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Evans CW, Egid A, Mamsa SSA, Paterson DJ, Ho D, Bartlett CA, Fehily B, Lins BR, Fitzgerald M, Hackett MJ, Smith NM. Elemental Mapping in a Preclinical Animal Model Reveals White Matter Copper Elevation in the Acute Phase of Central Nervous System Trauma. ACS Chem Neurosci 2023; 14:3518-3527. [PMID: 37695072 DOI: 10.1021/acschemneuro.3c00421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/12/2023] Open
Abstract
Understanding the chemical events following trauma to the central nervous system could assist in identifying causative mechanisms and potential interventions to protect neural tissue. Here, we apply a partial optic nerve transection model of injury in rats and use synchrotron X-ray fluorescence microscopy (XFM) to perform elemental mapping of metals (K, Ca, Fe, Cu, Zn) and other related elements (P, S, Cl) in white matter tracts. The partial optic nerve injury model and spatial precision of microscopy allow us to obtain previously unattained resolution in mapping elemental changes in response to a primary injury and subsequent secondary effects. We observed significant elevation of Cu levels at multiple time points following the injury, both at the primary injury site and in neural tissue near the injury site vulnerable to secondary damage, as well as significant changes in Cl, K, P, S, and Ca. Our results suggest widespread metal dyshomeostasis in response to central nervous system trauma and that altered Cu homeostasis may be a specific secondary event in response to white matter injury. The findings highlight metal homeostasis as a potential point of intervention in limiting damage following nervous system injury.
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Affiliation(s)
- Cameron W Evans
- School of Molecular Sciences, The University of Western Australia, Crawley, WA 6009, Australia
| | - Abigail Egid
- School of Molecular Sciences, The University of Western Australia, Crawley, WA 6009, Australia
- University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
| | - Somayra S A Mamsa
- School of Molecular Sciences, The University of Western Australia, Crawley, WA 6009, Australia
| | | | - Diwei Ho
- School of Molecular Sciences, The University of Western Australia, Crawley, WA 6009, Australia
| | - Carole A Bartlett
- Curtin Health and Innovation Research Institute, Faculty of Health Sciences, Curtin University, Bentley, WA 6102, Australia
| | - Brooke Fehily
- Curtin Health and Innovation Research Institute, Faculty of Health Sciences, Curtin University, Bentley, WA 6102, Australia
- Perron Institute for Neurological and Translational Sciences, 8 Verdun Street, Nedlands, WA 6009, Australia
| | - Brittney R Lins
- Curtin Health and Innovation Research Institute, Faculty of Health Sciences, Curtin University, Bentley, WA 6102, Australia
- Perron Institute for Neurological and Translational Sciences, 8 Verdun Street, Nedlands, WA 6009, Australia
| | - Melinda Fitzgerald
- Curtin Health and Innovation Research Institute, Faculty of Health Sciences, Curtin University, Bentley, WA 6102, Australia
- Perron Institute for Neurological and Translational Sciences, 8 Verdun Street, Nedlands, WA 6009, Australia
| | - Mark J Hackett
- Curtin Health and Innovation Research Institute, Faculty of Health Sciences, Curtin University, Bentley, WA 6102, Australia
- School of Molecular and Life Sciences, Faculty of Science and Engineering, Curtin University, Bentley, WA 6102, Australia
| | - Nicole M Smith
- School of Molecular Sciences, The University of Western Australia, Crawley, WA 6009, Australia
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Lins BR, Anyaegbu CC, Hellewell SC, Papini M, McGonigle T, De Prato L, Shales M, Fitzgerald M. Cannabinoids in traumatic brain injury and related neuropathologies: preclinical and clinical research on endogenous, plant-derived, and synthetic compounds. J Neuroinflammation 2023; 20:77. [PMID: 36935484 PMCID: PMC10026409 DOI: 10.1186/s12974-023-02734-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 02/13/2023] [Indexed: 03/21/2023] Open
Abstract
Traumatic brain injury is common, and often results in debilitating consequences. Even mild traumatic brain injury leaves approximately 20% of patients with symptoms that persist for months. Despite great clinical need there are currently no approved pharmaceutical interventions that improve outcomes after traumatic brain injury. Increased understanding of the endocannabinoid system in health and disease has accompanied growing evidence for therapeutic benefits of Cannabis sativa. This has driven research of Cannabis' active chemical constituents (phytocannabinoids), alongside endogenous and synthetic counterparts, collectively known as cannabinoids. Also of therapeutic interest are other Cannabis constituents, such as terpenes. Cannabinoids interact with neurons, microglia, and astrocytes, and exert anti-inflammatory and neuroprotective effects which are highly desirable for the management of traumatic brain injury. In this review, we comprehensively appraised the relevant scientific literature, where major and minor phytocannabinoids, terpenes, synthetic cannabinoids, and endogenous cannabinoids were assessed in TBI, or other neurological conditions with pathology and symptomology relevant to TBI, as well as recent studies in preclinical TBI models and clinical TBI populations.
