UMLS:C0011570 - FACTA Search

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Query: UMLS:C0011570 (depression)
172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Serotonin (5HT1A) is a chemical mediator of inflammation and the largest single neurotransmitter system of the brain. Its secretion and physiological actions mediate stress and pain, affecting both immune and nervous system functions through the hypothalamic-pituitary-adrenal axis. Serotonin receptor dysfunction is well-characterized in mental disturbances like depression and anxiety. Transcranial magnetic stimulation has been used therapeutically to treat refractory disorders like non-responsive depression and may act in part through its effect on 5HT1A receptors. Previously we have shown that in vitro, 5HT1A receptor binding to a radioactive agonist can be modulated by specific intensity and frequency electromagnetic fields (EMFs). In the present report we have used quantitative receptor autoradiography to evaluate 5HT1A receptor density in rat brain and the impact of pulsed EMF exposure on receptor binding in key brain regions. Rats used in this study had whole body exposures to either a geofield control or to pulsed EMFs to evaluate the treatment for chemically-induced tendinitis. Since the brains were exposed coincidentally as a consequence of the main experiment, we investigated the potential for EMF-induced changes in areas such as the hippocampus. This pilot study should provide a detailed understanding of magnetic field effects on stress-responsive brain regions and will lead to a more coordinated approach to the use of such modalities for therapeutic intervention in humans.
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PMID:Autoradiographic evaluation of electromagnetic field effects on serotonin (5HT1A) receptors in rat brain. 1272 37

The principal stakes of depression treatment are to accelerate and enhance the clinical effects of antidepressant drug. The onset of antidepressant action of Serotonin (5HT) selective reuptake inhibitors (SSRIs) was attributed in part to the decrease in firing activity of serotonin neurons produced by the activation of raphe 5HT1A autoreceptors at the time of treatment initiation. Pindolol, an antagonist at somatodendritic pre-synaptic 5HT1A receptors has been investigated as a potential accelerator or potentialisator of antidepressant response. Six open label studies and 12 controlled studies were identified for revue. The first open-label pilot study was conducted by Artigas et al. They showed promising results with pindolol, both in the acceleration of antidepressant response and in improving the efficacy of antidepressant. On the basis of these results five open-label studies were conducted. The open label studies suggest that pindolol accelerate the antidepressant response of serotoninergics therapeutics. The augmentation of antidepressant response was not clearly demonstrated by these studies particularly in the treatment of refractory depression. For example, Dinan et Scott that found the addition of pindolol in association with SSRI therapy had a poor efficacy. In the twelve controlled studies, 4 tried to underscore the shortening of the onset and the augmentation of efficacy of SSRI by pindolol [Berman et al., Maes et al., Perez et al., Tome et al. ], 3 tried to underscore shortening of the onset [Bordet, Zanardi ] and 3 tried to underscore the augmentation of efficacy [Maes et al., Moreno et al., Perez et al. ]. One study tried to underscore the augmentation of efficacy of sleep deprivation by pindolol and another one the shortening of the onset of ECT. Six studies included depressive resistant patients. Three studies were carried out with fluoxetine, 1 with fluvoxamine, 3 with paroxetine, 1 with trazodone. Two -studies were investigated with several antidepressant treatments. The results of the studies indicate one acceleration of antidepressant response in 6 studies, one augmentation of efficacy in 5 studies. Two studies clearly demonstrate that pindolol may -augment and accelerate antidepressant response. Three studies did not confirm these observations. Several points can be examined. For pindolol: 3 authors have demonstrated that the effect of pindolol did not rely upon small antidepressant effect mediated by b-blockers properties, because anxiety was not predominantly improved by pindolol plus SSRI while depressive symptoms were clearly improved. On the basis of data issues from recent positron emission tomography (PET) studies, several authors suggested that the dose of pindolol used in most clinical trials (3 yen 2,5 mg day-1) might be insufficient to induce a substantial occupancy of 5-HTA receptors (Rabiner et al. It is possible that higher doses will show a more evident benefit. On the whole, pindolol seemed to be well tolerated. Adverse effects most commonly reported were increased irritability, insomnia and nausea. Pindolol had poor adverse effects in cardiovascular functions. The variation of the results of the controlled studies can be explained by different points: Firstly by difficulty to determine good criterion of resistance. The most simplistic definition of treatment resistance is the failure to achieve and sustain euthymia with adequate antidepressant treatment. Secondly by the fact that depressive patients who present antecedents of depressive illness seem to be worst responders to the association pindolol/serotoninergic antidepressant than patients suffering of first episode of depression. We observed one antecedent of depression in the group of resistant patients who were good responders to the association pindolol/antidepressant therapy. We observed three anterior episodes of depression in negatives studies of the association pindolol/antidepressant therapy. Thirdly by the fact that the failure of the antidepressant treatment at the time of earlier (or actual) episode seems to be a criterion for less responsiveness to the association of this antidepressant treatment with pindolol. In fact, the open label studies who demonstrated efficacy of the association between pindolol and serotoninergic therapy in major resistant depression were realized with new antidepressant molecule for the episode. Other controlled trials could confirm these facts. Most of the studies failed to retrace clearly the historicity of depression, and it may be interesting in future investigations to analyze the response of the association -compared to the status of the patient with the antidepressant therapy. Further perspective could be envisaged especially in the utilization of pindolol for the treatment of pathologies which are usually treated with a serotoninergic antidepressant -therapy. For example, the antagonist 5HT(1A) Way 100635 was experimented with success in animals in order to augment the efficacy of clomipramine in the treatment of chronic pain. In other respects several psychopharmacogenetics studies could be investigated to examine, for instance, the role of the 5-HT transporter and its implication in the response to pindolol and antidepressant association. In summary, pindolol accele-rates, and in some cases enhances the clinical action of antidepressant drugs. It appears that this augmentation strategy has more limited effect on treatment resistant patient but there is experimental evidence for using higher doses in future augmentation trial.
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PMID:[Interest of the use of pindolol in the treatment of depression: review]. 1461 4

