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ABSTRACT: PURPOSE: Preclinical positron emission tomography studies are important to follow disease progression and develop new pharmacological agents. We investigated whether kinetic modeling of 5-HT2A tracer [(11)C]MDL 100907 is possible in rats. PROCEDURES AND RESULTS: Kinetic modeling with either metabolite-corrected plasma curve or with the cerebellum as a reference tissue resulted in a good correlation of nondisplaceable binding potential (BPND) calculated from a two-tissue compartment model (2TCM) or different reference tissue models. Injecting the tracer by a slower bolus decreases the variation in 2TCM outcome parameters and results in a good correlation between k3/k4 and the other models. Application of 0.2 mg/kg cold MDL 100907 resulted in almost complete occupancy of 5-HT2A receptors. CONCLUSIONS: A reference tissue model can be used for [(11)C]MDL kinetic modeling in rats, which is preferable in pharmacological or longitudinal studies.
Molecular imaging and biology: MIB: the official publication of the Academy of Molecular Imaging 05/2013; · 2.47 Impact Factor
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ABSTRACT: RATIONALE: A substantial body of research suggests that the neuropeptide oxytocin promotes social affiliative behaviors in a wide range of animals including humans. However, its antiaggressive action has not been unequivocally demonstrated in male laboratory rodents. OBJECTIVE: Our primary goal was to examine the putative serenic effect of oxytocin in a feral strain (wild type Groningen, WTG) of rats that generally show a much broader variation and higher levels of intermale aggression than commonly used laboratory strains of rats. METHODS: Resident animals were intracerebroventricularly (icv) administered with different doses of synthetic oxytocin and oxytocin receptor antagonist, alone and in combination, in order to manipulate brain oxytocin functioning and to assess their behavioral response to an intruder. RESULTS: Our data clearly demonstrate that acute icv administered oxytocin produces dose-dependent and receptor-selective changes in social behavior, reducing aggression and potentiating social exploration. These antiaggressive effects are stronger in the more offensive rats. On the other hand, administration of an oxytocin receptor antagonist tends to increase (nonsignificantly) aggression only in low-medium aggressive animals. CONCLUSIONS: These results suggest that transiently enhancing brain oxytocin function has potent antiaggressive effects, whereas its attenuation tends to enhance aggressiveness. In addition, a possible inverse relationship between trait aggression and endogenous oxytocinergic signaling is revealed. Overall, this study emphasizes the importance of brain oxytocinergic signaling for regulating intermale offensive aggression. This study supports the suggestion that oxytocin receptor agonists could clinically be useful for curbing heightened aggression seen in a range of neuropsychiatric disorders like antisocial personality disorder, autism, and addiction.
Psychopharmacologia 04/2013; · 4.08 Impact Factor
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ABSTRACT: To investigate the potential of white blood cells as probes for central processes we have measured gene expression in both the anterior cingulate cortex and white blood cells using a putative animal model of negative symptoms in schizophrenia.
The model is based on the capability of ketamine to induce psychotic symptoms in healthy volunteers and to worsen such symptoms in schizophrenic patients. Classical fear conditioning is used to assess emotional processing and cognitive function in animals exposed to sub-chronic ketamine vs. controls. Gene expression was measured using a commercially sourced whole genome rat gene array. Data analyses were performed using ANOVA (Systat 11).
In both anterior cingulate cortex and white blood cells a significant interaction between ketamine and fear conditioning could be observed. The outcome is largely supported by our subsequent metagene analysis. Moreover, the correlation between gene expression in brain and blood is about constant when no ketamine is present (r~0.4). With ketamine, however, the correlation becomes very low (r~0.2) when there is no fear, but it increases to ~0.6 when fear and ketamine are both present. Our results show that under normal conditions ketamine lowers gene expression in the brain, but this effect is completely reversed in combination with fear conditioning, indicating a stimulatory action.
This paradoxical outcome indicates that extreme care must be taken when using gene expression data from white blood cells as marker for psychiatric disorders, especially when pharmacological and environmental interactions are at play.
