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Depression is a chronic disease with a complex multifactorial and still not fully clarified etiology. Due to new insights after recent investigations of the microbiota-gut-brain (MGB) axis, a relationship between a disrupted gut microbiota composition and the probability to develop a depression can be assumed. This hypothesis is supported by evidence that there is a strong communication between gut microbiota and the central nervous system (CNS) and that this communication is mediated through the MGB axis. Apparently, this bidirectional axis can be modulated by environmental factors, such as stress, pharmaceuticals (in particular antibiotics) and dietary habits. Moreover, modulation of this axis can also result in mood alterations. As the hypothalamic-pituitary-adrenal (HPA) axis is a key element regulating the MGB axis and is also related to the pathophysiology of depression, it is important to understand the relationship between both biological systems. An English language literature search was conducted using the biomedical database PubMed. We used combined terms, such as "gut microbiota", "depression", "hypothalamic-pituitary-adrenal axis" or "microbiota-gut-brain axis". The current literature supports the idea that the MGB axis has an impact on the risk to develop depression and that stress modulation through the HPA axis plays a key role in this context. [ABSTRACT FROM AUTHOR]

Background Cosmetic changes are to be expected after radiotherapy for skin tumours. Objectives This study aimed to answer the questions: How frequent are cosmetic changes after soft X-ray therapy? Do treatment parameters, tumour thickness, localization and size of the irradiated field have a major influence? Were patients irritated by the visual appearance of the irradiated field? Methods In total, 2474 examinations of 1149 irradiated fields were performed. Results Hypopigmentation was found in 64.7% of examinations more than 90 days after therapy, teleangiectases in 43.1%, erythema in 24.8%, and hyperpigmentation in 16.8%. The frequency of hypopigmentation, teleangiectases and hyperpigmentation increased with time from X-ray exposure; more than 4 years after therapy hypopigmentation was diagnosed in 91.8% and teleangiectases in 82.2% of examinations. Total dose, the time–dose–fractionation factor (TDF), field size and dose per fraction were significantly related to the frequency of cosmetic changes. Incidence rates of cosmetic changes differed by less than 15% if different treatment conditions were compared: thicker vs. thinner tumours, larger vs. smaller fields, higher vs. lower total doses, doses per fraction, and TDF. Frequencies of hypopigmentation, teleangiectases, erythema and hyperpigmentation differed by more than 15% between some localizations on the head. Women reported irritation by the visual appearance of the irradiated field in 12.6% of 1116 interviews, and men in 4.4% of 1284 interviews. Conclusions Cosmetic changes after soft X-ray therapy are relatively frequent. Treatment parameters, tumour thickness and field size have only a minor influence. Few patients, but more women than men, were irritated by the visual appearance of the irradiated field. [ABSTRACT FROM AUTHOR]

Aminobutyric acid (GABA) is the most important inhibitory neurotransmitter in the central nervous system (CNS). It exerts its rapid inhibitory action mostly through GABA A receptors, which are targets for benzodiazepines, barbiturates, neuroactive steroids and distinct anticonvulsive agents. There is considerable evidence that dysfunction of GABA A receptors or dysregulation of GABA concentrations in the CNS (or both) plays an important role in the pathophysiology of panic disorder. Currently, benzodiazepines are the only drugs directly targeting the GABA A receptors that are approved for the treatment of anxiety disorders. Because of their well-known anxiolytic effects, they are widely used in this setting, but side effects limit their use in long-term treatment. The question of whether drugs that selectively increase GABA concentrations in the CNS could improve symptoms of anxiety has been discussed. Recent investigations by our group have demonstrated that enhancement of endogenous GABA (through blockade of GABA transaminase by vigabatrin or through inhibition of GABA transporters by tiagabine) exerts anxiolytic effects on experimentally induced panic. Our studies in healthy volunteers have shown that both compounds lead to a significant reduction in panic symptoms elicited by cholecystokinin-tetrapeptide. Moreover, benzodiazepine-like effects on the activity of the hypothalamic-pituitary-adrenal axis have been observed in association with vigabatrin treatment. Small open studies in patients with panic disorder also showed an improvement in panic and anxiety with both compounds. This review summarizes our recent research on the effects of selective GABAergic treatment in experimentally induced panic and outlines the possible role of compounds targeting the GABA binding site of the GABA A-benzodiazepine receptor for the treatment of panic and anxiety. [ABSTRACT FROM AUTHOR]

Steroids influence neuronal function through binding to cognate intracellular receptors which may act as transcription factors in the regulation of gene expression. In addition, certain so-called neuroactive steroids modulate ligand-gated ion channels via non-genomic mechanisms. Especially distinct 3α-reduced metabolites of progesterone and deoxycorticosterone are potent positive allosteric modulators of γ-aminobutyric acid type A (GABAA) receptors. However, also classical steroid hormones such as 17β-estradiol, testosterone and progesterone are neuroactive steroids because they may act as functional antagonists at the 5-hydroxytryptamine type 3 (5-HT3) receptor, a ligand-gated ion channel or distinct glutamate receptors. A structure–activity relationship for the actions of a variety of steroids at the 5-HT3 receptor was elaborated that differed considerably from that known for GABAA receptors. Although a bindings site for steroids at GABAA receptors is still a matter of debate, meanwhile there is also evidence that steroids interact allosterically with ligand-gated ion channels at the receptor membrane interface. On the other hand, also 3α-reduced neuroactive steroids may regulate gene expression via the progesterone receptor after intracellular oxidation into 5α-pregnane steroids. Animal studies showed that progesterone is converted rapidly into GABAergic neuroactive steroids in vivo. Progesterone reduces locomotor activity in a dose-dependent fashion in male Wistar rats. Moreover, progesterone and 3α-reduced neuroactive steroids produce a benzodiazepine-like sleep EEG profile in rats and humans. During major depression, there is a disequilibrium of such 3α-reduced neuroactive steroids which is corrected by successful treatment with antidepressant drugs. Neuroactive steroids may further be involved in the treatment of depression and anxiety with antidepressants in patients during ethanol withdrawal. Studies in patients with panic disorder suggest that neuroactive steroids may also play a role in modulating human anxiety. Both the genomic and non-genomic effects of steroids in the brain may contribute to the pathophysiology of psychiatric disorders and the mechanisms of action of antidepressants. Neuroactive steroids affect a broad spectrum of behavioral functions through their unique molecular properties and may represent a new treatment strategy for neuropsychiatric disorders. [Copyright &y& Elsevier]

Purpose: According to the World Health Organization classification for tumors of the central nervous system, mutation status of the isocitrate dehydrogenase (IDH) genes has become a major diagnostic discriminator for gliomas. Therefore, imaging-based prediction of IDH mutation status is of high interest for individual patient management. We compared and evaluated the diagnostic value of radiomics derived from dual positron emission tomography (PET) and magnetic resonance imaging (MRI) data to predict the IDH mutation status non-invasively. Methods: Eighty-seven glioma patients at initial diagnosis who underwent PET targeting the translocator protein (TSPO) using [18F]GE-180, dynamic amino acid PET using [18F]FET, and T1-/T2-weighted MRI scans were examined. In addition to calculating tumor-to-background ratio (TBR) images for all modalities, parametric images quantifying dynamic [18F]FET PET information were generated. Radiomic features were extracted from TBR and parametric images. The area under the receiver operating characteristic curve (AUC) was employed to assess the performance of logistic regression (LR) classifiers. To report robust estimates, nested cross-validation with five folds and 50 repeats was applied. Results: TBRGE-180 features extracted from TSPO-positive volumes had the highest predictive power among TBR images (AUC 0.88, with age as co-factor 0.94). Dynamic [18F]FET PET reached a similarly high performance (0.94, with age 0.96). The highest LR coefficients in multimodal analyses included TBRGE-180 features, parameters from kinetic and early static [18F]FET PET images, age, and the features from TBRT2 images such as the kurtosis (0.97). Conclusion: The findings suggest that incorporating TBRGE-180 features along with kinetic information from dynamic [18F]FET PET, kurtosis from TBRT2, and age can yield very high predictability of IDH mutation status, thus potentially improving early patient management. [ABSTRACT FROM AUTHOR]

