| 1. |
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| 2. |
- Burstein, ES, et al.
(author)
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II. In vitro evidence that (-)-OSU6162 and (+)-OSU6162 produce their behavioral effects through 5-HT2A serotonin and D2 dopamine receptors
- 2011
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In: JOURNAL OF NEURAL TRANSMISSION. - 0300-9564. ; 118:11, s. 1523-1533
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Journal article (peer-reviewed)abstract
- Abstract: (-)-OSU6162 has promise for treating Parkinson's disease, Huntington's disease and schizophrenia. Behavioral tests evaluating the locomotor effects of (-) and (+)-OSU6162 on 'low activity' animals (reserpinized mice and habituated rats) and 'high activity' animals (drug naive mice and non-habituated rats) revealed that both enantiomers of OSU6162 had dual effects on behavior, stimulating locomotor activity in 'low activity' animals and inhibiting locomotor activity in 'high activity' animals. To elucidate a plausible mechanism of action for their behavioral effects, we evaluated the intrinsic actions of (-)- and (+)-OSU6162, and a collection of other antipsychotic and antiparkinsonian agents at 5-HT2A and D2 receptors in functional assays with various degrees of receptor reserve, including cellular proliferation, phosphatidyl inositol hydrolysis, GTP gamma S and beta-arrestin recruitment assays. We also tested for possible allosteric actions of (-)-OSU6162 at D2 receptors. Both enantiomers of OSU6162 were medium intrinsic activity partial agonists at 5-HT2A receptors and low intrinsic activity partial agonists at D2 receptors. (+)-OSU6162 had higher efficacy at 5-HT2A receptors, which correlated with its greater stimulatory activity in vivo, but (-)-OSU6162 had higher potency at D2 receptors, which correlated with its greater inhibitory activity in vivo. (-)-OSU6162 did not display any convincing allosteric properties. Both (+)- and (-)-OSU6162 were significantly less active at 27 other monoaminergic receptors and reuptake transporters tested suggesting that D2 and 5-HT2A receptors play crucial roles in mediating their behavioral effects. Compounds with balanced effects on these two receptor systems may offer promise for treating neuropsychiatric diseases.
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| 3. |
- Carlsson, Arvid, 1923, et al.
(author)
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A dopaminergic deficit hypothesis of schizophrenia: the path to discovery.
- 2006
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In: Dialogues in clinical neuroscience. - 1294-8322. ; 8:1, s. 137-42
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Journal article (peer-reviewed)abstract
- In contrast to the conventional view of dopamine involvement in schizophrenia, which posits hyperactive dopaminergic transmission, we propose that for unknown developmental and/or biochemical reasons, a primary defect occurs in efficient, tight dopaminergic synaptic transmission, triggering feedback activation and receptor upregulation, and resulting in the well-characterized increase in dopaminergic tone. This hypothesis is driven by suggestive evidence for subpopulations of dopamine D2 receptors delivering contrasting forms of dopaminergic transmission: synaptic receptors, responsible for basic dopaminergic function and subject to effective feedback control, and poorly controlled extrasynaptic receptors partly responsible for the positive symptoms of psychosis. Since the primary defect is dopamine deficiency, we term this theory the dopaminergic deficit hypothesis of schizophrenia. It is currently informing clinical studies with novel partial dopamine antagonists (dopamine stabilizers) such as ACR16, which preferentially target extrasynaptic receptors while leaving synaptic transmission and basic dopamine function intact.
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| 4. |
- Carlsson, Arvid, 1923, et al.
(author)
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Adaptive properties and heterogeneity of dopamine D(2) receptors - pharmacological implications.
- 2008
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In: Brain research reviews. - : Elsevier BV. - 0165-0173. ; 58:2, s. 374-8
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Journal article (peer-reviewed)abstract
- In this review, we focus on the marked adaptability of dopamine D(2) receptors to varying agonist levels and we discuss the extent to which this phenomenon can account for the heterogeneity of these receptors in regard to function and pharmacological responsiveness. We emphasize the significance of a distinction between synaptic and extrasynaptic receptors in this context. For example, the application of this dichotomy appears to shed new light on the various subgroups of antipsychotic drugs and the mechanisms underlying their different profiles.
