Antipsychotics increase microtubule-associated protein 2 mRNA but not spinophilin mRNA in rat hippocampus and cortex

Maternal treatment with aripiprazole prevents the development of a valproic acid-induced autism-like phenotype in juvenile male mice

Autism spectrum disorder (ASD) describes a heterogeneous group of neurodevelopmental conditions characterized by deficits in social communication and repetitive behaviors. Aripiprazole (APZ) is an atypical antipsychotic that can safeguard mice against autism-like behavior induced by valproic acid (VPA). In the present study, we examined the effects of maternal treatment with APZ (10 mg/kg) in juvenile mice prenatally exposed to VPA on neurodevelopmental behaviors, social interactions, communication, and working memory, as well as synaptophysin (SYP), synaptosomal-associated protein, 25 kDa (SNAP-25) and microtubule-associated protein 2 (MAP-2) expression in the medial prefrontal cortex (mPFC) and cell viability in the hippocampus. In addition, to evaluate possible APZ interference with the anticonvulsant properties of VPA on pentylenetetrazole (PTZ)-induced seizures were evaluated. Maternal treatment with APZ significantly prevented body weight loss, self-righting, eye-opening, social interactions, social communication, and working memory deficits in mice prenatally exposed to VPA. Additionally, the decrease in the SYP, SNAP-25, and MAP-2 expressions in the mPFC and cell death in the hippocampus was prevented by APZ. Furthermore, APZ (10 mg/kg) did not interfere with the anticonvulsant effect of VPA (15 mg/kg) in animals with PTZ-induced seizures. These findings indicate that maternal treatment with APZ in pregnant mice exposed to VPA protects animals against the ASD-like behavioral phenotype, and this effect may be related, at least in part, to synaptic plasticity and neuronal protection in the PFC and hippocampus. APZ may serve as an effective pharmacological therapeutic target against autistic behaviors in the VPA animal model of ASD, which should be further investigated to verify its clinical relevance.

Spinophilin expression in postmortem prefrontal cortex of schizophrenic subjects: Effects of antipsychotic treatment

Schizophrenia has been associated with alterations in neurotransmission and synaptic dysfunction. Spinophilin is a multifunctional scaffold protein that modulates excitatory synaptic transmission and dendritic spine morphology. Spinophilin can also directly interact with and regulate several receptors for neurotransmitters, such as dopamine D₂ receptors, which play a role in the pathophysiology of schizophrenia and are targets of antipsychotics. Several studies have thus suggested an implication of spinophilin in schizophrenia. In the present study spinophilin protein expression was determined by western blot in the postmortem dorsolateral prefrontal cortex of 24 subjects with schizophrenia (12 antipsychotic-free and 12 antipsychotic-treated subjects) and 24 matched controls. Experiments were performed in synaptosomal membranes (SPM) and in postsynaptic density fractions (PSD). As previously reported, two specific bands for this protein were observed: an upper 120-130 kDa band and a lower 80-95 kDa band. The spinophilin lower band showed a significant decrease in schizophrenia subjects compared to matched controls, both in SPM and PSD fractions (-15%, p = 0.007 and -15%, p = 0.039, respectively). When schizophrenia subjects were divided by the presence or absence of antipsychotics in blood at death, the lower band showed a significant decrease in antipsychotic-treated schizophrenia subjects (-24%, p = 0.003 for SPM and -26%, p = 0.014 for PSD), but not in antipsychotic-free subjects, compared to their matched controls. These results suggest that antipsychotics could produce alterations in spinophilin expression that do not seem to be related to schizophrenia per se. These changes may underlie some of the side effects of antipsychotics.

Antipsychotics activate mTORC1-dependent translation to enhance neuronal morphological complexity

