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Almaguer-Melian W, Mercerón-Martínez D, Bergado-Rosado J. A unique erythropoietin dosage induces the recovery of long-term synaptic potentiation in fimbria-fornix lesioned rats. Brain Res 2023; 1799:148178. [PMID: 36442648 DOI: 10.1016/j.brainres.2022.148178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 11/19/2022] [Accepted: 11/22/2022] [Indexed: 11/27/2022]
Abstract
Synapses can experience long-term enhancements in its efficacy transmission in an activity-dependent manner (LTP, Long-Term Potentiation). This could contribute to store the living experiences in memory. Consequently, loss of synaptic plasticity can lead to failures in memory encoding and storage. Hence, finding ways to restore synaptic function can help restore learning and memory ability. Erythropoietin (EPO) has shown beneficial effects in the brain as a neuroprotector, improving affected learning, memory, and synaptic plasticity among other. In the present study, using the fimbria-fornix lesion model, we address the question whether the administration of erythropoietin restores the synaptic capacity to produce long-lasting increases in their transmission efficiency. A series of experiments was designed in which a control group of healthy young animals and one of injured young animals were formed. A subgroup of injured animals was injected with EPO or the vehicle in which the EPO is diluted (Veh). EPO or Veh was administered 15 min before LTP induction. Our data show that EPO produces a recovery in LTP in the group of fimbria-fornix lesioned animals, which show a severe impairment in the maintenance of LTP. Furthermore, LTP in the injured animals that received EPO was similar to that of the healthy control animals. LTP is widely accepted as a cellular mechanism of memory. Restoring LTP by EPO might be a potential tool for the treatment of memory disturbing diseases like Alzheimeŕs disease. Ongoing clinical trials are evaluating a potential therapeutic effect of low sialic acid-EPO (NeuroEPO) on degenerative diseases.
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Affiliation(s)
- William Almaguer-Melian
- Laboratorio de Electrofisiología Experimental, International Center for Neurological Restoration (CIREN), Ave. 25 No. 15806, entre 156 y 158, Playa 11300, Havana City, Cuba.
| | - Daymara Mercerón-Martínez
- Laboratorio de Electrofisiología Experimental, International Center for Neurological Restoration (CIREN), Ave. 25 No. 15806, entre 156 y 158, Playa 11300, Havana City, Cuba
| | - Jorge Bergado-Rosado
- Universidad del Sinú "Elías Bechara Zainum", Cra. 1w No. 38-153, Barrio Juan XXIII, Montería, Córdoba 4536534, Colombia.
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2
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Bulama I, Nasiru S, Bello A, Abbas AY, Nasiru JI, Saidu Y, Chiroma MS, Mohd Moklas MA, Mat Taib CN, Waziri A, Suleman BL. Antioxidant-based neuroprotective effect of dimethylsulfoxide against induced traumatic brain injury in a rats model. Front Pharmacol 2022; 13:998179. [PMID: 36353489 PMCID: PMC9638698 DOI: 10.3389/fphar.2022.998179] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 08/17/2022] [Indexed: 08/03/2023] Open
Abstract
Traumatic brain injury (TBI) has been the result of neurological deficit and oxidative stress. This study evaluated the antioxidative neuroprotective property and learning and memory-enhancing effects of dimethyl sulfoxide (DMSO) in a rat model after the induction of TBI. 21 albino rats with 7 rats per group were used in this study. Group I was induced with TBI and treated with DMSO at 67.5 mg/kg orally once daily which started 30 min after the induction of TBI and lasted 21 days. Group II was induced with TBI but not treated while Group III was neither induced with TBI nor treated. Assessment of behavioral function (Learning and memory, anxiety and motor function), the level of an antioxidant enzymes and their gene expression (superoxide dismutase, catalase, glutathione peroxidase), the biomarkers of oxidative stress (malondialdehyde) and S100B levels as well as brain tissues histological studies were conducted. Administration of DMSO to rats with induced TBI has improved learning and memory, locomotor function and decreased anxiety in Group I compared to Group II. Moreover, the level of S100B was significantly (p < 0.05) lower in Group I compared to Group II. Treatment with DMSO also decreased lipid peroxidation significantly (p < 0.05) compared to Group II. There exists a significant (p < 0.05) increase in CAT, SOD, and GPX activities in Group I compared to Group II. Therefore, DMSO has demonstrated a potential antioxidative neuroprotective effect through its ability to increase the level of antioxidant enzymes which they quench and inhibit the formation of ROS, thereby improving cognitive functions.
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Affiliation(s)
- Ibrahim Bulama
- Department of Veterinary Physiology and Biochemistry, Faculty of Veterinary Medicine, University of Maiduguri, Maiduguri, Nigeria
- Department of Human Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Suleiman Nasiru
- Department of Veterinary Physiology and Biochemistry, Faculty of Veterinary Medicine, Usman Danfodiyo University, Sokoto, Nigeria
| | - Abubakar Bello
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland
| | - Abdullahi Yahaya Abbas
- Department of Biochemistry, Faculty of Chemical and Life Sciences, Usman Danfodiyo University, Sokoto, Nigeria
| | - Jinjiri Ismail Nasiru
- Department of Surgery, Faculty of Clinical Sciences, Usman Danfodiyo University Teaching Hospital, Sokoto, Nigeria
| | - Yusuf Saidu
- Department of Biochemistry, Faculty of Chemical and Life Sciences, Usman Danfodiyo University, Sokoto, Nigeria
| | - Musa Samaila Chiroma
- Department of Human Anatomy, Faculty of Basic Clinical Sciences, University of Maiduguri, Maiduguri, Nigeria
| | - Mohamad Aris Mohd Moklas
- Department of Human Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Che Norma Mat Taib
- Department of Human Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Ali Waziri
- Department of Veterinary Pathology, Faculty of Veterinary Medicine, University of Maiduguri, Maiduguri, Nigeria
| | - Bilbis Lawal Suleman
- Department of Biochemistry, Faculty of Chemical and Life Sciences, Usman Danfodiyo University, Sokoto, Nigeria
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Johnsen SHW, Rytter HM. Dissociating spatial strategies in animal research: Critical methodological review with focus on egocentric navigation and the hippocampus. Neurosci Biobehav Rev 2021; 126:57-78. [PMID: 33771535 DOI: 10.1016/j.neubiorev.2021.03.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 03/11/2021] [Accepted: 03/18/2021] [Indexed: 11/26/2022]
Abstract
One major challenge in animal research on spatial learning and memory pertains to designing methods to dissociate spatial strategies (allocentric vs. egocentric). This is crucial for understanding the underlying cognitive processes and neural circuits that are recruited in navigational tasks. Taking the egocentric reference frames as a starting point, this review argues that in many extensively used spatial paradigms, multiple spatial reference frames are often available to the animals but remain unaccounted for. We discuss the implications this has for the inferences that can be made and propose a decision-algorithm to construct spatial learning paradigms that can reduce the influence of these confounding variables. Furthermore, with these considerations in mind, we review the role of the hippocampus in egocentric navigation forms, i.e. in response learning, egocentric sequential learning and path integration. This choice is based on the controversy surrounding the role of hippocampus in these spatial paradigms. We discuss the possible methodological confounders that may explain the inconclusive results.
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Affiliation(s)
- Svend Heini W Johnsen
- The Unit for Cognitive Neuroscience, Department of Psychology, University of Copenhagen, Oester Farimagsgade 2A, 1353 Copenhagen, Denmark.
| | - Hana Malá Rytter
- The Unit for Cognitive Neuroscience, Department of Psychology, University of Copenhagen, Oester Farimagsgade 2A, 1353 Copenhagen, Denmark; University Hospital Bispebjerg - Frederiksberg, Department of Neurology, Nielsine Nielsens vej 7, 2400 Copenhagen, Denmark; Danish Concussion Center, Amagerfælledvej 56A, 2300 Copenhagen, Denmark.
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Kjær K, Jørgensen MB, Hageman I, Miskowiak KW, Wörtwein G. The effect of erythropoietin on electroconvulsive stimulation induced cognitive impairment in rats. Behav Brain Res 2020; 382:112484. [PMID: 31954736 DOI: 10.1016/j.bbr.2020.112484] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 01/09/2020] [Accepted: 01/15/2020] [Indexed: 01/01/2023]
Abstract
Electroconvulsive therapy (ECT) is the most effective and fast-acting treatment for severe depression but associated with troublesome cognitive side-effects. Systemically administered erythropoietin (EPO) crosses the blood-brain-barrier and is a promising treatment for cognitive dysfunction in a wide array of neuropsychiatric and neurological disorders. In this study we trained rats to locate a submerged platform in a water maze and then subjected them to electroconvulsive stimulations (ECS, the rodent equivalent to ECT) and EPO treatment. We then analysed their ability to remember and relearn the location of the platform. In addition, we examined "wall-clinging" (thigmotaxis), a behavioural indicator of stress. ECS caused significant deficit in a probe trial administered after three weeks (nine stimulations) as well as one week (six stimulations) of treatment, indicative of induction of retrograde amnesia. ECS had no effect on relearning of the water maze task or performance in a subsequent probe trial. EPO treatment did not ameliorate the ECS-induced retrograde amnesia, but after nine ECS stimulations the animals that had received EPO relearned the position of the hidden platform faster than the animals that had not. We also found EPO to decrease "wall-clinging" behaviour, suggesting an effect of EPO on the stress response in rats. Thus, we establish the Morris Water Maze as a suitable model for ECS-induced memory loss in rats and provide some evidence for potential beneficial effects of EPO.