Progress in Neuro-Psychopharmacology and Biological Psychiatry 08/2012; 38(2):142-8. · 3.25 Impact Factor
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ABSTRACT: Sex differences in stress reactivity may be one of the factors underlying the increased sensitivity for the development of psychopathologies in women. Particularly, an increased hypothalamic-pituitary-adrenal (HPA) axis reactivity in females may exacerbate stress-induced changes in neuronal plasticity and neurogenesis, which in turn may contribute to an increased sensitivity to psychopathology. The main aim of the present study was to examine male-female differences in stress-induced changes in different aspects of hippocampal neurogenesis, i.e. cell proliferation, differentiation and survival. Both sexes were exposed to a wide variety of stressors, where after differences in HPA-axis reactivity and neurogenesis were assessed. To study the role of oestradiol in potential sex differences, ovariectomized females received low or high physiological oestradiol level replacement pellets. The results show that females in general have a higher basal and stress-induced HPA-axis activity than males, with minimal differences between the two female groups. Cell proliferation in the dorsal hippocampus was significantly higher in high oestradiol females compared to low oestradiol females and males, while doublecortin (DCX) expression as a marker of cell differentiation was significantly higher in males compared to females, independent of oestradiol level. Stress exposure did not significantly influence cell proliferation or survival of new cells, but did reduce DCX expression. In conclusion, despite the male-female differences in HPA-axis activity, the effect of repeated stress exposure on hippocampal cell differentiation was not significantly different between sexes.
Behavioural brain research 07/2012; 234(2):357-64. · 3.22 Impact Factor
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ABSTRACT: Alzheimer's disease (AD) is associated with an altered immune response, resulting in chronic increased inflammatory cytokine production with a prominent role of TNF-α. TNF-α signals are mediated by two receptors: TNF receptor 1 (TNFR1) and TNF receptor 2 (TNFR2). Signaling through TNFR2 is associated with neuroprotection, whereas signaling through TNFR1 is generally proinflammatory and proapoptotic. Here, we have identified a TNF-α-induced proinflammatory agent, lipocalin 2 (Lcn2) via gene array in murine primary cortical neurons. Further investigation showed that Lcn2 protein production and secretion were activated solely upon TNFR1 stimulation when primary murine neurons, astrocytes, and microglia were treated with TNFR1 and TNFR2 agonistic antibodies. Lcn2 was found to be significantly decreased in CSF of human patients with mild cognitive impairment and AD and increased in brain regions associated with AD pathology in human postmortem brain tissue. Mechanistic studies in cultures of primary cortical neurons showed that Lcn2 sensitizes nerve cells to β-amyloid toxicity. Moreover, Lcn2 silences a TNFR2-mediated protective neuronal signaling cascade in neurons, pivotal for TNF-α-mediated neuroprotection. The present study introduces Lcn2 as a molecular actor in neuroinflammation in early clinical stages of AD.
The FASEB Journal 03/2012; 26(7):2811-23. · 5.71 Impact Factor
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ABSTRACT: Dissociative identity disorder (DID) is a disputed psychiatric disorder. Research findings and clinical observations suggest that DID involves an authentic mental disorder related to factors such as traumatization and disrupted attachment. A competing view indicates that DID is due to fantasy proneness, suggestibility, suggestion, and role-playing. Here we examine whether dissociative identity state-dependent psychobiological features in DID can be induced in high or low fantasy prone individuals by instructed and motivated role-playing, and suggestion.
DID patients, high fantasy prone and low fantasy prone controls were studied in two different types of identity states (neutral and trauma-related) in an autobiographical memory script-driven (neutral or trauma-related) imagery paradigm. The controls were instructed to enact the two DID identity states. Twenty-nine subjects participated in the study: 11 patients with DID, 10 high fantasy prone DID simulating controls, and 8 low fantasy prone DID simulating controls. Autonomic and subjective reactions were obtained. Differences in psychophysiological and neural activation patterns were found between the DID patients and both high and low fantasy prone controls. That is, the identity states in DID were not convincingly enacted by DID simulating controls. Thus, important differences regarding regional cerebral bloodflow and psychophysiological responses for different types of identity states in patients with DID were upheld after controlling for DID simulation.
The findings are at odds with the idea that differences among different types of dissociative identity states in DID can be explained by high fantasy proneness, motivated role-enactment, and suggestion. They indicate that DID does not have a sociocultural (e.g., iatrogenic) origin.