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Affiliation(s)
- Brittney R Lins
- Curtin Health Innovation Research Institute, Curtin University, Bentley, 6102, Australia.
- Perron Institute for Neurological and Translational Science, Nedlands, 6009, Australia.
| | - Chidozie C Anyaegbu
- Curtin Health Innovation Research Institute, Curtin University, Bentley, 6102, Australia
- Perron Institute for Neurological and Translational Science, Nedlands, 6009, Australia
| | - Sarah C Hellewell
- Curtin Health Innovation Research Institute, Curtin University, Bentley, 6102, Australia
- Perron Institute for Neurological and Translational Science, Nedlands, 6009, Australia
| | - Melissa Papini
- Curtin Health Innovation Research Institute, Curtin University, Bentley, 6102, Australia
- Perron Institute for Neurological and Translational Science, Nedlands, 6009, Australia
| | - Terence McGonigle
- Curtin Health Innovation Research Institute, Curtin University, Bentley, 6102, Australia
| | - Luca De Prato
- MediCann Health Aust Pty Ltd, Osborne Park, 6017, Australia
| | - Matthew Shales
- MediCann Health Aust Pty Ltd, Osborne Park, 6017, Australia
| | - Melinda Fitzgerald
- Curtin Health Innovation Research Institute, Curtin University, Bentley, 6102, Australia
- Perron Institute for Neurological and Translational Science, Nedlands, 6009, Australia
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Lins BR, Anyaegbu CC, McGonigle T, Hellewell SC, Patel P, Reagan H, Rooke-Wiesner C, Warnock A, Archer M, Hemmi JM, Bartlett C, Fitzgerald M. Secondary Degeneration Impairs Myelin Ultrastructural Development in Adulthood following Adolescent Neurotrauma in the Rat Optic Nerve. Int J Mol Sci 2023; 24:ijms24043343. [PMID: 36834755 PMCID: PMC9966883 DOI: 10.3390/ijms24043343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 01/31/2023] [Accepted: 02/01/2023] [Indexed: 02/10/2023] Open
Abstract
Adolescence is a critical period of postnatal development characterized by social, emotional, and cognitive changes. These changes are increasingly understood to depend on white matter development. White matter is highly vulnerable to the effects of injury, including secondary degeneration in regions adjacent to the primary injury site which alters the myelin ultrastructure. However, the impact of such alterations on adolescent white matter maturation is yet to be investigated. To address this, female piebald-virol-glaxo rats underwent partial transection of the optic nerve during early adolescence (postnatal day (PND) 56) with tissue collection two weeks (PND 70) or three months later (PND 140). Axons and myelin in the transmission electron micrographs of tissue adjacent to the injury were classified and measured based on the appearance of the myelin laminae. Injury in adolescence impaired the myelin structure in adulthood, resulting in a lower percentage of axons with compact myelin and a higher percentage of axons with severe myelin decompaction. Myelin thickness did not increase as expected into adulthood after injury and the relationship between the axon diameter and myelin thickness in adulthood was altered. Notably, dysmyelination was not observed 2 weeks postinjury. In conclusion, injury in adolescence altered the developmental trajectory, resulting in impaired myelin maturation when assessed at the ultrastructural level in adulthood.