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Affiliation(s)
- Kristian Kjær
- Laboratory of Neuropsychiatry, Psychiatric Centre Copenhagen, Rigshospitalet, 2100, Copenhagen, Denmark
| | | | - Ida Hageman
- Department O, Psychiatric Centre Copenhagen, Rigshospitalet, 2100, Copenhagen, Denmark
| | - Kamilla Woznica Miskowiak
- Copenhagen Affective Disorder Research Centre (CADIC), Psychiatric Centre Copenhagen, Rigshospitalet, 2100 Copenhagen, Denmark; Department of Psychology, University of Copenhagen, 1353, Copenhagen, Denmark
| | - Gitta Wörtwein
- Laboratory of Neuropsychiatry, Psychiatric Centre Copenhagen, Rigshospitalet, 2100, Copenhagen, Denmark; Department of Public Health, University of Copenhagen, 1014, Copenhagen, Denmark.
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GSK3β: a plausible mechanism of cognitive and hippocampal changes induced by erythropoietin treatment in mood disorders? Transl Psychiatry 2018; 8:216. [PMID: 30310078 PMCID: PMC6181907 DOI: 10.1038/s41398-018-0270-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 06/11/2018] [Accepted: 07/14/2018] [Indexed: 12/16/2022] Open
Abstract
Mood disorders are associated with significant psychosocial and occupational disability. It is estimated that major depressive disorder (MDD) will become the second leading cause of disability worldwide by 2020. Existing pharmacological and psychological treatments are limited for targeting cognitive dysfunctions in mood disorders. However, growing evidence from human and animal studies has shown that treatment with erythropoietin (EPO) can improve cognitive function. A recent study involving EPO-treated patients with mood disorders showed that the neural basis for their cognitive improvements appeared to involve an increase in hippocampal volume. Molecular mechanisms underlying hippocampal changes have been proposed, including the activation of anti-apoptotic, antioxidant, pro-survival and anti-inflammatory signalling pathways. The aim of this review is to describe the potential importance of glycogen synthase kinase 3-beta (GSK3β) as a multi-potent molecular mechanism of EPO-induced hippocampal volume change in mood disorder patients. We first examine published associations between EPO administration, mood disorders, cognition and hippocampal volume. We then highlight evidence suggesting that GSK3β influences hippocampal volume in MDD patients, and how this could assist with targeting more precise treatments particularly for cognitive deficits in patients with mood disorders. We conclude by suggesting how this developing area of research can be further advanced, such as using pharmacogenetic studies of EPO treatment in patients with mood disorders.
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6
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Dik A, Saffari R, Zhang M, Zhang W. Contradictory effects of erythropoietin on inhibitory synaptic transmission in left and right prelimbic cortex of mice. Neurobiol Stress 2018; 9:113-123. [PMID: 30450377 PMCID: PMC6234276 DOI: 10.1016/j.ynstr.2018.08.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 08/08/2018] [Accepted: 08/24/2018] [Indexed: 12/28/2022] Open
Abstract
Erythropoietin (EPO) has been shown to improve cognitive function in mammals as well as in patients of psychiatric diseases by directly acting on the brain. In addition, EPO attenuates the synaptic transmission and enhances short- and long-term synaptic plasticity in hippocampus of mice, although there are still many discrepancies between different studies. It has been suggested that the divergences of different studies take root in different in-vivo application schemata or in long-term trophic effects of EPO. In the current study, we investigated the direct effects of EPO in slices of prelimbic cortex (PrL) by acute ex-vivo application of EPO, so that the erythropoietic or other trophic effects could be entirely excluded. Our results showed that the EPO effects were contradictory between the left and the right PrL. It enhanced the inhibitory transmission in the left and depressed the inhibitory transmission in the right PrL. Strikingly, this lateralized effect of EPO could be consistently found in individual bi-lateral PrL of all tested mice. Thus, our data suggest that EPO differentially modulates the inhibitory synaptic transmission of neuronal networks in the left and the right PrL. We hypothesize that such lateralized effects of EPO contribute to the development of the lateralization of stress reaction in PFC and underlie the altered bilateral GAGAergic synaptic transmission and oscillation patterns under stress that impact the central emotional and cognitive control in physiology as well as in pathophysiology. EPO showed fast effects on inhibitory transmission in the prefrontal cortex of mice. EPO enhanced the inhibitory transmission in the left and depressed it in the right prelimbic cortex of mice. The expression of EPOR in GAD+-neurons is different between the left and right PFC.
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Affiliation(s)
- Andre Dik
- Laboratory of Molecular Psychiatry, Department of Psychiatry, University of Münster, Germany.,Department of Neurology, University of Muenster, Germany
| | - Roja Saffari
- Laboratory of Molecular Psychiatry, Department of Psychiatry, University of Münster, Germany
| | - Mingyue Zhang
- Laboratory of Molecular Psychiatry, Department of Psychiatry, University of Münster, Germany
| | - Weiqi Zhang
- Laboratory of Molecular Psychiatry, Department of Psychiatry, University of Münster, Germany
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Sommer JB, Bach A, Malá H, Strømgaard K, Mogensen J, Pickering DS. Effects of the dimeric PSD-95 inhibitor UCCB01-144 on functional recovery after fimbria-fornix transection in rats. Pharmacol Biochem Behav 2017; 161:62-67. [PMID: 28943199 DOI: 10.1016/j.pbb.2017.09.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Revised: 08/22/2017] [Accepted: 09/18/2017] [Indexed: 01/05/2023]
Abstract
Pharmacological inhibition of PSD-95 is a promising therapeutic strategy in the treatment of stroke, and positive effects of monomeric and dimeric PSD-95 inhibitors have been reported in numerous studies. However, whether therapeutic effects will generalize to other types of acute brain injury such as traumatic brain injury (TBI), which has pathophysiological mechanisms in common with stroke, is currently uncertain. We have previously found a lack of neuroprotective effects of dimeric PSD-95 inhibitors in the controlled cortical impact model of TBI in rats. However, as no single animal model is currently able to mimic the complex and heterogeneous pathophysiology of TBI, it is necessary to assess treatment effects across a range of models. In this preliminary study we investigated the neuroprotective abilities of the dimeric PSD-95 inhibitor UCCB01-144 after fimbria-fornix (FF) transection in rats. UCCB01-144 or saline was injected into the lateral tail vein of rats immediately after sham surgery or FF-transection, and effects on spatial delayed alternation in a T-maze were assessed over a 28-day period. Task acquisition was significantly impaired in FF-transected animals, but there were no significant effects of UCCB01-144 on spatial delayed alternation after FF-transection or sham surgery, although decelerated learning curves were seen after treatment with UCCB01-144 in FF-transected animals. The results of the present study are consistent with previous research showing a lack of neuroprotective effects of PSD-95 inhibition in experimental models of TBI.
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Affiliation(s)
- Jens Bak Sommer
- Department of Drug Design and Pharmacology, University of Copenhagen, Denmark; The Unit for Cognitive Neuroscience (UCN), Department of Psychology, University of Copenhagen, Denmark.
| | - Anders Bach
- Department of Drug Design and Pharmacology, University of Copenhagen, Denmark.
| | - Hana Malá
- The Unit for Cognitive Neuroscience (UCN), Department of Psychology, University of Copenhagen, Denmark.
| | - Kristian Strømgaard
- Department of Drug Design and Pharmacology, University of Copenhagen, Denmark.
| | - Jesper Mogensen
- The Unit for Cognitive Neuroscience (UCN), Department of Psychology, University of Copenhagen, Denmark.
| | - Darryl S Pickering
- Department of Drug Design and Pharmacology, University of Copenhagen, Denmark.
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Wogensen E, Marschner L, Gram MG, Mehlsen S, Uhre VHB, Bülow P, Mogensen J, Malá H. Effects of different delayed exercise regimens on cognitive performance in fimbria-fornix transected rats. Acta Neurobiol Exp (Wars) 2017. [DOI: 10.21307/ane-2017-065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Wogensen E, Gram MG, Sommer JB, Vilsen CR, Mogensen J, Malá H. Delayed voluntary exercise does not enhance cognitive performance after hippocampal injury: an investigation of differentially distributed exercise protocols. J Exerc Rehabil 2016; 12:401-412. [PMID: 27807517 PMCID: PMC5091054 DOI: 10.12965/jer.1632680.340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 09/05/2016] [Indexed: 11/22/2022] Open
Abstract
Voluntary exercise has previously been shown to enhance cognitive recovery after acquired brain injury (ABI). The present study evaluated effects of two differentially distributed protocols of delayed, voluntary exercise on cognitive recovery using an allocentric place learning task in an 8-arm radial maze. Fifty-four Wistar rats were subjected to either bilateral transection of the fimbria-fornix (FF) or to sham surgery. Twenty-one days postinjury, the animals started exercising in running wheels either for 14 consecutive days (FF/exercise daily [ExD], sham/ExD) or every other day for 14 days (FF/exercise every second day [ExS], sham/ExS). Additional groups were given no exercise treatment (FF/not exercise [NE], sham/NE). Regardless of how exercise was distributed, we found no cognitively enhancing effects of exercise in the brain injured animals. Design and protocol factors possibly affecting the efficacy of post-ABI exercise are discussed.
