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Progressive recruitment of cortical and striatal regions by inducible postsynaptic density transcripts after increasing doses of antipsychotics with different receptor profiles: insights for psychosis treatment.

Antipsychotics may modulate the transcription of multiple gene programs, including those belonging to postsynaptic density (PSD) network, within cortical and subcortical brain regions. Understanding which brain region is activated progressively by increasing doses of antipsychotics and how their different receptor profiles may impact such an activation could be relevant to better correlate the mechanism of action of antipsychotics both with their efficacy and side effects. We analyzed the differential topography of PSD transcripts by incremental doses of two antipsychotics: haloperidol, the prototypical first generation antipsychotic with prevalent dopamine D2 receptors antagonism, and asenapine, a second generation antipsychotic characterized by multiple receptors occupancy. We investigated the expression of PSD genes involved in synaptic plasticity and previously demonstrated to be modulated by antipsychotics: Homer1a, and its related interacting constitutive genes Homer1b/c and PSD95, as well as Arc, C-fos and Zif-268, also known to be induced by antipsychotics administration. We found that increasing acute doses of haloperidol induced immediate-early genes (IEGs) expression in different striatal areas, which were progressively recruited by incremental doses with a dorsal-to-ventral gradient of expression. Conversely, increasing acute asenapine doses progressively de-recruited IEGs expression in cortical areas and increased striatal genes signal intensity. These effects were mirrored by a progressive reduction in locomotor animal activity by haloperidol, and an opposite increase by asenapine. Thus, we demonstrated for the first time that antipsychotics may progressively recruit PSD-related IEGs expression in cortical and subcortical areas when administered at incremental doses and these effects may reflect a fine-tuned dose-dependent modulation of the PSD.

Intracellular pathways of antipsychotic combined therapies: Implication for psychiatric disorders treatment

Dysfunctions in the interplay among multiple neurotransmitter systems have been implicated in the wide range of behavioral, emotional and cognitive symptoms displayed by major psychiatric disorders, such as schizophrenia, bipolar disorder or major depression. The complex clinical presentation of these pathologies often needs the use of multiple pharmacological treatments, in particular (1) when monotherapy provides insufficient improvement of the core symptoms; (2) when there are concurrent additional symptoms requiring more than one class of medication and (3) in order to improve tolerability, by using two compounds below their individual dose thresholds to limit side effects. To date, the choice of drug combinations is based on empirical paradigm guided by clinical response. Nonetheless, several preclinical studies have demonstrated that drugs commonly used to treat psychiatric disorders may impact common intracellular target molecules (e.g. Akt/GSK-3 pathway, MAP kinases pathway, postsynaptic density proteins). These findings support the hypothesis that convergence at crucial steps of transductional pathways could be responsible for synergistic effects obtained in clinical practice by the co-administration of those apparently heterogeneous pharmacological compounds. Here we review the most recent evidence on the molecular crossroads in antipsychotic combined therapies with antidepressants, mood stabilizers, and benzodiazepines, as well as with antipsychotics. We first discuss clinical clues and efficacy of such combinations. Then we focus on the pharmacodynamics and on the intracellular pathways underpinning the synergistic, or concurrent, effects of each therapeutic add-on strategy, as well as we also critically appraise how pharmacological research may provide new insights on the putative molecular mechanisms underlying major psychiatric disorders.

The Glucocorticoid Analog Dexamethasone Alters the Expression and the Distribution of Dopamine Receptors and Enkephalin within Cortico- Subcortical Regions

In humans, glucocorticoid excess may cause neuropsychiatric symptoms, including psychosis and cognitive impairment, and glucocorticoid signaling hyperactivation may sensitize to substance of abuse. The aim of this work was to evaluate whether exposure to glucocorticoid excess triggers molecular changes in dopaminergic and opioidergic systems within relevant forebrain areas. We acutely exposed Sprague-Dawley rats to dexamethasone, a glucocorticoid analog, or vehicle and evaluated the mRNA expression of dopamine D1 and D2 receptors and enkephalin within the cortex, the striatum, and the midbrain. Dexamethasone reduced mRNA expression of D1 receptor and enkephalin in the cortex. In the striatum, dexamethasone reduced the expression of D1 receptor mRNA, but not that of D2 receptor and enkephalin. No significant changes in D2 receptor mRNA expression were observed in the midbrain. Basal distribution of D1 and D2 receptor mRNA showed a clear-cut striatal/cortical gradient, while this distribution was less obvious for enkephalin mRNA. Dexamethasone increased the cortico-striatal separation in terms of D1 and D2 receptor mRNA expression. These molecular changes may represent adaptive mechanisms to dexamethasone-induced potentiation of dopaminergic and opioidergic transmission, mostly in cortical areas.

Postsynaptic density protein transcripts are differentially modulated by minocycline alone or in add-on to haloperidol: Implications for treatment resistant schizophrenia.

