Stanley Foundation Neuropathology Consortium Research Articles

Phosphodiesterases PDE2A and PDE10A both change mRNA expression in the human brain with age, but only PDE2A changes in a region-specific manner with psychiatric disease

Many studies implicate altered cyclic nucleotide signaling in the pathophysiology of major depressive disorder (MDD), bipolar disorder (BPD), and schizophrenia (SCZ). As such, we explored how phosphodiesterases 2A (PDE2A) and 10A (PDE10A)—enzymes that break down cyclic nucleotides—may be altered in brains of these patients. Using autoradiographic in situ hybridization on postmortem brain tissue from the Stanley Foundation Neuropathology Consortium, we measured expression of PDE2 and PDE10 mRNA in multiple brain regions implicated in psychiatric pathophysiology, including cingulate cortex, orbital frontal cortex (OFC), superior temporal gyrus, hippocampus, parahippocampal cortex, amygdala, and the striatum. We also assessed how PDE2A and PDE10A expression changes in these brain regions across development using the Allen Institute for Brain Science Brainspan database. Compared to controls, patients with SCZ, MDD and BPD all showed reduced PDE2A mRNA in the amygdala. In contrast, PDE2A expression changes in frontal cortical regions were only significant in patients with SCZ, while those in caudal entorhinal cortex, hippocampus, and the striatum were most pronounced in patients with BPD. PDE10A expression was only detected in striatum and did not differ by disease group; however, all groups showed significantly less PDE10A mRNA expression in ventral versus dorsal striatum. Across development, PDE2A mRNA increased in these brain regions; whereas, PDE10A mRNA expression decreased in all regions except striatum. Thus, PDE2A mRNA expression changes in both a disorder- and brain region-specific manner, potentially implicating PDE2A as a novel diagnostic and/or patient-selection biomarker or therapeutic target.

Prefrontal fatty acid composition in schizophrenia and bipolar disorder: Association with reelin expression

ObjectiveThe extracellular matrix protein reelin regulates early brain development and synaptic plasticity in adulthood. Reelin is decreased in the postmortem brain in schizophrenia patients. Reelin's two receptors, ApoER2 and VLDLR, are also substrates for ApoE - a key lipoprotein that regulates phospholipid homeostasis in the brain. The goal of the present study was therefore to examine phospholipids and their constituent fatty acids, and determine whether there is an association between reelin, its receptors and phospholipids in the brain. MethodsDorsolateral prefrontal cortex (BA9) grey matter was obtained from the Stanley Foundation Neuropathology Consortium. Samples included tissue from 35 controls, 35 schizophrenia and 34 bipolar disorder patients. Phospholipids were measured using gas liquid chromatography. ResultsWe quantified 15 individual fatty acid or plasmalogen species for phosphatidylethanolamine and phosphatidylcholine fractions, each comprising >0.5% of the total fatty acid pool. There were no group differences in phospholipids or individual fatty acid species after correcting for multiple comparisons. However, for the entire cohort, both the polyunsaturated subclass of fatty acids, and ApoE, correlated significantly with reelin expression, with a number of individual ω-6 fatty acid species also demonstrating a significant positive correlation. There was a non-significant trend for similar effects with VLDLR expression as for reelin. ConclusionPhospholipids and fatty acids in the dorsolateral cortex do not differ in patients with schizophrenia, bipolar disorder and controls. Reelin expression in this brain region is associated with polyunsaturated fatty acids and ApoE, suggesting further study of potential physiological interactions between these substrates is warranted.

Metabolic profile alterations in the postmortem brains of patients with schizophrenia using capillary electrophoresis-mass spectrometry

ObjectiveWe aimed to find the alterations in the profiles of low-molecular-weight metabolites in the brains of schizophrenia patients that may reflect the pathophysiology of the disorder. MethodHuman postmortem brain tissues from the frontal cortex (15 schizophrenia patients and 15 controls) and the hippocampus (14 schizophrenia patients and 15 controls) were obtained from the Stanley Foundation Neuropathology Consortium. We analyzed ~300 metabolites, using capillary electrophoresis with time-of-flight mass spectrometry. ResultsIn the frontal cortex, the mean levels of 29 metabolites were significantly different between the schizophrenia and control groups. In the hippocampus, only a dipeptide, glycylglycine was significantly (p≤0.001, nominal p-value) increased in schizophrenia. Glycylglycine was also significantly (p=0.007) increased in the frontal cortex of schizophrenia. The pathway analyses revealed that several metabolic pathways including KEGG “Central carbon metabolism in cancer” and “Protein digestion and absorption” were commonly affected in the frontal cortex and the hippocampus of schizophrenia patients. ConclusionThese findings point out alterations in glucose metabolism and proteolysis in the brains of schizophrenia.