Although antipsychotic drugs can reduce psychotic behavior within a few hours, full efficacy is not achieved for several weeks, implying that there may be rapid, short-term changes in neuronal function, which are consolidated into long-lasting changes. We showed that the antipsychotic drug haloperidol, a dopamine receptor type 2 (D₂R) antagonist, stimulated the kinase Akt to activate the mRNA translation pathway mediated by the mammalian target of rapamycin complex 1 (mTORC1). In primary striatal D₂R-positive neurons, haloperidol-mediated activation of mTORC1 resulted in increased phosphorylation of ribosomal protein S6 (S6) and eukaryotic translation initiation factor 4E-binding protein (4E-BP). Proteomic mass spectrometry revealed marked changes in the pattern of protein synthesis after acute exposure of cultured striatal neurons to haloperidol, including increased abundance of cytoskeletal proteins and proteins associated with translation machinery. These proteomic changes coincided with increased morphological complexity of neurons that was diminished by inhibition of downstream effectors of mTORC1, suggesting that mTORC1-dependent translation enhances neuronal complexity in response to haloperidol. In vivo, we observed rapid morphological changes with a concomitant increase in the abundance of cytoskeletal proteins in cortical neurons of haloperidol-injected mice. These results suggest a mechanism for both the acute and long-term actions of antipsychotics.

AKAPs integrate genetic findings for autism spectrum disorders

Autism spectrum disorders (ASDs) are highly heritable, and six genome-wide association studies (GWASs) of ASDs have been published to date. In this study, we have integrated the findings from these GWASs with other genetic data to identify enriched genetic networks that are associated with ASDs. We conducted bioinformatics and systematic literature analyses of 200 top-ranked ASD candidate genes from five published GWASs. The sixth GWAS was used for replication and validation of our findings. Further corroborating evidence was obtained through rare genetic variant studies, that is, exome sequencing and copy number variation (CNV) studies, and/or other genetic evidence, including candidate gene association, microRNA and gene expression, gene function and genetic animal studies. We found three signaling networks regulating steroidogenesis, neurite outgrowth and (glutamatergic) synaptic function to be enriched in the data. Most genes from the five GWASs were also implicated--independent of gene size--in ASDs by at least one other line of genomic evidence. Importantly, A-kinase anchor proteins (AKAPs) functionally integrate signaling cascades within and between these networks. The three identified protein networks provide an important contribution to increasing our understanding of the molecular basis of ASDs. In addition, our results point towards the AKAPs as promising targets for developing novel ASD treatments.

9-Methyl-β-carboline-induced cognitive enhancement is associated with elevated hippocampal dopamine levels and dendritic and synaptic proliferation

β-Carbolines (BCs) belong to the heterogenous family of carbolines, which have been found exogenously, that is, in various fruits, meats, tobacco smoke, alcohol and coffee, but also endogenously, that is, blood, brain and CSF. These exogenous and endogenous BCs and some of their metabolites can exert neurotoxic effects, however, an unexpected stimulatory effect of 9-methyl-β-carboline (9-me-BC) on dopaminergic neurons in primary mesencephalic cultures was recently discovered. The aim of the present study was to extend our knowledge on the stimulatory effects of 9-me-BC and to test the hypothesis that 9-me-BC may act as a cognitive enhancer. We found that 10 days (but not 5 days) of pharmacological treatment with 9-me-BC (i) improves spatial learning in the radial maze, (ii) elevates dopamine levels in the hippocampal formation, and (iii) results after 10 days of treatment in elongated, more complex dendritic trees and higher spine numbers on granule neurons in the dentate gyrus of 9-me-BC-treated rats. Our results demonstrate that beyond its neuroprotective/neurorestorative and anti-inflammatory effects, 9-me-BC acts as a cognitive enhancer in a hippocampus-dependent task, and that the behavioral effects may be associated with a stimulatory impact on hippocampal dopamine levels and dendritic and synaptic proliferation.

Effects of chronic clozapine administration on markers of arachidonic acid cascade and synaptic integrity in rat brain

BACKGROUND

The mode of action of clozapine, an atypical antipsychotic approved for treating schizophrenia (SZ) and used for bipolar disorder (BD) mania, remains unclear. We tested for overlap with the actions of the mood stabilizers, lithium, carbamazepine and valproate, which downregulate arachidonic acid (AA) cascade markers in rat brain and upregulate BDNF. AA cascade markers are upregulated in BD and SZ postmortem BD brain in association with neuroinflammation and synaptic loss, while BDNF is decreased.

METHODS

Rats were injected intraperitoneally with a therapeutically relevant dose of clozapine (10 mg/kg/day) or with saline for 30 days, and AA cascade and synaptic markers and BDNF were measured in the brain.