PLoS ONE 01/2012; 7(6):e39279. · 4.09 Impact Factor
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ABSTRACT: Due to the lack of a specific diagnostic tool for neuropathic pain, a grading system to categorize pain as 'definite', 'probable', 'possible' and 'unlikely' neuropathic was proposed. Somatosensory abnormalities are common in neuropathic pain and it has been suggested that a greater number of abnormalities would be present in patients with 'probable' and 'definite' grades. To test this hypothesis, we investigated the presence of somatosensory abnormalities by means of Quantitative Sensory Testing (QST) in patients with a clinical diagnosis of neuropathic pain and correlated the number of sensory abnormalities and sensory profiles to the different grades. Of patients who were clinically diagnosed with neuropathic pain, only 60% were graded as 'definite' or 'probable', while 40% were graded as 'possible' or 'unlikely' neuropathic pain. Apparently, there is a mismatch between a clinical neuropathic pain diagnosis and neuropathic pain grading. Contrary to the expectation, patients with 'probable' and 'definite' grades did not have a greater number of abnormalities. Instead, similar numbers of somatosensory abnormalities were identified for each grade. The profiles of sensory signs in 'definite' and 'probable' neuropathic pain were not significantly different, but different from the 'unlikely' grade. This latter difference could be attributed to differences in the prevalence of patients with a mixture of sensory gain and loss and with sensory loss only. The grading system allows a separation of neuropathic and non-neuropathic pain based on profiles but not on the total number of sensory abnormalities. Our findings indicate that patient selection based on grading of neuropathic pain may provide advantages in selecting homogenous groups for clinical research.
PLoS ONE 01/2012; 7(8):e43526. · 4.09 Impact Factor
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ABSTRACT: In patients who experience unilateral chronic pain, abnormal sensory perception at the non-painful side has been reported. Contralateral sensory changes in these patients have been given little attention, possibly because they are regarded as clinically irrelevant. Still, bilateral sensory changes in these patients could become clinically relevant if they challenge the correct identification of their sensory dysfunction in terms of hyperalgesia and allodynia. Therefore, we have used the standardized quantitative sensory testing (QST) protocol of the German Research Network on Neuropathic Pain (DFNS) to investigate somatosensory function at the painful side and the corresponding non-painful side in unilateral neuropathic pain patients using gender- and age-matched healthy volunteers as a reference cohort. Sensory abnormalities were observed across all QST parameters at the painful side, but also, to a lesser extent, at the contralateral, non-painful side. Similar relative distributions regarding sensory loss/gain for non-nociceptive and nociceptive stimuli were found for both sides. Once a sensory abnormality for a QST parameter at the affected side was observed, the prevalence of an abnormality for the same parameter at the non-affected side was as high as 57% (for Pressure Pain Threshold). Our results show that bilateral sensory dysfunction in patients with unilateral neuropathic pain is more rule than exception. Therefore, this phenomenon should be taken into account for appropriate diagnostic evaluation in clinical practice. This is particularly true for mechanical stimuli where the 95% Confidence Interval for the prevalence of sensory abnormalities at the non-painful side ranges between 33% and 50%.
PLoS ONE 01/2012; 7(5):e37524. · 4.09 Impact Factor
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Nikoletta Dobos,
Erik F J de Vries,
Ido P Kema,
Konstantinos Patas,
Marloes Prins,
Ingrid M Nijholt,
Rudi A Dierckx,
Jakob Korf, Johan A den Boer,
Paul G M Luiten,
Ulrich L M Eisel
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ABSTRACT: Indoleamine 2,3-dioxygenase (IDO), an enzyme which is activated by pro-inflammatory cytokines, has been suggested as a potential link between neuroinflammatory processes in neurodegenerative diseases (like Alzheimer's disease) and depression. The present study aimed to determine whether neuroinflammation-induced increased IDO levels in the mammalian brain will lead to depressive-like behavior. Neuroinflammation was initiated in mice by a single intracerebroventricular injection of lipopolysaccharide (LPS). Cerebral inflammation was monitored 1, 2, 3 and 4 days after the injection with small-animal positron emission tomography (PET) using the inflammatory marker [(11)C]-PK11195. In the presence or absence of systemically applied 1-methyl-tryptophan (1-MT), a competitive IDO-inhibitor, we assessed the development of depressive-like behavioral symptoms in parallel with IDO expression and activity. The PK11195 PET signal reached a highly significant peak 3 days after LPS injection, while these animals displayed a significant increase of depressive-like behavior in the forced swim test compared to vehicle-injected animals. These findings were paralleled by a significant increase of IDO in the brainstem, and an increased kynurenine/tryptophan ratio in the serum. Moreover, we report here for the first time, that inhibition of IDO by 1-MT in centrally induced neuroinflammation under experimental conditions can prevent the development of depressive-like behavior.