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Affiliation(s)
- Brittney R. Lins
- Curtin Health Innovation Research Institute, Curtin University, Bentley, WA 6845, Australia
- Perron Institute for Neurological and Translational Sciences, Nedlands, WA 6009, Australia
| | - Chidozie C. Anyaegbu
- Curtin Health Innovation Research Institute, Curtin University, Bentley, WA 6845, Australia
- Perron Institute for Neurological and Translational Sciences, Nedlands, WA 6009, Australia
- Correspondence:
| | - Terence McGonigle
- Curtin Health Innovation Research Institute, Curtin University, Bentley, WA 6845, Australia
- Perron Institute for Neurological and Translational Sciences, Nedlands, WA 6009, Australia
| | - Sarah C. Hellewell
- Curtin Health Innovation Research Institute, Curtin University, Bentley, WA 6845, Australia
- Perron Institute for Neurological and Translational Sciences, Nedlands, WA 6009, Australia
| | - Parth Patel
- Curtin Health Innovation Research Institute, Curtin University, Bentley, WA 6845, Australia
- Perron Institute for Neurological and Translational Sciences, Nedlands, WA 6009, Australia
| | - Harry Reagan
- School of Biological Sciences, The University of Western Australia, Perth, WA 6009, Australia
| | - Cara Rooke-Wiesner
- Curtin Health Innovation Research Institute, Curtin University, Bentley, WA 6845, Australia
- Perron Institute for Neurological and Translational Sciences, Nedlands, WA 6009, Australia
| | - Andrew Warnock
- Curtin Health Innovation Research Institute, Curtin University, Bentley, WA 6845, Australia
- Perron Institute for Neurological and Translational Sciences, Nedlands, WA 6009, Australia
| | - Michael Archer
- Curtin Health Innovation Research Institute, Curtin University, Bentley, WA 6845, Australia
- Perron Institute for Neurological and Translational Sciences, Nedlands, WA 6009, Australia
| | - Jan M. Hemmi
- School of Biological Sciences, The University of Western Australia, Perth, WA 6009, Australia
- Oceans Institute, The University of Western Australia, Perth, WA 6009, Australia
| | - Carole Bartlett
- Curtin Health Innovation Research Institute, Curtin University, Bentley, WA 6845, Australia
- Perron Institute for Neurological and Translational Sciences, Nedlands, WA 6009, Australia
| | - Melinda Fitzgerald
- Curtin Health Innovation Research Institute, Curtin University, Bentley, WA 6845, Australia
- Perron Institute for Neurological and Translational Sciences, Nedlands, WA 6009, Australia
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Roebuck AJ, Liu MC, Lins BR, Scott GA, Howland JG. Acute stress, but not corticosterone, facilitates acquisition of paired associates learning in rats using touchscreen-equipped operant conditioning chambers. Behav Brain Res 2018; 348:139-149. [PMID: 29684470 DOI: 10.1016/j.bbr.2018.04.027] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 04/13/2018] [Accepted: 04/18/2018] [Indexed: 12/16/2022]
Abstract
Acute stress influences learning and memory in humans and rodents, enhancing performance in some tasks while impairing it in others. Typically, subjects preferentially employ striatal-mediated stimulus-response strategies in spatial memory tasks following stress, making use of fewer hippocampal-based strategies which may be more cognitively demanding. Previous research demonstrated that the acquisition of rodent paired associates learning (PAL) relies primarily on the striatum, while task performance after extensive training is impaired by hippocampal disruption. Therefore, we sought to explore whether the acquisition of PAL, an operant conditioning task involving spatial stimuli, could be enhanced by acute stress. Male Long-Evans rats were trained to a predefined criterion in PAL and then subjected to either a single session of restraint stress (30 min) or injection of corticosterone (CORT; 3 mg/kg). Subsequent task performance was monitored for one week. We found that rats subjected to restraint stress, but not those rats injected with CORT, performed with higher accuracy and efficiency, when compared to untreated controls. These results suggest that while acute stress enhances the acquisition of PAL, CORT alone does not. This dissociation may be due to differences between these treatments and their ability to produce sufficient catecholamine release in the amygdala, a requirement for stress effects on memory.
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Affiliation(s)
- Andrew J Roebuck
- Department of Physiology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Max C Liu
- Department of Physiology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Brittney R Lins
- Department of Physiology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Gavin A Scott
- Department of Physiology, University of Saskatchewan, Saskatoon, SK, Canada
| | - John G Howland
- Department of Physiology, University of Saskatchewan, Saskatoon, SK, Canada.