Aging is typically accompanied by increasing inflammation. It is assumed, based mainly on data of older adults younger than ninety years, that higher increases in inflammation are related with faster declines in functional health and psychosocial well-being. We set out here to extend these results to high-functioning Nonagerians, to better understand factors contributing to longevity. N = 125 participants between 90 and 100 years (mean = 91.85; 53.2% female) who were sufficiently mobile for a lab visit were enrolled. N = 105 provided blood samples for measurement of interleukin (IL)-6 and IL-10, and were interviewed to gather data on psychosocial well-being and functional health. Interleukin-6 ranged from 0.66 to 4.79 pg/ml (mean = 2.29), IL-10 ranged from 0.09 to 5.40 pg/ml (mean = 1.09). IL-6, but not IL-10 was correlated with age (r = 0.37; p < 0.001). IL-6, as well as IL-6/IL-10 ratio, were inversely related with depression (beta=-.26; p = 0.016; beta = −.24; p = 0.038). Quality of close relationships, self-efficacy, and valuing longevity were positively related with IL-6, and IL-6/IL-10 ratio (all beta's > 0.21; all p's < 0.05). In contrast to our hypotheses, we found positive relationships of inflammation with psychosocial well-being and functional health, and inverse relationships with depressive symptoms. It appears that in this group, associations of inflammation with psychosocial and functional health are reversed. This might be interpreted as inflammation serving protective functions in highly mobile very old adults. [ABSTRACT FROM AUTHOR]

Examines a patient with angiodema associated with transient ischemic attack due to an angiotensin II receptor antagonist losartan. Use of cerebral magnetic resonance imaging; Measurement of the increased plasma bradykinin concentrations; Pathogenetic mechanism of angiodema.

The classical mechanisms of action of antidepressants suggest that they act through inhibition of monoamine transporters. There is evidence that antipressants indirectly modulate GABA-A receptors through neurosteroids. We showed that antidepressants may also directly modulate the function of the serotonin type 3 (5-HT3) receptor in an allosteric fashion. This non-competitive inhibition of receptor function occurred with different classes of antidepressants including tricyclic antidepressants, SSRIs and NARIs. Moreover, these antidepressants were differentially accumulated in lipid rafts. Their concentartions in lipid rafts were related to their ability to allosterically modulate this ligand gated ion channel. However, lipid raft integrity was not a prerequisite for the allosteric modulation of this ion channel by antidepressants. Morover, differential results were observed with regard to NMDA and GABA-A receptors. Our data show that the allosteric modulation of ligand gated ion channels is an underestimated pharmacologcical principle which challenges the concept of target specificty of antidepressants for monoamine transporters. [Copyright &y& Elsevier]

Presents a letter to the editor in response to the article "GABA-ergic Drugs: Exit Stage Left, Enter Stage Right," by H. Ashton and A. H. Young in a 2003 issue of "Journal of Psychopharmacology."

Microbiological ecology and its ambition to describe the complete genome of complex living communities as a whole, have given us powerful tools to characterize the human gut microbiome on a genetic and, hence, taxonomic and abundance level; for a decade now, they have become sufficiently inexpensive, fast and feasible. Thus, opportunities arose to have a fresh and closer look at the microbiota-gut-brain-axis and its impact on human health; this axis comprises a complex multisystemic network of multidirectional interactions between brain and gut including influences beyond one generation. Gnotobiotic animal models have become essential for specific research targets. Combining gut microbiome analysis with observations on the hypothalamus-pituitary-adrenal axis and various aspects of inflammation helped to gain first insights into the role of the microbiota-gut-brain-axis in depressive disorders. Therapeutic endeavors with psychobiotics have not yet shown their value in clinical studies. [ABSTRACT FROM AUTHOR]

According to epidemiological studies anxiety disorders are among the most frequent psychiatric disorders. Depending on the diagnosis and severity, both cognitive behaviour therapy and pharmacological approaches are applied. In today's drug therapy antidepressants are the standard first-line treatment for most anxiety disorders, and enzodiazepines for the treatment of acute anxiety states. However, many patients do not respond to the first drug prescribed, prove to have conditions that are resistant to therapy or complain of side effects. There is therefore still a need for new medicamentous treatment strategies. There are numerous studies suggesting that anticonvulsants also have potentially anxiolytic properties and might therefore be an alternative treatment option in anxiety syndromes. This article gives an overview of investigations to date on the effects of various anticonvulsants in panic disorder, generalized anxiety disorder and social phobia. [ABSTRACT FROM AUTHOR]

There is now considerable neurobiological evidence on the pathogenesis and pathophysiology of depression. Nevertheless the underlying pathophysiology is far from fully elucidated. Norepinephrine and serotonin deficit hypotheses have been known for quite a long time. Other theories also claim a dysfunction of the dopaminergic and GABA-ergic system in depression, an altered expression of neuropeptides (e.g. of substance P), and neuroimmunologic and neuroendocrinologic mechanisms such as an overdrive of the hypothalamic-pituitary adrenal system. The neurotrophin hypothesis suggests that decreased production of neurotrophic factors and impaired neurogenesis are crucial for the pathophysiology of depression. These upcoming pathophysiological concepts have also initiated novel treatment approaches whose clinical utility still has to be demonstrated. [ABSTRACT FROM AUTHOR]

Introduction: The effect of concomitant medication on repetitive transcranial magnetic stimulation (rTMS) outcomes in depression remains understudied. Recent analyses show attenuation of rTMS effects by antipsychotic medication and benzodiazepines, but data on the effects of antiepileptic drugs and lithium used as mood stabilizers or augmenting agents are sparse despite clinical relevance. Preclinical electrophysiological studies suggest relevant impact of the medication on treatment, but this might not translate into clinical practice. We aimed to investigate the role of lithium (Li), lamotrigine (LTG) and valproic acid (VPA) by analyzing rTMS treatment outcomes in depressed patients. Methods: 299 patients with uni- and bipolar depression treated with rTMS were selected for analysis in respect to intake of lithium, lamotrigine and valproic acid. The majority (n = 251) were treated with high-frequency (10–20 Hz) rTMS of the lDLPFC for an average of 17 treatment sessions with a figure-of-8 coil with a MagVenture system aiming for 110% resting motor threshold, and smaller groups of patients were being treated with other protocols including intermittent theta-burst stimulation and bilateral prefrontal and medial prefrontal protocols. For group comparisons, we used analysis of variance with the between-subjects factor group or Chi-Square Test of Independence depending on the scales of measurement. For post-hoc tests, we used least significant difference (LSD). For differences in treatment effects between groups, we used an ANOVA with the between-subjects factor group (groups: no mood stabilizer, Li, LTG, VPA, Li + LTG) the within-subjects factor treatment (pre vs. post treatment with rTMS) and also Chi-Square Tests of independence for response and remission. Results: Overall, patients showed an amelioration of symptoms with no significant differences for the main effect of group and for the interaction effect treatment by group. Based on direct comparisons between the single groups taking mood stabilizers against the group taking no mood stabilizers, we see a superior effect of lamotrigine, valproic acid and combination of lithium and lamotrigine for the response and remission rates. Motor threshold was significantly and markedly higher for patients taking valproic acid. Conclusion: Being treated with lithium, lamotrigine and valproic acid had no relevant influence on rTMS treatment outcome. The results suggest there is no reason for clinicians to withhold or withdraw these types of medication from patients who are about to undergo a course of rTMS. Prospective controlled work on the subject is encouraged. [ABSTRACT FROM AUTHOR]

B Background: b In the search for novel anxiolytic treatment with a favourable profile of side effects, the translocator protein 18kDa (TSPO; former peripheral benzodiazepine receptor), yields a promising target [1]. To gain further insights into the role of this receptor in stress, the present study compared the effects of a benzodiazepine and a TSPO ligand on TSPO expression in an unstimulated state as well as in response to a psychosocial stress task. Bonferroni-corrected follow-up tests showed a difference between etifoxine and placebo (p=0.037) but not between alprazolam and placebo (p = 1.0) or alprazolam and etifoxine (p=0.314). [Extracted from the article]