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| 5. |
- Carlsson, Arvid, 1923, et al.
(author)
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Interactions between monoamines, glutamate, and GABA in schizophrenia: new evidence
- 2001
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In: Annu Rev Pharmacol Toxicol. - 0362-1642. ; 41, s. 237-60
-
Research review (peer-reviewed)abstract
- In spite of its proven heuristic value, the dopamine hypothesis of schizophrenia is now yielding to a multifactorial view, in which the other monoamines as well as glutamate and GABA are included, with a focus on neurotransmitter interactions in complex neurocircuits. The primary lesion(s) in schizophrenia does not necessarily involve any of these neurotransmitters directly but could deal with a more general defect, such as a faulty connectivity of developmental origin. Nevertheless, a precise identification of neurotransmitter aberrations in schizophrenia will probably provide clues for a better understanding of the disease and for the development of new treatment and prevention strategies.
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| 6. |
- Carlsson, Maria L., 1959, et al.
(author)
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Schizophrenia: from dopamine to glutamate and back.
- 2004
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In: Current medicinal chemistry. - 0929-8673. ; 11:3, s. 267-77
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Journal article (peer-reviewed)abstract
- The first part of the present review describes the exciting journey of dopamine stabilizers, starting in the early eighties with the development of the partial dopamine agonist (-)-3-PPP of phenylpiperidine structure, via various compounds with aminotetraline structure with preferential autoreceptor antagonist properties, and then back again to phenylpiperidine compounds carrying substituents on the aromatic ring that transformed them from partial dopamine agonists to partial dopamine receptor antagonists, such as OSU6162. OSU6162 was brought to the clinic and has in preliminary trials showed antidyskinetic and antipsychotic efficacy. The second part of this review describes results from a hypoglutamatergia mouse model for cognitive symptoms of schizophrenia, where we have tested traditional neuroleptics, new generation antipsychotics with marked 5-HT2 vs dopamine D2 receptor blockade as well as a dopamine stabilizer belonging to the partial dopamine receptor antagonist category.
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| 7. |
- Carlsson, Maria L., 1959, et al.
(author)
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The 5-HT2A receptor antagonist M100907 is more effective in counteracting NMDA antagonist- than dopamine agonist-induced hyperactivity in mice
- 1999
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In: J Neural Transm. - 0300-9564. ; 106:2, s. 123-9
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Journal article (peer-reviewed)abstract
- The purpose of the present study was to compare the effectiveness of the selective 5-HT2A antagonist M100907 in different psychosis models. The classical neuroleptic haloperidol was used as reference compound. Two hyperdopaminergia and two hypoglutamatergia mouse models were used. Hyperdopaminergia was produced by the DA releaser d-amphetamine or the DA uptake inhibitor GBR 12909. Hypoglutamatergia was produced by the un-competitive NMDA receptor antagonist MK-801 or the competitive NMDA receptor antagonist D-CPPene. M100907 was found to counteract the locomotor stimulant effects of the NMDA receptor antagonists MK-801 and D-CPPene, but spontaneous locomotion, d-amphetamine- and GBR-12909-induced hyperactivity were not significantly affected. Haloperidol, on the other hand, antagonized both NMDA antagonist- and DA agonist-induced hyperactivity, as well as spontaneous locomotion in the highest dose used. Based on the present and previous results we draw the conclusion that 5-HT2A receptor antagonists are particularly effective against behavioural anomalies resulting from hypoglutamatergia of various origins. The clinical implications of our results and conclusions would be that a 5-HT2A receptor antagonist, due to i a the low side effect liability, could be the preferable treatment strategy in various disorders associated with hypoglutamatergia; such conditions might include schizophrenia, childhood autism and dementia disorders.