The goal of this study was to determine if serotonergic activity, which is impaired in depression, regulates the phosphorylation of glycogen synthase kinase-3beta (GSK3beta) in mouse brain in vivo. GSK3beta is inhibited by phosphorylation on serine-9 and is a target of the mood stabilizer lithium. Following administration to mice of d-fenfluramine to stimulate serotonin (5HT) release and reduce its reuptake, and clorgyline to inhibit 5HT catabolism, levels of phospho-Ser9-GSK3beta were 300-400% of control levels in the prefrontal cortex, hippocampus, and striatum. Treatment with monoamine reuptake inhibitors fluoxetine and imipramine also increased the level of phospho-Ser9-GSK3beta. Using receptor selective agonists and antagonists, 5HT1A receptors were found to mediate increases, and 5HT2 receptors decreases, in phospho-Ser9-GSK3beta levels. This indicates that serotonergic regulation of the phosphorylation of GSK3beta is achieved by a balance between the opposing actions of these 5HT receptor subtypes. These findings demonstrate for the first time that serotonergic activity regulates the phosphorylation of GSK3beta and show that this regulation occurs in mammalian brain in vivo. These results raise the possibility that impaired inhibitory control of GSK3beta may occur in conditions where serotonergic activity is dysregulated, such as in mood disorders.
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PMID:In vivo regulation of glycogen synthase kinase-3beta (GSK3beta) by serotonergic activity in mouse brain. 1503 69

cAMP regulates immune responses, and modifications in cAMP signaling are involved in the pathophysiology and treatment of depression. In the present report, basal and forskolin-stimulated levels of cAMP were determined in mononuclear cells and lymphocytes from control individuals and major depression patients. Twenty-eight patients between 24 and 59 years old were diagnosed for a major depression episode according to the criteria of the Structural Clinical Interview for Disorders of Axis I of the American Psychiatric Association. These patients presented a score of 25 for severity as measured by Hamilton Rating Scale of Depression (HAM-D), and 23 for Beck Inventory of Depression (BID). Control and patient mononuclear cells were isolated by Ficoll/Hypaque gradients and their lymphocytes were separated from the total mononuclear population by differential adhesion to plastic surface. The basal concentration of cAMP was 50% lower in mononuclear cells and lymphocytes from the depressed patients compared with the control subjects. The response to forskolin was significantly smaller in lymphocytes of major depression patients than in the controls, but no difference was evident in the mononuclear cell preparations. There was a significant increase in cAMP produced by 5HT in mononuclear cells from the control group, but not in their lymphocytes. This effect on mononuclear cells was reduced by the antagonist of 5HT1A receptors, WAY-100,135. However, the simultaneous addition of a specific agonist of 5HT1A receptors, 8-hydroxy-(dipropylamino)tetralin (DPAT) and WAY-100,135 resulted in higher levels of cAMP than with the agonist alone. This effect probably indicates the blockade of 5HT1A receptors and action of 5HT1A agonist on the other subtypes of serotonin receptors expressed on human lymphocytes. This response was not observed in the patient's lymphocytes. In lymphocytes from major depression patients, serotonin and 8-hydroxy-(dipropylamino)tetralin significantly increased cAmp levels, which was slightly reduced by WAY-100,135. The present report indicates: (1) differential responses of immune cells from control individuals and depressed patients, with lower apparent adenylate cyclase activity in patient's cells; (2) variation in the population of cells, with responses to serotonergic agonists being lower in mononuclear cells and higher in lymphocytes from major depression patients; (3) increases of cAMP levels by serotonin and 5HT1A agonist in the patient's cells; and (4) evidence of impairment in serotonergic transduction systems in immune cells during depression.
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PMID:Differential cAMP levels and serotonin effects in blood peripheral mononuclear cells and lymphocytes from major depression patients. 1527 25

