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Mundorf A, Ocklenburg S. Hemispheric asymmetries in mental disorders: evidence from rodent studies. J Neural Transm (Vienna) 2023; 130:1153-1165. [PMID: 36842091 PMCID: PMC10460727 DOI: 10.1007/s00702-023-02610-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 02/20/2023] [Indexed: 02/27/2023]
Abstract
The brain is built with hemispheric asymmetries in structure and function to enable fast neuronal processing. In neuroimaging studies, several mental disorders have been associated with altered or attenuated hemispheric asymmetries. However, the exact mechanism linking asymmetries and disorders is not known. Here, studies in animal models of mental disorders render important insights into the etiology and neuronal alterations associated with both disorders and atypical asymmetry. In this review, the current literature of animal studies in rats and mice focusing on anxiety and fear, anhedonia and despair, addiction or substance misuse, neurodegenerative disorders as well as stress exposure, and atypical hemispheric asymmetries is summarized. Results indicate overall increased right-hemispheric neuronal activity and a left-sided behavioral bias associated with symptoms of anxiety, fear, anhedonia, behavioral despair as well as stress exposure. Addiction behavior is associated with right-sided bias and transgenic models of Alzheimer's disease indicate an asymmetrical accumulation of fibrillar plaques. Most studies focused on changes in the bilateral amygdala and frontal cortex. Across studies, two crucial factors influencing atypical asymmetries arose independently of the disorder modeled: sex and developmental age. In conclusion, animal models of mental disorders demonstrate atypical hemispheric asymmetries similar to findings in patients. Particularly, increased left-sided behavior and greater right-hemispheric activity were found across models applying stress-based paradigms. However, sex- and age-dependent effects on atypical hemispheric asymmetries are present that require further investigation. Animal models enable the analysis of hemispheric changes on the molecular level which may be most effective to detect early alterations.
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Affiliation(s)
- Annakarina Mundorf
- Institute for Systems Medicine and Department of Human Medicine, MSH Medical School Hamburg, Hamburg, Germany.
| | - Sebastian Ocklenburg
- Department of Psychology, Medical School Hamburg, Hamburg, Germany
- ICAN Institute for Cognitive and Affective Neuroscience, Medical School Hamburg, Hamburg, Germany
- Institute of Cognitive Neuroscience, Biopsychology, Department of Psychology, Ruhr-University Bochum, Bochum, Germany
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Zemba Cilic A, Zemba M, Cilic M, Balenovic I, Strbe S, Ilic S, Vukojevic J, Zoricic Z, Filipcic I, Kokot A, Drmic D, Blagaic AB, Tvrdeic A, Seiwerth S, Sikiric P. Pentadecapeptide BPC 157 counteracts L-NAME-induced catalepsy. BPC 157, L-NAME, L-arginine, NO-relation, in the suited rat acute and chronic models resembling 'positive-like' symptoms of schizophrenia. Behav Brain Res 2020; 396:112919. [PMID: 32956773 DOI: 10.1016/j.bbr.2020.112919] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 08/15/2020] [Accepted: 09/14/2020] [Indexed: 12/13/2022]
Abstract
In the suited rat-models, we focused on the stable pentadecapeptide BPC 157, L-NAME, NOS-inhibitor, and L-arginine, NOS-substrate, relation, the effect on schizophrenia-like symptoms. Medication (mg/kg intraperitoneally) was L-NAME (5), L-arginine (100), BPC 157 (0.01), given alone and/or together, at 5 min before the challenge for the acutely disturbed motor activity (dopamine-indirect/direct agonists (amphetamine (3.0), apomorphine (2.5)), NMDA-receptor non-competitive antagonist (MK-801 (0.2)), or catalepsy, (dopamine-receptor antagonist haloperidol (2.0)). Alternatively, BPC 157 10 μg/kg was given immediately after L-NAME 40 mg/kg intraperitoneally. To induce or prevent sensitization, we used chronic methamphetamine administration, alternating 3 days during the first 3 weeks, and challenge after next 4 weeks, and described medication (L-NAME, L-arginine, BPC 157) at 5 min before the methamphetamine at the second and third week. Given alone, BPC 157 or L-arginine counteracted the amphetamine-, apomorphine-, and MK-801-induced effect, haloperidol-induced catalepsy and chronic methamphetamine-induced sensitization. L-NAME did not affect the apomorphine-, and MK-801-induced effects, haloperidol-induced catalepsy and chronic methamphetamine-induced sensitization, but counteracted the acute amphetamine-induced effect. In combinations (L-NAME + L-arginine), as NO-specific counteraction, L-NAME counteracts L-arginine-induced counteractions in the apomorphine-, MK-801-, haloperidol- and methamphetamine-rats, but not in amphetamine-rats. Unlike L-arginine, BPC 157 maintains its counteracting effect in the presence of the NOS-blockade (L-NAME + BPC 157) or NO-system-over-stimulation (L-arginine + BPC 157). Illustrating the BPC 157-L-arginine relationships, BPC 157 restored the antagonization (L-NAME + L-arginine + BPC 157) when it had been abolished by the co-administration of L-NAME with L-arginine (L-NAME + L-arginine). Finally, BPC 157 directly inhibits the L-NAME high dose-induced catalepsy. Further studies would determine precise BPC 157/dopamine/glutamate/NO-system relationships and clinical application.