RESULTS

Compared with saline-injected rats, chronic clozapine increased brain activity, mRNA and protein levels of docosahexaenoic acid (DHA)-selective calcium-independent phospholipase A₂ type VIA (iPLA₂), mRNA and protein levels of BDNF and of the postsynaptic marker, drebrin, while decreasing cyclooxygenase (COX) activity and concentration of prostaglandin E₂ (PGE₂), a proinflammatory AA metabolite. Activity and expression of AA-selective calcium-dependent cytosolic cPLA₂ type IVA and of secretory sPLA₂ Type II were unchanged.

CONCLUSIONS

These results show overlap with effects of mood stabilizers with regard to downregulation of COX activity and PGE₂ and to increased BDNF and suggest a common action against the reported neuropathology of BD and SZ. The increased iPLA₂ expression following clozapine suggests increased production of anti-inflammatory DHA metabolites, and, with increased BDNF and drebrin, clear neuroprotective action.

Early exposure to haloperidol or olanzapine induces long-term alterations of dendritic form

Exposure of the developing brain to a wide variety of drugs of abuse (e.g., stimulants, opioids, ethanol, etc.) can induce life-long changes in behavior and neural circuitry. However, the long-term effects of exposure to therapeutic, psychotropic drugs have only recently begun to be appreciated. Antipsychotic drugs are little studied in this regard. Here, we quantitatively analyzed dendritic architecture in adult mice treated with paradigmatic typical- (haloperidol) or atypical (olanzapine) antipsychotic drugs at developmental stages corresponding to fetal or fetal plus early childhood stages in humans. In layer 3 pyramidal cells of the medial and orbital prefrontal cortices and the parietal cortex and in spiny neurons of the core of the nucleus accumbens, both drugs induced significant changes (predominantly reductions) in the amount and complexity of dendritic arbor and the density of dendritic spines. The drug-induced plasticity of dendritic architecture suggests changes in patterns of neuronal connectivity in multiple brain regions that are likely to be functionally significant.

Expression of kinase interacting with stathmin (KIS, UHMK1) in human brain and lymphoblasts: Effects of schizophrenia and genotype

Single nucleotide polymorphisms (SNPs) within the gene encoding the serine/threonine kinase KIS (Kinase Interacting with Stathmin, also known as UHMK1) have recently been associated with schizophrenia. As none of the disease associated SNPs are coding, they may confer susceptibility by altering some facet of KIS expression. Here we have characterised the cellular distribution of KIS in human brain using in situ hybridisation and immunohistochemistry, and quantified KIS protein and mRNA in two large brain series to determine if KIS expression is altered in schizophrenia or bipolar disorder or in relation to a schizophrenia-associated SNP (rs7513662). Post-mortem tissue from the superior temporal gyrus of schizophrenia and control subjects, and also dorsolateral prefrontal cortex, anterior cingulate cortex, and cerebellum from schizophrenia, bipolar disorder, and control subjects were used. KIS expression was measured by quantitative PCR (mRNA) and immunoautoradiography (protein), and was also quantified by immunoblot in lymphoblast cell lines derived from schizophrenia and control subjects. Our results demonstrate that KIS is expressed in neurons, and its encoded protein is localised to the nucleus and cytoplasm. No difference in KIS expression was found between diagnostic groups, or in the lymphoblast cell lines, and no effect of rs7513662 genotype on KIS expression was found. Hence, these data do not provide support for the hypothesis that altered expression is the mechanism by which genetic variation of KIS may increase susceptibility to schizophrenia, nor evidence that KIS expression is altered in the disease itself, at least in terms of the parameters studied here.

Gene expression in the anterior cingulate cortex and amygdala of adolescent marmoset monkeys following parental separations in infancy

Early life adversities are risk factors for later mood and emotional disorders. Repeated separation of infant marmosets from their parents provides a validated primate model of depression vulnerability, producing in-vivo biochemical and behavioural effects indicative of persistently altered stress reactivity and mild anhedonia. Here we report the long-term effect (in adolescence) of this intervention on the expression of synaptophysin, GAP-43, VGluT1, VGAT, MAP-2, spinophilin, and 5-HT1A and 5-HT2A receptors, in the anterior cingulate cortex (ACC; supragenual and subgenual areas) and amygdala (lateral, basal and central nuclei). These genes and regions are implicated in the response to stress or in mood disorder. The profile of 5-HT1A receptor binding in ACC was affected by early deprivation, notably in the subgenual region, with a decrease in deep laminae but an increase in superficial laminae. Following early deprivation, spinophilin mRNA was reduced in subgenual ACC. In the amygdala, no significant effects of the manipulation were seen, but expression of several transcripts was sexually dimorphic. There were correlations between expression of some transcripts and in-vivo measurements. The results show that early deprivation in a non-human primate has a selective long-term effect on expression of genes in the ACC, particularly the subgenual area. The results differ from those reported in the hippocampus of the same animals, indicating the presence of limbic region-specific long-term molecular responses to early life stress.

