studies, both schizophrenia and dyslexia groups showed less M100 asymmetry than did controls. Schizophrenia and dyslexia subjects also had higher MPA scores than normal controls. Although neither total MPA nor FA measures predicted M100 asymmetry, analyses on individual MPA items revealed a relationship between high palate and M100 asymmetry. Findings suggest that M100 positional asymmetry is not a diagnostically specific feature in several neurodevelopmental conditions. Continued research examining DI and brain asymmetry relationships is warranted.     

Schizotypal personality disorder and MRI abnormalities of temporal lobe gray matter.

BACKGROUND: Structural MRI data indicate schizophrenics have reduced left-sided temporal lobe gray matter volumes, especially in the superior temporal gyrus (STG) and medial temporal lobe. Our data further suggest a specificity to schizophrenia spectrum disorders of STG volume reduction. Interpretation of research studies involving schizophrenics may be complicated by the effects of exposure to neuroleptics and chronic illness. Sharing the same genetic diathesis of schizophrenics, subjects with schizotypal personality disorder (SPD) offer a unique opportunity to evaluate commonalities between schizophrenia and SPD, particularly as SPD subjects are characterized by cognitive and perceptual distortions, an inability to tolerate close friendships, and odd behavior, but they are not psychotic and so have generally not been prescribed neuroleptics nor hospitalized. Evaluation of brain structure in SPD may thus offer insight into the "endophenotype" common to both disorders. In addition, differences between groups may suggest which are the brain structures of schizophrenics that contribute to the development of psychosis. METHODS: To test the hypothesis of whether SPD subjects might show similar STG abnormalities, STG and medial temporal lobe regions of interest (ROI) were manually drawn on high resolution coronal MRI 1.5 mm thick slices. Images were derived from 16 right-handed male SPD subjects, without regard to family history, and 14 healthy, right-handed, comparison males who did not differ from the SPD group on parental socio-economic status, age, or verbal IQ. RESULTS: As predicted, SPD subjects showed a reduction in left STG gray matter volume compared with age and gender matched comparison subjects. SPD subjects also showed reduced parahippocampal left/right asymmetry and a high degree of disordered thinking. Comparisons with chronic schizophrenics previously studied by us showed the SPD group had a similarity of left STG gray matter volume reduction, but fewer medial temporal lobe abnormalities. CONCLUSIONS: These abnormalities strengthen the hypothesis of a temporal lobe abnormality in SPD, and the similarity of STG findings in schizophrenia and SPD suggest that STG abnormalities may be part of the spectrum "endophenotype." It is also possible that presence of medial temporal lobe abnormalities may help to differentiate who will develop schizophrenia and who will develop the less severe schizophrenia spectrum disorder, SPD.     

Hippocampal and parahippocampal volumes in schizophrenia: a structural MRI study

Smaller medial temporal lobe volume is a frequent finding in studies of patients with schizophrenia, but the relative contributions of the hippocampus and three surrounding cortical regions (entorhinal cortex, perirhinal cortex, and parahippocampal cortex) are poorly understood. We tested the hypothesis that the volumes of medial temporal lobe regions are selectively changed in schizophrenia. We studied 19 male patients with schizophrenia and 19 age-matched male control subjects. Hippocampal and cortical volumes were estimated using a three-dimensional morphometric protocol for the analysis of high-resolution structural magnetic resonance images, and repeated measures ANOVA was used to test for region-specific differences. Patients had smaller overall medial temporal lobe volumes compared to controls. The volume difference was not specific for either region or hemisphere. The finding of smaller medial temporal lobe volumes in the absence of regional specificity has important implications for studying the functional role of the hippocampus and surrounding cortical regions in schizophrenia.     

A follow-up MRI study of the fusiform gyrus and middle and inferior temporal gyri in schizophrenia spectrum

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 gyrus reduction (left, − 2.6%/year; right, − 2.3%/year) compared with schizotypal patients (left: − 0.4%/year; right: − 0.2%/year) and controls (left: 0.1%/year; right: 0.0%/year). However, the middle and inferior temporal gyri did not exhibit significant progressive gray matter change in all diagnostic groups. In the schizophrenia patients, a higher cumulative dose of antipsychotics during follow-up was significantly correlated with less severe gray matter reduction in the left fusiform gyrus. The annual gray matter loss of the fusiform gyrus did not correlate with that of the STG previously reported in the same subjects. Our findings suggest regional specificity of the progressive gray matter reduction in the temporal lobe structures, which might be specific to overt schizophrenia within the schizophrenia spectrum.     

Diagnostic utility of neuropsychological performance and quantitative MRI-based measurement in Alzheimer disease

This study was designed to examine the roles of the characteristic cognitive indicators and specific MRI-based measurements in the differential diagnoses of Alzheimer disease (AD), vascular dementia (VaD), and normal aging. Fifty-two probable AD patients were recruited for the study. Twenty-seven VaD patients and 35 age-matched normal older adults (NC) were included as controls. All subjects underwent a battery of standardized neuropsychological tests. The MRI-based quantification technique was used to measure the volumes and T2 relaxation time (T2) of medial temporal lobe structures. Stepwise discriminant analyses showed cognitive indicators had a sensitivity ranging from 82% to 100% and specificity from 82% to 97% for differentiating AD from non-AD cases (VaD and normal controls), and the quantitative MRI-based measurements of medial temporal lobe structures correctly classified AD cases from non-AD cases with sensitivity from 80% to 96% and specificity from 83% to 97%. ROC curve analyses showed that the combination of cognitive and MRI measurements slightly increased the diagnostic accuracy of AD. The results suggest that both cognitive indicators and MRI-based medial temporal lobe measurements may be useful in differentiating AD from VaD and normal older adults. The combination of these possible indicators is promising in the early diagnosis of AD.     