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Affiliation(s)
- Andrea Zemba Cilic
- Departments of Pharmacology and Pathology, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Mladen Zemba
- Departments of Pharmacology and Pathology, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Matija Cilic
- Departments of Pharmacology and Pathology, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Igor Balenovic
- Departments of Pharmacology and Pathology, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Sanja Strbe
- Departments of Pharmacology and Pathology, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Spomenko Ilic
- Departments of Pharmacology and Pathology, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Jaksa Vukojevic
- Departments of Pharmacology and Pathology, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Zoran Zoricic
- Departments of Pharmacology and Pathology, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Igor Filipcic
- Departments of Pharmacology and Pathology, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Antonio Kokot
- Departments of Pharmacology and Pathology, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Domagoj Drmic
- Departments of Pharmacology and Pathology, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Alenka Boban Blagaic
- Departments of Pharmacology and Pathology, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Ante Tvrdeic
- Departments of Pharmacology and Pathology, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Sven Seiwerth
- Departments of Pharmacology and Pathology, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Predrag Sikiric
- Departments of Pharmacology and Pathology, School of Medicine, University of Zagreb, Zagreb, Croatia.
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A nitric oxide synthase inhibitor, L-NAME, prevents L-arginine-induced downregulation of the rat cortical somatostatinergic system. Neuroreport 2020; 31:87-91. [PMID: 31834145 DOI: 10.1097/wnr.0000000000001373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Activation of NMDA receptors leads to nitric oxide (NO) synthesis by NO synthase (NOS) from L-arginine. Neuronal NOS colocalizes with somatostatinergic (SRIF) neurons and there is growing evidence of an interaction between NO and the cerebral SRIFergic system in several neurological diseases. Our aim was to study the effect of L-arginine on the regulation of the SRIFergic system in the frontoparietal cortex of male Sprague-Dawley rats. Intraperitoneal administration of L-arginine (150 mg/Kg), twice-daily during eight days, induced a decrease in SRIF receptor density, which was accompanied by a reduction in the capacity of SRIF to stimulate inositol-1,4,5-triphosphate (IP3) accumulation and SRIF-like immunoreactivity (SRIF-LI) levels. To determine if these changes were related to L-arginine-derived NO synthesis, a NOS inhibitor, Nω-nitro-L-arginine methyl ester was coadministered with L-arginine. Its coadministration prevented the reduction in the SRIF receptor density, accumulation of IP3 and SRIF-LI content. These findings indicate that L-arginine induces a deleterious effect on the cortical somatostatinergic system and that the inhibition of NOS could be helpful in some neurological disorders where this neurotransmitter system is affected.
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Acute and Chronic Sleep Deprivation-Related Changes in N-methyl-D-aspartate Receptor-Nitric Oxide Signalling in the Rat Cerebral Cortex with Reference to Aging and Brain Lateralization. Int J Mol Sci 2019; 20:ijms20133273. [PMID: 31277281 PMCID: PMC6651230 DOI: 10.3390/ijms20133273] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 06/13/2019] [Accepted: 06/27/2019] [Indexed: 12/12/2022] Open
Abstract
Aging and chronic sleep deprivation (SD) are well-recognized risk factors for Alzheimer’s disease (AD), with N-methyl-D-aspartate receptor (NMDA) and downstream nitric oxide (NO) signalling implicated in the process. Herein, we investigate the impact of the age- and acute or chronic SD-dependent changes on the expression of NMDA receptor subunits (NR1, NR2A, and NR2B) and on the activities of NO synthase (NOS) isoforms in the cortex of Wistar rats, with reference to cerebral lateralization. In young adult controls, somewhat lateralized seasonal variations in neuronal and endothelial NOS have been observed. In aged rats, overall decreases in NR1, NR2A, and NR2B expression and reduction in neuronal and endothelial NOS activities were found. The age-dependent changes in NR1 and NR2B significantly correlated with neuronal NOS in both hemispheres. Changes evoked by chronic SD (dysfunction of endothelial NOS and the increasing role of NR2A) differed from those evoked by acute SD (increase in inducible NOS in the right side). Collectively, these results demonstrate age-dependent regulation of the level of NMDA receptor subunits and downstream NOS isoforms throughout the rat brain, which could be partly mimicked by SD. As described herein, age and SD alterations in the prevalence of NMDA receptors and NOS could contribute towards cognitive decline in the elderly, as well as in the pathobiology of AD and the neurodegenerative process.