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Affiliation(s)
- Elise Wogensen
- The Unit for Cognitive Neuroscience, Department of Psychology, University of Copenhagen, Copenhagen,
Denmark
| | - Marie Gajhede Gram
- The Unit for Cognitive Neuroscience, Department of Psychology, University of Copenhagen, Copenhagen,
Denmark
| | - Jens Bak Sommer
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen,
Denmark
| | - Christina Rytter Vilsen
- The Unit for Cognitive Neuroscience, Department of Psychology, University of Copenhagen, Copenhagen,
Denmark
| | - Jesper Mogensen
- The Unit for Cognitive Neuroscience, Department of Psychology, University of Copenhagen, Copenhagen,
Denmark
| | - Hana Malá
- The Unit for Cognitive Neuroscience, Department of Psychology, University of Copenhagen, Copenhagen,
Denmark
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Gram MG, Wogensen E, Moseholm K, Mogensen J, Malá H. Exercise-induced improvement in cognitive performance after fimbria-fornix transection depends on the timing of exercise administration. Brain Res Bull 2016; 125:117-26. [DOI: 10.1016/j.brainresbull.2016.06.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Revised: 06/15/2016] [Accepted: 06/21/2016] [Indexed: 01/29/2023]
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Mercerón-Martínez D, Almaguer-Melian W, Alberti-Amador E, Estupiñán B, Fernández I, Bergado J. Amygdala electrical stimulation inducing spatial memory recovery produces an increase of hippocampal bdnf and arc gene expression. Brain Res Bull 2016; 124:254-61. [DOI: 10.1016/j.brainresbull.2016.05.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 05/26/2016] [Accepted: 05/31/2016] [Indexed: 11/30/2022]
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Gram MG, Wogensen E, Wörtwein G, Mogensen J, Malá H. Delayed restraint procedure enhances cognitive recovery of spatial function after fimbria-fornix transection. Restor Neurol Neurosci 2015; 34:1-17. [PMID: 26518669 DOI: 10.3233/rnn-140396] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
PURPOSE To i) evaluate the effect of a restraint procedure (7 days, 2 h/day) on place learning after fimbria-fornix transection (FF), ii) investigate effects of early vs. late administration of restraint, and iii) establish effects of the restraint procedure on expression of brain derived neurotrophic factor (BDNF) in prefrontal cortex and hippocampus. METHODS Fifty rats subjected to FF or sham surgery and divided into groups exposed to restraint immediately (early restraint) or 21 days (late restraint) after surgery were trained to acquire an allocentric place learning task. In parallel, 29 animals were subjected to FF or sham surgery and an identical restraint procedure in order to measure concentrations of BDNF and corticosterone. RESULTS The performance of the sham operated rats was positively affected by the late restraint. In FF-lesioned animals, the late restraint significantly improved task performance compared to the lesioned group with no restraint, while the early restraint was associated with a negative impact on task acquisition. Biochemical analysis after restraint procedure revealed a lesion-induced upregulation of BDNF in FF animals. CONCLUSIONS The improved task performance of lesioned animals suggests a therapeutic effect of this manipulation, independent of BDNF. This effect is sensitive to the temporal administration of treatment.
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Affiliation(s)
- Marie Gajhede Gram
- The Unit for Cognitive Neuroscience, Department of Psychology, University of Copenhagen, Copenhagen, Denmark
| | - Elise Wogensen
- The Unit for Cognitive Neuroscience, Department of Psychology, University of Copenhagen, Copenhagen, Denmark
| | - Gitta Wörtwein
- Laboratory of Neuropsychiatry, Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Jesper Mogensen
- The Unit for Cognitive Neuroscience, Department of Psychology, University of Copenhagen, Copenhagen, Denmark
| | - Hana Malá
- The Unit for Cognitive Neuroscience, Department of Psychology, University of Copenhagen, Copenhagen, Denmark
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Gajhede Gram M, Gade L, Wogensen E, Mogensen J, Malá H. Equal effects of typical environmental and specific social enrichment on posttraumatic cognitive functioning after fimbria-fornix transection in rats. Brain Res 2015; 1629:182-95. [PMID: 26499260 DOI: 10.1016/j.brainres.2015.10.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 10/08/2015] [Accepted: 10/12/2015] [Indexed: 12/11/2022]
Abstract
Enriched environment (EE) has been shown to have beneficial effects on cognitive recovery after brain injury. Typical EE comprises three components: (i) enlarged living area providing physical activation, (ii) sensory stimulation, and (iii) social stimulation. The present study assessed the specific contribution of the social stimulation. Animals were randomly divided into groups of (1) a typical EE, (2) pure social enrichment (SE), or (3) standard housing (SH) and subjected to either a sham operation or transection of the fimbria-fornix (FF). The effect of these conditions on acquisition of a delayed alternation task in a T-maze was assessed. The sham control groups were not affected by housing conditions. In the lesioned groups, both typical EE and SE improved the task acquisition, compared to SH. A baseline one-hour activity measurement confirmed an equal level of physical activity in the EE and SE groups. After delayed alternation testing, pharmacological challenges (muscarinergic antagonist scopolamine and dopaminergic antagonist SKF-83566) were used to assess cholinergic and dopaminergic contributions to task solution. Scopolamine led to a marked impairment in all groups. SKF-83566 significantly enhanced the performance of the lesioned group subjected to SE. The results demonstrate that housing in a typical as well as atypical EE can enhance cognitive recovery after mechanical injury to the hippocampus. The scopolamine challenge revealed a cholinergic dependency during task performance in all groups, regardless of lesion and housing conditions. The dopaminergic challenge revealed a difference in the neural substrates mediating recovery in the lesioned groups exposed to different types of housing.
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Affiliation(s)
- Marie Gajhede Gram
- The Unit for Cognitive Neuroscience, Department of Psychology, University of Copenhagen, Oester Farimagsgade 2A, DK-1353 Copenhagen K, Denmark.
| | - Louise Gade
- The Unit for Cognitive Neuroscience, Department of Psychology, University of Copenhagen, Oester Farimagsgade 2A, DK-1353 Copenhagen K, Denmark.
| | - Elise Wogensen
- The Unit for Cognitive Neuroscience, Department of Psychology, University of Copenhagen, Oester Farimagsgade 2A, DK-1353 Copenhagen K, Denmark.
| | - Jesper Mogensen
- The Unit for Cognitive Neuroscience, Department of Psychology, University of Copenhagen, Oester Farimagsgade 2A, DK-1353 Copenhagen K, Denmark.
| | - Hana Malá
- The Unit for Cognitive Neuroscience, Department of Psychology, University of Copenhagen, Oester Farimagsgade 2A, DK-1353 Copenhagen K, Denmark.
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Malá H, Andersen LG, Christensen RF, Felbinger A, Hagstrøm J, Meder D, Pearce H, Mogensen J. Prefrontal cortex and hippocampus in behavioural flexibility and posttraumatic functional recovery: Reversal learning and set-shifting in rats. Brain Res Bull 2015; 116:34-44. [DOI: 10.1016/j.brainresbull.2015.05.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 05/17/2015] [Accepted: 05/18/2015] [Indexed: 11/25/2022]
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Almaguer-Melian W, Mercerón-Martínez D, Pavón-Fuentes N, Alberti-Amador E, Leon-Martinez R, Ledón N, Delgado Ocaña S, Bergado Rosado JA. Erythropoietin Promotes Neural Plasticity and Spatial Memory Recovery in Fimbria-Fornix-Lesioned Rats. Neurorehabil Neural Repair 2015; 29:979-88. [PMID: 25847024 DOI: 10.1177/1545968315572389] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Erythropoietin (EPO) upregulates the mitogen activated protein kinase (MAPK) cascade, a central signaling pathway in cellular plastic mechanisms, and is critical for normal brain development. OBJECTIVE We hypothesized that EPO could modulate the plasticity mechanisms supporting spatial memory recovery in fimbria-fornix-transected animals. METHODS Fimbria-fornix was transected in 3 groups of rats. Seven days later, EPO was injected daily for 4 consecutive days within 10 minutes after training on a water maze task. RESULTS Our results show that EPO injections 10 minutes after training produced a substantial spatial memory recovery in fimbria-fornix-lesioned animals. In contrast, an EPO injection shortly after fimbria-fornix lesion surgery does not promote spatial-memory recovery. Neither does daily EPO injection 5 hours after the water maze performance. EPO, on the other hand, induced the expression of plasticity-related genes like arc and bdnf, but this effect was independent of training or lesion. CONCLUSIONS This finding supports our working hypothesis that EPO can modulate transient neuroplastic mechanisms triggered by training in lesioned animals. Consequently, we propose that EPO administration can be a useful trophic factor to promote neural restoration when given in combination with training.