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| 8. |
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| 9. |
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| 10. |
- Haghighi, S., et al.
(author)
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Open-label study with the monoamine stabilizer (-)-OSU6162 in myalgic encephalomyelitis/chronic fatigue syndrome
- 2021
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In: Brain and Behavior. - : Wiley. - 2162-3279. ; 11:4
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Journal article (peer-reviewed)abstract
- Objectives The purpose of the present study was to investigate the safety and tolerability of the monoaminergic stabilizer (-)-OSU6162 in patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). In addition, a potential therapeutic effect of (-)-OSU6162 in ME/CFS was evaluated by means of observer-rated scales and self-assessment rating scales. Materials and Methods In the current study using an open-label single-arm design ME/CFS patient received treatment with (-)-OSU6162 during 12 weeks. The patients received the following doses of (-)-OSU6162: 15 mg b.i.d. during the first 4-week period, up to 30 mg b.i.d. during the second 4-week period and up to 45 mg b.i.d. during the third 4-week period, with follow-up visits after 16 and 20 weeks. Results Out of 33 included patients, 28 completed the 12 weeks treatment period. (-)-OSU6162 was well tolerated; only one patient discontinued due to an adverse event. Vital signs and physical examinations showed no abnormal changes. Blood analyses showed an increase in serum prolactin. Therapeutically, improvements were seen on the Clinical Global Impression of Change scale, the FibroFatigue scale, the Mental Fatigue Scale, the Fatigue Severity Scale, Beck Depression Inventory, and the Short Form 36 Health Survey Questionnaire. Conclusions (-)-OSU6162 is well tolerated in ME/CFS patients and shows promise as a novel treatment to mitigate fatigue and improve mood and health-related quality of life in ME/CFS. Obviously, the present results need to be confirmed in future placebo-controlled double-blind trials.
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| 11. |
- Haghighi, S., et al.
(author)
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Open study with (-)-OSU6162 in multiple sclerosis-related fatigue
- 2018
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In: Acta Neurologica Scandinavica. - : Hindawi Limited. - 0001-6314. ; 138:6, s. 482-489
-
Journal article (peer-reviewed)abstract
- Objectives The main objective of this study was to investigate the tolerability and safety of the monoaminergic stabilizer (-)-OSU6162 in patients with multiple sclerosis (MS). In addition, a potential therapeutic effect of (-)-OSU6162 with focus on MS-related fatigue was estimated by means of various self-assessment rating scales as well as a clinical investigator-rated scale. Materials and methods In this open-label, single-arm study, 30 MS patients received treatment with the monoaminergic stabilizer (-)-OSU6162 during 12 weeks. The dose of (-)-OSU6162 was 15 mg twice daily during the first 4-week period, up to 30 mg twice daily during the second 4-week period and up to 45 mg twice daily during the third 4-week period, with follow-up visits after 16 and 20 weeks. MS-related fatigue was rated by the clinical investigator or by self-assessments, using mainly established rating scales. Twenty-five patients completed the study. Results (-)-OSU6162 was well tolerated by all patients, and no serious adverse events were observed. Therapeutically, improvements were observed with respect to fatigue and mood, as judged by ratings on the Mental Fatigue Scale (MFS), Short Form-36 (SF-36) scale and Beck Depression Inventory (BDI). Furthermore, the large majority of patients were rated as globally improved in the medical observers' rating scale Clinical Global Impression of Change (CGI-C). Conclusions In view of its good tolerability, (-)-OSU6162 may offer a new treatment option for alleviating mental fatigue, as well as depression, in MS. Larger, randomized double-blind controlled trials are warranted to confirm the present preliminary observations.
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| 12. |
- Johansson, Birgitta, 1957, et al.