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ZHONG JIANBIN, LI XIE, WAN LIMEI, CHEN ZHIBANG, ZHONG SIMIN, XIAO SONGHUA, YAN ZHENGWEN. Knockdown of NogoA prevents MPP+-induced neurotoxicity in PC12 cells via the mTOR/STAT3 signaling pathway. Mol Med Rep 2015; 13:1427-33. [DOI: 10.3892/mmr.2015.4637] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 11/17/2015] [Indexed: 11/06/2022] Open
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Kristofikova Z, Ricny J, Sirova J, Ripova D, Lubitz I, Schnaider-Beeri M. Differences Between Tg2576 and Wild Type Mice in the NMDA Receptor-Nitric Oxide Pathway After Prolonged Application of a Diet High in Advanced Glycation End Products. Neurochem Res 2015; 40:1709-18. [PMID: 26189181 DOI: 10.1007/s11064-015-1654-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 06/25/2015] [Accepted: 06/28/2015] [Indexed: 10/23/2022]
Abstract
It has been suggested that advanced glycation end (AGE) products, via cognate receptor activation, are implicated in several diseases, including Alzheimer's disease. The NMDA receptor-nitric oxide pathway appears to be influenced by AGE products and involved in the pathogenesis of this type of dementia. In this study, C57BL/6J (WT) and transgenic (Tg2576) mice expressing human mutant amyloid precursor protein were kept on prolonged (8 months) diets containing regular or high amounts of AGE products. After the decapitation of 11-months old mice, brain tissue analyses were performed [expressions of the NR1, NR2A and NR2B subunits of NMDA receptors, activities of neuronal, endothelial and inducible nitric oxide synthase (nNOS, eNOS and iNOS)]. Moreover, levels of malondialdehyde and of human amyloid β 1-42 were estimated. We found increased activity of nNOS in WT mice maintained on a high compared to regular AGE diet; however, no similar differences were found in Tg2576 mice. In addition, we observed an increase in NR1 expression in Tg2576 compared to WT mice, both kept on a diet high in AGE products. Correlation analyses performed on mice kept on the regular AGE diet supported close links between particular subunits (NR2A-NR2B, in WT as well as in Tg2576 mice), between subunits and synthase (NR2A/NR2B-nNOS, only in WT mice) or between particular synthases (nNOS-iNOS, only in WT). Correlation analysis also revealed differences between WT mice kept on both diets (changed correlations between NR2A/NR2B-nNOS, between nNOS-eNOS and between eNOS-iNOS). Malondialdehyde levels were increased in both Tg2576 groups when compared to the corresponding WT mice, but no effects of the diets were observed. Analogously, no significant effects of diets were found in the levels of soluble or insoluble amyloid β 1-42 in Tg2576 mice. Our results demonstrate that prolonged ingestion of AGE products can influence the NMDA receptor-nitric oxide pathway in the brain and that only WT mice, not Tg2576 mice, are able to maintain homeostasis among subunits and synthases or among particular synthases. The prolonged application of AGE products enhanced differences between 11-months old Tg2576 and WT mice regarding this pathway. Observed differences in the pathway between WT mice kept on regular or high AGE diets suggest that the prolonged application of a diet low in AGE products could have beneficial effects in older or diabetic people and perhaps also in people with Alzheimer's disease.