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Affiliation(s)
| | | | | | | | | | - Nuris Ledón
- Centro de Inmunología Molecular, La Habana, Cuba
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Only repeated administration of the serotonergic agonist 8-OH-DPAT improves place learning of rats subjected to fimbria-fornix transection. Pharmacol Biochem Behav 2013; 109:50-8. [PMID: 23680575 DOI: 10.1016/j.pbb.2013.05.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Revised: 04/27/2013] [Accepted: 05/04/2013] [Indexed: 01/19/2023]
Abstract
Serotonergic agonists may act neuroprotectively against brain injury. This study addressed the therapeutic potential of 8-hydroxy-2-di-n-propylamino-tetralin (8-OH-DPAT), a selective 5-HT1A/7 receptor agonist, after mechanical brain injury, and evaluated its effects in terms of acquisition of an allocentric place learning task in a water maze. Rats were divided into 6 experimental groups, three of which were subjected to bilateral transection of fimbria-fornix (FF), while three groups were given control surgery (Sham). After surgery, within both the lesioned, and sham-operated animals, respectively, one group was administered a single dose of saline, one group was given a single dose (0.5 mg/kg/b.w.) of 8-OH-DPAT, and one group was treated with daily administration of 8-OH-DPAT (0.5 mg/kg/b.w.) for eight days. The acquisition of the water maze based place learning task started on the 8th day post-surgery and continued for 20 days. The results show that the lesioned group subjected to repeated administration of 8-OH-DPAT demonstrated a significantly improved acquisition of the place learning task compared to the vehicle injected lesion group. In contrast, the lesioned group treated with a single administration displayed impaired performance compared to the baseline lesion group. There were no significant effects of the 8-OH-DPAT administration in the sham control groups. We conclude that only the repeated stimulation of the 5-HT1A/7 system was associated with beneficial, recovery enhancing effects.
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Simonsen LO, Harbak H, Bennekou P. Cobalt metabolism and toxicology--a brief update. THE SCIENCE OF THE TOTAL ENVIRONMENT 2012; 432:210-5. [PMID: 22732165 DOI: 10.1016/j.scitotenv.2012.06.009] [Citation(s) in RCA: 299] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Revised: 05/20/2012] [Accepted: 06/01/2012] [Indexed: 05/13/2023]
Abstract
Cobalt metabolism and toxicology are summarized. The biological functions of cobalt are updated in the light of recent understanding of cobalt interference with the sensing in almost all animal cells of oxygen deficiency (hypoxia). Cobalt (Co(2+)) stabilizes the transcriptional activator hypoxia-inducible factor (HIF) and thus mimics hypoxia and stimulates erythropoietin (Epo) production, but probably also by the same mechanism induces a coordinated up-regulation of a number of adaptive responses to hypoxia, many with potential carcinogenic effects. This means on the other hand that cobalt (Co(2+)) also may have beneficial effects under conditions of tissue hypoxia, and possibly can represent an alternative to hypoxic preconditioning. Cobalt is acutely toxic in larger doses, and in mammalian in vitro test systems cobalt ions and cobalt metal are cytotoxic and induce apoptosis and at higher concentrations necrosis with inflammatory response. Cobalt metal and salts are also genotoxic, mainly caused by oxidative DNA damage by reactive oxygen species, perhaps combined with inhibition of DNA repair. Of note, the evidence for carcinogenicity of cobalt metal and cobalt sulfate is considered sufficient in experimental animals, but is as yet considered inadequate in humans. Interestingly, some of the toxic effects of cobalt (Co(2+)) have recently been proposed to be due to putative inhibition of Ca(2+) entry and Ca(2+)-signaling and competition with Ca(2+) for intracellular Ca(2+)-binding proteins. The tissue partitioning of cobalt (Co(2+)) and its time-dependence after administration of a single dose have been studied in man, but mainly in laboratory animals. Cobalt is accumulated primarily in liver, kidney, pancreas, and heart, with the relative content in skeleton and skeletal muscle increasing with time after cobalt administration. In man the renal excretion is initially rapid but decreasing over the first days, followed by a second, slow phase lasting several weeks, and with a significant long-term retention in tissues for several years. In serum cobalt (Co(2+)) binds to albumin, and the concentration of free, ionized Co(2+) is estimated at 5-12% of the total cobalt concentration. In human red cells the membrane transport pathway for cobalt (Co(2+)) uptake appears to be shared with calcium (Ca(2+)), but with the uptake being essentially irreversible as cobalt is effectively bound in the cytosol and is not itself extruded by the Ca-pump. It is tempting to speculate that this could perhaps also be the case in other animal cells. If this were actually the case, the tissue partitioning and biokinetics of cobalt in cells and tissues would be closely related to the uptake of calcium, with cobalt partitioning primarily into tissues with a high calcium turn-over, and with cobalt accumulation and retention in tissues with a slow turn-over of the cells. The occupational cobalt exposure, e.g. in cobalt processing plants and hard-metal industry is well known and has probably been somewhat reduced in more recent years due to improved work place hygiene. Of note, however, adverse reactions to heart and lung have recently been demonstrated following cobalt exposure near or slightly under the current occupational exposure limit. Over the last decades the use of cobalt-chromium hard-metal alloys in orthopedic joint replacements, in particular in metal-on-metal bearings in hip joint arthroplasty, has created an entirely new source of internal cobalt exposure. Corrosion and wear produce soluble metal ions and metal debris in the form of huge numbers of wear particles in nanometric size, with systemic dissemination through lymph and systemic vascular system. This may cause adverse local reactions in peri-prosthetic soft-tissues, and in addition systemic toxicity. Of note, the metal nanoparticles have been demonstrated to be clearly more toxic than larger, micrometer-sized particles, and this has made the concept of nanotoxicology a crucial, new discipline. As another new potential source of cobalt exposure, suspicion has been raised that cobalt salts may be misused by athletes as an attractive alternative to Epo doping for enhancing aerobic performance. The cobalt toxicity in vitro seems to reside mainly with ionized cobalt. It is tempting to speculate that ionized cobalt is also the primary toxic form for systemic toxicity in vivo. Under this assumption, the relevant parameter for risk assessment would be the time-averaged value for systemic cobalt ion exposure that from a theoretical point of view might be obtained by measuring the cobalt content in red cells, since their cobalt uptake reflects uptake only of free ionized cobalt (Co(2+)), and since the uptake during their 120 days life span is practically irreversible. This clearly calls for future clinical studies in exposed individuals with a systematic comparison of concurrent measurements of cobalt concentration in red cells and in serum.
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Affiliation(s)
- Lars Ole Simonsen
- Department of Biology, University of Copenhagen, August Krogh Building, 13 Universitetsparken, DK-2100 Copenhagen Ø, Denmark.
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Erythropoietin: a candidate treatment for mood symptoms and memory dysfunction in depression. Psychopharmacology (Berl) 2012; 219:687-98. [PMID: 21947319 DOI: 10.1007/s00213-011-2511-1] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Accepted: 09/12/2011] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Current pharmacological treatments for depression have a significant treatment-onset-response delay, an insufficient efficacy for many patients and fail to reverse cognitive dysfunction. Erythropoietin (EPO) has neuroprotective and neurotrophic actions and improves cognitive function in animal models of acute and chronic neurodegenerative conditions and in patients with cognitive decline. METHODS We systematically reviewed the published findings from animal and human studies exploring the potential of EPO to treat depression-related cognitive dysfunction and depression. RESULTS We identified five animal studies (two in male rats, two in male mice and one in male rats and mice) and seven human proof-of-concept studies (five in healthy volunteers and two in depressed patients) that investigated the above. All of the reviewed animal studies but one and all human studies demonstrated beneficial effects of EPO on hippocampus-dependent memory and antidepressant-like effects. These effects appear to be mediated through direct neurobiological actions of EPO rather than upregulation of red cell mass. CONCLUSIONS The reviewed studies demonstrate beneficial effects of EPO on hippocampus-dependent memory function and on depression-relevant behavior, thus highlighting EPO as a candidate agent for future management of cognitive dysfunction and mood symptoms in depression. Larger-scale clinical trials of EPO as a treatment for mood and neurocognitive symptoms in patients with mood disorder are therefore warranted.
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Klencklen G, Després O, Dufour A. What do we know about aging and spatial cognition? Reviews and perspectives. Ageing Res Rev 2012; 11:123-35. [PMID: 22085884 DOI: 10.1016/j.arr.2011.10.001] [Citation(s) in RCA: 140] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2011] [Revised: 10/14/2011] [Accepted: 10/25/2011] [Indexed: 11/30/2022]
Abstract
In order to cope with normal cognitive aging we must understand the patterns and neurofunctional underpinnings of cognitive and behavioral changes throughout adulthood. In this review, we summarize recent advances in our understanding of age-related behavioral differences and changes in brain structure throughout the spatial domain. Although spatial cognition is critically important to everyday life, few studies have examined the relationship between this cognitive function and neural changes in the aged brain. Thus, spatial cognition is considered a key area in which the cognitive neuroscience of aging may expand in the near future. The first section of this review examines the methodologies and studies used to assess differences in spatial cognition during normal cognitive aging in animals and humans. We then relate how each domain of spatial cognition (e.g., visuospatial perception, mental imagery, memory and navigation) is affected by the aging process, and discuss possible links with changes in neural mechanisms. Lastly, we address putative links among the age-related deterioration patterns of the various spatial domains and make suggestions for future research.
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Affiliation(s)
- Giuliana Klencklen
- Laboratoire d'Imagerie & Neurosciences Cognitives, UMR 7237 CNRS - Université de Strasbourg, France.