Background: The 18-kDa translocator protein (TSPO) is overexpressed in brain tumours and represents an interesting target for glioma imaging. 18F-GE-180, a novel TSPO ligand, has shown improved binding affinity and a high target-to-background contrast in patients with glioblastoma. However, the association of uptake characteristics on TSPO PET using 18F-GE-180 with the histological WHO grade and molecular genetic features so far remains unknown and was evaluated in the current study. Methods: Fifty-eight patients with histologically validated glioma at initial diagnosis or recurrence were included. All patients underwent 18F-GE-180 PET, and the maximal and mean tumour-to-background ratios (TBRmax, TBRmean) as well as the PET volume were assessed. On MRI, presence/absence of contrast enhancement was evaluated. Imaging characteristics were correlated with neuropathological parameters (i.e. WHO grade, isocitrate dehydrogenase (IDH) mutation, O-6-methylguanine-DNA methyltransferase (MGMT) promoter methylation and telomerase reverse transcriptase (TERT) promoter mutation). Results: Six of 58 patients presented with WHO grade II, 16/58 grade III and 36/58 grade IV gliomas. An (IDH) mutation was found in 19/58 cases, and 39/58 were classified as IDH-wild type. High 18F-GE-180-uptake was observed in all but 4 cases (being WHO grade II glioma, IDH-mutant). A high association of 18F-GE-180-uptake and WHO grades was seen: WHO grade IV gliomas showed the highest uptake intensity compared with grades III and II gliomas (median TBRmax 5.15 (2.59–8.95) vs. 3.63 (1.85–7.64) vs. 1.63 (1.50–3.43), p < 0.001); this association with WHO grades persisted within the IDH-wild-type and IDH-mutant subgroup analyses (p < 0.05). Uptake intensity was also associated with the IDH mutational status with a trend towards higher 18F-GE-180-uptake in IDH-wild-type gliomas in the overall group (median TBRmax 4.67 (1.56–8.95) vs. 3.60 (1.50–7.64), p = 0.083); however, within each WHO grade, no differences were found (e.g. median TBRmax in WHO grade III glioma 4.05 (1.85–5.39) vs. 3.36 (2.32–7.64), p = 1.000). No association was found between uptake intensity and MGMT or TERT (p > 0.05 each). Conclusion: Uptake characteristics on 18F-GE-180 PET are highly associated with the histological WHO grades, with the highest 18F-GE-180 uptake in WHO grade IV glioblastomas and a PET-positive rate of 100% among the investigated high-grade gliomas. Conversely, all TSPO-negative cases were WHO grade II gliomas. The observed association of 18F-GE-180 uptake and the IDH mutational status seems to be related to the high inter-correlation of the IDH mutational status and the WHO grades. [ABSTRACT FROM AUTHOR]

Background: PET represents a valuable tool for glioma imaging. In addition to amino acid tracers such as 18F-FET, PET targeting the 18-kDa mitochondrial translocator-protein (TSPO) is of high interest for high-grade glioma (HGG) imaging due to its upregulation in HGG cells. 18F-GE-180, a novel TSPO ligand, has shown a high target-to-background contrast in HGG. Therefore, we intra-individually compared its uptake characteristics to dynamic 18F-FET PET and contrast-enhanced MRI in patients with HGG.Methods: Twenty HGG patients (nine IDH-wildtype, 11 IDH-mutant) at initial diagnosis (n = 8) or recurrence (n = 12) were consecutively included and underwent 18F-GE-180 PET, dynamic 18F-FET PET, and MRI. The maximal tumour-to-background ratios (TBRmax) and biological tumour volumes (BTV) were evaluated in 18F-GE-180 and 18F-FET PET. Dynamic 18F-FET PET analysis included the evaluation of minimal time-to-peak (TTPmin). In MRI, the volume of contrast-enhancement was delineated (VOLCE). Volumes were spatially correlated using the Sørensen-Dice coefficient.Results: The median TBRmax tended to be higher in 18F-GE-180 PET compared to 18F-FET PET [4.58 (2.33-8.95) vs 3.89 (1.56-7.15); p = 0.062] in the overall group. In subgroup analyses, IDH-wildtype gliomas showed a significantly higher median TBRmax in 18F-GE-180 PET compared to 18F-FET PET [5.45 (2.56-8.95) vs 4.06 (1.56-4.48); p = 0.008]; by contrast, no significant difference was observed in IDH-mutant gliomas [3.97 (2.33-6.81) vs 3.79 (2.01-7.15) p = 1.000]. Only 5/20 cases showed higher TBRmax in 18F-FET PET compared to 18F-GE-180 PET, all of them being IDH-mutant gliomas. No parameter in 18F-GE-180 PET correlated with TTPmin (p > 0.05 each). There was a tendency towards higher median BTVGE-180 [32.1 (0.4-236.0) ml] compared to BTVFET [19.3 (0.7-150.2) ml; p = 0.062] with a moderate spatial overlap [median Sørensen-Dice coefficient 0.55 (0.07-0.85)]. In MRI, median VOLCE [9.7 (0.1-72.5) ml] was significantly smaller than both BTVFET and BTVGE180 (p < 0.001 each), leading to a poor spatial correlation with BTVGE-180 [0.29 (0.01-0.48)] and BTVFET [0.38 (0.01-0.68)].Conclusion: PET with 18F-GE-180 and 18F-FET provides differing imaging information in HGG dependent on the IDH-mutational status, with diverging spatial overlap and vast exceedance of contrast-enhancement in MRI. Combined PET imaging might reveal new insights regarding non-invasive characterization of tumour heterogeneity and might influence patients' management. [ABSTRACT FROM AUTHOR]

Purpose: Expression of the translocator protein (TSPO) is upregulated in activated macrophages/microglia and is considered to be a marker of neuroinflammation. We investigated the novel TSPO ligand [18F]GE-180 in patients with relapsing-remitting multiple sclerosis (RRMS) to determine the feasibility of [18F]GE-180 PET imaging in RRMS patients and to assess its ability to detect active inflammatory lesions in comparison with the current gold standard, contrast-enhanced magnetic resonance imaging (MRI).Methods: Nineteen RRMS patients were prospectively included in this study. All patients underwent TSPO genotyping and were classified as high-affinity, medium-affinity or low-affinity binders (HAB/MAB/LAB). PET scans were performed after administration of 189 ± 12 MBq [18F]GE-180, and 60-90 min summation images were used for visual analysis and assessment of standardized uptake values (SUV). The frontal nonaffected cortex served as a pseudoreference region (PRR) for evaluation of SUV ratios (SUVR). PET data were correlated with MRI signal abnormalities, i.e. T2 hyperintensity or contrast enhancement (CE). When available, previous MRI data were used to follow the temporal evolution of individual lesions.Results: Focal lesions were identified as hot spots by visual inspection. Such lesions were detected in 17 of the 19 patients and overall 89 [18F]GE-180-positive lesions were found. TSPO genotyping revealed 11 patients with HAB status, 5 with MAB status and 3 with LAB status. There were no associations between underlying binding status (HAB, MAB and LAB) and the signal intensity in either lesions (SUVR 1.87 ± 0.43, 1.95 ± 0.48 and 1.86 ± 0.80, respectively; p = 0.280) or the PRR (SUV 0.36 ± 0.03, 0.40 ± 0.06 and 0.37 ± 0.03, respectively; p = 0.990). Of the 89 [18F]GE-180-positive lesions, 70 showed CE on MRI, while the remainder presented as T2 lesions without CE. SUVR were significantly higher in lesions with CE than in those without (2.00 ± 0.53 vs. 1.60 ± 0.15; p = 0.001). Notably, of 19 [18F]GE-180-positive lesions without CE, 8 previously showed CE, indicating that [18F]GE-180 imaging may be able to detect lesional activity that is sustained beyond the blood-brain barrier breakdown.Conclusion: [18F]GE-180 PET can detect areas of focal macrophage/microglia activation in patients with RRMS in lesions with and without CE on MRI. Therefore, [18F]GE-180 PET imaging is a sensitive and quantitative approach to the detection of active MS lesions. It may provide information beyond contrast-enhanced MRI and is readily applicable to all patients. [18F]GE-180 PET imaging is therefore a promising new tool for the assessment of focal inflammatory activity in MS. [ABSTRACT FROM AUTHOR]