(author)
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Placebo-controlled cross-over study of the monoaminergic stabiliser (-)-OSU6162 in mental fatigue following stroke or traumatic brain injury
- 2012
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In: Acta Neuropsychiatrica. - : Cambridge University Press (CUP). - 0924-2708 .- 1601-5215. ; 24:5, s. 266-274
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Journal article (peer-reviewed)abstract
- Objective Mental fatigue occurring after a stroke or traumatic brain injury (TBI) often results in difficulties returning to work and pursuing social activities. No effective treatment of this condition is available today. In this study, we have tested a novel pharmacological strategy using the monoaminergic stabiliser (-)-OSU6162. Methods (-)-OSU6162 was given orally for 4 weeks in doses increasing from 15 to 45 mg b.i.d. to 12 patients suffering from mental fatigue, following upon stroke (n?=?6) or TBI (n?=?6). (-)-OSU6162 was compared with placebo using a double-blind, randomised cross-over design. Patients included were well rehabilitated physically with no gross impairment in cognitive functions other than those related to the mental fatigue. Results (-)-OSU6162 caused a remarkable improvement in mental stamina, as evaluated by a self-assessment scale on mental fatigue. Statistical significance was reached on the primary endpoint (Mental Fatigue Scale). There was a trend towards improvement in the secondary endpoints processing speed and attention. Principal component analysis showed an overall positive treatment effect in 7 of 12 patients. Beneficial responses were seen already during the first few days of active drug treatment. Increasing dosage caused no further improvement. Adverse reactions consisted of short-lasting mild nausea and attenuated appetite. These side effects disappeared upon dose reduction. Conclusion The monoaminergic stabiliser (-)-OSU6162 offers promise as a candidate for treatment of mental fatigue after a stroke or TBI.
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| 13. |
- Kloberg, A., et al.
(author)
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Tolerability and efficacy of the monoaminergic stabilizer (-)-OSU6162 (PNU-96391A) in Huntington's disease: A double-blind cross-over study
- 2014
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In: Acta Neuropsychiatrica. - : Cambridge University Press. - 0924-2708 .- 1601-5215. ; 26:5, s. 298-306
-
Journal article (peer-reviewed)abstract
- Objective To evaluate the safety (primary objective) and efficacy (secondary objective) of (-)-OSU6162 in Huntington's disease (HD). Methods In a double-blind, cross-over trial, patients with HD were randomly assigned to start treatment on either (-)-OSU6162 or placebo. After 4 weeks, those patients who initially received active drug were switched to placebo for another 4 weeks, and vice versa. During the first week the (-)-OSU6162 dose was 15 mg twice daily, during the second week 30 mg twice daily, and during the last 2 weeks 45 mg twice daily. Motor, cognitive, mental and social functions were rated by the clinical investigator or by self-assessment, using established rating scales. Results Fifteen patients fulfilling inclusion and exclusion criteria completed the study. (-)-OSU6162 was well tolerated by all patients and no adverse effects were observed. (-)-OSU6162 treatment significantly improved the Short Form 36 Vitality score, mainly due to an improvement of the individual item 'worn-out' (VT3). In addition, an improvement of depressive symptoms was found using Beck Depression Inventory. In contrast to a general trend of improvement in several non-motor variables only small and non-significant differences between (-)-OSU6162 and placebo were found regarding motor functions. Conclusions (-)-OSU6162 offers promise for the treatment of HD, as a drug with good tolerability, capable of improving the patients' experienced non-motor functions such as energy and mood and thus alleviating symptoms of great importance for their quality of life. © © Scandinavian College of Neuropsychopharmacology 2014.
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| 14. |
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| 15. |
- Nilsson, Marie, 1968, et al.