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Goetghebeur PJD, Lerdrup L, Sylvest A, Dias R. Erythropoietin reverses the attentional set-shifting impairment in a rodent schizophrenia disease-like model. Psychopharmacology (Berl) 2010; 212:635-42. [PMID: 20734030 DOI: 10.1007/s00213-010-1990-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Accepted: 08/04/2010] [Indexed: 12/11/2022]
Abstract
RATIONALE Executive function impairment, as classically assessed using the Wisconsin Card Sort Test or intradimensional/extradimensional tests, is a key feature of schizophrenia but remains inadequately treated by existing therapies. Recently, however, erythropoietin has been shown to improve attentional set-shifting performance in schizophrenic patients. OBJECTIVE The present study utilized the rat intradimensional/extradimensional task to investigate the potential of erythropoietin to reverse a phencyclidine-induced extradimensional shift impairment when given alone or in combination with subchronic haloperidol treatment. METHODS Rats were subjected to a subchronic systemic administration (7 days, b.i.d) of either saline vehicle or phencyclidine (5 mg/kg) followed by a 7-day washout period during which haloperidol was given. Subsequently, rats were trained to dig in baited bowls for a food reward and to discriminate on the basis of digging media or bowl odor. In experiment 1, rats performed a series of discriminations following acute administration of vehicle, erythropoietin, or modafinil. In a second experiment, rats receiving either haloperidol in the drinking water or just normal drinking water were run in the attentional set-shifting task after acute administration of erythropoietin (1,000 or 10,000 IU/ml i.p., selected from experiment 1). RESULTS The subchronic phencyclidine-induced extradimensional deficit was ameliorated by both erythropoietin and modafinil. When combined with subchronic haloperidol, the higher dose of erythropoietin tested was able to reverse the extradimensional shift impairment. CONCLUSIONS Overall, these findings further support the use of erythropoietin as an adjunct to antipsychotic therapy in order to address, at least part of, the cognitive dysfunction associated with schizophrenia.
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Rasmussen P, Foged EM, Krogh-Madsen R, Nielsen J, Nielsen TR, Olsen NV, Petersen NC, Sørensen TA, Secher NH, Lundby C. Effects of erythropoietin administration on cerebral metabolism and exercise capacity in men. J Appl Physiol (1985) 2010; 109:476-83. [DOI: 10.1152/japplphysiol.00234.2010] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Recombinant human erythropoietin (EPO) increases exercise capacity by stimulating erythropoiesis and subsequently enhancing oxygen delivery to the working muscles. In a large dose, EPO crosses the BBB and may reduce central fatigue and improve cognition. In turn, this would augment exercise capacity independent of erythropoiesis. To test this hypothesis, 15 healthy young men (18–34 years old, 74 ± 7 kg) received either 3 days of high-dose (30,000 IU/day; n = 7) double-blinded placebo controlled or 3 mo of low-dose (5,000 IU/wk; n = 8) counter-balanced open but controlled administration of EPO. We recorded exercise capacity, transcranial ultrasonography-derived middle cerebral artery blood velocity, and arterial-internal jugular venous concentration differences of glucose and lactate. In addition, cognitive function, ratings of perceived exertion, ventilation, and voluntary activation by transcranial magnetic stimulation-induced twitch force were evaluated. Although EPO in a high dose increased cerebrospinal fluid EPO concentration ∼20-fold and affected ventilation and cerebral glucose and lactate metabolism ( P < 0.05), 3 days of high-dose EPO administration had no effect on cognition, voluntary activation, or exercise capacity, but ratings of perceived exertion increased ( P < 0.05). We confirmed that 3 mo of administration of EPO increases exercise capacity, but the improvement could not be accounted for by other mechanisms than enhanced oxygen delivery. In conclusion, EPO does not attenuate central fatigue or change cognitive performance strategy, suggesting that EPO enhances exercise capacity exclusively by increased oxygen delivery to the working muscles.
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Affiliation(s)
- P. Rasmussen
- Departments of 1Anesthesia, and
- Copenhagen Muscle Research Centre, and
- Zurich Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | | | - R. Krogh-Madsen
- Infectious Diseases,
- Centre of Inflammation and Metabolism, Rigshospitalet, Copenhagen
| | | | | | - N. V. Olsen
- Departments of 1Anesthesia, and
- Neuroscience and Pharmacology, and
| | - N. C. Petersen
- Exercise Sciences, University of Copenhagen, Denmark; and
| | | | - N. H. Secher
- Departments of 1Anesthesia, and
- Copenhagen Muscle Research Centre, and
| | - C. Lundby
- Copenhagen Muscle Research Centre, and
- Zurich Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
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Mogensen J, Malá H. Post-traumatic functional recovery and reorganization in animal models: a theoretical and methodological challenge. Scand J Psychol 2010; 50:561-73. [PMID: 19930255 DOI: 10.1111/j.1467-9450.2009.00781.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Studies addressing cerebral functional localization face methodological and theoretical problems. Lesion experiments expect that when a functionally specialized structure is missing, its function can be deduced from the resulting impairments. Mostly, however, initial impairments are partially or fully eliminated through functional recovery. Apparently, such a recovery contradicts the notion of functional localization. In order to understand the mechanisms of recovery, improved methodology and a new theoretical framework are required. Insights into the mechanisms of recovery can be achieved by using "challenge" techniques, where functionally recovered individuals are exposed to organic and behavioral challenges, e.g. pharmacological manipulations or additional lesions, as well as modified test situations. Using such methods, a number of principles of functional recovery have emerged. We evaluate some of the available theories of post-traumatic recovery against these principles and find that none of them can account for the principles. Finally, we present a new conceptual framework - the Reorganization of Elementary Functions (REF) model. This model reconceptualizes the term "function", suggests mechanisms of post-traumatic reorganizations, and resolves the contradiction between localization and functional recovery.
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Affiliation(s)
- Jesper Mogensen
- The Unit for Cognitive Neuroscience, Department of Psychology, University of Copenhagen, Denmark.
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Girgenti MJ, Hunsberger J, Duman CH, Sathyanesan M, Terwilliger R, Newton SS. Erythropoietin induction by electroconvulsive seizure, gene regulation, and antidepressant-like behavioral effects. Biol Psychiatry 2009; 66:267-74. [PMID: 19185286 DOI: 10.1016/j.biopsych.2008.12.005] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2008] [Revised: 12/03/2008] [Accepted: 12/03/2008] [Indexed: 12/11/2022]
Abstract
BACKGROUND The neuroprotective and trophic actions of erythropoietin (EPO) have been tested in several animal models of insult, injury, and neurodegeneration. Recent studies in human volunteers demonstrated that EPO improves cognition and also elicits antidepressant effects. It is believed that the behavioral effects are mediated by EPO's trophic effect on neuronal systems. We therefore tested whether EPO is able to alter behavior and brain gene expression in rats. METHODS The expression of EPO and EPO receptor (EPOR) in multiple brain regions was examined by quantitative polymerase chain reaction, in situ hybridization, and immunohistochemistry. The regulation of EPO and the transcription factor hypoxia-induced factor-alpha (HIF1alpha) after electroconvulsive seizure (ECS) was investigated. Behavioral effects of EPO were tested in the rodent forced swimming and novelty-induced hypophagia (NIH) models. EPO gene profiles were obtained by microarray analysis of the hippocampus after intracerebroventricular infusion. RESULTS EPO and EPOR were widely expressed in the brain albeit at low levels. Highest level of EPO and EPOR were in the choroid plexus and striatum, respectively. Peripheral administration of EPO was sufficient to produce a robust antidepressant-like effect in the forced swim and NIH tests. Gene expression profiles revealed that EPO induces the expression of neurotrophic genes such as brain-derived neurotrophic factor, VGF (nonacronymic), and neuritin. CONCLUSIONS EPO is induced by ECS and independently exhibits antidepressant-like efficacy in the forced swim and NIH tests. EPO regulates the expression of genes implicated in antidepressant action and appears to be a candidate molecule for further testing in neuropsychiatry.
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Affiliation(s)
- Matthew J Girgenti
- Division of Molecular Psychiatry, Abraham Ribicoff Research Facilities, Connecticut Mental Health Center, Yale University School of Medicine, New Haven, Connecticut, USA
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Kristensen PL, Høi-Hansen T, Olsen NV, Pedersen-Bjergaard U, Thorsteinsson B. Erythropoietin during hypoglycaemia in type 1 diabetes: relation to basal renin-angiotensin system activity and cognitive function. Diabetes Res Clin Pract 2009; 85:75-84. [PMID: 19211168 DOI: 10.1016/j.diabres.2009.01.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2008] [Revised: 01/02/2009] [Accepted: 01/12/2009] [Indexed: 10/21/2022]
Abstract
AIMS Preservation of cognitive function during hypoglycaemic episodes is crucial for patients with insulin-treated diabetes to avoid severe hypoglycaemic events. Erythropoietin has neuroprotective potential. However, the role of erythropoietin during hypoglycaemia is unclear. The aim of the study was to explore plasma erythropoietin response to hypoglycaemia and the relationship to basal renin-angiotensin system (RAS) activity and cognitive function. METHODS We performed a single-blinded, controlled, cross-over study with induced hypoglycaemia or maintained glycaemic level. Nine patients with type 1 diabetes with high and nine with low activity in RAS were studied. Hypoglycaemia was induced using a standardized insulin-infusion. RESULTS Overall, erythropoietin concentrations increased during hypoglycaemia. In the high RAS group erythropoietin rose 29% (p=0.032) whereas no significant response was observed in the low RAS group (7% increment; p=0.43). Independently, both hypoglycaemia and high RAS activity were associated with higher levels of erythropoietin (p=0.02 and 0.04, respectively). Low plasma erythropoietin at baseline was associated with poorer cognitive performance during hypoglycaemia. CONCLUSIONS Hypoglycaemia triggers a rise in plasma erythropoietin in patients with type 1 diabetes. The response is influenced by basal RAS activity. Erythropoietin may carry a neuroprotective potential during hypoglycaemia.