In this study, we investigated whether minocycline, a second-generation tetracycline proposed as an add-on to antipsychotics in treatment-resistant schizophrenia (TRS), may affect the expression of Homer and Arc postsynaptic density (PSD) transcripts, implicated in synaptic regulation. Minocycline was administered alone or with haloperidol in rats exposed or not to ketamine, mimicking acute glutamatergic psychosis or naturalistic conditions, respectively. Arc expression was significantly reduced by minocycline compared with controls. Minocycline in combination with haloperidol also significantly reduced Arc expression compared with both controls and haloperidol alone. Moreover, haloperidol/minocycline combination significantly affected Arc expression in cortical regions, while haloperidol alone was ineffective on cortical gene expression. These results suggest that minocycline may strongly affect the expression of Arc as mediated by haloperidol, both in terms of quantitative levels and of topography of haloperidol-related expression. It is noteworthy that no significant pre-treatment effect was found, suggesting that pre-exposure to ketamine did not grossly affect gene expression. Minocycline was not found to significantly affect haloperidol-related Homer1a expression. No significant changes in Homer1b/c expression were observed. These results are consistent with previous observations that minocycline may modulate postsynaptic glutamatergic transmission, affecting distinct downstream pathways initiated by N-methyl-D-aspartate (NMDA) receptor modulation, i.e. Arc-mediated but not Homer1a-mediated pathways.

The expression of genes involved in glucose metabolism is affected by N-methyl-D-aspartate receptor antagonism: a putative link between metabolism and an animal model of psychosis.

Psychosis has been associated with glucose metabolism impairment. Here, we explored the gene expression of hexokinase 1 (Hk1) and glucose transporter 3 (GLUT3) after the administration of a subanesthetic or a subconvulsant dose of ketamine in rats, considered to provide an animal model of psychosis. Indeed, Hk1 and GLUT3 are crucially involved in the glucose utilization in brain tissues and have also been implicated in the pathophysiology of psychosis. Quantitative brain imaging of transcripts was used to evaluate Hk1 and GLUT3 mRNA in rat brain regions related to ketamine‐induced behavioral abnormalities. Hk1 transcript was significantly increased by 50 mg/kg ketamine in cortical and subcortical areas, whereas 12 mg/kg ketamine affected Hk1 expression in the auditory cortex only. GLUT3 expression was increased by 12 mg/kg ketamine in the frontal cortex and decreased by 50 mg/kg ketamine in subcortical areas. The results show that Hk1 and GLUT3 are extensively and differentially affected by ketamine dose, supporting the view that glucose metabolism and psychosis may be causally related and suggesting that these molecules may play a role in the pathophysiology of ketamine‐induced behavioral abnormalities.

Nicotine and caffeine modulate haloperidol-induced changes in postsynaptic density transcripts expression: Translational insights in psychosis therapy and treatment resistance

Caffeine and nicotine are widely used by schizophrenia patients and may worsen psychosis and affect antipsychotic therapies. However, they have also been accounted as augmentation strategies in treatment-resistant schizophrenia. Despite both substances are known to modulate dopamine and glutamate transmission, little is known about the molecular changes induced by these compounds in association to antipsychotics, mostly at the level of the postsynaptic density (PSD), a site of dopamine-glutamate interplay. Here we investigated whether caffeine and nicotine, alone or combined with haloperidol, elicited significant changes in the levels of both transcripts and proteins of the PSD members Homer1 and Arc, which have been implicated in synaptic plasticity, schizophrenia pathophysiology, and antipsychotics molecular action. Homer1a mRNA expression was significantly reduced by caffeine and nicotine, alone or combined with haloperidol, compared to haloperidol. Haloperidol induced significantly higher Arc mRNA levels than both caffeine and caffeine plus haloperidol in the striatum. Arc mRNA expression was significantly higher by nicotine plus haloperidol vs. haloperidol in the cortex, while in striatum gene expression by nicotine was significantly lower than that by both haloperidol and nicotine plus haloperidol. Both Homer1a and Arc protein levels were significantly increased by caffeine, nicotine, and nicotine plus haloperidol. Homer1b mRNA expression was significantly increased by nicotine and nicotine plus haloperidol, while protein levels were unaffected. Locomotor activity was not significantly affected by caffeine, while it was reduced by nicotine. These data indicate that both caffeine and nicotine trigger relevant molecular changes in PSD sites when given in association with haloperidol.

Chronobiology of Mood Disorders

The strong intimate relationship between mood disorders and life rhythms has been nowadays clearly recognized and analyzed, becoming one of the cornerstones for pathophysiological theorizations and therapeutic interventions in these diseases. Several body functions undergo biological rhythm, e.g., daily variations in hormone secretion or in body temperature or the sleep-wake cycle. Endogenous rhythms are primarily regulated by the circadian clock, a cluster of nerve cells that have their main localization in the hypothalamic suprachiasmatic nucleus. Endogenous rhythms may in turn be modulated by multiple exogenous clues, first of all the dark/light daily variations. Endogenous and exogenous rhythms intermingle in very complex associations, whose effects on human behavior, as well as their molecular determinants, are becoming to be elucidated. The term chronobiology refers both to the characterization of the biological underpinnings of life rhythms and to the clarification of their effects on several biological functions, including behavioral disease. The scope of this chapter is to provide an appraisal of the newest reports on the chronobiology of mood disorders. We will first describe the structural and functional anatomy, as well as the genetic, of the circadian clock, i.e., the suprachiasmatic nucleus. Then, we will review recent findings on the neurobiology and neuroimaging of the sleep-wake cycle. In the third part of the chapter, we will deal with the neurobiology of stress and its relationship with circadian rhythms. In the last section of the chapter, the biological effects of circadian rhythms and stress on affective states and mood disorders will be summarized and discussed.