Histone methylation at H3K9: Evidence for a restrictive epigenome in schizophrenia

ObjectiveEpigenetic changes are stable and long-lasting chromatin modifications that regulate genomewide and local gene activity. The addition of two methyl groups to the 9th lysine of histone 3 (H3K9me2) by histone methyltransferases (HMT) leads to a restrictive chromatin state, and thus reduced levels of gene transcription. Given the numerous reports of transcriptional down-regulation of candidate genes in schizophrenia, we tested the hypothesis that this illness can be characterized by a restrictive epigenome. MethodsWe obtained parietal cortical samples from the Stanley Foundation Neuropathology Consortium and lymphocyte samples from the University of Illinois at Chicago (UIC). In both tissues we measured mRNA expression of HMTs GLP, SETDB1 and G9a via real-time RT-PCR and H3K9me2 levels via western blot. Clinical rating scales were obtained from the UIC cohort. ResultsA diagnosis of schizophrenia is a significant predictor for increased GLP, SETDB1 mRNA expression and H3K9me2 levels in both postmortem brain and lymphocyte samples. G9a mRNA is significantly increased in the UIC lymphocyte samples as well. Increased HMT mRNA expression is associated with worsening of specific symptoms, longer durations of illness and a family history of schizophrenia. ConclusionsThese data support the hypothesis of a restrictive epigenome in schizophrenia, and may associate with symptoms that are notoriously treatment resistant. The histone methyltransferases measured here are potential future therapeutic targets for small molecule pharmacology, and better patient prognosis.

Synapsin II gene expression in the dorsolateral prefrontal cortex of brain specimens from patients with schizophrenia and bipolar disorder: effect of lifetime intake of antipsychotic drugs

Synapsins are neuronal phosphoproteins crucial to regulating the processes required for normal neurotransmitter release. Synapsin II, in particular, has been implied as a candidate gene for schizophrenia. This study investigated synapsin II mRNA expression, using Real Time RT-PCR, in coded dorsolateral prefrontal cortical samples provided by the Stanley Foundation Neuropathology Consortium. Synapsin IIa was decreased in patients with schizophrenia when compared to both healthy subjects and patients with bipolar disorder, whereas the synapsin IIb was only significantly reduced in patients with schizophrenia when compared to healthy subjects, but not patients with bipolar disorder. Furthermore, lifetime antipsychotic drug use was positively associated with synapsin IIa expression in patients with schizophrenia. Results suggest that impairment of synaptic transmission by synapsin II reduction may contribute to dysregulated convergent molecular mechanisms which result in aberrant neural circuits that characterize schizophrenia, while implicating involvement of synapsin II in therapeutic mechanisms of currently prescribed antipsychotic drugs.

DNA Methylation/Demethylation Network Expression in Psychotic Patients with a History of Alcohol Abuse