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Affiliation(s)
- Zdena Kristofikova
- Alzheimer's Disease Center, National Institute of Mental Health, Topolova 748, 250 67, Klecany, Czech Republic,
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Schawkat K, Di Santo S, Seiler S, Ducray AD, Widmer HR. Loss of Nogo-A-expressing neurons in a rat model of Parkinson's disease. Neuroscience 2014; 288:59-72. [PMID: 25554426 DOI: 10.1016/j.neuroscience.2014.12.035] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 12/15/2014] [Accepted: 12/15/2014] [Indexed: 11/15/2022]
Abstract
The myelin-associated protein Nogo-A is among the most potent neurite growth inhibitors in the adult CNS. Recently, Nogo-A expression was demonstrated in a number of neuronal subpopulations of the adult and developing CNS but at present, little is known about the expression of Nogo-A in the nigrostriatal system, a brain structure severely affected in Parkinson's disease (PD). The present study sought to characterize the expression pattern of Nogo-A immunoreactive (ir) cells in the adult ventral mesencephalon of control rats and in the 6-hydroxydopamine (6-OHDA) rat model of PD. Immunohistochemical analyses of normal adult rat brain showed a distinct expression of Nogo-A in the ventral mesencephalon, with the highest level in the substantia nigra pars compacta (SNc) where it co-localized with dopaminergic neurons. Analyses conducted 1week and 1 month after unilateral striatal injections of 6-OHDA disclosed a severe loss of the number of Nogo-A-ir cells in the SNc. Notably, at 1week after treatment, more dopaminergic neurons expressing Nogo-A were affected by the 6-OHDA toxicity than Nogo-A-negative dopaminergic neurons. However, at later time points more of the surviving dopaminergic neurons expressed Nogo-A. In the striatum, both small and large Nogo-A-positive cells were detected. The large cells were identified as cholinergic interneurons. Our results suggest yet unidentified functions of Nogo-A in the CNS beyond the inhibition of axonal regeneration and plasticity, and may indicate a role for Nogo-A in PD.
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Affiliation(s)
- K Schawkat
- Department of Neurosurgery, Neurocenter and Regenerative Neuroscience Cluster, University of Bern, Inselspital, CH-3010 Bern, Switzerland.
| | - S Di Santo
- Department of Neurosurgery, Neurocenter and Regenerative Neuroscience Cluster, University of Bern, Inselspital, CH-3010 Bern, Switzerland.
| | - S Seiler
- Department of Neurosurgery, Neurocenter and Regenerative Neuroscience Cluster, University of Bern, Inselspital, CH-3010 Bern, Switzerland.
| | - A D Ducray
- Department of Neurosurgery, Neurocenter and Regenerative Neuroscience Cluster, University of Bern, Inselspital, CH-3010 Bern, Switzerland.
| | - H R Widmer
- Department of Neurosurgery, Neurocenter and Regenerative Neuroscience Cluster, University of Bern, Inselspital, CH-3010 Bern, Switzerland.
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Stuchlik A, Sumiyoshi T. Cognitive deficits in schizophrenia and other neuropsychiatric disorders: convergence of preclinical and clinical evidence. Front Behav Neurosci 2014; 8:444. [PMID: 25566009 PMCID: PMC4275052 DOI: 10.3389/fnbeh.2014.00444] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 12/09/2014] [Indexed: 12/29/2022] Open
Affiliation(s)
- Ales Stuchlik
- Institute of Physiology Academy of Sciences of the Czech Republic , Prague , Czech Republic
| | - Tomiki Sumiyoshi
- National Center of Neurology and Psychiatry, National Center Hospital , Tokyo , Japan
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Petrasek T, Prokopova I, Sladek M, Weissova K, Vojtechova I, Bahnik S, Zemanova A, Schönig K, Berger S, Tews B, Bartsch D, Schwab ME, Sumova A, Stuchlik A. Nogo-A-deficient Transgenic Rats Show Deficits in Higher Cognitive Functions, Decreased Anxiety, and Altered Circadian Activity Patterns. Front Behav Neurosci 2014; 8:90. [PMID: 24672453 PMCID: PMC3957197 DOI: 10.3389/fnbeh.2014.00090] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 03/02/2014] [Indexed: 11/19/2022] Open
Abstract
Decreased levels of Nogo-A-dependent signaling have been shown to affect behavior and cognitive functions. In Nogo-A knockout and knockdown laboratory rodents, behavioral alterations were observed, possibly corresponding with human neuropsychiatric diseases of neurodevelopmental origin, particularly schizophrenia. This study offers further insight into behavioral manifestations of Nogo-A knockdown in laboratory rats, focusing on spatial and non-spatial cognition, anxiety levels, circadian rhythmicity, and activity patterns. Demonstrated is an impairment of cognitive functions and behavioral flexibility in a spatial active avoidance task, while non-spatial memory in a step-through avoidance task was spared. No signs of anhedonia, typical for schizophrenic patients, were observed in the animals. Some measures indicated lower anxiety levels in the Nogo-A-deficient group. Circadian rhythmicity in locomotor activity was preserved in the Nogo-A knockout rats and their circadian period (tau) did not differ from controls. However, daily activity patterns were slightly altered in the knockdown animals. We conclude that a reduction of Nogo-A levels induces changes in CNS development, manifested as subtle alterations in cognitive functions, emotionality, and activity patterns.