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Lins BR, Marks WN, Phillips AG, Howland JG. Dissociable effects of the d- and l- enantiomers of govadine on the disruption of prepulse inhibition by MK-801 and apomorphine in male Long-Evans rats. Psychopharmacology (Berl) 2017; 234:1079-1091. [PMID: 28180960 DOI: 10.1007/s00213-017-4540-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Accepted: 01/23/2017] [Indexed: 01/02/2023]
Abstract
RATIONALE The search for novel antipsychotic drugs to treat schizophrenia is driven by the poor treatment efficacy, serious side effects, and poor patient compliance of current medications. Recently, a class of compounds known as tetrahydroprotoberberines, which includes the compound d,l-govadine, have shown promise in preclinical rodent tests relevant to schizophrenia. To date, the effect of govadine on prepulse inhibition (PPI), a test for sensorimotor gating commonly used to assess the effects of putative treatments for schizophrenia, has not been determined. OBJECTIVES The objective of the present study was to determine the effects of each enantiomer of govadine (d- and l-govadine) on PPI alone and its disruption by the distinct pharmacological compounds apomorphine and MK-801. METHODS Male Long-Evans rats were treated systemically with d- or l-govadine and apomorphine or MK-801 prior to PPI. The PPI paradigm employed here included parametric manipulations of the prepulse intensity and the interval between the prepulse and pulse. RESULTS Acute MK-801 (0.15 mg/kg) significantly increased the startle response to startle pulses alone, while both MK-801 and apomorphine (0.2 mg/kg) significantly increased reactivity to prepulse-alone trials. Both MK-801 and apomorphine disrupted PPI. In addition, d-govadine alone significantly disrupted PPI in the apomorphine experiment. Pretreatment with l-, but not d-, govadine (1.0 mg/kg) blocked the effect of apomorphine and MK-801 on PPI. Treatment of rats with l-govadine alone (0.3, 1.0, 3.0 mg/kg) also dose-dependently increased PPI. CONCLUSIONS Given the high affinity of l-govadine for dopamine D2 receptors, these results suggest that further testing of l-govadine as an antipsychotic is warranted.
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Affiliation(s)
- Brittney R Lins
- Department of Physiology, University of Saskatchewan, GD30.7, Health Sciences Building, 107 Wiggins Rd, Saskatoon, SK, S7N 5E5, Canada
| | - Wendie N Marks
- Department of Physiology, University of Saskatchewan, GD30.7, Health Sciences Building, 107 Wiggins Rd, Saskatoon, SK, S7N 5E5, Canada
| | - Anthony G Phillips
- Department of Psychiatry, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
| | - John G Howland
- Department of Physiology, University of Saskatchewan, GD30.7, Health Sciences Building, 107 Wiggins Rd, Saskatoon, SK, S7N 5E5, Canada.
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Paylor JW, Lins BR, Greba Q, Moen N, de Moraes RS, Howland JG, Winship IR. Developmental disruption of perineuronal nets in the medial prefrontal cortex after maternal immune activation. Sci Rep 2016; 6:37580. [PMID: 27876866 PMCID: PMC5120325 DOI: 10.1038/srep37580] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 11/01/2016] [Indexed: 02/06/2023] Open
Abstract
Maternal infection during pregnancy increases the risk of offspring developing schizophrenia later in life. Similarly, animal models of maternal immune activation (MIA) induce behavioural and anatomical disturbances consistent with a schizophrenia-like phenotype in offspring. Notably, cognitive impairments in tasks dependent on the prefrontal cortex (PFC) are observed in humans with schizophrenia and in offspring after MIA during pregnancy. Recent studies of post-mortem tissue from individuals with schizophrenia revealed deficits in extracellular matrix structures called perineuronal nets (PNNs), particularly in PFC. Given these findings, we examined PNNs over the course of development in a well-characterized rat model of MIA using polyinosinic-polycytidylic acid (polyI:C). We found selective reductions of PNNs in the PFC of polyI:C offspring which did not manifest until early adulthood. These deficits were not associated with changes in parvalbumin cell density, but a decrease in the percentage of parvalbumin cells surrounded by a PNN. Developmental expression of PNNs was also significantly altered in the amygdala of polyI:C offspring. Our results indicate MIA causes region specific developmental abnormalities in PNNs in the PFC of offspring. These findings confirm the polyI:C model replicates neuropathological alterations associated with schizophrenia and may identify novel mechanisms for cognitive and emotional dysfunction in the disorder.