Recent studies suggest that protracted and excessive alcohol use induces an epigenetic dysregulation in human and rodent brains. We recently reported that DNA methylation dynamics are altered in brains of psychotic (PS) patients, including schizophrenia and bipolar disorder patients. Because PS patients are often comorbid with chronic alcohol abuse, we examined whether the altered expression of multiple members of the DNA methylation/demethylation network observed in postmortem brains of PS patients was modified in PS patients with a history of chronic alcohol abuse. DNA-methyltransferase-1 (DNMT1) mRNA-positive neurons were counted in situ in prefrontal cortex samples obtained from the Harvard Brain Tissue Resource Center, Belmont, MA. 10-11-translocation (TETs 1, 2, 3), apolipoprotein B editing complex enzyme (APOBEC-3C), growth and DNA-damage-inducible protein 45β (GADD45β), and methyl-binding domain protein-4 (MBD4) mRNAs were measured by quantitative real-time polymerase chain reaction in inferior parietal cortical lobule samples obtained from the Stanley Foundation Neuropathology Consortium, Bethesda, MD. We observed an increase in DNMT1 mRNA-positive neurons in PS patients compared with non-PS subjects. In addition, there was a pronounced decrease in APOBEC-3C and a pronounced increase in GADD45β and TET1 mRNAs in PS patients with no history of alcohol abuse. In PS patients with a history of chronic alcohol abuse, the numbers of DNMT1-positive neurons were not increased significantly. Furthermore, the decrease in APOBEC-3C mRNA was less pronounced, while the increase in TET1 mRNA had a tendency to be potentiated in those PS patients that were chronic alcohol abusers. GADD45β and MBD4 mRNAs were not influenced by alcohol abuse. The effect of chronic alcohol abuse on DNA methylation/demethylation network enzymes cannot be attributed to confounding demographic variables or to the type and dose of medication used. Based on these results, we hypothesize that PS patients may abuse alcohol as a potential attempt at self-medication to normalize altered DNA methylation/demethylation network pathways. However, before accepting this conclusion, we need to study alterations in the DNA methylation/demethylation pathways and the DNA methylation dynamics in a substantial number of alcoholic PS and non-PS patients. Additional investigation may also be necessary to determine whether the altered DNA methylation dynamics are direct or the consequence of an indirect interaction of alcohol with the neuropathogenetic mechanisms underlying psychosis.

Upregulation of TET1 and downregulation of APOBEC3A and APOBEC3C in the parietal cortex of psychotic patients

Increasing evidence suggests that epigenetic dysfunction may account for the alteration of gene transcription present in neuropsychiatric disorders such as schizophrenia (SZ), bipolar disorder (BP) and autism. Here, we studied the expression of the ten-eleven translocation (TET) gene family and activation-induced deaminase/apolipoprotein B mRNA-editing enzymes (AID/APOBEC) in the inferior parietal lobule (IPL) (BA39-40) and the cerebellum of psychotic (PSY) patients, depressed (DEP) patients and nonpsychiatric (CTR) subjects obtained from the Stanley Foundation Neuropathology Consortium Medical Research Institute. These two sets of enzymes have a critical role in the active DNA demethylation pathway. The results show that TET1, but not TET2 and TET3, mRNA and protein expression was increased (two- to threefold) in the IPL of the PSY patients compared with the CTR subjects. TET1 mRNA showed no change in the cerebellum. Consistent with the increase of TET1, the level of 5-hydroxymethylcytosine (5hmC) was elevated in the IPL of PSY patients but not in the other groups. Moreover, higher 5hmC levels were detected at the glutamic acid decarboxylase67 (GAD67) promoter only in the PSY group. This increase was inversely related to the decrease of GAD67 mRNA expression. Of 11 DNA deaminases measured, APOBEC3A mRNA was significantly decreased in the PSY and DEP patients, while APOBEC3C was decreased only in PSY patients. The other APOBEC mRNA studied failed to change. Increased TET1 and decreased APOBEC3A and APOBEC3C found in this study highlight the possible role of altered DNA demethylation mechanisms in the pathophysiology of psychosis.

Growth Arrest and DNA-Damage-Inducible, Beta (GADD45b)-Mediated DNA Demethylation in Major Psychosis

Aberrant neocortical DNA methylation has been suggested to be a pathophysiological contributor to psychotic disorders. Recently, a growth arrest and DNA-damage-inducible, beta (GADD45b) protein-coordinated DNA demethylation pathway, utilizing cytidine deaminases and thymidine glycosylases, has been identified in the brain. We measured expression of several members of this pathway in parietal cortical samples from the Stanley Foundation Neuropathology Consortium (SFNC) cohort. We find an increase in GADD45b mRNA and protein in patients with psychosis. In immunohistochemistry experiments using samples from the Harvard Brain Tissue Resource Center, we report an increased number of GADD45b-stained cells in prefrontal cortical layers II, III, and V in psychotic patients. Brain-derived neurotrophic factor IX (BDNF IXabcd) was selected as a readout gene to determine the effects of GADD45b expression and promoter binding. We find that there is less GADD45b binding to the BDNF IXabcd promoter in psychotic subjects. Further, there is reduced BDNF IXabcd mRNA expression, and an increase in 5-methylcytosine and 5-hydroxymethylcytosine at its promoter. On the basis of these results, we conclude that GADD45b may be increased in psychosis compensatory to its inability to access gene promoter regions.