Reduced dendritic spine density in auditory cortex of subjects with schizophrenia

We have previously identified reductions in mean pyramidal cell somal volume in deep layer 3 of BA 41 and 42 and reduced axon terminal density in deep layer 3 of BA 41. In other brain regions demonstrating similar deficits, reduced dendritic spine density has also been identified, leading us to hypothesize that dendritic spine density would also be reduced in BA 41 and 42. Because dendritic spines and their excitatory inputs are regulated in tandem, we further hypothesized that spine density would be correlated with axon terminal density. We used stereologic methods to quantify a marker of dendritic spines, spinophilin-immunoreactive (SP-IR) puncta, in deep layer 3 of BA 41 and 42 of 15 subjects with schizophrenia, each matched to a normal comparison subject. The effect of long-term haloperidol exposure on SP-IR puncta density was evaluated in nonhuman primates. SP-IR puncta density was significantly lower by 27.2% in deep layer 3 of BA 41 in the schizophrenia subjects, and by 22.2% in deep layer 3 of BA 42. In both BA 41 and 42, SP-IR puncta density was correlated with a marker of axon terminal density, but not with pyramidal cell somal volume. SP-IR puncta density did not differ between haloperidol-exposed and control monkeys. Lower SP-IR puncta density in deep layer 3 of BA 41 and 42 of subjects with schizophrenia may reflect concurrent reductions in excitatory afferent input. This may contribute to impairments in auditory sensory processing that are present in subjects with schizophrenia.

Decreased mRNA expression of netrin-G1 and netrin-G2 in the temporal lobe in schizophrenia and bipolar disorder

The membrane-bound axon guidance molecules netrin-G1 (NTNG1) and netrin-G2 (NTNG2) play a role in synaptic formation and maintenance. Non-coding single nucleotide polymorphisms (SNPs) in both genes have been reported to be associated with schizophrenia. The main aim of this study was to determine if NTNG1 and NTNG2 mRNA expression is altered in schizophrenia or bipolar disorder, and/or influenced by disease-associated SNPs. NTNG1 and NTNG2 mRNAs were examined in the medial and inferior temporal lobe using in situ hybridization and RT-PCR in the Stanley Medical Research Institute array collection, and in rat hippocampus during development and after antipsychotic administration. NTNG1 mRNA isoforms were also examined during human brain development. For NTNG1, the G1c isoform was reduced in bipolar disorder and with a similar trend in schizophrenia; expression of four other NTNG1 isoforms was unchanged. In both schizophrenia and bipolar disorder, NTNG2 mRNA was reduced in CA3, with reductions also found in CA4 and perirhinal cortex in bipolar disorder. The SNPs did not affect NTNG1 or NTNG2 mRNA expression. Both NTNG1 and NTNG2 mRNAs were developmentally regulated, and were unaltered by haloperidol, but NTNG2 mRNA was modestly increased by clozapine. These data implicate NTNG1 and NTNG2 in the pathophysiology of schizophrenia and bipolar disorder, but do not support the hypothesis that altered mRNA expression is the mechanism by which genetic variation of NTNG1 or NTNG2 may confer disease susceptibility.

d-Amino acid oxidase and serine racemase in human brain: normal distribution and altered expression in schizophrenia

The N-methyl-D-aspartate receptor co-agonist d-serine is synthesized by serine racemase and degraded by D-amino acid oxidase. Both D-serine and its metabolizing enzymes are implicated in N-methyl-D-aspartate receptor hypofunction thought to occur in schizophrenia. We studied D-amino acid oxidase and serine racemase immunohistochemically in several brain regions and compared their immunoreactivity and their mRNA levels in the cerebellum and dorsolateral prefrontal cortex in schizophrenia. D-Amino acid oxidase immunoreactivity was abundant in glia, especially Bergmann glia, of the cerebellum, whereas in prefrontal cortex, hippocampus and substantia nigra, it was predominantly neuronal. Serine racemase was principally glial in all regions examined and demonstrated prominent white matter staining. In schizophrenia, D-amino acid oxidase mRNA was increased in the cerebellum, and as a trend for protein. Serine racemase was increased in schizophrenia in the dorsolateral prefrontal cortex but not in cerebellum, while serine racemase mRNA was unchanged in both regions. Administration of haloperidol to rats did not significantly affect serine racemase or D-amino acid oxidase levels. These findings establish the major cell types wherein serine racemase and D-amino acid oxidase are expressed in human brain and provide some support for aberrant D-serine metabolism in schizophrenia. However, they raise further questions as to the roles of D-amino acid oxidase and serine racemase in both physiological and pathophysiological processes in the brain.