Aging involves neuronal and synaptic loss, and maintenance of function depends on adaptations in cellular responsiveness. We studied olfactory bulbectomy (OBX), a model that recapitulates monoaminergic dysfunction in depression, in 10-week vs 19-month-old rats, and evaluated 5HT (5-hydroxytryptamine, serotonin) mechanisms. OBX elicited little change in 5HT1A receptors in the cerebral cortex or striatum of either age group. In contrast, 5HT2 receptors showed disparate effects, with a decrease in the cerebral cortex of young OBX but not aging OBX rats, whereas the latter group showed a selective decrease in striatal 5HT2 receptors. Greater differences were apparent for 5HT-mediated cell signaling, assessed for the adenylyl cyclase (AC) cascade. In young animals, 5HT had a stimulatory effect on AC that was unaltered by OBX. However, in aging animals, the pattern of 5HT responses showed marked alterations in response to OBX: under basal conditions, stimulatory effects were enhanced but when AC was activated with forskolin, 5HT became markedly inhibitory in the striatum of aged OBX animals. Assessment of the relative AC responses to two direct stimulants that act on different epitopes of the enzyme, forskolin and Mn2+, pointed to a shift in the AC isoform and/or its ability to associate with G-proteins as the mechanism underlying the age-related differences for OBX effects. These data indicate that there are biological distinctions in the response of 5HT systems to OBX in young adult vs aging animals, which, if present in geriatric depression, could provide a mechanistic basis for differences in responses to antidepressants that act on 5HT.
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PMID:Serotonergic cell signaling in an animal model of aging and depression: olfactory bulbectomy elicits different adaptations in brain regions of young adult vs aging rats. 1536 26

The impact of acute and chronic stress on the hypothalamic-pituitary-adrenal (HPA) axis is reviewed and evidence presented that corticotrophin releasing factor (CRF) is the stress neurotransmitter which plays an important role in the activation of the central sympathetic and serotonergic systems. The activity of CRF is expressed through specific receptors (CRF 1 and 2) that are antagonistic in their actions and widely distributed in the limbic regions of the brain, as well as in the hypothalamus, and on immune cells. The mechanism whereby chronic stress, via the CRF induced activation of the dorsal raphe nucleus, can induce a change in the serotonergic system, involves an increase in the 5HT2A and a decrease in the 5HT1A receptor mediated function. Such changes contribute to the onset of anxiety and depression. In addition, the hypersecretion of glucocorticoids that is associated with chronic stress and depression desensitises the central glucocorticoid receptors to the negative feedback inhibition of the HPA axis. This indirectly results in the further activation of the HPA axis. The rise in pro-inflammatory cytokines that usually accompanies the chronic stress response results in a further stimulation of the HPA axis thereby adding to the stress response. While CRF would appear to play a pivotal role, evidence is provided that simultaneous changes in the serotonergic and noradrenergic systems, combined with the activation of peripheral and central macrophages that increase the pro-inflammatory cytokine concentrations in the brain and blood, also play a critical role in predisposing to anxiety and depression. Neurodegenerative changes in the brain that frequently occur in the elderly patient with major depression, could result from the activation of indoleaminedioxygenase (IDO), a widely distributed enzyme that converts tryptophan via the kynenine pathway to for the neurotoxic end product quinolinic acid.
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PMID:The HPA and immune axes in stress: the involvement of the serotonergic system. 1645 40