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Affiliation(s)
- John W Paylor
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, T6G 2E1, AB, Canada.,Neurochemical Research Unit, Department of Psychiatry, University of Alberta, Edmonton, T6G 2B7, AB, Canada
| | - Brittney R Lins
- Department of Physiology, University of Saskatchewan, Saskatoon, S7N 5E5, SK, Canada
| | - Quentin Greba
- Department of Physiology, University of Saskatchewan, Saskatoon, S7N 5E5, SK, Canada
| | - Nicholas Moen
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, T6G 2E1, AB, Canada
| | | | - John G Howland
- Department of Physiology, University of Saskatchewan, Saskatoon, S7N 5E5, SK, Canada
| | - Ian R Winship
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, T6G 2E1, AB, Canada.,Neurochemical Research Unit, Department of Psychiatry, University of Alberta, Edmonton, T6G 2B7, AB, Canada
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Lins BR, Pushie JM, Jones M, Howard DL, Howland JG, Hackett MJ. Mapping Alterations to the Endogenous Elemental Distribution within the Lateral Ventricles and Choroid Plexus in Brain Disorders Using X-Ray Fluorescence Imaging. PLoS One 2016; 11:e0158152. [PMID: 27351594 PMCID: PMC4924862 DOI: 10.1371/journal.pone.0158152] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 06/10/2016] [Indexed: 12/21/2022] Open
Abstract
The choroid plexus and cerebral ventricles are critical structures for the production of cerebral spinal fluid (CSF) and play an important role in regulating ion and metal transport in the brain, however many aspects of its roles in normal physiology and disease states, such as psychiatric illness, remain unknown. The choroid plexus is difficult to examine in vivo, and in situ ex vivo, and as such has typically been examined indirectly with radiolabeled tracers or ex vivo stains, making measurements of the endogenous K+, Cl-, and Ca+ distributions unreliable. In the present study, we directly examined the distribution of endogenous ions and biologically relevant transition metals in the choroid plexus and regions surrounding the ventricles (ventricle wall, cortex, corpus callosum, striatum) using X-ray fluorescence imaging (XFI). We find that the choroid plexus was rich in Cl- and Fe while K+ levels increase further from the ventricle as Cl- levels decrease, consistent with the known role of ion transporters in the choroid plexus CSF production. A polyI:C offspring displayed enlarged ventricles, elevated Cl- surrounding the ventricles, and intraventricular calcifications. These observations fit with clinical findings in patients with schizophrenia and suggest maternal treatment with polyI:C may lead to dysfunctional ion regulation in offspring. This study demonstrates the power of XFI for examining the endogenous elemental distributions of the ventricular system in healthy brain tissue as well as disease models.
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Affiliation(s)
- Brittney R. Lins
- Department of Physiology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Jake M. Pushie
- College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Michael Jones
- Australian Synchrotron, Clayton, Victoria, Australia
- ARC Centre of Excellence in Advanced Molecular Imaging, La Trobe Institute for Molecular Sciences, La Trobe University, Victoria, Australia
| | | | - John G. Howland
- Department of Physiology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Mark J. Hackett
- Department of Chemistry, Curtin University, Perth, WA, Australia
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Lins BR, Howland JG. Effects of the metabotropic glutamate receptor 5 positive allosteric modulator CDPPB on rats tested with the paired associates learning task in touchscreen-equipped operant conditioning chambers. Behav Brain Res 2015; 301:152-60. [PMID: 26721467 DOI: 10.1016/j.bbr.2015.12.029] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 11/30/2015] [Accepted: 12/17/2015] [Indexed: 02/03/2023]
Abstract
Effective treatments for the cognitive symptoms of schizophrenia are critically needed. Positive allosteric modulation (PAM) of metabotropic glutamate receptor subtype 5 (mGluR5) is one strategy currently under investigation to improve these symptoms. Examining cognition using touchscreen-equipped operant chambers may increase translation between preclinical and clinical research through analogous behavioral testing paradigms in rodents and humans. We used acute CDPPB (1-30mg/kg) treatment to examine the effects of mGluR5 PAM in the touchscreen paired associates learning (PAL) task using well-trained rats with and without co-administration of acute MK-801 (0.15mg/kg). CDPPB had no consistent effects on task performance when administered alone and failed to reverse the MK-801 induced impairments at any of the examined doses. Overall, the disruptive effects of MK-801 on PAL were consistent with previous research but increasing mGluR5 signaling is not beneficial in the PAL task. Future research should test whether administration of CDPPB during PAL acquisition increases performance.
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Affiliation(s)
- Brittney R Lins
- Department of Physiology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
| | - John G Howland
- Department of Physiology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada.