Amygdala astrocyte reduction in subjects with major depressive disorder but not bipolar disorder

Several magnetic resonance imaging studies have found changes in amygdala volumes in adults with mood disorders. The cellular basis for these changes has not been explored in detail. Specifically, it is not known whether differences in the density and/or volume of neurons or glial cells contribute to tissue volume changes seen on magnetic resonance images. Postmortem amygdala samples were obtained from the Stanley Foundation Neuropathology Consortium from subjects diagnosed with bipolar disorder (n = 10), major depressive disorder (n = 11), and schizophrenia (n = 9), and from normal controls (n = 14). Samples were first stained with glial fibrillary acidic protein (GFAP) and counter-stained with hematoxylin to ascertain neuron and glia (astrocyte) densities. No significant differences in neuronal densities were found between groups. However, a reduction in the density of GFAP immunoreactive astrocytes was observed in the amygdala of subjects with major depressive disorder compared to the bipolar disorder, schizophrenia, and normal control postmortem samples. A decrease in density of GFAP immunoreactive astrocytes in the amygdala of depressed subjects is consistent with prior histologic reports and might contribute to amygdala volume reductions reported in several in vivo neuroimaging studies.

Decreased levels of glutathione, the major brain antioxidant, in post-mortem prefrontal cortex from patients with psychiatric disorders

Accruing data suggest that oxidative stress may be a factor underlying the pathophysiology of bipolar disorder (BD), major depressive disorder (MDD), and schizophrenia (SCZ). Glutathione (GSH) is the major free radical scavenger in the brain. Diminished GSH levels elevate cellular vulnerability towards oxidative stress; characterized by accumulating reactive oxygen species. The aim of this study was to determine if mood disorders and SCZ are associated with abnormal GSH and its functionally related enzymes. Post-mortem prefrontal cortex from patients with BD, MDD, SCZ, and from non-psychiatric comparison controls were provided by the Stanley Foundation Neuropathology Consortium. Spectrophotometric analysis was utilized for the quantitative determination of GSH, while immunoblotting analyses were used to examine expression of glutamyl-cysteine ligase (GCL), GSH reductase (GR), and GSH peroxidase (GPx). We found that the levels of reduced, oxidized, and total GSH were significantly decreased in all psychiatric conditions compared to the control group. Although GCL and GR levels did not differ between groups, the levels of GPx were reduced in MDD and SCZ compared to control subjects. Since oxidative damage has been demonstrated in MDD, BD, and SCZ, our finding that GSH levels are reduced in post-mortem prefrontal cortex suggests that these patient groups may be more susceptible to oxidative stress.

Vesicular glutamate transporter mRNA expression in the medial temporal lobe in major depressive disorder, bipolar disorder, and schizophrenia

Altered glutamate transmission has been found in the medial temporal lobe in severe psychiatric illnesses, including major depressive disorder (MDD) and bipolar disorder (BD). The vesicular glutamate transporters (VGLUTs) have a pivotal role in presynaptic release of glutamate into the synaptic cleft. We investigated this presynaptic marker in major psychiatric illness by measuring transcript expression of the VGLUTs in the medial temporal lobe. The study sample comprised four groups of 13 subjects with MDD, BD, or schizophrenia (SCZ), and a comparison group from the Stanley Foundation Neuropathology Consortium. In situ hybridization was performed to quantify messenger RNA (mRNA) expression of VGLUT 1, 2, and 3 in medial temporal lobe structures. We also examined the same areas of rats treated with antidepressants, a mood stabilizer, and antipsychotics to assess the effects of these medications on VGLUT mRNA expression. We found decreased VGLUT1 mRNA expression in both MDD and BD in the entorhinal cortex (ERC), decreased VGLUT2 mRNA expression in MDD in the middle temporal gyrus, and increased VGLUT2 mRNA expression in SCZ in the inferior temporal gyrus (ITG). We also found a negative correlation between age and VGLUT1 mRNA expression in BD in the ERC and ITG. We did not find any changes in VGLUT mRNA expression in the hippocampus in any diagnostic group. We found decreased VGLUT1 mRNA expression in rats treated with haloperidol in the temporal cortex. These data indicate region-specific alterations of presynaptic glutamate innervation in the medial temporal lobe in the mood disorders.