(author)
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A randomised controlled trial of the monoaminergic stabiliser (−)-OSU6162 in treatment of myalgic encephalomyelitis/chronic fatigue syndrome
- 2018
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In: Acta Neuropsychiatrica. - : Cambridge University Press (CUP). - 0924-2708 .- 1601-5215. ; 30:3, s. 148-57
-
Journal article (peer-reviewed)abstract
- © Scandinavian College of Neuropsychopharmacology 2017 Objective: The monoaminergic stabiliser (−)-OSU6162 has in previous studies shown promising effects on mental fatigue after stroke and traumatic brain injury. This study investigated the safety and effectiveness of (−)-OSU6162 in patients with myalgic encephalomyelitis/chronic fatigue syndrome. Methods: A total of 62 patients were randomly assigned to placebo or (−)-OSU6162. Primary outcomes were assessment on the mental fatigue scale (MFS) and the clinical global impression of change (CGI-C) scale. Secondary outcomes were results on the FibroFatigue scale (FF), the Beck Depression Inventory (BDI), the pain visual analogue scale and neuropsychological tests. Assessments were performed at baseline, after 1 and 2 weeks of treatment and at follow-up after 6 weeks. Results: MFS and CGI-C showed significant improvements for both treatment groups after treatment but not at follow-up; a similar pattern was seen for FF and BDI. However, significant differences between groups could not be demonstrated. On the other hand, correlation analyses showed a significant correlation between (−)-OSU6162 concentration and change in MFS, FF, and BDI score within the concentration interval 0.1–0.7 µM. Exploratory subgroup analyses showed a larger treatment effect with (−)-OSU6162 in improving MFS and FF symptoms in patients on antidepressant therapy compared to those without antidepressant treatment. Conclusion: (−)-OSU6162 was found to be safe and well tolerated. When analysing the entire material (−)-OSU6162 was not found to differ significantly from placebo in alleviating fatigue in ME patients but was superior to placebo in counteracting fatigue in a subgroup of ME patients who received concomitant pharmacological treatment for depression.
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| 16. |
- Nilsson, Marie, 1968, et al.
(author)
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Differential effects of the N-methyl-d-aspartate receptor antagonist MK-801 on different stages of object recognition memory in mice.
- 2007
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In: Neuroscience. - : Elsevier BV. - 0306-4522. ; 149:1, s. 123-30
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Journal article (peer-reviewed)abstract
- The aim of the present study was to evaluate the effects of systemic administration of the N-methyl-d-aspartate (NMDA) receptor antagonist MK-801 on different stages of non-spatial object recognition memory processing in mice. To this end we used the object recognition test, where the animal is tested for its ability to discriminate between an old, familiar, and a novel object. MK-801 (0.1 or 0.2 mg/kg) or saline was administered 1) 30 min before or 2) directly after the first, introductory, session or 3) 30 min before the recognition session. Memory retention was evaluated 1.5 h after the introductory session. MK-801 appeared to decrease memory retention when given prior to the introductory session, but not when given directly after the introductory session or before the recognition session, where MK-801 instead induced an increased interest for the novel object. These results suggest that activation of NMDA receptors is a requisite for encoding of recognition memory in mice but not for consolidation and retrieval processes. The increased interest for the novel object showing up when MK-801 was given directly after the introductory session or before the recognition session may reflect a facilitation of retention. Alternatively, the phencyclidine-like, psychotogenic properties of MK-801 could result in an amplification of the perceived salience of the novel object, and/or anxiolytic mechanisms could result in neophilic effects.
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| 17. |
- Nilsson, Marie, 1968, et al.
(author)
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Glycine and D-serine decrease MK-801-induced hyperactivity in mice
- 1997
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In: J Neural Transm. - 0300-9564. ; 104:11-12, s. 1195-205
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Journal article (peer-reviewed)abstract
- It is well known that the un-competitive N-methyl-D-aspartate (NMDA) receptor antagonist phencyclidine can induce a syndrome in humans that mimics both positive and negative symptoms of schizophrenia. In the light of this observation, it has been hypothesised that schizophrenia might be due to a hypofunction of central glutamate systems. A glycine agonist, by strengthening glutamatergic transmission, has been suggested to be useful as treatment. A crucial issue is the uncertainty regarding the degree of saturation of the glycine site associated with the NMDA receptor. The purpose of this study was to investigate if it is possible to strengthen NMDA receptor-mediated neurotransmission by modulating the associated glycine site. The effects of systemic and intraventricular administration of glycine. D-serine and L-serine on the hyperactivity induced in mice by the uncompetitive NMDA receptor antagonist MK-801 were tested. Systemically administered glycine and D-serine were found to decrease MK-801-induced hyperactivity. Intraventricularly administered D-serine in doses of 50 or 100 micrograms/side was found to decrease MK-801-induced hyperactivity during the second half hour of registration; L-serine given in the same doses did not affect the MK-801-induced hyperactivity during this period. These data may suggest that the NMDA receptor-associated glycine site is not saturated in vivo.