Altered expression of synaptic protein mRNAs in STOP (MAP6) mutant mice

Stable tubule-only polypeptide (STOP) proteins are a family of microtubule associated proteins (MAPs) important in microtubule stabilization. Data indicating a role for microtubules in synaptic function has come from studies of the STOP null mouse, which exhibits synaptic deficits, in association with behavioural changes that are alleviated by antipsychotic treatment. These findings suggested that STOP mutant mice may be useful in studies of synaptic function, and could be especially relevant to schizophrenia, postulated to be a disorder of the synapse. Moreover, a genetic association between STOP and schizophrenia has been reported. This study aimed to further characterize synaptic alterations in STOP null and heterozygous mice. Using in situ hybridization histochemistry, the mRNA expression of three pre-synaptic (synaptophysin; growth associated protein-43 (GAP-43); vesicular glutamate transporter-1 (VGlut1)) and two post-synaptic (spinophilin; MAP2) proteins, was quantified in female STOP null (n = 7), heterozygous (n = 5) and wild type (n = 6) mice. For STOP null and heterozygous mice, synaptophysin, VGlut1, GAP-43 and spinophilin mRNAs were decreased in the hippocampus, whilst in addition in the null mice, synaptophysin, VGlut1 and spinophilin mRNAs were decreased in the cerebellum. Alterations in synaptic protein mRNA expression were also detected in the frontal and occipital cortex. MAP2 mRNA expression was unchanged in all brain regions. The profile of mRNA changes is broadly similar to that observed in schizophrenia. Together the data provide supporting evidence for a role for microtubules in synaptic function, and suggest that STOP, or other microtubule proteins, may contribute to the synaptic pathology of schizophrenia.

Dopamine receptor signaling molecules are altered in elderly schizophrenic cortex

Alterations of molecules that mediate dopaminergic signal transduction have been found in schizophrenia, supporting the hypothesis of altered dopaminergic neurotransmission in this illness. To further explore this hypothesis, the authors measured transcript expression of three proteins involved in dopamine (DA) signaling in postmortem dorsolateral prefrontal and anterior cingulate cortex of elderly schizophrenic subjects and a comparison group. The transcript encoding calcyon, a protein that potentiates crosstalk between D1 DA receptors and Gq/11-linked receptors, was increased in schizophrenic prefrontal and cingulate cortex by 25%. Transcript levels of spinophilin, a protein enriched in dendritic spines that modulates excitatory neurotransmission, were increased 22% in dorsolateral prefrontal cortex but were unchanged in anterior cingulate cortex in schizophrenia. Levels of DARPP-32 mRNA, a downstream effector of dopaminergic neurotransmission, were similar in both groups for both cortical groups. These alterations in spinophilin and calcyon mRNA levels in schizophrenic prefrontal and cingulate cortex provide further evidence of altered dopaminergic neurotransmission in this illness.

Clozapine and haloperidol differentially regulate dendritic spine formation and synaptogenesis in rat hippocampal neurons

Antipsychotic drugs are the primary therapeutic treatment for schizophrenia. In addition to their dopaminergic/serotonergic function, atypical antipsychotics differ from conventional antipsychotics in the way they affect glutamatergic receptor function. A cellular correlate of this may be the modulation of dendritic spines (DS). Here, we demonstrate that in rat dissociated hippocampal neurons 1.0 microM clozapine administration increased DS-enriched protein spinophilin by 70%, increased post-synaptic protein shank1a puncta density by 26% and increased overall primary dendrite DS density by 59%. Filopodia and mushroom DS were particularly affected by clozapine. Conversely, 0.1 microM haloperidol decreased spinophilin protein by 40%, caused a 25% decrease in shank1a puncta and reduced the numbers of filopodia. In contrast, neither haloperidol nor clozapine induced any change in the levels of the pre-synaptic protein synapsin. This indicates that clozapine and haloperidol differentially regulate DS and post-synaptic plasticity. These findings may provide a molecular and cellular correlate to the superior therapeutic profile of clozapine when compared with haloperidol.