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Affiliation(s)
- Peter Lommer Kristensen
- Endocrinology Section, Department of Cardiology and Endocrinology, Hillerød Hospital, Dyrehavevej 29, DK-3400, Hillerød, Denmark.
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Adamcio B, Sargin D, Stradomska A, Medrihan L, Gertler C, Theis F, Zhang M, Müller M, Hassouna I, Hannke K, Sperling S, Radyushkin K, El-Kordi A, Schulze L, Ronnenberg A, Wolf F, Brose N, Rhee JS, Zhang W, Ehrenreich H. Erythropoietin enhances hippocampal long-term potentiation and memory. BMC Biol 2008; 6:37. [PMID: 18782446 PMCID: PMC2562991 DOI: 10.1186/1741-7007-6-37] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2008] [Accepted: 09/09/2008] [Indexed: 12/05/2022] Open
Abstract
BACKGROUND Erythropoietin (EPO) improves cognition of human subjects in the clinical setting by as yet unknown mechanisms. We developed a mouse model of robust cognitive improvement by EPO to obtain the first clues of how EPO influences cognition, and how it may act on hippocampal neurons to modulate plasticity. RESULTS We show here that a 3-week treatment of young mice with EPO enhances long-term potentiation (LTP), a cellular correlate of learning processes in the CA1 region of the hippocampus. This treatment concomitantly alters short-term synaptic plasticity and synaptic transmission, shifting the balance of excitatory and inhibitory activity. These effects are accompanied by an improvement of hippocampus dependent memory, persisting for 3 weeks after termination of EPO injections, and are independent of changes in hematocrit. Networks of EPO-treated primary hippocampal neurons develop lower overall spiking activity but enhanced bursting in discrete neuronal assemblies. At the level of developing single neurons, EPO treatment reduces the typical increase in excitatory synaptic transmission without changing the number of synaptic boutons, consistent with prolonged functional silencing of synapses. CONCLUSION We conclude that EPO improves hippocampus dependent memory by modulating plasticity, synaptic connectivity and activity of memory-related neuronal networks. These mechanisms of action of EPO have to be further exploited for treating neuropsychiatric diseases.
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Affiliation(s)
- Bartosz Adamcio
- Division of Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Derya Sargin
- Division of Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Alicja Stradomska
- Dept. of Neurophysiology, Georg-August-University, Göttingen, Germany
- DFG Research Center for Molecular Physiology of the Brain (CMPB), Göttingen, Germany
| | - Lucian Medrihan
- Dept. of Neurophysiology, Georg-August-University, Göttingen, Germany
- DFG Research Center for Molecular Physiology of the Brain (CMPB), Göttingen, Germany
| | - Christoph Gertler
- Dept. of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Fabian Theis
- Dept. of Nonlinear Dynamics, Max Planck Institute of Dynamics and Self-Organization, Göttingen, Germany
| | - Mingyue Zhang
- Dept. of Neurophysiology, Georg-August-University, Göttingen, Germany
- DFG Research Center for Molecular Physiology of the Brain (CMPB), Göttingen, Germany
| | - Michael Müller
- Dept. of Neurophysiology, Georg-August-University, Göttingen, Germany
- DFG Research Center for Molecular Physiology of the Brain (CMPB), Göttingen, Germany
| | - Imam Hassouna
- Division of Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Kathrin Hannke
- Division of Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Swetlana Sperling
- Division of Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Konstantin Radyushkin
- Division of Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- DFG Research Center for Molecular Physiology of the Brain (CMPB), Göttingen, Germany
| | - Ahmed El-Kordi
- Division of Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Lizzy Schulze
- Dept. of Neurophysiology, Georg-August-University, Göttingen, Germany
- DFG Research Center for Molecular Physiology of the Brain (CMPB), Göttingen, Germany
| | - Anja Ronnenberg
- Division of Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Fred Wolf
- Dept. of Nonlinear Dynamics, Max Planck Institute of Dynamics and Self-Organization, Göttingen, Germany
| | - Nils Brose
- DFG Research Center for Molecular Physiology of the Brain (CMPB), Göttingen, Germany
- Dept. of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Jeong-Seop Rhee
- Dept. of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Weiqi Zhang
- Dept. of Neurophysiology, Georg-August-University, Göttingen, Germany
- DFG Research Center for Molecular Physiology of the Brain (CMPB), Göttingen, Germany
| | - Hannelore Ehrenreich
- Division of Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- DFG Research Center for Molecular Physiology of the Brain (CMPB), Göttingen, Germany
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Mogensen J, Boyd MH, Nielsen MD, Kristensen RS, Malá H. Erythropoietin improves spatial delayed alternation in a T-maze in rats subjected to ablation of the prefrontal cortex. Brain Res Bull 2008; 77:1-7. [PMID: 18639740 DOI: 10.1016/j.brainresbull.2008.05.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2007] [Revised: 05/16/2008] [Accepted: 05/21/2008] [Indexed: 10/21/2022]
Abstract
Systemically administered human recombinant erythropoietin (EPO) may have the potential to reduce the cognitive and behavioural symptoms of mechanical brain injury. In a series of studies we address this possibility. Previously, we studied the effects of EPO given to fimbria-fornix transected rats at the moment of injury. We have found that such treatment improves substantially the posttraumatic acquisition of allocentric place learning tasks administered in a water maze and in an 8-arm radial maze as well as a spatial delayed alternation task administered in a T-maze. It is, however, essential also to evaluate this clinically important ability of EPO after other types of mechanical brain injury. Consequently, we presently studied the effects of similarly administered EPO in rats subjected to bilateral subpial aspiration of the anteromedial prefrontal cortex as well as control operated rats, respectively. We evaluated the posttraumatic behavioural/cognitive abilities of these animals in a spatial delayed alternation task performed in a T-maze. Administration of EPO to the prefrontally ablated rats was associated with a reduction of the lesion-associated behavioural impairment--while such an impairment was clearly seen in the saline injected prefrontally ablated group. In sham operated rats administration of EPO did not influence the task acquisition significantly. The results of the present study confirm our previous demonstrations that EPO is able to reduce the behavioural/cognitive consequences of mechanical brain injury. This ability is emphasized by its relative independence on the type of lesion as well as the neural structure affected.
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Affiliation(s)
- Jesper Mogensen
- The Unit for Cognitive Neuroscience, Department of Psychology, University of Copenhagen, Denmark.
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Malá H, Castro MR, Knippel J, Køhler PJ, Lassen P, Mogensen J. Therapeutic effects of a restraint procedure on posttraumatic place learning in fimbria-fornix transected rats. Brain Res 2008; 1217:221-31. [DOI: 10.1016/j.brainres.2008.04.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2007] [Revised: 04/01/2008] [Accepted: 04/04/2008] [Indexed: 11/27/2022]
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Malá H, Rodriguez Castro M, Dall Jørgensen K, Mogensen J. Effects of erythropoietin on posttraumatic place learning in fimbria-fornix transected rats after a 30-day postoperative pause. J Neurotrauma 2007; 24:1647-57. [PMID: 17970627 DOI: 10.1089/neu.2007.0292] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Human recombinant erythropoietin (EPO) has been shown to exert neuroprotective effects following both vascular and mechanical brain injury. Previously, we showed that behavioral symptoms associated with mechanical lesions of the hippocampus are nearly abolished due to EPO treatment. In these studies, the EPO administration took place simultaneously with the infliction of brain injury and the rehabilitation training started 6-7 days postoperatively. In the present study, we tested whether the therapeutic effect of EPO on the acquisition of an allocentric eight-arm radial maze spatial task also manifests itself if the rehabilitative training is postponed. Postoperatively, the animals were left without any specific stimulation for 30 days. The current results show an improved behavioral performance of the EPO-treated lesioned group relative to the saline-treated lesioned group, and confirm EPO's therapeutic effect even in case of postponed rehabilitation. However, compared to the control group, the EPO-treated lesioned group demonstrated an impaired task acquisition. All subjects eventually recovered functionally. Subsequently, the animals were given behavioral challenges during which the cue constellation in the room was changed. The challenges revealed that, although the EPO-treated lesion group had achieved the same level of task proficiency as the control group, the cognitive mechanisms mediating the task performance in the EPO-treated lesion group (as well as in the saline-treated lesion group) were dissimilar from those mediating the task in the control group. Both the EPO-treated and the saline-treated lesion group demonstrated an increased dependency on the original cue configuration.