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| 18. |
- Nilsson, Marie, 1968, et al.
(author)
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The dopaminergic stabiliser ACR16 counteracts the behavioural primitivization induced by the NMDA receptor antagonist MK-801 in mice: implications for cognition
- 2004
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In: Prog Neuropsychopharmacol Biol Psychiatry. - : Elsevier BV. - 0278-5846. ; 28:4, s. 677-85
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Journal article (peer-reviewed)abstract
- The Carlsson research group has developed a series of compounds capable of stabilising the dopamine system without inducing the deleterious hypodopaminergia that encumbers the currently used antipsychotic drugs. In the present study one of these dopaminergic stabilisers, ACR16, was tested in a mouse model for cognitive deficits of schizophrenia and autism. Since we believe that hypoglutamatergia is a key element in both schizophrenia and autism we used mice rendered hypoglutamatergic by treatment with the N-methyl-D-aspartate (NMDA) antagonist MK-801. MK-801 causes both hyperactivity and a behavioural primitivization. ACR16 attenuated the MK-801-induced hyperactivity and, in addition, caused a marked improvement of behavioural quality with a movement pattern approaching that of control animals. Since we believe that the impoverishment of the behavioural repertoire caused by MK-801 may correspond to the cognitive deficits seen in schizophrenia and autism, these results suggest that ACR16 may improve cognitive status in these disorders.
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| 19. |
- Nydén, Agneta, 1945, et al.
(author)
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Interhemispheric transfer in high-functioning children and adolescents with autism spectrum disorders: a controlled pilot study.
- 2004
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In: Developmental medicine and child neurology. - 0012-1622. ; 46:7, s. 448-54
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Journal article (peer-reviewed)abstract
- Autism is a neurodevelopmental disorder with strong genetic influences. Clinical experience and limited empirical evidence support the view that autism may be associated with aberrant interhemispheric information transfer. This empirical controlled study examined whether, at neuropsychological testing, children with autism showed problems with interhemispheric information transfer. The study included auditory, visual, and motor measures covering information transfer within, as well as across, modalities. Thirty children (24 males, 6 females; mean age 12 years 8 months, SD 2 years 8 months; range 9 years 5 months to 17 years 5 months) without learning disability but with autism spectrum disorders were compared with 30 children from a mainstream school matched for age, sex, and IQ>75. Children with autism spectrum disorder performed significantly worse than the comparison group on most of the tests (p=0.02 for auditory perception and attention, p=0.005 for visual perception, p=0.0001 for motor control, p=0.04 for tactile perception). Results support the notion that aberrant interhemispheric transfer may be involved in the pathogenesis or clinical course of autism. The findings were not accounted for by lower IQ in the group with autism.
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| 20. |
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| 21. |
- Rung, Johan P., 1973, et al.
(author)
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Effects of (-)-OSU6162 and ACR16 on motor activity in rats, indicating a unique mechanism of dopaminergic stabilization.