Molecular mechanisms contributing to dendritic spine alterations in the prefrontal cortex of subjects with schizophrenia

Postmortem studies have revealed reduced densities of dendritic spines in the dorsal lateral prefrontal cortex (DLPFC) of subjects with schizophrenia. However, the molecular mechanisms that might contribute to these alterations are unknown. Recent studies of the intracellular signals that regulate spine dynamics have identified members of the RhoGTPase family (e.g., Cdc42, Rac1, RhoA) as critical regulators of spine structure. In addition, Duo and drebrin are spine-specific proteins that are critical for spine maintenance and spine formation, respectively. In order to determine whether the mRNA expression levels of Cdc42, Rac1, RhoA, Duo or drebrin are altered in schizophrenia, tissue sections containing DLPFC area 9 from 15 matched pairs of subjects with schizophrenia and control subjects were processed for in situ hybridization. Expression levels of these mRNAs were also correlated with DLPFC spine density in a subset of the same subjects. In order to assess the potential influence of antipsychotic medications on the expression of these mRNAs, similar studies were conducted in monkeys chronically exposed to haloperidol or olanzapine. The expression of each of these mRNAs was lower in the gray matter of the subjects with schizophrenia compared to the control subjects, although only the reductions in Cdc42 and Duo remained significant after corrections for multiple comparisons. In addition, spine density was strongly correlated with the expression levels of both Duo (r=0.73, P=0.007) and Cdc42 (r=0.71, P=0.009) mRNAs. In contrast, the expression levels of Cdc42 and Duo mRNAs were not altered in monkeys chronically exposed to antipsychotic medications. In conclusion, reduced expression of Cdc42 and Duo mRNAs may represent molecular mechanisms that contribute to the decreased density of dendritic spines in the DLPFC of subjects with schizophrenia.

Neonatal exposure to MK801 induces structural reorganization of the central nervous system

Schizophrenia, a progressive disorder displaying widespread pathological changes, is associated with the loss of glutamatergic function and selective loss of cytoskeletal proteins, such as MAP2, in regions severely affected by this disease. As schizophrenia is associated with perinatal brain trauma, we monitored changes in several functionally different proteins following injury-promoting MK801 blockade of N-methyl-D-aspartate receptors in neonatal rats. Within the somatosensory cortex, MK801 triggered robust, caspase-3-dependent apoptotic injury, reduced expression of cytoskeletal proteins MAP2 and tau, and increased synapse associated protein SNAP25. Thus, both neuronal injury and loss of structural elements important for successful cell-cell contact may reorganize brain circuitry, which at later ages could promote similar behavioral changes observed in schizophrenia.

Evidence for increased expression of the vesicular glutamate transporter, VGLUT1, by a course of antidepressant treatment

The therapeutic effect of a course of antidepressant treatment is believed to involve a cascade of neuroadaptive changes in gene expression leading to increased neural plasticity. Because glutamate is linked to mechanisms of neural plasticity, this transmitter may play a role in these changes. This study investigated the effect of antidepressant treatment on expression of the vesicular glutamate transporters, VGLUT1-3 in brain regions of the rat. Repeated treatment with fluoxetine, paroxetine or desipramine increased VGLUT1 mRNA abundance in frontal, orbital, cingulate and parietal cortices, and regions of the hippocampus. Immunoautoradiography analysis showed that repeated antidepressant drug treatment increased VGLUT1 protein expression. Repeated electroconvulsive shock (ECS) also increased VGLUT1 mRNA abundance in regions of the cortex and hippocampus compared to sham controls. The antidepressant drugs and ECS did not alter VGLUT1 mRNA abundance after acute administration, and no change was detected after repeated treatment with the antipsychotic agents, haloperidol and chlorpromazine. In contrast to VGLUT1, the different antidepressant treatments did not commonly increase the expression of VGLUT2 or VGLUT3 mRNA. These data suggest that a course of antidepressant drug or ECS treatment increases expression of VGLUT1, a key gene involved in the regulation of glutamate secretion.