The 5HT1A receptor is one of at least 14 different receptors for serotonin which has a role in moderating several brain functions and may be involved in the aetiology of several psychiatric disorders. The C(-1019)G 5-HT1A promoter polymorphism was reported to be associated with major depression, depression-related personality traits and suicidal behavior in various samples. The G(-1019) allele carriers are prone to depressive personality traits and suicidal behavior, because serotonergic neurotransmission is reduced. The aim of this study is to replicate previous findings in a sample of 185 Alcohol-dependent individuals. Personality traits were evaluated using the NEO FFI and TCI. History of suicidal behavior was assessed by a standardized semistructured interview (SSAGA). No significant differences across C(-1019)G 5-HT1A genotype groups were found for TCI temperament and character traits and for NEO FFI personality scales. No association was detected between this genetic variant and history of suicide attempts. These results neither support a role of C(-1019)G 5-HT1A promoter polymorphism in the disposition of personality traits like harm avoidance or neuroticism, nor confirm previous research reporting an involvement of the G allele in suicidal behavior in alcoholics. Significant associations, however, were detected between Babor's Type B with number of suicide attempts in history, high neuroticism and harm avoidance scores in alcoholics.
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PMID:The C(-1019)G 5-HT1A promoter polymorphism and personality traits: no evidence for significant association in alcoholic patients. 1650 34

Anxiety and depression are common disorders that frequently co-exist. Both disorders show good response to antidepressants, especially the selective serotonin reuptake inhibitors. Some suggest that these disorders are variants of the same underlying brain pathology. This review examines the similarities and differences between anxiety and depression in terms of the known neurobiological etiologic mechanisms as well as their biological underpinnings and response to treatment. Sufficient and significant differences between these disorders support the view that they are independent entities. Shared abnormalities in the 5HT1A receptor function, for example, may help explain some of the comorbidity.
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PMID:Understanding the neurobiology of comorbidity in anxiety disorders. 1700 26

Genetic background influences the responsiveness to stress and plays a crucial role in the pathophysiology of depression. In an animal model of depression, Flinders Sensitive Line rats, and Sprague Dawley controls we analyzed if 7 weeks of social isolation of adult animals affect the number of newly proliferated cells in the dentate gyrus or mRNAs of Neuropeptide Y (NPY), the NPY-Y1 receptor, nociceptin, BDNF, and the serotonin 5HT1A and 5HT2A receptors, which are molecules involved in hippocampal plasticity. Since depressive illness more frequently affects women than men, and females seem to respond differently to stressful experiences than males, female rats were used in this study. Bromodeoxyuridine, which is a thymidin analogue that is incorporated into the DNA of newly formed cells, was administered during 9 days to even out the effects of hormonal fluctuations. Social isolation increased the number of newly proliferated Bromodeoxyuridine-immunoreactive cells in the Flinders Sensitive Line rats, whereas it had no impact on the number of cells in the Sprague Dawley strain. Group housed Sprague Dawley rats had a higher expression of BDNF, NPY, and the serotonin 5HT2A receptor mRNA than "depressed" Flinders Sensitive Line. Social isolation downregulated these molecules in Sprague Dawley but not in Flinders Sensitive Line rats thereby eliminating the differences between the two strains. We demonstrate strain and gender specific responses to stress induced regulation of factors important for hippocampal plasticity.
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PMID:Social isolation increases number of newly proliferated cells in hippocampus in female flinders sensitive line rats. 1787 75

The 5-HT re-uptake inhibitor (SSRI) fluoxetine and the adrenal hormone dehydroepiandrosterone (DHEA) both increase the proliferation of progenitor cells in the adult hippocampus and also have antidepressant activity. This paper explores the combined ability of fluoxetine and DHEA to affect this process in the dentate gyrus of adult rats. We show that DHEA can render an otherwise ineffective dose of fluoxetine (2.5 mg/kg) able to increase progenitor cell proliferation to the same extent as doses four times higher (10 mg/kg). This synergistic action does not appear to be mediated by alterations in brain-derived neurotrophic factor (BDNF) gene expression; or by TrkB, mineralocorticoid, glucocorticoid, or 5-HT (5HT1A) receptor expression in the dentate gyrus; or by altered levels of plasma corticosterone. In a second experiment, the synergism between DHEA and fluoxetine was replicated. Furthermore, flattening the diurnal rhythm of plasma corticosterone by implanting additional corticosterone pellets s.c. prevented the effect of fluoxetine on progenitor cell division. This was not overcome by simultaneous treatment with DHEA, despite the latter's reported anti-glucocorticoid actions. The cellular mechanism for the potentiating action of DHEA on the pro- proliferative effects of fluoxetine in the adult hippocampus remains to be revealed. Since altered neurogenesis has been linked to the onset or recovery from depression, one consequence of these results is to suggest DHEA as a useful adjunct therapy for depression.
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PMID:Synergistic effects of dehydroepiandrosterone and fluoxetine on proliferation of progenitor cells in the dentate gyrus of the adult male rat. 1906 26

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