Context The loss of progesterone during menopause is linked to sleep complaints of the affected women. Previously we demonstrated sleep promoting effects of oral progesterone replacement in postmenopausal women. The oral administration of progesterone, however, is compromised by individual differences in bioavailability and metabolism of the steroid. Objective We compared the sleep-endocrine effects after intranasal progesterone (MPP22), zolpidem and placebo in healthy postmenopausal women. Design This was a randomized double-blind cross-over study. Setting German monocentric study Participants Participants were 12 healthy postmenopausal women. Interventions Subjects received in randomized order four treatments, 2 doses of intranasal progesterone (4.5 mg and 9 mg of MPP22), 10 mg of zolpidem and placebo. Outcome measures Main outcome were conventional and quantitative sleep-EEG variables. Secondary outcomes were the subjective sleep variables and the sleep related concentrations of cortisol, growth hormone (GH), melatonin and progesterone. Results Sleep promoting effects were found after the higher dosage of MPP22 and after zolpidem. Zolpidem prompted benzodiazepine-like effects on quantitative sleep EEG as expected, whereas no such changes were found after the two dosages of MP22. Nocturnal progesterone levels increased after 9.0 mg MPP22. No other changes of hormone secretion were found. Conclusions Our study shows sleep promoting effects after intranasal progesterone. The spectral signature of intranasal progesterone did not resemble the sleep-EEG alterations induced by GABA active compounds. Progesterone levels were elevated after 9.0 mg MPP22. No other endocrine effects were observed. [ABSTRACT FROM AUTHOR]

Objective: The 18-kDa mitochondrial translocator protein (TSPO) was reported to be upregulated in gliomas. F-GE-180 is a novel 3rd generation TSPO receptor ligand with improved target-to-background contrast compared to previous tracers. In this pilot study, we compared PET imaging with F-GE-180 and MRI of patients with untreated and recurrent pretreated glioblastoma. Methods: Eleven patients with histologically confirmed IDH wildtype gliomas (10 glioblastomas, 1 anaplastic astrocytoma) underwent F-GE-180 PET at initial diagnosis or recurrence. The PET parameters mean background uptake (SUV), maximal tumour-to-background ratio (TBR) and PET volume using different thresholds (SUV × 1.6, 1.8 and 2.0) were evaluated in the 60-80 min p.i. summation images. The different PET volumes were compared to the contrast-enhancing tumour volume on MRI. Results: All gliomas were positive on F-GE-180 PET and were depicted with extraordinarily high tumour-to-background contrast (median SUV 0.47 (0.37-0.93), TBR 6.61 (3.88-9.07)). F-GE-180 uptake could be found even in areas without contrast enhancement on MRI, leading to significantly larger PET volumes than MRI-based volumes (median 90.5, 74.5, and 63.8 mL vs. 31.0 mL; p = 0.003, 0.004, 0.013). In percentage difference, the PET volumes were on average 179%, 135%, and 90% larger than the respective MRI volumes. The median spatial volumetric correlation (Sørensen-Dice coefficient) of PET volumes and MRI volumes prior to radiotherapy was 0.48, 0.54, and 0.58. Conclusion: F-GE-180 PET provides a remarkably high tumour-to-background contrast in untreated and pretreated glioblastoma and shows tracer uptake even beyond contrast enhancement on MRI. To what extent F-GE-180 uptake reflects the tumour extent of human gliomas and inflammatory cells remains to be evaluated in future prospective studies with guided stereotactic biopsies and correlation of histopathological results. [ABSTRACT FROM AUTHOR]

Introduction Psychopathy is characterized by superficial charm, untruthfulness, lack of remorse, antisocial behavior, egocentricity as well as poverty in major affective reactions. This clinical profile has been empirically conceptualized and validated. Recent brain imaging studies suggest abnormal brain activity underlying psychopathic behavior. However, no reliable pattern of altered neural activity has been disclosed so far. Objective To identify consistent changes of brain activity in psychopaths and to investigate whether these could explain known psychopathology. Methods First, we used activation likelihood estimation to meta-analyze brain activation changes in psychopaths across 28 functional magnetic resonance imaging studies reporting 753 foci from 155 analyses ( P < 0.05, corrected). Second, we functionally characterized the ensuing regions employing meta-data of a large-scale neuroimaging database ( P < 0.05, corrected). Results Psychopathy was consistently associated with decreased brain activity in the right amygdala, the dorsomedial prefrontal cortex (DMPFC), and bilaterally in the lateral prefrontal cortex (LPFC). Consistently increased activity was observed bilaterally in the fronto-insular cortex (FIC) ( Fig. 1 ). Moreover, we found that the physiological functional role of the candidate regions related to social cognition (DMFPC), cognitive speech and semantic processing (left FIC/LPFC), emotional and cognitive reward processing (right amygdala/FIC) as well as somesthesis and executive functions (RLPFC). Conclusion Psychopathy is characterized by abnormal brain activity of bilateral prefrontal cortices and the right amygdala, which mediate psychological functions known to be impaired in psychopaths. Hence, aberrant neural activity can account for pertinent psychopathology in psychopathy. [ABSTRACT FROM AUTHOR]

We reported previously that repetitive intravenous injections of corticotropin-releasing hormone (CRH) around sleep onset prompt depression-like changes in certain sleep and endocrine activity parameters (e.g. decrease of slow-wave sleep during the second half of the night, blunted growth hormone peak, elevated cortisol concentration during the first half of the night). Furthermore a sexual dimorphism of the sleep-endocrine effects of the hormones growth hormone-releasing hormone and ghrelin was observed. In the present placebo-controlled study we investigated the effect of pulsatile administration of 4 × 50 μg CRH on sleep electroencephalogram (EEG) and nocturnal cortisol and GH concentration in young healthy women. After CRH compared to placebo, intermittent wakefulness increased during the total night and the sleep efficiency index decreased. During the first third of the night, REM sleep and stage 2 sleep increased and sleep stage 3 decreased. Cortisol concentration was elevated throughout the night and during the first and second third of the night. GH secretion remained unchanged. Our data suggest that after CRH some sleep and endocrine activity parameters show also depression-like changes in healthy women. These changes are more distinct in women than in men. [ABSTRACT FROM AUTHOR]

Mental disorders are among the greatest medical and social challenges facing us. They can occur at all stages of life and are among the most important commonly occurring diseases. In Germany 28 % of the population suffer from a mental disorder every year, while the lifetime risk of suffering from a mental disorder is almost 50 %. Mental disorders cause great suffering for those affected and their social network. Quantitatively speaking, they can be considered to be among those diseases creating the greatest burden for society due to reduced productivity, absence from work and premature retirement. The Federal Ministry of Education and Research is funding a new research network from 2015 to 2019 with up to 35 million euros to investigate mental disorders in order to devise and develop better therapeutic measures and strategies for this population by means of basic and translational clinical research. This is the result of a competitive call for research proposals entitled research network for mental diseases. It is a nationwide network of nine consortia with up to ten psychiatric and clinical psychology partner institutions from largely university-based research facilities for adults and/or children and adolescents. Furthermore, three cross-consortia platform projects will seek to identify shared causes of diseases and new diagnostic modalities for anxiety disorders, attention deficit hyperactivity disorders (ADHS), autism, bipolar disorders, depression, schizophrenia and psychotic disorders as well as substance-related and addictive disorders. The spectrum of therapeutic approaches to be examined ranges from innovative pharmacological and psychotherapeutic treatment to novel brain stimulation procedures. In light of the enormous burden such diseases represent for society as a whole, a sustainable improvement in the financial support for those researching mental disorders seems essential. This network aims to become a nucleus for long overdue and sustained support for a German center for mental disorders. [ABSTRACT FROM AUTHOR]

Introduction: A promising candidate in the field of pharmacological treatment options regarding major depressive disorder (MDD) is the mitochondrial translocator protein (18 kDa) (TSPO). TSPO is crucial for neurosteroid synthesis, which is in turn important for the regulation of emotions. It has already been shown that TSPO expression in platelets of depressed patients is reduced compared to healthy subjects. Methods: We measured TSPO levels in platelets of 37 depressed patients before and after 6 weeks of pharmacological treatment to test the hypotheses that i) such treatment would increase TSPO expression and ii) that this increase would be correlated with therapeutic response. Results: Surprisingly, TSPO levels in platelets of all patients were significantly reduced after 6 weeks of treatment (p = 0.044). Within the responder group, a non-significant trend towards greater TSPO level reduction could be observed. Discussion: These results challenge our hypotheses that TSPO levels might increase during antidepressant therapy along with a decrease in depressive symptoms. Thus, we assume that TSPO expression in platelets is not a suitable state marker for MDD. [ABSTRACT FROM AUTHOR]