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Affiliation(s)
- Tomas Petrasek
- Department of Neurophysiology of Memory, Institute of Physiology, Academy of Sciences of the Czech Republic , Prague , Czech Republic ; First Faculty of Medicine, Charles University in Prague , Prague , Czech Republic
| | - Iva Prokopova
- Department of Neurophysiology of Memory, Institute of Physiology, Academy of Sciences of the Czech Republic , Prague , Czech Republic
| | - Martin Sladek
- Department of Neurohumoral Regulations, Institute of Physiology, Academy of Sciences of the Czech Republic , Prague , Czech Republic
| | - Kamila Weissova
- Department of Neurohumoral Regulations, Institute of Physiology, Academy of Sciences of the Czech Republic , Prague , Czech Republic
| | - Iveta Vojtechova
- Department of Neurophysiology of Memory, Institute of Physiology, Academy of Sciences of the Czech Republic , Prague , Czech Republic
| | - Stepan Bahnik
- Department of Neurophysiology of Memory, Institute of Physiology, Academy of Sciences of the Czech Republic , Prague , Czech Republic ; Social Psychology, Department of Psychology II, University of Würzburg , Würzburg , Germany
| | - Anna Zemanova
- Department of Neurophysiology of Memory, Institute of Physiology, Academy of Sciences of the Czech Republic , Prague , Czech Republic
| | - Kai Schönig
- Department of Molecular Biology, Central Institute of Mental Health , Mannheim , Germany
| | - Stefan Berger
- Department of Molecular Biology, Central Institute of Mental Health , Mannheim , Germany
| | - Björn Tews
- Brain Research Institute, University of Zurich , Zurich , Switzerland ; Neurosciences, Department of Biology, Swiss Federal Institute of Technology Zurich , Zurich , Switzerland ; Division of Molecular Mechanisms of Tumor Invasion, German Cancer Research Center , Heidelberg , Germany
| | - Dusan Bartsch
- Department of Molecular Biology, Central Institute of Mental Health , Mannheim , Germany
| | - Martin E Schwab
- Brain Research Institute, University of Zurich , Zurich , Switzerland ; Neurosciences, Department of Biology, Swiss Federal Institute of Technology Zurich , Zurich , Switzerland
| | - Alena Sumova
- Department of Neurohumoral Regulations, Institute of Physiology, Academy of Sciences of the Czech Republic , Prague , Czech Republic
| | - Ales Stuchlik
- Department of Neurophysiology of Memory, Institute of Physiology, Academy of Sciences of the Czech Republic , Prague , Czech Republic
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Enkel T, Berger SM, Schönig K, Tews B, Bartsch D. Reduced expression of nogo-a leads to motivational deficits in rats. Front Behav Neurosci 2014; 8:10. [PMID: 24478657 PMCID: PMC3898325 DOI: 10.3389/fnbeh.2014.00010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Accepted: 01/07/2014] [Indexed: 12/24/2022] Open
Abstract
Nogo-A is an important neurite growth-regulatory protein in the adult and developing nervous system. Mice lacking Nogo-A, or rats with neuronal Nogo-A deficiency, exhibit behavioral abnormalities such as impaired short-term memory, decreased pre-pulse inhibition, and behavioral inflexibility. In the current study, we extended the behavioral profile of the Nogo-A deficient rat line with respect to reward sensitivity and motivation, and determined the concentrations of the monoamines dopamine and serotonin in the prefrontal cortex (PFC), dorsal striatum (dSTR), and nucleus accumbens (NAcc). Using a limited access consumption task, we found similar intake of a sweet condensed milk solution following ad libitum or restricted feeding in wild-type and Nogo-A deficient rats, indicating normal reward sensitivity and translation of hunger into feeding behavior. When tested for motivation in a spontaneous progressive ratio task, Nogo-A deficient rats exhibited lower break points and tended to have lower "highest completed ratios." Further, under extinction conditions responding ceased substantially earlier in these rats. Finally, in the PFC we found increased tissue levels of serotonin, while dopamine was unaltered. Dopamine and serotonin levels were also unaltered in the dSTR and the NAcc. In summary, these results suggest a role for Nogo-A regulated processes in motivated behavior and related neurochemistry. The behavioral pattern observed resembles aspects of the negative symptomatology of schizophrenia.
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Affiliation(s)
- Thomas Enkel
- Department of Molecular Biology, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Stefan M. Berger
- Department of Molecular Biology, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Kai Schönig
- Department of Molecular Biology, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Björn Tews
- Schaller Research Group, Division of Molecular Mechanisms of Tumor Invasion, University of Heidelberg and German Cancer Research Center, Heidelberg, Germany
| | - Dusan Bartsch
- Department of Molecular Biology, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
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