- 2008
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In: Journal of neural transmission. - : Springer Science and Business Media LLC. - 0300-9564 .- 1435-1463. ; 115:6, s. 899-908
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Journal article (peer-reviewed)abstract
- Dopaminergic stabilizers can be defined as drugs that stimulate or inhibit dopaminergic signalling depending on the dopaminergic tone. (-)-OSU6162 and ACR16 appear to possess such a profile. They have been proposed to act as partial dopamine receptor agonists or as antagonists with preferential action on dopaminergic autoreceptors. Previous studies have shown either stimulation or inhibition of behaviour in response to (-)-OSU6162 and ACR16, which has been suggested to reflect their dual effects on dopaminergic signalling. The aims of the present work are to (1) examine the relation between behavioural response to these drugs and activity baseline, and (2) test the suggested mechanisms of action by means of close comparisons with the known partial D2-receptor agonists (-)-3-PPP and aripiprazole, and the D2 autoreceptor preferring antagonist amisulpride with respect to effects on behaviour. From the results of these experiments it can be concluded that: (1) The direction of the response to (-)-OSU6162 and ACR16 is dependent on activity baseline, which in turn, under physiological conditions, is determined primarily by test arena size of and degree of habituation to the environment. (2) The effects of (-)-OSU6162 and ACR16 cannot be explained on the basis of either partial dopamine receptor agonism or preferential dopamine autoreceptor antagonism. Nevertheless, the current data suggest at least two different D2-receptor-associated targets which mediate opposite effects on activity. This result fits in with a mechanism proposed from a recent in vitro study, according to which (-)-OSU6162 has a dual action on dopamine D2 receptors, (a) an allosteric effect causing an enhanced response to dopamine, and (b) the previously proposed orthosteric effect antagonizing the action of dopamine.
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| 22. |
- Rung, Johan P., 1973, et al.
(author)
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Effects of the dopamine stabilizers (S)-(-)-OSU6162 and ACR16 on prolactin secretion in drug-naive and monoamine-depleted rats.
- 2011
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In: Naunyn-Schmiedeberg's archives of pharmacology. - : Springer Science and Business Media LLC. - 1432-1912 .- 0028-1298.
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Journal article (peer-reviewed)abstract
- Dopaminergic stabilizers may be conceptualized as drugs with normalizing effects on dopamine-mediated behaviours and neurochemical events. (S)-(-)-OSU6162 (OSU6162) and ACR16 are two structurally related compounds ascribed such properties, principally because of their stabilizing effects on motor activity in rodents. Reports in the literature indicate possible partial D2 receptor agonist effects using various in vitro systems. This study aimed to measure D2 receptor antagonist and agonist effects of OSU6162 and ACR16 in vivo. To address this, we have studied the effects of both compounds on prolactin secretion in drug-naive and dopamine-depleted rats; dopamine depletion was induced by pretreatment with reserpine plus α-methyl-DL: -p-tyrosine. We find that OSU6162 and ACR16 both stimulate prolactin secretion in drug-naive rats with OSU6162 being considerably more potent and efficacious. Both compounds show a non-significant trend towards reversal of the increased secretion caused by dopamine depletion, whereas the D2 receptor antagonist haloperidol further increased prolactin secretion. Thus, this study suggests that OSU6162 and ACR16 act as D2 receptor antagonists under normal conditions in vivo, possibly with minor agonist effects in a state of dopamine depletion.
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| 23. |
- Rung, Johan P., 1973, et al.
(author)
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(+)-MK-801 induced social withdrawal in rats; a model for negative symptoms of schizophrenia.