Journal of Alzheimer's disease: JAD 11/2011; 28(4):905-15. · 3.74 Impact Factor
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ABSTRACT: A major component in the protection of the brain against blood-borne toxic influences is the multispecific efflux pump P-glycoprotein. This pump, a 170 kD protein, located at the luminal side of the capillary endothelial cells, has a large capacity and is capable of extruding a wide array of structurally divergent substrates. The brain uptake of the majority of antidepressants and antipsychotics, as well as many other psychotropic drugs and endogenous compounds is hampered by the activity of P-glycoprotein. In this review we discuss the current state of knowledge concerning the role of Pglycoprotein on pharmacokinetics of psychiatric drugs and the impact of modulation of P-glycoprotein on major psychiatric disorders. Relevant issues in reference to the function of P-glycoprotein and other efflux pumps in the blood-brain barrier related to mood disorders and schizophrenia are addressed, such as a possible role of P-glycoprotein as a susceptibility factor in depressive disorders and psychotic disorders.
Central Nervous System Agents in Medicinal Chemistry(Formerly Current Medicinal Chemistry - Central Nervous System Agents) 09/2011; 11(3):197-209.
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ABSTRACT: The antidepressant agomelatine acts as a melatonergic receptor (MT(1)/MT(2)) agonist and 5-HT(2C) receptor antagonist. Agomelatine has demonstrated efficacy in treating depression, but its neurobiological effects merit further investigation. Preclinical studies reported that agomelatine enhances adult hippocampal neurogenesis and increases expression of several neuroplasticity-associated molecules. Recently, we showed that agomelatine normalizes hippocampal neuronal activity and promotes neurogenesis in the stress-compromised brain. To characterize further the effects of this antidepressant in the stressed brain, here we investigated whether it induces changes in the expression of synapsin I (SynI), a regulator of synaptic transmission and plasticity. Adult male rats were subjected to daily footshock stress and agomelatine treatment for 3 weeks. Their brains were subsequently stained for total and phosphorylated SynI. Chronic footshock and agomelatine induced region-specific changes in SynI expression. Whereas chronic stress increased total SynI expression in all layers of the medial prefrontal cortex, agomelatine treatment abolished some of these effects. Furthermore, chronic agomelatine administration decreased total SynI expression in the hippocampal subregions of both stressed and nonstressed rats. Importantly, chronic stress decreased the fraction of phosphorylated SynI in all layers of the medial prefrontal cortex as well as selectively in the outer and middle molecular layers of the hippocampal dentate gyrus. These stress effects were at least partially abolished by agomelatine. Altogether, our data show that chronic stress and agomelatine treatment induce region-specific changes in SynI expression and its phosphorylation. Moreover, agomelatine partially counteracts the stress effects on SynI, suggesting a modulation of synaptic function by this antidepressant.
Journal of Neuroscience Research 06/2011; 89(10):1646-57. · 2.74 Impact Factor
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ABSTRACT: Cognitive behaviour therapy (CBT) is considered to be effective in the reduction of obsessive compulsive symptoms. However, questions remain as to how CBT works. Cognitive-behavioural models postulate that negative appraisals of intrusive thoughts and dysfunctional beliefs that give rise to them underlie the development and maintenance of obsessive-compulsive disorder (OCD). The current study aimed to study this hypothesis by investigating the processes of change over the course of cognitive treatment for OCD. Furthermore, a new theoretical approach and method for studying processes of change was presented. The participants were seven patients suffering from OCD with predominantly checking symptoms. Process variables (beliefs, anxiety and compulsions) were measured using idiosyncratic diaries and were analysed on an intra- and inter-individual level using dynamic systems methods. Results showed significant decreases in credibility of dysfunctional beliefs in six out of the seven participants, which is in line with the cognitive-behavioural model. Associations between process variables were in general medium to high. However, the actual patterns of change showed important intra- and interpersonal differences. Results indicated that different paths can lead to clinical recovery, and it was concluded that process studies that focus on individual trajectories of change can contribute to our understanding of OCD and its treatment. Furthermore, dynamic systems methods provide insight into intra-individual processes and shed a new light on variability.