Introduction: The treatment of anxiety disorders is still a challenge; novel pharmacological approaches that combine rapid anxiolytic efficacy with fewer side effects are needed. A promising target for such compounds is the mitochondrial translocator protein (18 kDa) (TSPO). TSPO plays an important role for the synthesis of neurosteroids, known to modulate GABAA receptors, thereby exerting anxiolytic effects. Methods: We investigated the pharmacological profile of 2 well established TSPO ligands (XBD173 and etifoxine) compared to the benzodiazepine diazepam with regard to TSPO binding affinity, TSPO expression and neurosteroidogenesis. Results: In BV-2 microglia and C6 glioma cells all compounds significantly enhanced TSPO protein expression. Radioligand binding assays revealed the highest binding affinity to TSPO for XBD173, followed by diazepam and etifoxine. Pregnenolone synthesis was most potently enhanced by etifoxine. Discussion: Etifoxine turned out to be the most potent enhancer of neurosteroidogenesis, although its binding affinity to TSPO was lowest. These results indicate that the efficacy of TSPO ligands to stimulate neurosteroid synthesis, thereby leading to anxiolytic effects cannot be concluded from their binding affinity to TSPO. [ABSTRACT FROM AUTHOR]

Abstract: The onset of action of antidepressants (ADs) usually takes several weeks, but first molecular responses to these drugs may appear already after acute administration. The Extracellular Signal-regulated Kinase/Mitogen-Activated Protein Kinase (ERK/MAPK) signaling pathway is a target of ADs and an important pathway involved in cellular plasticity. In major depressive disorder (MDD), especially the prefrontal cortex (PFC) and hippocampus (Hip) are most likely affected in depressive patients and recent work revealed a hyperactivated ERK signaling in the rat PFC after chronic stress, a precipitating factor for MDD. Strong evidences support that not only neurons but also astrocytes participate in neuronal activity and may therefore additionally be a substrate of AD action. In this study, we show by Western blot that neither fluoxetine (FLX) nor desipramine (DMI) preferentially affects the activation of one of the two ERK isoforms, ERK1 and ERK2, with respect to the other. Further immunohistochemical analysis in the PFC revealed that basal levels of phospho-activated ERK (pERK) are mostly found in neurons in contrast to very few astrocytes. Both ADs can inhibit neuronal pERK as early as 15min after drug administration with peculiar regional and layer specificities. Contrarily, at this time point none of the two ADs shows a clear modulation of astrocytic pERK. We propose that this mechanism of action of ADs may be protective against an exacerbated cortical ERK activity that may exert detrimental effects on susceptible neuronal populations. Our findings on acute effects of AD treatment in the adult mouse PFC encourage to examine further how this treatment might influence pERK in animal models of depression to identify early targets of AD action. [Copyright &y& Elsevier]

Summary: Introduction: The renin–angiotensin–aldosterone-system (RAAS) is one of the most important systems involved in the pathogenesis of cardiovascular diseases. Its role in stress response has been generally neglected, although the progression of cardiovascular disease is considerably increased in the presence of stress and especially in the presence of depression risk. With the present analysis we aimed to evaluate whether the activity of the RAAS correlates with depressive symptomatology and with chronic stress. Moreover, we aimed to analyse whether stress response is altered in the presence of depressed symptomatology. We chose “living alone” to be our paradigm of chronic stress. Methods and results: Aldosterone and renin levels were assessed in 1743 (829 men, 914 women) from the population-based KORA study (Cooperative Health Research in the Region of Augsburg). The relationship between aldosterone, renin levels and the different combinations of living alone and depressive symptomatology was examined in three different multiple linear regression models adjusted for age, sex, creatinine levels, potassium levels, body mass index (BMI) and bio-behavioural factors. Neither “living alone” nor depressive symptomatology alone were associated with an activation of the RAAS, but the combination of living alone and depressive symptomatology yielded a highly significant increase in the aldosterone (p <0.01) and renin level (p =0.03). Conclusion: Our findings show that depressive symptomatology is associated with a hyper-responsiveness to chronic stress. Under the condition of chronic stress depressed individuals have an activated RAAS. Activation of the RAAS might explain the known increased risk of negative cardiovascular disease outcomes in this group. [ABSTRACT FROM AUTHOR]

Abstract: Leptin, involved in energy regulation and contributor to cardiovascular disease, has been implicated to play a role in depression and sleep disturbances, two closely intertwined conditions. Previous results investigating leptin level alterations either in sleep disorders or in depression have been inconsistent. We investigate the association between leptin levels and the different combinations of depressed mood and sleep disturbances in 1369 subjects (706 men, 663 women), derived from the population-based MONIKA/KORA study. As leptin regulation is known to differ by sex and weight, analyses were performed in normal weight and overweight men and women separately. We found a highly significant association between leptin levels and the combination of depressed mood and sleep disturbances in normal-weight women (BMI≤25) (p <0.01). No associations were found in men and in overweight women. Our results suggest that leptin regulation in depressed mood and sleep disturbances very much depend on sex and weight. [Copyright &y& Elsevier]

Anxiety disorders are frequent and highly disabling diseases with considerable socio-economic impact. In the treatment of anxiety disorders, benzodiazepines (BZDs) as direct modulators of the GABAA receptor are used as emergency medication because of their rapid onset of action. However, BZDs act also as sedatives and rather quickly induce tolerance and abuse liability associated with withdrawal symptoms. Antidepressants with anxiolytic properties are also applied as first line long-term treatment of anxiety disorders. However, the onset of action of antidepressants takes several weeks. Obviously, novel pharmacological approaches are needed that combine a rapid anxiolytic efficacy with the lack of tolerance induction, abuse liability and withdrawal symptoms. Neurosteroids are potent allosteric modulators of GABAA receptor function. The translocator protein (18 kDa) (TSPO) plays an important role for the synthesis of neurosteroids by promoting the transport of cholesterol from the outer to the inner mitochondrial membrane, which is the rate-limiting step in neurosteroidogenesis. Etifoxine not only exerts anxiolytic effects as a TSPO ligand by enhancing neurosteroidogenesis, but also acts as a weak direct GABAA receptor enhancer. The TSPO ligand XBD173 enhances GABAergic neurotransmission via the promotion of neurosteroidogenesis without direct effects at the GABAA receptor. XBD173 counteracts pharmacologically-induced panic in rodents in the absence of sedation and tolerance development. Also in humans, XBD173 displays antipanic activity and does not cause sedation and withdrawal symptoms after 7 days of treatment. XBD173 therefore appears to be a promising candidate for fast-acting anxiolytic drugs with less severe side-effects than BZDs. In this review, we focus on the pathophysiology of anxiety disorders and TSPO ligands as a novel pharmacological approach in the treatment of these disorders. [ABSTRACT FROM AUTHOR]

After a traumatic injury of the nervous system or in the course of a neurodegenerative disease, the speed of axonal regeneration and the control of the inflammatory response are fundamental parameters of functional recovery. Spontaneous regeneration takes place in the peripheral nervous system, although the process is slow and often incomplete. There is currently no efficient treatment for enhancing axonal regeneration, including elongation speed and functional reinnervation. Ligands of the translocator protein 18 kDa (TSPO) are currently under investigation as therapeutic means for promoting neuroprotection, accelerating axonal regeneration and modulating inflammation. The mechanisms of action of TSPO ligands involve the regulation of mitochondrial activity and the stimulation of steroid biosynthesis. In the peripheral nervous system, TSPO expression is strongly up-regulated after injury, primarily in Schwann cells and macrophages, but also in neurones. Its levels return to low control values when nerve regeneration is completed, strongly supporting an important role in regenerative processes. We have demonstrated a role for the benzoxazine etifoxine in promoting axonal regeneration in the lesioned rat sciatic nerve, either after freeze-injury or complete transection. Etifoxine is already clinically approved for the treatment of anxiety disorders (Stresam®, Biocodex, Gentilly, France). Daily treatment with etifoxine resulted in a two-fold acceleration in axonal regeneration, as well as in a marked improvement of both the speed and quality of functional recovery. The neuroregenerative effects of etifoxine are likely to be mediated by TSPO, and they may involve an increased synthesis of pregnenolone and its metabolites, such as progesterone. After freeze-injury of the sciatic nerve, administration of etifoxine also strongly reduced the number of activated macrophages and decreased the production of the inflammatory cytokines tumour necrosis factor-α and interleukin-1β. Thus, this drug offers promise for the treatment of peripheral nerve injuries and axonal neuropathies. It may also be used as a lead compound in the development of new TSPO-based neuroprotective approaches. [ABSTRACT FROM AUTHOR]