Increased oxidative stress in the anterior cingulate cortex of subjects with bipolar disorder and schizophrenia

Recent studies indicate the presence of mitochondrial dysfunction in brains of subjects with bipolar disorder (BD). Because the mitochondrial electron transport chain is a major source for production of reactive oxygen species that cause oxidative stress, we sought to determine in the present study if BD is associated with oxidative stress. Postmortem anterior cingulate brain sections from subjects with BD, major depressive disorder (MDD), or schizophrenia, and from nonpsychiatric, non-neurologic comparison controls were generously provided by the Stanley Foundation Neuropathology Consortium. Oxidative stress was determined by analyzing 4-hydroxynonenal (4-HNE), a major product of lipid peroxidation. The level of 4-HNE was determined by measuring 4-HNE protein adducts using immunohistochemistry. We found that 4-HNE levels were significantly increased by 59% in BD subjects and by 47% in schizophrenia subjects, but not in MDD subjects, when compared with controls. Levels of 4-HNE were negatively correlated with pH in all 60 subjects. When pH was used as covariate, 4-HNE levels were still significantly increased in BD subjects when compared with controls. Further, 4-HNE levels were significantly correlated with pH values only in BD subjects, but not in MDD, schizophrenia, or control subjects. Oxidative damage in the brain may contribute in part to the pathological process in BD and schizophrenia. This finding also suggests antioxidative stress as a probable alternative approach to the pharmacological treatment of these psychiatric disorders.

Expression of hippocampal brain-derived neurotrophic factor and its receptors in Stanley consortium brains

Several lines of evidence implicate BDNF in the pathophysiology of psychiatric illness. BDNF polymorphisms have also been associated with the risk of schizophrenia and mood disorders. We therefore investigated whether levels of (pro)BDNF and receptor proteins, TrkB and p75, are altered in hippocampus in schizophrenia and mood disorder and whether polymorphisms in each gene influenced protein expression. Formalin-fixed paraffin-embedded hippocampal sections from subjects with schizophrenia, major depressive disorder (MDD), bipolar disorder (BPD) and non-psychiatric controls were obtained from the Stanley Foundation Neuropathology Consortium. (pro)BDNF, TrkB(T1) and p75 protein densities were quantified by immunoautoradiography and DNA extracted from each subject was used to determine the effect of genotype on protein expression. In MDD, reductions in (pro)BDNF were seen in all layers of the right but not the left hippocampus with no changes in the dentate gyrus. The pattern was similar but less marked for BPD. In addition, BPD but not MDD patients, had bilateral reductions in p75 in hippocampal layers but not in dentate gyrus. No changes in TrkB(T1) density were seen in any diagnosis. These findings suggest MDD and BPD may share impairment in (pro)BDNF expression. However, BPD may involve impairments of both (pro)BDNF and p75 receptor, whereas MDD may involve impaired (pro)BDNF alone. Moreover, the lateralisation of changes may indicate a role of asymmetry in vulnerability to MDD. Hippocampal (pro)BDNF and receptor levels were also affected by genotype, suggesting that allelic variations are important in the hippocampal abnormalities seen in these psychiatric disorders.

Lamina-Specific Abnormalities of NMDA Receptor-Associated Postsynaptic Protein Transcripts in the Prefrontal Cortex in Schizophrenia and Bipolar Disorder