Clinical Psychology & Psychotherapy 05/2011; 18(3):256-73. · 1.66 Impact Factor
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ABSTRACT: The antidepressant agomelatine is a MT(1)/MT(2) receptor agonist and 5-HT(2C) antagonist. Its antidepressant activity is proposed to result from the synergy between these sets of receptors. Agomelatine-induced changes in the brain have been reported under basal conditions. Yet, little is known about its effects in the brain exposed to chronic stress as a risk factor for major depressive disorder. Recently, we described agomelatine-induced changes on neuronal activity and adult neurogenesis in the hippocampus of rats subjected to chronic footshock stress. In order to better characterize the actions of agomelatine in the stress-compromised brain, here we investigated its effects on hippocampal neurogenesis in the chronic mild stress (CMS) model. Adult male rats were subjected to various mild stressors for 5 weeks, and treated with agomelatine during the last 3 weeks of the stress period. The sucrose preference test was performed weekly to measure anhedonia, and the marble burying test was carried out at the end of the experiment to assess anxiety-like behavior. In our model, the CMS paradigm did not change sucrose preference; however, it increased marble burying behavior, indicating enhanced anxiety. Interestingly, this stress model differentially affected distinct stages of the neurogenesis process. Whereas CMS did not influence the rate of hippocampal cell proliferation, it significantly decreased the newborn cell survival and doublecortin expression in the dentate gyrus. Importantly, treatment with agomelatine completely normalized stress-affected cell survival and partly reversed reduced doublecortin expression. Taken together, these data show that agomelatine has beneficial effects on hippocampal neurogenesis in the CMS paradigm.
Behavioural brain research 03/2011; 218(1):121-8. · 3.22 Impact Factor
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ABSTRACT: The serotonergic system of the brain is complex, with an extensive innervation pattern covering all brain regions and endowed with at least 15 different receptors (each with their particular distribution patterns), specific reuptake mechanisms and synthetic processes. Many aspects of the functioning of the serotonergic system are still unclear, partially because of the difficulty of measuring physiological processes in the living brain. In this review we give an overview of the conventional methods of measuring serotonin synthesis and methods using positron emission tomography (PET) tracers, more specifically with respect to serotonergic function in affective disorders. Conventional methods are invasive and do not directly measure synthesis rates. Although they may give insight into turnover rates, a more direct measurement may be preferred. PET is a noninvasive technique which can trace metabolic processes, like serotonin synthesis. Tracers developed for this purpose are α-[(11)C]methyltryptophan ([(11)C]AMT) and 5-hydroxy-L-[β-(11)C]tryptophan ([(11)C]5-HTP). Both tracers have advantages and disadvantages. [(11)C]AMT can enter the kynurenine pathway under inflammatory conditions (and thus provide a false signal), but this tracer has been used in many studies leading to novel insights regarding antidepressant action. [(11)C]5-HTP is difficult to produce, but trapping of this compound may better represent serotonin synthesis. AMT and 5-HTP kinetics are differently affected by tryptophan depletion and changes of mood. This may indicate that both tracers are associated with different enzymatic processes. In conclusion, PET with radiolabelled substrates for the serotonergic pathway is the only direct way to detect changes of serotonin synthesis in the living brain.