Abstract: In the past decades considerable evidence has emerged that so-called neuroactive steroids do not only act as transcriptional factors in the regulation of gene expression but may also alter neuronal excitability through interactions with specific neurotransmitter receptors such as the GABAA receptor. In particular, 3α-reduced neuroactive steroids such as allopregnanolone or allotetrahydrodeoxycorticosterone have been shown to act as positive allosteric modulators of the GABAA receptor and to play an important role in the pathophysiology of depression and anxiety. During depression, the concentrations of 3α,5α-tetrahydroprogesterone and 3α,5β-tetrahydroprogesterone are decreased, while the levels of 3β,5α-tetrahydroprogesterone, a stereoisomer of 3α,5α-tetrahydroprogesterone, which may act as an antagonist for GABAergic steroids, are increased. Antidepressant drugs such as selective serotonin reuptake inhibitors (SSRIs) or mirtazapine apparently have an impact on key enzymes of neurosteroidogenesis and have been shown to normalize the disequilibrium of neuroactive steroids in depression by increasing 3α-reduced pregnane steroids and decreasing 3β,5α-tetrahydroprogesterone. Moreover, 3α-reduced neuroactive steroids have been demonstrated to possess antidepressant- and anxiolytic-like effects both in animal and human studies for themselves. In addition, the translacator protein (18 kDa) (TSPO), previously called peripheral benzodiazepine receptor, is the key element of the mitochondrial import machinery supplying the substrate cholesterol to the first steroidogenic enzyme (P450scc), which transforms cholesterol into pregnenolone, the precursor of all neurosteroids. TSPO ligands increase neurosteroidogenesis and are a target of novel anxiolytic drugs producing anxiolytic effects without causing the side effects normally associated with conventional benzodiazepines such as sedation or tolerance. This article is part of a Special Issue entitled: Neuroactive Steroids: Focus on Human Brain. [Copyright &y& Elsevier]

The present study investigated the functional antagonism of different antidepressants on 5-HT3 receptor function and the role of lipid rafts for these modulatory effects. Electrophysiological recordings of 5-HT evoked cation currents were recorded with NIE-115 and HEK-5-HT3A cells and hippocampal neurons. The characterization of the antagonism of antidepressants was made by the displacement of [³H]GR65630 binding. For membrane fractionation, sucrose density gradient centrifugation was used. Gradient fractions were assayed for antidepressant concentrations by HPLC; 5-HT3 receptor membrane distribution was determined by Western blot. Colocalization experiments were performed by means of immunocytochemistry. Most antidepressants acted as non-competitive antagonists at the 5-HT3 receptor. Moreover, some of these compounds were enriched within lipid rafts. Cholesterol depletion impaired lipid raft integrity thereby affecting 5- HT3 receptor function, whereas the antagonistic effects of antidepressants were not altered. In conclusion, most antidepressants directly antagonize 5-HT3 receptor activity. 5-HT3 receptor function per se appears to depend on lipid raft integrity, which is, however, not a prerequisite for the modulatory potency of antidepressants at this receptor. [ABSTRACT FROM AUTHOR]

Summary: Background: Leptin, involved in energy homeostasis and a predictor of cardiovascular disease, has recently been recognized as mediator in stress reactions. We aimed to explore the association between leptin levels and two stress-related conditions, social isolation and depressed mood, both associated with increased cardiovascular mortality. Methods: We analysed leptin levels in 1229 subjects (643 men, 586 women), derived from the population-based MONIKA/KORA study. Standardized questionnaires were used to assess depressive mood and social isolation. In a multiple linear regression adjusted for body weight, age and survey, the association between leptin, social isolation and depressed mood and its interaction was explored in men and women separately. Leptin was then dichotomized and four analyses, adjusted for age, BMI, lifestyle factors, psychosomatic complaints and metabolic variables were performed to compare the risk of elevated leptin levels in the risk groups. Results: Increased leptin levels were associated with social isolation (p =0.04) and the interaction between social isolation and depressed mood (p =0.02) in men but not in women. In socially isolated and depressed men, leptin levels (mean: 6.07ng/ml) were significantly increased compared to neither depressed nor isolated men (mean: 4.51ng/ml, p =0.04). In the multivariate adjusted logistic regression model, the combination of depressed state and social isolation was associated with a 4-fold increased risk (p <0.001) for elevated leptin levels. Conclusion: The finding of elevated leptin levels in socially isolated and depressed men raises the possibility that increased cardiovascular mortality in socially isolated men is partially mediated by hyperleptinemia. [ABSTRACT FROM AUTHOR]

Since little is known concerning regulation of immunological parameters in rapid changing psychiatric states like panic attacks, we measured cytokines at different time points in healthy subjects, which underwent experimental panic induction using the CCK-4 paradigm. Apart from a challenge related IL-6 increase, we could not observe any changes of neuroimmunological markers in relation to acute anxiety with regard to time and group. Herein we conducted for the first time a new approach to immunological research in panic disorder, suggesting immune changes are more related to long term disease stress. [ABSTRACT FROM AUTHOR]

The serotonergic system is involved in the pathophysiology of major depression as well as in the early central nervous system development and adult neuroplasticity. The aim of the study was to examine in 77 patients with major depression and 77 healthy controls the association between the triallelic polymorphism in the promoter region of the serotonin transporter gene (5-HTTLPR) and gray matter (GM) brain volumes measured with 1.5 T magnetic resonance imaging. Voxel-based morphometry were estimated on magnetic resonance images and genotyping was performed. We found that healthy controls have a strong association between the 5-HTTLPR and GM volumes of the dorsolateral prefrontal cortex, left anterior gyrus cinguli, left amygdala as well as right hippocampus, whereas there is no such association in patients with major depression. Healthy subjects carrying the S- or LG-allele have smaller GM volumes than those with the LA-allele, indicating that 5-HTTLPR contributes to the development of brain structures. Patients with depression show reduced GM volumes, particularly when they are homozygous for the LA-allele, suggesting that these patients are more vulnerable for morphological changes during depressive episodes.Molecular Psychiatry (2008) 13, 1093–1101; doi:10.1038/mp.2008.62; published online 1 July 2008 [ABSTRACT FROM AUTHOR]

Objective: There is overwhelming evidence that activation of the hypothalamic-pituitary-adrenal (HPA) system plays a major role in depression and cardiovascular disease in genetically susceptible individuals. We hypothesized that due to the multiple interactions between the sympathetic and the HPA systems via adrenoceptors, polymorphisms in these genes could have an impact on HPA axis activity in major depression. Methods: Using the dexamethasone/corticotrophin-releasing hormone (DEX/CRH) test, we investigated the association of α2-adrenoceptor (ADRA2A –1291C→G) and the β2-adrenoceptor gene (ADRB2 Arg16Gly) in 189 patients with major depression during the acute state of the disease and after remission. Results: Male ADRA2A –1291G allele homozygotes showed significant pretreatment HPA axis hyperactivity, with increased adrenocorticotropin (ACTH; F = 4.9, d.f. = 2, p = 0.009) and cortisol responses (F = 6.4, d.f. = 2, p = 0.003). In contrast, female ADRB2 Arg/Arg homozygotes had increased pretreatment ACTH (F = 7.17, d.f. = 2, p = 0.001) and cortisol (F = 8.95, d.f. = 2, p = 0.000) levels. Interestingly, in the respective genotypes, the stress hormones remained elevated in the second DEX/CRH test, despite a reduction in depressive symptoms. Conclusions: This study provides evidence that, depending on gender and polymorphisms, there is continuous HPA axis overdrive in a proportion of patients irrespective of the status of depression. Considering the importance of stress hormones for cardiovascular disorders, our data might suggest that these patients are at high risk of comorbidity between depression and cardiovascular disorders. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background Pruritus, burning, epiphora and insufficient occlusion of the mouth have been less extensively studied than cosmetic changes in irradiated fields. Objectives How frequent are these late adverse effects? Do they usually occur permanently? Are they influenced by treatment and tumour parameters, sex and age of the patients? Methods Patients were interviewed at least once later than 90 days after soft X-ray therapy. Results Pruritus has been reported in 18.5% of the interviews, burning in 7.7%, epiphora in 36.2% and insufficient occlusion of the mouth in 11.5%. Patients were usually not permanently troubled and irritated by these symptoms: pruritus more than once per week was reported in every interview for 0.6% of the fields, burning for 0.2%, epiphora for 6.4% and insufficient occlusion for 0%. Irritation by these symptoms has been stated in every interview for 5.1% of fields around the eye and for 1.4% of fields at other sites. Late pruritus, burning and epiphora were less frequently reported after irradiation with lower total doses, lower time–dose–fractionation factor (TDF) and by men. Patients older than 70 years of age experienced pruritus and burning less frequently. The largest diameter of the irradiated field influenced pruritus and the half value depth of the X-rays influenced burning and epiphora. Conclusions Late pruritus, burning, epiphora and insufficient occlusion of the mouth do not considerably reduce the value of soft X-ray therapy because these adverse effects usually are not experienced permanently. Total dose and TDF should not be chosen higher than necessary. [ABSTRACT FROM AUTHOR]