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Affiliation(s)
- Hana Malá
- Unit for Cognitive Neuroscience, Department of Psychology, University of Copenhagen, Copenhagen, Denmark
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Miskowiak K, O'Sullivan U, Harmer CJ. Erythropoietin reduces neural and cognitive processing of fear in human models of antidepressant drug action. Biol Psychiatry 2007; 62:1244-50. [PMID: 17553466 DOI: 10.1016/j.biopsych.2007.01.011] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2006] [Revised: 01/18/2007] [Accepted: 01/19/2007] [Indexed: 12/15/2022]
Abstract
BACKGROUND Erythropoietin (Epo) has neuroprotective and neurotrophic effects in animal models and affects cognitive and associated neural responses in humans. These effects have highlighted Epo as a candidate for treatment of psychiatric disease including schizophrenia and depression. The current study aimed to explore the effects of Epo on neural and behavioral measures of emotional processing relevant for depression and the effects of conventional antidepressant medication. METHODS In the present study, we used functional magnetic resonance imaging to explore the effects of Epo (40,000 IU) versus saline on the neural processing of happy and fearful faces in 23 healthy volunteers. Facial expression recognition was assessed outside the scanner. RESULTS One week after administration, Epo reduced neural response to fearful versus neutral faces in the occipito-parietal cortex consistent with reduced attention to fear. Erythropoietin additionally reduced recognition of fearful facial expressions without affecting recognition of other emotional expressions. These actions occurred in the absence of changes in hematological parameters. CONCLUSIONS The present study demonstrates that Epo directly modulates brain responses to emotional information in humans in a manner consistent with the actions of conventional antidepressants. The characterization of the effects of Epo in a clinically depressed group is therefore warranted.
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Affiliation(s)
- Kamilla Miskowiak
- Department of Experimental Psychology, University of Oxford, South Parks Road, Oxford, United Kingdom.
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30
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Neuroprotection by erythropoietin administration after experimental traumatic brain injury. Brain Res 2007; 1182:99-105. [PMID: 17935704 DOI: 10.1016/j.brainres.2007.08.078] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2007] [Revised: 08/27/2007] [Accepted: 08/30/2007] [Indexed: 11/23/2022]
Abstract
A large body of evidence indicates that the hormone erythropoietin (EPO) exerts beneficial effects in the central nervous system (CNS). To date, EPO's effect has been assessed in several experimental models of brain and spinal cord injury. This study was conducted to validate whether treatment with recombinant human EPO (rHuEPO) would limit the extent of injury following experimental TBI. Experimental TBI was induced in rats by a cryogenic injury model. rHuEPO or placebo was injected intraperitoneally immediately after the injury and then every 8 h until 2 or 14 days. Forty-eight hours after injury brain water content, an indicator of brain edema, was measured with the wet-dry method and blood-brain barrier (BBB) breakdown was evaluated by assay of Evans blue extravasation. Furthermore, extent of cerebral damage was assessed. Administration of rHuEPO markedly improved recovery from motor dysfunction compared with placebo group (P<0.05). Brain edema was significantly reduced in the cortex of the EPO-treated group relative to that in the placebo-treated group (80.6+/-0.3% versus 91.8%+/-0.8% respectively, P<0.05). BBB breakdown was significantly lower in EPO-treated group than in the placebo-treated group (66.2+/-18.7 mug/g versus 181.3+/-21 mug/g, respectively, P<0.05). EPO treatment reduced injury volume significantly compared with placebo group (17.4+/-5.4 mm3 versus 37.1+/-5.3 mm3, P<0.05). EPO, administered in its recombinant form, affords significant neuroprotection in experimental TBI model and may hold promise for future clinical applications.
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Mogensen J, Hjortkjaer J, Ibervang KL, Stedal K, Malá H. Prefrontal cortex and hippocampus in posttraumatic functional recovery: Spatial delayed alternation by rats subjected to transection of the fimbria–fornix and/or ablation of the prefrontal cortex. Brain Res Bull 2007; 73:86-95. [PMID: 17499641 DOI: 10.1016/j.brainresbull.2007.02.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2006] [Revised: 01/25/2007] [Accepted: 02/13/2007] [Indexed: 11/22/2022]
Abstract
Lesions of the prefrontal cortex and the hippocampus often lead to impairment of the same behavioural tasks (e.g., allocentric as well as egocentric spatial orientation and spatial delayed alternation). In case of allocentric and egocentric spatial orientation we have previously found that the two structures mutually contribute to the posttraumatic functional recovery of such tasks. We therefore presently tested the hypothesis that this would even be true in case of spatial delayed alternation. The acquisition of a spatial delayed alternation task in a T-maze was studied in four groups of rats: animals in which the fimbria-fornix had been transected bilaterally, rats who had received bilateral ablations of the anteromedial prefrontal cortex, animals in which both of these structures had been lesioned, and a sham operated control group. All three lesion groups demonstrated an impaired task acquisition. The group given prefrontal cortical lesions in isolation underwent a complete functional recovery. Both of the fimbria-fornix transected groups were significantly impaired even when compared to the group given prefrontal cortical ablations in isolation. The two fimbria-fornix lesioned groups did, however, exhibit levels of functional recovery. The group in which both structures had been lesioned demonstrated a task acquisition, which was significantly inferior to that of the group given fimbria-fornix transections in isolation. After completion of the task acquisition period, all animals were subjected to two behavioural challenges including a session on which the duration of the inter-trial delay was doubled. This expansion of the inter-trial delay rather selectively impaired the task performance of the group given fimbria-fornix transections in isolation. Consequently, both during the acquisition period and in one of the challenges a differentiation of functional recovery was seen between the combined lesioned group and the group given fimbria-fornix lesions only. This indicates that even in case of a spatial delayed alternation task the prefrontal cortex normally contributes significantly to mediation of posttraumatic functional recovery after isolated lesions of the fimbria-fornix. The results are discussed in the context of models of posttraumatic functional recovery.
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Affiliation(s)
- Jesper Mogensen
- The Unit for Cognitive Neuroscience, Department of Psychology, University of Copenhagen, Denmark.
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32
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Miskowiak K, O'Sullivan U, Harmer CJ. Erythropoietin enhances hippocampal response during memory retrieval in humans. J Neurosci 2007; 27:2788-92. [PMID: 17360900 PMCID: PMC6672568 DOI: 10.1523/jneurosci.5013-06.2007] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Although erythropoietin (Epo) is best known for its effects on erythropoiesis, recent evidence suggests that it also has neurotrophic and neuroprotective properties in animal models of hippocampal function. Such an action in humans would make it an intriguing novel compound for the treatment of neurological and psychiatric disorders. The current study therefore aimed to explore the effects of Epo on neural and behavioral measures of hippocampal function in humans using a functional magnetic resonance imaging paradigm. Volunteers were randomized to receive intravenous injection of Epo (40,000 IU) or saline in a between-subjects, double-blind, randomized design. Neural response during picture encoding and retrieval was tested 1 week later. Epo increased hippocampus response during picture retrieval (n = 11) compared with placebo (n = 12; p = 0.04) independent of changes in hematocrit. This is consistent with upregulation of hippocampal BDNF and neurotrophic actions found in animals and highlights Epo as a promising candidate for treatment of psychiatric disorders.
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Affiliation(s)
- Kamilla Miskowiak
- Department of Experimental Psychology, University of Oxford, Oxford OX1 3UD, United Kingdom.
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33
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Ehrenreich H, Hinze-Selch D, Stawicki S, Aust C, Knolle-Veentjer S, Wilms S, Heinz G, Erdag S, Jahn H, Degner D, Ritzen M, Mohr A, Wagner M, Schneider U, Bohn M, Huber M, Czernik A, Pollmächer T, Maier W, Sirén AL, Klosterkötter J, Falkai P, Rüther E, Aldenhoff J, Krampe H. Hemoglobin-Independent Organ Protection by EPO in Humans: Amelioration of Cognitive Loss in Chronic Schizophrenia. J Am Soc Nephrol 2007. [DOI: 10.1681/asn.2006111278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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34
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Yatsiv I, Grigoriadis N, Simeonidou C, Stahel PF, Schmidt OI, Alexandrovitch AG, Tsenter J, Shohami E. Erythropoietin is neuroprotective, improves functional recovery, and reduces neuronal apoptosis and inflammation in a rodent model of experimental closed head injury. FASEB J 2005; 19:1701-3. [PMID: 16099948 DOI: 10.1096/fj.05-3907fje] [Citation(s) in RCA: 181] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Traumatic brain injury (TBI) is a leading cause of morbidity and mortality in young people in industrialized countries. Although various anti-inflammatory and antiapoptotic modalities have shown neuroprotective effects in experimental models of TBI, to date, no specific pharmacological agent aimed at blocking the progression of secondary brain damage has been approved for clinical use. Erythropoietin (Epo) belongs to the cytokine superfamily and has traditionally been viewed as a hematopoiesis-regulating hormone. The newly discovered neuroprotective properties of Epo lead us to investigate its effect in TBI in a mouse model of closed head injury. Recombinant human erythropoietin (rhEpo) was injected at 1 and 24 h after TBI, and the effect on recovery of motor and cognitive functions, tissue inflammation, axonal degeneration, and apoptosis was evaluated up to 14 days. Motor deficits were lower, cognitive function was restored faster, and less apoptotic neurons and caspase-3 expression were found in rhEpo-treated as compared with vehicle-treated animals (P<0.05). Axons at the trauma area in rhEpo-treated mice were relatively well preserved compared with controls (shown by their density; P<0.01). Immunohistochemical analysis revealed a reduced activation of glial cells by staining for GFAP and complement receptor type 3 (CD11b/CD18) in the injured hemisphere of Epo- vs. vehicle-treated animals. We propose that further studies on Epo in TBI should be conducted in order to consider it as a novel therapy for TBI.