European Journal of Nuclear Medicine 03/2011; 38(3):576-91. · 4.53 Impact Factor
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ABSTRACT: Stressful events during childhood are thought to increase the risk for the development of adult psychopathology. A widely used animal model for early life stress is maternal separation (MS), which is thought to affect development and cause alterations in neuroendocrine stress reactivity and emotionality lasting into adulthood. However, results obtained with this paradigm are inconsistent. Here we investigated whether this variation may be related to the type of stressor or the tests used to assess adult stress sensitivity and behavioral performance. Rat pups were exposed to a 3h daily MS protocol during postnatal weeks 1-2. In adulthood, animals were subjected to a wide variety of stressors and tests to obtain a better view on the effects of MS on adult hypothalamic-pituitary-adrenal (HPA) axis regulation, anxiety-like behavior, social interaction and cognition. Also, the influence of MS on adult hippocampal neurogenesis was studied because it might underlie changes in neuroendocrine regulation and behavioral performance. The results show that, independent of the nature of the stressor, MS did not affect the neuroendocrine response. MS did not influence anxiety-like behavior, explorative behavior and social interaction, but did affect cognitive function in an object recognition task. The amount of new born cells in the hippocampal dentate gyrus was significantly decreased in MS animals; yet, cell differentiation and survival were not altered. In conclusion, while interfering with the mother-infant relationship early in life did affect some aspects of adult neuroplasticity and cognitive function, it did not lead to permanent changes in stress sensitivity and emotionality.
Behavioural brain research 01/2011; 216(2):552-60. · 3.22 Impact Factor
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ABSTRACT: Extensive research has been performed to unravel the mechanistic signaling pathways mediated by tumor necrosis factor receptor 1 (TNFR1), by contrast there is limited knowledge on cellular signaling upon activation of TNFR2. Recently published data have revealed that these two receptors not only function independently, but also can influence each other via cross-talk between the different signaling pathways initiated by TNFR1 and TNFR2 stimulation. Furthermore, the complexity of this cross-talk is also dependent on the different signaling kinetics between TNFR1 and TNFR2, by which a delicate balance between cell survival and apoptosis can be maintained. Some known signaling factors and the kinetics that are involved in the receptor cross-talk between TNFR1 and TNFR2 are the topic of this review.
FEBS Journal 01/2011; 278(6):888-98. · 3.79 Impact Factor
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Fokko J Bosker,
Marit A C Tanke,
Minke E Jongsma,
Thomas I F H Cremers,
Evelien Jagtman,
Charmaine Y Pietersen,
Marieke G C van der Hart,
Anatoliy V Gladkevich,
Ido P Kema,
Ben H C Westerink,
Jakob Korf, Johan A den Boer
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ABSTRACT: We have investigated effects of continuous SSRI administration and abrupt discontinuation on biochemical and behavioral indices of rat brain serotonin function, and attempted to identify underlying mechanisms. Biochemistry of serotonin was assessed with brain tissue assays and microdialysis; behavior was assessed as the acoustic startle reflex. Long-term SSRI administration to rats reduced the content of 5-HT and its main metabolite shortly after inhibition of 5-HT synthesis in many brain areas with more than 50%. Turnover was not appreciably decreased, but significantly increased within 48h of drug discontinuation. The microdialysis experiments indicate that neuronal release of 5-HT depends strongly on new synthesis and emphasize the role of 5-HT(1B) receptors in the regulation of these processes. Discontinuation of the SSRI rapidly increased behavioral reactivity to the external stimulus. Additional startle experiments suggest that the increased reactivity is more likely related to the reduced extracellular 5-HT levels than to impaired synthesis. The combination of the marked reduction of serotonin content and limited synthesis may destabilize brain serotonin transmission during long-term SSRI treatment. These combined effects may compromise the efficacy of an SSRI therapy and facilitate behavioral changes following non-compliance.
Neurochemistry International 10/2010; 57(8):948-57. · 2.86 Impact Factor
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ABSTRACT: P-glycoprotein (P-gp), a major efflux pump in the blood-brain barrier (BBB) has a profound effect on entry of drugs, peptides and other substances into the central nervous system (CNS). The brain's permeability can be negatively influenced by modulation of the transport function of P-gp. Inflammatory mediators play a role in schizophrenia, and may be able to influence the integrity of the BBB, via P-gp modulation. We hypothesized that P-gp function in the BBB is changed in patients with schizophrenia. Positron-emission tomography was used to measure brain uptake of [(11)C]verapamil, which is normally extruded from the brain by P-gp. We found that patients with chronic schizophrenia under treatment with antipsychotic drugs compared with healthy controls showed a significant decrease in [(11)C]verapamil uptake in the temporal cortex, the basal ganglia, and the amygdala, and amygdalae, and a trend towards a significant decrease was seen throughout the brain. The decrease of [(11)C]verapamil uptake correlates with an increased activity of the P-gp pump. Increased P-gp activity may be a factor in drug resistance in schizophrenia, induced by the use of antipsychotic agents.