The hypothesis of N-methyl-D-aspartate (NMDA) receptor hypofunction in schizophrenia was initially based on observations that blockade of the NMDA subtype of glutamate receptor by noncompetitive antagonists, such as phencyclidine and ketamine, can lead to clinical symptoms similar to those present in schizophrenia. Recently, glutamate has also been implicated in the pathophysiology of the mood disorders. As impaired NMDA receptor activity may be the result of a primary defect in the NMDA receptors themselves, or secondary to dysfunction in the protein complexes that mediate their signaling, we measured expression of both NMDA subunits and associated postsynaptic density (PSD) proteins (PSD95, neurofilament-light (NF-L), and SAP102) transcripts in the dorsolateral prefrontal cortex in subjects with schizophrenia, bipolar disorder, major depression, and a comparison group using tissue from the Stanley Foundation Neuropathology Consortium. We found decreased NR1 expression in all three illnesses, decreased NR2A in schizophrenia and major depression, and decreased NR2C in schizophrenia. We found no changes of NR2B or NR2D. Receptor autoradiography revealed no alterations in receptor binding in any of the illnesses, indicating no change in total receptor number, but taken with the subunit data suggests abnormal receptor stoichiometry. In the same subjects, PSD95 was unchanged in all three illnesses, while reduced NF-L expression was found in schizophrenia, especially in large cells of layer V. SAP102 expression was reduced in bipolar disorder restricted to small cells of layer II and large cells of layer III in bipolar disorder. These alterations likely reflect altered signaling cascades associated with glutamate-mediated neurotransmission within specific cortical circuits in these psychiatric illnesses.

Deficit of perineuronal oligodendrocytes in the prefrontal cortex in schizophrenia and mood disorders

ObjectiveA deficit of oligodendrocytes has been reported in the prefrontal cortex (PFC) in schizophrenia (SCH), bipolar disorder (BPD) and major depression (MDD). Also, a decreased size of pyramidal neurons has been detected in layer III in SCH and in mood disorders. Since oligodendrocytes have a trophic influence on neurons, reduced neuronal size reported in these disorders might be associated with the deficit in subpopulation of perineuronal oligodendrocytes. We hypothesized that deficit of perineuronal oligodendrocytes might occur in SCH and mood disorders. MethodWe estimated the number of oligodendroglial satellites of pyramidal neurons and the size of pyramidal neurons in layer III (Brodmann's area 9) in Nissl stained sections in SCH, BPD, MDD and normal controls. The Stanley Foundation Neuropathology Consortium brain collection consisted of 15 cases in each of four groups was used. ResultsWe detected a prominent and significant reduction in the number of perineuronal oligodendrocytes in the sublayers IIIa, IIIb and IIIc in SCH, BPD and MDD as compared to controls. The BPD group differed significantly from SCH group and from MDD group. There were no significant differences in somal sizes of pyramidal neurons in the sublayers IIIa, IIIb, IIIc between each of the psychiatric groups and the control group. Only BPD group showed significantly smaller neuronal size in sublayer IIIc as compared to controls. ConclusionsOur data provide evidence for a deficit of perineuronal oligodendrocytes in severe mental disorders that may play a key role in the pathophysiology of SCH, BPD and MDD.

Reduction of synapsin III in the prefrontal cortex of individuals with schizophrenia

We analyzed the expression of a presynaptic protein, synapsin III, in individuals with schizophrenia. Since levels of synapsin III were previously found to be significantly reduced in the hippocampus of individuals with schizophrenia, we examined another brain region believed to be a major locus of dysfunction in schizophrenia, the dorsolateral prefrontal cortex (DLPFC). Western blot analyses using tissue obtained from the Stanley Foundation Neuropathology Consortium revealed that synapsin III levels were significantly decreased in the DLPFC of individuals with schizophrenia compared to controls. These findings are consistent with growing evidence of presynaptic abnormalities and prefrontal cortical dysfunction in schizophrenia.

S-adenosyl methionine and DNA methyltransferase-1 mRNA overexpression in psychosis

Prefrontal cortex (Brodmann's area 9) levels of the methyl donor S-adenosyl methionine were increased by about two-fold in schizophrenia and bipolar disorder patients, but not in unipolar depressed patients compared with nonpsychiatric subjects from the Stanley Foundation Neuropathology Consortium (Bethesda, Maryland, USA). Neither age, brain weight and pH, hemisphere, post-mortem interval, disease onset/duration, nor cumulative dose of fluphenazine affected S-adenosyl methionine content. In schizophrenia and bipolar disorder patients, the increase of S-adenosyl methionine is associated with an overexpression of DNA methyltransferase-1 mRNA in Brodmann's area 9 GABAergic neurons. Hence, the increased expression of S-adenosyl methionine and DNA methyltransferase-1 may contribute to promoter cytosine 5-methylation and to downregulation of the expression of mRNAs encoding for reelin and GAD67 in cortical GABAergic neurons of schizhophrenia and bipolar disorder patients.