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Affiliation(s)
- I Yatsiv
- Department of Pharmacology, School of Pharmacy,Hebrew University Hadassah Medical Center, Jerusalem, Israel
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35
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Viviani B, Bartesaghi S, Corsini E, Villa P, Ghezzi P, Garau A, Galli CL, Marinovich M. Erythropoietin protects primary hippocampal neurons increasing the expression of brain-derived neurotrophic factor. J Neurochem 2005; 93:412-21. [PMID: 15816864 DOI: 10.1111/j.1471-4159.2005.03033.x] [Citation(s) in RCA: 129] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Erythropoietin, the principal regulator of erythroids progenitor cells, also promotes neuronal survival. Using primary cultures of rat hippocampal neurons, we investigated whether erythropoietin could mediate neuroprotection favouring the transcription of brain-derived neurotrophic factor (BDNF). Erythropoietin 2.7 nm reduced by approximately 50% the neuronal death triggered by the prototypic neurotoxicant trimethyltin (TMT) and time-dependently induced BDNF mRNA. This effect resulted in an increased production of biologically active BDNF, which led to a sustained activation of the specific BDNF receptor tyrosine kinase B (TrkB). Reduction of TMT-induced neuronal death by erythropoietin was specifically prevented by a neutralizing anti-BDNF antibody (15 microg/mL), indicating the involvement of this neurotrophin in erythropoietin neuroprotective effect. Intracerebroventricular administration of erythropoietin in mice significantly increases BDNF mRNA expression in brain, supporting the idea of the involvement of this neurotrophin in erythropoietin action within the CNS. BDNF expression in neuronal cells is induced by activation of voltage Ca(2+)-channels and recruitment of Ca(2+)-sensitive transcription factors. Consistently, 2.7 nm erythropoietin increased intracellular Ca(2+) in 5 min and cAMP response element binding protein (CREB) phosphorylation at Ser 133 in 30 min. Both effects were abolished by 1 microm nitrendipine, a selective blocker of L-type voltage Ca(2+)-channels. These data demonstrate that erythropoietin activates the CREB transcription pathway and increases BDNF expression and production, which contributes to erythropoietin mediated neuroprotection.
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Affiliation(s)
- Barbara Viviani
- Laboratory of Toxicology and Centre of Excellence on Neurodegenerative Diseases, Department of Pharmacological Sciences, University of Milan, Milan, Italy.
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36
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Ghezzi P, Brines M. Erythropoietin as an antiapoptotic, tissue-protective cytokine. Cell Death Differ 2005; 11 Suppl 1:S37-44. [PMID: 15243580 DOI: 10.1038/sj.cdd.4401450] [Citation(s) in RCA: 251] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Erythropoietin (EPO) increases the number of circulating erythrocytes primarily by preventing apoptosis of erythroid progenitors. In addition to this proerythroid action, results of recent studies show that systemically administered EPO is protective in vivo, in several animal models of neuronal injury. In vitro, EPO prevents neuronal apoptosis induced by a variety of stimuli. This review summarizes the neuroprotective actions of EPO and discusses the underlying mechanisms in terms of signal transduction pathways involved. The understanding of these mechanisms will help differentiate the neuroprotective actions of EPO from its role in the bone marrow.
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Affiliation(s)
- P Ghezzi
- Laboratory of Neuroimmunology, Mario Negri Institute, Milan, Italy.
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37
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Mogensen J, Moustgaard A, Khan U, Wörtwein G, Nielsen KS. Egocentric spatial orientation in a water maze by rats subjected to transection of the fimbria-fornix and/or ablation of the prefrontal cortex. Brain Res Bull 2005; 65:41-58. [PMID: 15680544 DOI: 10.1016/j.brainresbull.2004.11.010] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2003] [Revised: 10/28/2004] [Accepted: 11/10/2004] [Indexed: 10/26/2022]
Abstract
The acquisition of a water maze based task requiring egocentric spatial orientation in the absence of distal cues was studied in four groups of rats: animals in which the fimbria-fornix had been transected, rats that received bilateral ablations of the anteromedial prefrontal cortex, animals in which both of these structures had been lesioned, and a sham-operated control group. Isolated lesions of both the anteromedial prefrontal cortex and the hippocampus were associated with a significantly impaired task acquisition. Both of these individually lesioned groups did, however, eventually demonstrate full functional recovery by reaching the task proficiency of the sham-operated control group. In contrast, the group in which both of these structures had been lesioned failed to demonstrate full functional recovery and was severely and long-lastingly impaired when compared to all other groups. Behavioural challenges in the form of a no-platform session and two reversals of platform position demonstrated that while the sham-operated control group and the group subjected to fimbria-fornix transections in isolation utilized rather pure egocentric orientation strategies, the two prefrontally lesioned groups (and especially the combined lesion group) employed a different set of solution strategies which at least partly relied on a "circling" method. Even in the behaviour of the prefrontally lesioned groups, however, indications of a certain level of cognitive representations of the platform positions were seen. It is concluded that both the prefrontal cortex and the hippocampus contribute to the mediation of egocentric spatial orientation. Furthermore, the hippocampus is a significant and potentially irreplaceable part of the neural substrate of functional recovery of the presently studied task after prefrontal lesions--while the prefrontal cortex may play a similar role with respect to hippocampal lesions.
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Affiliation(s)
- Jesper Mogensen
- The Unit for Cognitive Neuroscience, Department of Psychology, University of Copenhagen, Amager, Njalsgade 88, DK-2300 Copenhagen S, Denmark.
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38
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Miu AC, Olteanu AI, Chiş I, Heilman RM. Have no fear, erythropoietin is here: erythropoietin protects fear conditioning performances after functional inactivation of the amygdala. Behav Brain Res 2004; 155:223-9. [PMID: 15364481 DOI: 10.1016/j.bbr.2004.04.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2004] [Revised: 04/19/2004] [Accepted: 04/26/2004] [Indexed: 10/26/2022]
Abstract
This study investigated the capacity of erythropoietin (EPO) to protect fear conditioning performances against functional inactivation of the amygdala. We infused an excitotoxic dose of glutamate in the lateral nucleus of the amygdala (LA) of adult rats in order to block the output projections to brainstem areas controlling the expression of conditioned fear responses. Subsequently, animals with excitotoxic lesions in the LA displayed altered short and long-term fear conditioned responses, but the integrity of their general emotional reactivity was preserved, as indicated by their open-field behavior. EPO infused immediately after glutamate succeeded to protect the conditioned fear performances of rats. This effect was reliably represented on both short, and long-term memory tests of conditioned fear. This and other studies have supported the potent neuroprotective activity of EPO, discriminable both morphologically, and behaviorally.
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Affiliation(s)
- Andrei C Miu
- Laboratory of Cognitive Neuroscience, Department of Psychology, Babeş-Bolyai University, 37 Republicii, Cluj-Napoca CJ 3400, Romania.
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Mogensen J, Lauritsen KT, Elvertorp S, Hasman A, Moustgaard A, Wörtwein G. Place learning and object recognition by rats subjected to transection of the fimbria-fornix and/or ablation of the prefrontal cortex. Brain Res Bull 2004; 63:217-36. [PMID: 15145141 DOI: 10.1016/j.brainresbull.2004.02.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2003] [Revised: 02/12/2004] [Accepted: 02/24/2004] [Indexed: 11/30/2022]
Abstract
The acquisition of a water maze-based allocentric place learning task and an exploration based object recognition task were studied in four groups of rats: animals in which the fimbria-fornix had been transected, rats who had received bilateral ablations of the anteromedial prefrontal cortex, animals in which both of these structures had been lesioned, and a sham operated control group. None of the groups showed impairments of object recognition. Ablations of the prefrontal cortex caused a mild impairment in the acquisition of the place learning task. The two fimbria-fornix transected groups exhibited a severe impairment during the acquisition of this task. All groups reached criterion level task performance eventually. All groups were subjected to a number of behavioural and pharmacological challenges in order to elucidate the neural and cognitive mechanisms of this behavioural recovery. During a no-platform session both the fimbria-fornix transected group and the prefrontally ablated group demonstrated a normal preference for the former platform position. The combined lesion group, however, failed to show a similar preference for this position. The outcome of the pharmacological challenges demonstrated that while the task performance of all four groups relied equally on catecholaminergic mediation, only the task solution of the fimbria-fornix transected group was significantly impaired by disturbance of the catecholaminergic systems. The data indicated a high likelihood that prefrontal cortical mechanisms contribute to the recovery of allocentric place learning after fimbria-fornix transections.
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Affiliation(s)
- Jesper Mogensen
- Department of Psychology, University of Copenhagen, Amager, Njalsgade 88, DK-2300 Copenhagen S, Denmark.
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