Psychiatry Research 08/2010; 183(2):151-6. · 2.52 Impact Factor
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Kevin L Delucchi,
Hilga Katerberg,
S Evelyn Stewart,
Damiaan A J P Denys,
Christine Lochner,
Denise E Stack, Johan A den Boer,
Anton J L M van Balkom,
Michael A Jenike,
Dan J Stein,
Danielle C Cath,
Carol A Mathews
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ABSTRACT: Obsessive-compulsive disorder (OCD) is phenomenologically heterogeneous, and findings of underlying structure classification based on symptom grouping have been ambiguous to date. Variable-centered approaches, primarily factor analysis, have been used to identify homogeneous groups of symptoms; but person-centered latent methods have seen little use. This study was designed to uncover sets of homogeneous groupings within 1611 individuals with OCD based on symptoms.
Latent class analysis models using 61 obsessive-compulsive symptoms collected from the Yale-Brown Obsessive-Compulsive Scale were fit. Relationships between latent class membership and treatment response, sex, symptom severity, and comorbid tic disorders were tested for relationship to class membership.
Latent class analysis models of best fit yielded 3 classes. Classes differed only in frequency of symptom endorsement. Classes with higher symptom endorsement were associated with earlier age of onset, being male, higher Yale-Brown Obsessive-Compulsive Scale symptom severity scores, and comorbid tic disorders. There were no differences in treatment response between classes.
These results provide support for the validity of a single underlying latent OCD construct, in addition to the distinct symptom factors identified previously via factor analyses.
Comprehensive psychiatry 08/2010; 52(3):334-41. · 2.08 Impact Factor
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ABSTRACT: To establish the long-term effectiveness of 3 treatments for DSM-IV panic disorder with or without agoraphobia: cognitive-behavioral therapy (CBT), pharmacotherapy using a selective serotonin reuptake inhibitor (SSRI), or the combination of both (CBT + SSRI). As a secondary objective, the relationship between treatment outcome and 7 predictor variables was investigated.
Patients were enrolled between April 2001 and September 2003 and were randomly assigned to treatment. Academic and nonacademic clinical sites participated. Each treatment modality lasted 1 year. Pharmacotherapists were free to choose between 5 SSRIs currently marketed in The Netherlands. Outcome was assessed after 9 months of treatment (posttest 1), after discontinuation of treatment (posttest 2), and 6 and 12 months after treatment discontinuation (follow-up 1 and follow-up 2).
In the sample (N = 150), 48% did not suffer from agoraphobia or suffered from only mild agoraphobia, while 52% suffered from moderate or severe agoraphobia. Patients in each treatment group improved significantly from pretest to posttest 1 on the primary outcome measures of level of anxiety (P < .001), degree of coping (P < .001), and remitter status (P < .001), as well as on the secondary outcome measures of depressive symptomatology (P < .001), and from pretest to posttest 2 for health-related quality of life (P < .001). Gains were preserved from posttest 2 throughout the follow-up period. Some superiority of CBT + SSRI and SSRI as compared with CBT was observed at posttest 1. However, at both follow-ups, differences between treatment modalities proved nonsignificant. Client satisfaction appeared to be high at treatment endpoint, while patients receiving CBT + SSRI appeared slightly (P < .05) more satisfied than those receiving CBT only.
No fall-off in gains was observed for either treatment modality after treatment discontinuation. SSRIs were associated with adverse events. Gains produced by CBT were slower to emerge than those produced by CBT + SSRI and SSRI, but CBT ended sooner.
Netherlands Trial Register (www.trialregister.nl) Identifier: ISRCTN8156869.
The Journal of Clinical Psychiatry 05/2010; 71(5):574-86. · 5.80 Impact Factor