Assessing the onset of structural change in familial Alzheimer's disease

Regional and global cerebral atrophy are inevitable features of Alzheimer's disease (AD). We assessed volumes and atrophy rates of brain structures in patients with familial AD during the period that they developed symptoms. Five patients with presymptomatic AD and 20 controls had two or more annual volumetric MRI brain scans. Volumes of brain, ventricles, temporal lobes, hippocampi, and entorhinal cortices (ECs) were measured. Rates of volume change were calculated from serial scans. There were no significant differences in baseline measures of whole brain, temporal lobe, or ventricular volume between patients and controls; averaged volumes of medial temporal lobe structures (both hippocampi and ECs) were 16.6% (95% confidence interval [CI], 3.3-28.0%) lower in patients. Atrophy rates for brain, temporal lobe, hippocampus, and EC were significantly increased in patients compared with controls (p < 0.05). Averaged atrophy rates from both hippocampi and ECs were 5.1% (95% CI, 3.0-7.1%) greater in patients than controls. Linear extrapolation backward suggested medial temporal lobe atrophy commenced 3.5 years (95% CI, 0.7-7.5 years) before onset, when all patients were asymptomatic. We conclude that increased medial temporal lobe atrophy rates are an early and distinguishing feature of AD and that pathological atrophy probably is occurring several years before the onset of symptoms.     

Volume reduction of the left planum temporale gray matter associated with long duration of untreated psychosis in schizophrenia: a preliminary report

A longer duration of untreated psychosis (DUP) in schizophrenia is reported to lead to a poorer clinical outcome, possibly reflecting a neurodegenerative process after the onset of overt psychosis. However, the effect of DUP on brain morphology in schizophrenia is still poorly understood. In this study, we used magnetic resonance imaging to investigate the relation between DUP and volumetric measurements for the superior temporal sub-regions (Heschl's gyrus, planum temporale, and caudal superior temporal gyrus), the medial temporal lobe structures (hippocampus and amygdala), and the frontal lobe regions (prefrontal area and anterior cingulate gyrus) in a sample of 38 schizophrenia patients (20 males and 18 females) whose illness duration was less than five years. We found a significant negative correlation between DUP and the volume of gray matter in the left planum temporale even after controlling for age, age at illness onset, and duration and dosage of neuroleptic medication. There was no such correlation for the other brain regions including each sub-region of the prefrontal cortex (the superior frontal gyrus, middle frontal gyrus, inferior frontal gyrus, ventral medial prefrontal cortex, orbitofrontal cortex, and straight gyrus). When subjects were divided into two groups around the median DUP, the long-DUP group had a significantly smaller planum temporale gray matter than the short-DUP group. These findings may reflect a progressive pathological process in the gray matter of the left planum temporale during the initial untreated phase of schizophrenia, whereas abnormalities in the medial temporal regions might be, as has been suggested from previous longitudinal findings, relatively static at least during the early course of the illness.     

SPECT study of visual fixation in schizophrenia and comparison subjects.

BACKGROUND: The consistent association of impaired eye movements and schizophrenia suggests a relationship between the neurobiology of the illness and visual pursuit systems. Visual fixation (VF), an eye "movement" task at zero velocity, is the simplest such abnormality in schizophrenia patients and their relatives. METHODS: We used a VF task for a functional imaging study. Six neuroleptic-free schizophrenia patients and eight gender and mean age matched comparison subjects had SPECT scans with 20 mCi of Tc99-HMPAO, during VF on a simple blue line intersection. MEDX data saved in ANALYZE format for SPM 95 was used to generate paired t-test statistical data for display in Talairach space, with rCBF changes given as Z-scores. RESULTS: Patients, compared to controls, had increased rCBF in both the parahippocampal gyrus (bilaterally) and in the right fusiform gyrus. They had decreased rCBF in the left frontal cortex, including medial and superior frontal gyri and anterior cingulate. Overall, compared to controls, patients had medial temporal lobe hyperperfusion along with left prefrontal hypoperfusion. CONCLUSIONS: These findings are consistent with the hypothesized imbalance between the medial temporal and frontal lobes that is postulated for schizophrenia. It was of interest that the relative rCBF differences between schizophrenia patients and controls in this small sample were observable with this cognitively non-demanding visual fixation task.     

Expression of equilibrative nucleoside transporter type 1 protein in elderly patients with schizophrenia

Alterations in glutamatergic neurotransmission are thought to be involved in several psychiatric disorders, including schizophrenia. Equilibrative nucleoside transporter type 1 (ENT1) regulates glutamate levels by regulating excitatory amino acid transporter expression and activity in the brain. In this study, we investigated whether ENT1 is abnormally expressed in the brain of elderly patients with schizophrenia. We measured protein expression of ENT1 in the superior temporal gyrus (STG) and anterior cingulate cortex (ACC) in patients with schizophrenia (STG, n=22; ACC, n=34) and a comparison group (STG, n=24; ACC, n=29). We found decreased ENT1 expression in the STG in patients with schizophrenia, supporting the hypothesis of altered glutamate transport in this illness.