P.1.009 Effects of caffeine, nicotine and their combination with haloperidol on PSD molecules: relevance to psychiatric diseases

cultures from hippocampus and cortex of E18 mouse (C57BL/6J) embryos. Dendritic branching was analyzed (at weeks 1 and 2 post-infection) using Simple Neurite Tracer and Sholl analysis plugins for ImageJ/Fiji. We counted spines per 15mm dendritic segment and classified according to their morphologies [4]. Sholl analysis revealed reduced dendritic branching (Table 1) by overexpression of NOS1AP-L and NOS1APLDC20, supporting the findings that the NOS1AP aminoterminal domain also influences neurite development [5]. On the other hand, overexpression of each NOS1AP isoform/domain resulted in highly altered spine plasticity (Table 1) including significant reduction in mature spines (particularly thin and mushroom spines) and increased filopodia growth. We believe that the alteration in spine plasticity is primarily dependent on NOS1AP/NOS-I interaction, considering NOS1APLC20 overexpression was sufficient to disrupt spine development. NOS-IN133 overexpression had mild effects on spine development.

EPA-1118 - Knowledge of the illness and its relations with quality of life, social functioning, cognitive performances, and adherence in psychotic patients: Toward effectiveness-focused interventions

Introduction Psychosocial factors are often underestimated in psychotic patients, although they may profoundly influence (and be influenced by) clinical presentation and effectiveness of therapeutic interventions in these people. Objectives To investigate relevance, relationship with clinical presentation and overall quality of life of multiple psychosocial factors in psychotic patients. Aims To evaluate whether knowledge about the illness and utilization of health services are defective in psychotic vs. non-psychotic patients and whether these correlates with the type of psychotic symptoms, cognitive performances, global social functioning, quality of life, and acceptance of pharmacotherapy. Methods Approximately 110 patients were enrolled after written informed consent. Patients were administered the Positive and Negative Syndrome Scale (PANSS), the Personal and Social Performance scale (PSP), the Drug Attitude Inventory (DAI), the Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q). All patients were also screened for cognitive performances. Patients and relatives completed a questionnaire on knowledge about the illness and on the level of utilization of mental health services. Patients were subdivided in psychotic (cases) and non-psychotic (controls) based on their score on the PANSS. Results Psychotic patients and their relatives showed lower levels of knowledge about the illness. These features were associated with the other variables assessed in a very complex and multidimensional model of reciprocal influences. Conclusions Lack of response to pharmacological treatments and to overall therapeutic interventions in psychotic patients may also depend on multiple psychosocial factors, which may be carefully investigated and become the target of adjunctive, effectiveness-focused interventions.

P.1.031 Expression of glucose metabolism genes in a psychosis model: a molecular link between NMDA receptor hypofunction and metabolism disorders?

of bisulfite-treated DNA (EpigenDx, Worcester MA). Altogether, we examined the methylation level across 39 CpG sites in the GR exon 1F promoter region for each subject. Two genes were genotyped; the 5HTTLPR and the ESR1. All statistical tests were carried out using SPSS version 15. A linear regression model was used to ascertain the effects of sex, GR methylation level and genes on stress response. Statistical normality of the data was checked using the Kolmogorov-Smirnov test. Results: Marked individual differences were observed in methylation levels of GR exon 1F at individual CpG sites for females and males. Overall, women showed significantly greater methylation levels than did men (t = 2.538, p = 0.013). There was a correlation between total cortisol output (area under the curve, AUC) and average methylation level at GR exon 1F in female subjects (R2D= 0.214, F(1,44) = 11.997, p = 0.001) accounting for 21.4% of the variance. Additionally, variations in the ESR1 and the 5-HTTLPR genes were significant predictors of AUC. A significant main effect of 5-HTTLPR (R2D= 0.172, F1,42 = 12.032, p = 0.001) and ESR1 (R2D= 0.132, F2,40 = 5.634, p = 0.007) was observed on AUC but there was no interaction between methylation and either gene. The full model accounted for nearly half of the variance (48%) in total cortisol output. Conclusions: We provide the first evidence that accumulated epigenetic changes at the peripheral GR exon 1F correlate with HPAA reactivity. Importantly, women show significantly greater methylation across the GR promoter exon 1F compared to men. The averaged methylation levels and each of the two polymorphisms are highly significant independent predictors of total cortisol response (AUC) in the TSST. These findings have important implications for understanding the molecular mechanisms underlying gender differences in stressrelated mental health disorders, and underscore the unique value of modeling both epigenetic and genetic information in conferring vulnerability to stress.