B Background: b Astrocytes are non-professional phagocytes, which engulf synapses to favour the remodelling of neuronal circuits. Accordingly, mice lacking MEGF10 astrocytes display about 50% reduction in their relative engulfment ability, supporting the astrocytic activity-dependent role in synapses refinement [3]. B Conclusion: b We observed that cortical astrocytes mediate a remodelling of excitatory synapses shortly after ADs treatment via MEGF10 both in vitro and in vivo. [Extracted from the article]

Angiotensin-converting enzyme (ACE) is assumed to influence the activity of the hypothalamic-pituitary-adrenocortical (HPA) system, which shows hyperactivity in the majority of patients with major depression. The ACE gene, known to be associated with cardiovascular disorders, which in turn are accompanied with an increased susceptibility for depression, is therefore a promising candidate gene for affective disorders. We investigated the genetic association between 35 single-nucleotide polymorphisms (SNPs) and an insertion/deletion (I/D)-polymorphism in the ACE gene and the susceptibility for unipolar major depression together with the genetic association with ACE serum activity and functional parameters of the HPA system. Two independent case/control samples with a total of 843 unrelated unipolar depressed patients and 1479 healthy controls were investigated. A case/control sample was screened to detect genetic associations with unipolar major depression. In addition, a replication sample was used to confirm the detected associations and to further investigate functional consequences of the genetic variants associated with depression. In the screening sample, two SNPs within the ACE gene were significantly associated with unipolar major depression. The association with unipolar major depression of one SNP (rs4291) located in the promoter region of the ACE gene was confirmed in our replication sample. The T-allele of this SNP was associated with depression and depressed T-allele carriers showed higher ACE serum activity and HPA-axis hyperactivity. Variants of the ACE gene such as SNP rs4291 are suggested susceptibility factors for unipolar major depression. We could show that SNP rs4291 influences ACE activity and HPA-axis hyperactivity and might therefore represent a common pathophysiologic link for unipolar depression and cardiovascular disease.Molecular Psychiatry (2006) 11, 1003–1015. doi:10.1038/sj.mp.4001884; published online 22 August 2006 [ABSTRACT FROM AUTHOR]

Abstract: Neuroactive steroids modulate neurotransmission through modulation of specific neurotransmitter receptors such as γ-aminobutyric acid type A (GABAA) receptors. Preclinical studies suggested that neuroactive steroids may modulate anxiety and depression-related behaviour and may contribute to the therapeutical effects of antidepressant drugs. Attenuations of such neuroactive steroids have been observed during major depression and in several anxiety disorders, suggesting a pathophysiological role in such psychiatric conditions. In panic disorder patients a dysequilibrium of neuroactive steroid composition has been observed, which may represent a counterregulatory mechanism against the occurrence of spontaneous panic attacks. Furthermore, alterations of 3α-reduced pregnane steroids during major depression were corrected by successful treatment with antidepressant drugs. However in contrast, non-pharmacological antidepressant treatment strategies did not affect neuroactive steroid composition. In addition, changes in neuroactive steroid concentrations after mirtazapine therapy occurred independently from the clinical response, thereby suggesting that changes in neuroactive steroid concentrations more likely reflect direct pharmacological effects of antidepressants rather than clinical improvement in general. Nevertheless, the effects of antidepressant pharmacotherapy on the composition of neuroactive steroids may contribute to the alleviation of certain depressive symptoms, such as amelioration of anxiety, inner tension or sleep disturbances. Moreover, first studies investigating the therapeutical effects of dehydroepiandrosterone revealed promising results in the treatment of major depression. In conclusion, neuroactive steroids are important endogenous modulators of depression and anxiety and may provide a basis for development of novel therapeutic agents in the treatment of affective disorders. [Copyright &y& Elsevier]

Abstract: Certain neuroactive steroids modulate ligand-gated ion channels via non-genomic mechanisms. Especially 3α-reduced pregnane steroids are potent positive allosteric modulators of the GABA type A-receptor. During major depression there is a dysequilibrium of 3α-reduced neuroactive steroids, which is corrected by clinically effective pharmacological treatment. To investigate whether these alterations are a general principle of successful antidepressant treatment we studied the impact of non-pharmacological treatment options on neuroactive steroid concentrations during major depression. Neither partial sleep deprivation, transcranial magnetic stimulation nor electroconvulsive therapy affected neuroactive steroid levels irrespectively of the response to these treatments. These studies suggest that the changes in neuroactive steroids observed after antidepressant pharmacotherapy more likely reflect distinct pharmacological properties of antidepressants rather than the clinical response. In patients with panic disorder changes in neuroactive steroid composition have been observed opposite of those seen in depression. These changes may represent counterregulatory mechanisms against the occurrence of spontaneous panic attacks. However, during experimental panic induction with either cholecystokinin-tetrapeptide or sodium lactate there was a pronounced decline in the concentrations of 3α-reduced neuroactive steroids in patients with panic disorder, which might result in a decreased GABAergic tone. In contrast, no changes in neuroactive steroid concentrations could be observed in healthy controls with the exception of 3α, 5α-tetrahydrodeoxycorticosterone, allotetrahydrodeoxycorticosterone. The modulation of GABA type A-receptors by neuroactive steroids might contribute to the pathophysiology of depression and anxiety disorders and might offer new targets for the development of novel anxiolytic compounds. [Copyright &y& Elsevier]

Concentrations of 3α-reduced neuroactive steroids are altered in depression and normalize after antidepressant pharmacotherapy with selective serotonin re-uptake inhibitors (SSRIs). We investigated the impact of mirtazapine on the activity of a key neurosteroidogenic enzyme, the 3α-hydroxysteroid dehydrogenase (3α-HSD), and on the levels of neuroactive steroids in relation to clinical response. A total of 23 drug-free in-patients suffering from a major depressive episode (DSM-IV criteria) underwent 5-week treatment with mirtazapine (45 mg/day). Plasma samples were taken weekly at 0800 and quantified for neuroactive steroids by means of combined gas chromatography/mass spectrometry analysis. Enzyme activity was determined by assessment of steroid conversion rates. Irrespective of clinical outcome, there were significant increases in 3α,5α-tetrahydroprogesterone, 3α,5β-tetrahydroprogesterone, 5α-dihydroprogesterone, and 5β-dihydroprogesterone after mirtazapine treatment, whereas 3β,5α-tetrahydroprogesterone levels were significantly decreased. In vitro investigations demonstrated a dose-dependent inhibitory effect of mirtazapine on the activity of the microsomal 3α-HSD in the oxidative direction (conversion of 3α,5α-tetrahydroprogesterone to 5α-dihydroprogesterone). Mirtazapine affects neuroactive steroid composition similarly as do SSRIs. The inhibition of the oxidative pathway catalyzed by the microsomal 3α-HSD is compatible with an enhanced formation of 3α-reduced neuroactive steroids. However, the changes in neuroactive steroid concentrations more likely reflect direct pharmacological effects of this antidepressant rather than clinical improvement in general.Molecular Psychiatry (2006) 11, 261–272. doi:10.1038/sj.mp.4001782; published online 13 December 2005 [ABSTRACT FROM AUTHOR]