5HTTLPR Polymorphism and Enlargement of the Pulvinar: Unlocking the Backdoor to the Limbic System

The 5HTTLPR genetic variant of the serotonin transporter (SERT), which consists of a long (SERT-l) and short (SERT-s) allele, has emerged as a major factor influencing emotional behavior and brain anatomy. The pulvinar nucleus of the thalamus projects to important limbic nuclei including the amygdala and cingulate cortex, is involved in the processing of stimuli with emotional content, and contains an abundance of SERT. Stereological methods were used to measure pulvinar neuron number in postmortem tissue from major depressive disorder (n = 11), bipolar disorder (n = 11), schizophrenia (n = 12), and control (n = 15) specimens from the Stanley Foundation Neuropathology Consortium. The effect of SERT genotype on pulvinar volume and neuron number was investigated by using analysis of covariance. Analysis of covariance with diagnosis, SERT genotype, age, hemisphere, postmortem interval, and time-in-formalin covariates identified a 20% increase in pulvinar neuron number and volume in SERT-ss subjects. The elevated number of pulvinar neurons in subjects with a SERT-ss genotype may serve to enhance subcortical input of emotionally relevant stimuli to the limbic system, providing a mechanism for the 5HTTLPR genetic variant to affect predisposition to conditions such as major depression.

Protein expression profiling of postmortem brain in schizophrenia

Surface enhanced laser desorption/ionization time of flight mass spectrometry (SELDI-TOF-MS) enables the sensitive, high-throughput protein profiling of complex biological mixtures. In combination with bioinformatics, this technology has the potential to identify combinations of spectral peaks that can differentiate individuals with a particular disease from normal controls. SELDI-TOF-MS was used to screen postmortem tissue derived from the dorsolateral prefrontal cortex of individuals with schizophrenia ( n = 34) and matched controls ( n = 35), obtained from the Stanley Foundation Neuropathology Consortium. Tissue samples were homogenized in urea buffer, applied to four different chip arrays which possess different chromatographic surfaces, and analyzed using the Ciphergen ProteinChip® Biomarkers System (Model PBS II). Protein expression profiles of the schizophrenia and control groups were compared and analyzed using the Ciphergen Express (CE) and Biomarker Patterns Software (BPS) package. We detected several protein peaks whose intensities differed between the schizophrenia and control groups to a highly significant degree. A combination of these peaks was capable of distinguishing between schizophrenia and controls with a sensitivity and specificity of about 70%. The classification model that distinguished schizophrenia from controls was complex, suggesting that the biochemical abnormalities underlying schizophrenia are heterogeneous. Our results suggest that SELDI-TOF-MS has the potential for distinguishing individuals with schizophrenia from normal controls and may eventually lead to a better understanding of the classification, diagnosis and pathogenesis of this disorder.

Translocation of AIF in the human and rat striatum following protracted haloperidol, but not clozapine treatment

Loss of mitochondrial membrane integrity and consequent release of apoptogenic factors may be involved in mediating striatal neurodegeneration after prolonged treatment with the typical antipsychotic drug haloperidol. Apoptosis-inducing factor (AIF), an intramitochondrial protein, may have a large influence on mediating haloperidol-induced striatal neuron destruction. Translocation of this protein from mitochondria to the nucleus promotes cell death independently of the caspase cascade. To examine how AIF may contribute to haloperidol-induced apoptosis, AIF translocation was observed in three haloperidol treatment paradigms. SH-SY5Y cells were treated with both haloperidol and clozapine and examined for AIF immunofluorescence. Immunohistochemistry was also performed on human striatal sections obtained from the Stanley Foundation Neuropathology Consortium and on rat brain sections following 28 days of antipsychotic drug treatment. In the cellular model haloperidol, but not clozapine treatment increased the nuclear AIF immunofluorescent signal and decreased cell viability. Corollary to these findings, striatal sections from patients who had taken haloperidol and rats who were administered haloperidol both had an elevated nuclear AIF signal. The results provide novel evidence implicating the involvement of AIF in haloperidol-associated apoptosis and its relevance to the development of typical antipsychotic drug-related adverse effects such as tardive dyskinesia.