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9
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Lins BR, Phillips AG, Howland JG. Effects of D- and L-govadine on the disruption of touchscreen object-location paired associates learning in rats by acute MK-801 treatment. Psychopharmacology (Berl) 2015; 232:4371-82. [PMID: 26359226 DOI: 10.1007/s00213-015-4064-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 08/26/2015] [Indexed: 11/26/2022]
Abstract
RATIONALE New pharmacological treatments for the cognitive deficits in schizophrenia are needed. Tetrahydroprotoberberines, such as govadine, are one class of compounds with dopaminergic activities that may be useful in treating some aspects of the cognitive symptoms of the disorder. OBJECTIVE The objective of the present studies was to test the effects of the D- and L-enantiomers of govadine on the impairment in a paired-associate learning (PAL) task produced by acute MK-801 in rats. We also assessed effects of the typical antipsychotic haloperidol as a comparator compound. METHODS MK-801 (0.05, 0.1, 0.15, and 0.2 mg/kg), D- and L-govadine (0.3, 1.0, and 3.0 mg/kg), and haloperidol (0.05, 0.1, and 0.25 mg/kg) were administered acutely to rats well trained on the PAL task in touchscreen-equipped operant conditioning chambers. RESULTS Acute MK-801 impaired performance of PAL in a dose-dependent manner by reducing accuracy and increasing correction trials. L-Govadine (1.0 mg/kg), but not D-govadine, blocked the disruptive effects of MK-801 (0.15 mg/kg) on PAL. Haloperidol failed to affect the MK-801-induced disruption of PAL. Higher doses of L-govadine and haloperidol dramatically impaired performance of the task which confounded interpretation of cognitive outcomes. CONCLUSION L-Govadine appears unique in its ability to improve performance of the MK-801-induced impairment in the PAL task. This behavioral effect may relate the ability of L-govadine to antagonize dopamine D2 receptors while also promoting dopamine efflux. Future research should further characterize the role of the dopamine system in the rodent PAL task to elucidate the mechanisms of its pro-cognitive effects.
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Affiliation(s)
- Brittney R Lins
- Department of Physiology, University of Saskatchewan, GB33, Health Sciences Building, 107 Wiggins Rd, Saskatoon, SK, Canada, S7N 5E5
| | - Anthony G Phillips
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada, V6T 2A1
| | - John G Howland
- Department of Physiology, University of Saskatchewan, GB33, Health Sciences Building, 107 Wiggins Rd, Saskatoon, SK, Canada, S7N 5E5.
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10
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Lins BR, Ballendine SA, Howland JG. Altered object exploration but not temporal order memory retrieval in an object recognition test following treatment of rats with the group II metabotropic glutamate receptor agonist LY379268. Neurosci Lett 2013; 560:41-5. [PMID: 24361135 DOI: 10.1016/j.neulet.2013.12.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 12/08/2013] [Accepted: 12/10/2013] [Indexed: 10/25/2022]
Abstract
Temporal order memory refers to the ability to distinguish past experiences in the order that they occurred. Temporal order memory for objects is often tested in rodents using spontaneous object recognition paradigms. The circuitry mediating memory in these tests is distributed and involves ionotropic glutamate receptors in the perirhinal cortex and medial prefrontal cortex. It is unknown what role, if any, metabotropic glutamate receptors have in temporal order memory for objects. The present experiment examined the role of metabotropic glutamate receptors in temporal memory retrieval using the group II metabotropic glutamate receptor selective agonist LY379268. Rats were trained on a temporal memory test with three phases: two sample phases (60 min between them) in which rats explored two novel objects and a test phase (60 min after the second sample phase) which included a copy of each object previously encountered. Under these conditions, we confirmed that rats showed a significant exploratory preference for the object presented during the first sample phase. In a second experiment, we found that LY379268 (0.3, 1.0, or 3.0mg/kg; i.p.; 30 min before the test phase) had no effect on temporal memory retrieval but dose-dependently reduced time spent exploring the objects. Our results show that enhancing mGluR2 activity under conditions when TM is intact does not influence memory retrieval.
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Affiliation(s)
- Brittney R Lins
- Department of Physiology, University of Saskatchewan, GB33, Health Sciences Building, 107 Wiggins Road, Saskatoon, SK S7N 5E5, Canada
| | - Stephanie A Ballendine
- Department of Physiology, University of Saskatchewan, GB33, Health Sciences Building, 107 Wiggins Road, Saskatoon, SK S7N 5E5, Canada
| | - John G Howland
- Department of Physiology, University of Saskatchewan, GB33, Health Sciences Building, 107 Wiggins Road, Saskatoon, SK S7N 5E5, Canada.
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