- 2005
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In: Progress in neuro-psychopharmacology & biological psychiatry. - : Elsevier BV. - 0278-5846. ; 29:5, s. 827-32
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Journal article (peer-reviewed)abstract
- Dopaminergic agonists and NMDA-receptor antagonists form the basis for the dopamine and glutamate models of schizophrenia, respectively. In human subjects dopaminergic agonists evoke a psychosis resembling positive symptoms of schizophrenia, while NMDA-receptor antagonists produce both positive and negative symptoms. Consequently, the glutamate model may be considered the most complete of the two models. Alterations in animal behaviour, in response to amphetamine or NMDA-receptor antagonists, are widely used to model schizophrenia. NMDA-receptor antagonist induced social withdrawal in rat is an established model for negative symptoms of schizophrenia. In this study we have set up an automated method, based on video tracking, to assess social behaviour, motor activity and movement pattern in rats. This method was then used to evaluate the effects of amphetamine and the NMDA-receptor antagonist (+)-MK-801, administered as single intraperitoneal injections, on rat behaviour. Amphetamine caused significantly increased motor activity and a tendency towards stimulation of social interactions. (+)-MK-801 also stimulated motor activity, but induced a significant inhibition of social interactions. These results indicate that a single injection of (+)-MK-801 to rats models both positive and negative symptoms of schizophrenia. Amphetamine, in contrast, reflects only the positive symptoms of schizophrenia in this model.
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| 24. |
- Rung, Johan P., 1973, et al.
(author)
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The dopaminergic stabilizers (-)-OSU6162 and ACR16 reverse (+)-MK-801-induced social withdrawal in rats.
- 2005
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In: Progress in neuro-psychopharmacology & biological psychiatry. - : Elsevier BV. - 0278-5846. ; 29:5, s. 833-9
-
Journal article (peer-reviewed)abstract
- Schizophrenia is manifested by positive and negative symptoms, as well as cognitive deficits. Most existing antipsychotic agents have poor effects on the negative symptoms of schizophrenia, thus emphasizing the necessity for developing new antipsychotic treatments. Dopaminergic stabilizers constitute one of the latest novelties in the quest for new antipsychotic drugs. Social withdrawal in rats, in response to treatment with NMDA-receptor antagonists such as (+)-MK-801, may be used to model negative symptoms. In this study we aimed to evaluate the dopaminergic stabilizers (-)-OSU6162 and ACR16, compared to haloperidol and clozapine, in a rat model for schizophrenia, focusing on (+)-MK-801 induced social withdrawal. Social behaviour and motor activity were assessed using a videotracking system, allowing automated analysis of the behaviour. Both (-)-OSU6162 and ACR16 were capable of restoring social behaviour, measured as proximity, to control level. These results indicate that these drugs may be effective in the treatments of negative symptoms.
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| 25. |
- Starck, Göran, et al.
(author)
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A 1H magnetic resonance spectroscopy study in adults with obsessive compulsive disorder: relationship between metabolite concentrations and symptom severity.
- 2008
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In: Journal of neural transmission (Vienna, Austria : 1996). - : Springer Science and Business Media LLC. - 0300-9564 .- 1435-1463. ; 115:7, s. 1051-62
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Journal article (peer-reviewed)abstract
- 1H magnetic resonance spectroscopy (1H MRS) studies exploring brain metabolites, especially glutamine + glutamate (Glx), in obsessive compulsive disorder (OCD) are of vital interest for trying to understand more about the pathophysiology of OCD. Therefore, we conducted the present 1H MRS study with the aims of (1) comparing MRS metabolites in a group of adult patients with OCD and a group of healthy controls, and (2) examining the relationship between MRS metabolite concentrations and symptom severity in the patient group. Three brain regions were studied, the right caudate nucleus, the anterior gyrus cinguli and the occipital cortex bilaterally. Since multivariate analysis is a highly useful tool for extraction of 1H MRS data, we applied principal component analysis (PCA) and partial least square projection to latent structures (PLS) to the MRS data. PLS disclosed a strong relationship between several of the metabolites and OCD symptom severity, as measured with Yale-Brown obsessive-compulsive scale (YBOCS): the YBOCS score was found to be positively correlated to caudate creatine, Glx, glutamate, and choline compounds as well as occipital cortex myoinositol, and negatively correlated to occipital cortex Glx. The negative correlation between occipital cortex Glx and YBOCS was the most impressive. PCA did not reveal any tendency for a separation between the patients with OCD and controls with respect to MRS metabolites. The results are discussed in relation to corticostriatothalamocortical feedback and previous observations of poor visuospatial ability in OCD.
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