Tryptophan hydroxylase (TPH), being the rate-limiting enzyme in the biosynthesis of serotonin plays a major role as candidate gene in several psychiatric disorders. Recently, a second TPH isoform (TPH2) was identified in mice, which was exclusively present in the brain. In a previous post-mortem study of our own group, we could demonstrate that TPH2 is also expressed in the human brain, but not in peripheral tissues. This is the first report of an association study between polymorphisms in the TPH2 gene and major depression (MD). We performed single-nucleotide polymorphism (SNP), haplotype and linkage disequlibrium studies on 300 depressed patients and 265 healthy controls with 10 SNPs in the TPH2 gene. Significant association was detected between one SNP (P=0.0012, global P=0.0051) and MD. Haplotype analysis produced additional support for association (P<0.0001, global P=0.0001). Our findings provide evidence for an involvement of genetic variants of the TPH2 gene in the pathogenesis of MD and might be a hint on the repeatedly discussed duality of the serotonergic system. These results may open up new research strategies for the analysis of the observed disturbances in the serotonergic system in patients suffering from several other psychiatric disorders.Molecular Psychiatry (2004) 9, 1030-1036. doi:10.1038/sj.mp.4001525 Published online 4 May 2004 [ABSTRACT FROM AUTHOR]

The serotonin type 3 (5-HT3) receptor is the only ligand-gated ion channel receptor for serotonin (5-HT). 5-HT3 receptors play an important role in modulating the inhibitory action of dopamine in mesocorticolimbic brain regions. Neuroleptic drugs are commonly thought to exert their psychopharmacological action mainly through dopamine and serotonin type 2 (5-HT2) receptors. Except for clozapine, a direct pharmacological interaction of neuroleptics with 5-HT3 receptors has not yet been described. Using the concentration-clamp technique, we investigated the effects of flupentixol, various phenothiazines, haloperidol, clozapine and risperidone on Na+-inward currents through 5-HT3 receptors stably expressed in human embryonic kidney 293 cells, and through endogenous 5-HT3 receptors of murine N1E-115 neuroblastoma cells. In addition, we studied their effects on Ca2+ influx, measured as a change in intracellular Ca2+ concentrations ([Ca2+]i). All neuroleptic drugs, but not risperidone, antagonized Na+- and Ca2+-inward currents evoked by 5-HT (10?µM for 2?s and 1?µM, respectively) in a voltage-independent manner. Only clozapine was a competitive antagonist, while all other compounds turned out to be noncompetitive. Fluphenazine and haloperidol affected membrane anisotropy at concentrations below their IC50 values, indicating that a change in membrane anisotropy might contribute to their antagonistic effect at the 5-HT3 receptor. Only structure analogues of flupentixol and fluphenazine with a lipophilic side chain were potent antagonists against 5-HT-evoked Na+ and Ca2+ currents. Since 5-HT3 receptors modulate mesolimbic and mesocortical dopaminergic activity, the functional antagonism of neuroleptics at 5-HT3 receptors may contribute to their antipsychotic efficacy and may constitute a not yet recognized pharmacological principle of these drugs.Molecular Psychiatry (2004) 9, 846-858. doi:10.1038/sj.mp.4001490 Published online 16 March 2004 [ABSTRACT FROM AUTHOR]

The convulsant effects of α-thujone, the psychotropic component of absinthe, were attributed to inhibitory actions at the GABAA receptor. Here, we investigated for the first time the 5-HT3 receptor as a potential site of the psychotropic actions of α-thujone. This cation permeable ligand-gated ion channel shows considerable homology to the GABAA receptor. We previously demonstrated that in homomeric assemblies of cloned human 5-HT3A receptor subunits, the endogenous agonist 5-HT induced desensitization via channel blockade. When the 5-HT3B receptor subunit was co-expressed, the resulting heteromeric assemblies desensitized independent from channel blockade. In the present study, patch-clamp experiments revealed an inhibitory action of α-thujone on both homomeric and heteromeric 5-HT3 receptors. This inhibitory action was mediated via channel blockade. However, it was not α-thujone itself which blocked the channel. The present experiments suggested that, in homomeric receptors, α-thujone enhanced the inherent channel-blocking potency of the natural ligand, 5-HT. In heteromeric receptors, α-thujone recruited an additional channel-blocking component of the agonist. By means of kinetic modeling, we simulated possible mechanisms by which α-thujone decreased the 5-HT-induced responses. It is suggested that α-thujone reduced 5-HT3 receptor activity by an effect on mechanisms involved in receptor desensitization, which depend on receptor subunit composition. It remains to be shown if this inhibitory action on serotonergic responses contributes to behavioral effects of α-thujone. [Copyright &y& Elsevier]

Antidepressants are commonly supposed to enhance serotonergic and/or noradrenergic neurotransmission by inhibition of neurotransmitter reuptake through binding to the respective neurotransmitter transporters or through inhibition of the monoamine oxidase. Using the concentration-clamp technique and measurements of intracellular Ca2+, we demonstrate that different classes of antidepressants act as functional antagonists at the human 5-HT3A receptor stably expressed in HEK 293 cells and at endogenous 5-HT3 receptors of rat hippocampal neurons and N1E-115 neuroblastoma cells. The tricyclic antidepressants desipramine, imipramine, and trimipramine, the serotonin reuptake inhibitor fluoxetine, the norepinephrine reuptake inhibitor reboxetine, and the noradrenergic and specific serotonergic antidepressant mirtazapine effectively reduced the serotonin-induced Na+- and Ca2+-currents in a dose-dependent fashion. This effect was voltage-independent and, with the exception of mirtazapine, noncompetitive. Desipramine, imipramine, trimipramine, and fluoxetine also accelerated receptor desensitization. Moclobemide and carbamazepine had no effect on the serotonin-induced cation current. By analyzing analogues of desipramine and carbamazepine, we found that a basic propylamine side chain increases the antagonistic potency of tricyclic compounds, whereas it is abolished by an uncharged carboxamide group. The antagonistic effects of antidepressants at the 5-HT3 receptor did not correlate with their effects on membrane fluidity. In conclusion, structurally different types of antidepressants modulate the function of this ligand-gated ion channel. This may represent a yet unrecognized pharmacological principle of antidepressants.Molecular Psychiatry (2003) 8, 994-1007. doi:10.1038/sj.mp.4001314 [ABSTRACT FROM AUTHOR]

Cholecystokinin-tetrapeptide (CCK-4) induces panic attacks both in patients with panic disorder (PD) and healthy volunteers. It has been shown that panic elicited by CCK-4 is improved after treatment with antidepressants. Moreover, a reduction of CCK-4-induced panic has also been demonstrated after treatment with lorazepam in single subjects and after selective GABAergic treatment with vigabatrin. Although benzodiazepines are widely used as anxiolytics, no controlled study on the effects of benzodiazepines on CCK-4-induced panic symptoms is available so far. Therefore, we investigated the effects of alprazolam and placebo on CCK-4-induced panic symptoms in a double-blind, placebo-controlled study. A total of 30 healthy subjects were challenged with 50 µg CCK-4. Out of these 30 subjects, 26 showed a marked panic response to CCK-4. Subjects were rechallenged after a 7-day interval and treated with 1 mg alprazolam or placebo 1 h prior to the second CCK-4 challenge. Panic was assessed using the acute panic inventory (API) and a DSM-IV-derived panic symptom scale (PSS). Moreover, the number of reported symptoms and self-rated anxiety and arousal were recorded. We found a significant reduction of the API and PSS scores and of the number of reported symptoms compared to placebo. Moreover, compared to placebo the CCK-4-induced ACTH and cortisol release were significantly attenuated during the CCK-4 challenge after alprazolam treatment. However, also placebo treatment reduced CCK-4-induced anxiety and HPA-axis activation to a certain extent. In conclusion, our data show that alprazolam reduces CCK-4-induced panic, which supports the hypothesis of a possible interaction between the GABA and the CCK system. [ABSTRACT FROM AUTHOR]