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Monaco SA, Matamoros AJ, Gao WJ. Conditional GSK3β deletion in parvalbumin-expressing interneurons potentiates excitatory synaptic function and learning in adult mice. Prog Neuropsychopharmacol Biol Psychiatry 2020; 100:109901. [PMID: 32113851 DOI: 10.1016/j.pnpbp.2020.109901] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 02/12/2020] [Accepted: 02/24/2020] [Indexed: 01/03/2023]
Abstract
Glycogen synthase kinase 3β (GSK3β) has gained interest regarding its involvement in psychiatric and neurodegenerative disorders. Recently GSK3 inhibitors were highlighted as promising rescuers of cognitive impairments for a gamut of CNS disorders. Growing evidence supports that fast-spiking parvalbumin (PV) interneurons are critical regulators of cortical computation. Albeit, how excitatory receptors on PV interneurons are regulated and how this affects cognitive function remains unknown. To address these questions, we have generated a novel triple-transgenic conditional mouse with GSK3β genetically deleted from PV interneurons. PV-GSK3β-/- resulted in increased excitability and augmented excitatory synaptic strength in prefrontal PV interneurons. More importantly, these synaptic changes are correlated with accelerated learning with no changes in locomotion and sociability. Our study, for the first time, examined how GSK3β activity affects learning capability via regulation of PV interneurons. This study provides a novel insight into how GSK3β may contribute to disorders afflicted by cognitive deficits.
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Affiliation(s)
- Sarah A Monaco
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, 2900 W School House Ln, Philadelphia, PA 19129, United States of America
| | - Andrew J Matamoros
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, 3401 Civic Center Blvd, Philadelphia, PA 19104, United States of America; Deparment of Pathology and Laboratory Medicine, University of Pennsylvania, 3400 Spruce St, Philadelphia, PA 19104-4238, United States of America
| | - Wen-Jun Gao
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, 2900 W School House Ln, Philadelphia, PA 19129, United States of America.
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Monaco SA, Ferguson BR, Gao WJ. Lithium Inhibits GSK3β and Augments GluN2A Receptor Expression in the Prefrontal Cortex. Front Cell Neurosci 2018; 12:16. [PMID: 29449801 PMCID: PMC5799274 DOI: 10.3389/fncel.2018.00016] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2017] [Accepted: 01/11/2018] [Indexed: 12/12/2022] Open
Abstract
Glycogen synthase kinase 3β (GSK3β) is a highly conserved serine/threonine kinase that has been implicated in both psychiatric and neurodegenerative diseases including schizophrenia, bipolar disorder, and Alzheimer's disease; therefore regulating its activity has become an important strategy for treatment of cognitive impairments in these disorders. This study examines the effects of lithium on GSK3β and its interaction with β-catenin and NMDA receptors within the prefrontal cortex. Lithium, a clinically relevant drug commonly prescribed as a mood stabilizer for psychiatric disorders, significantly increased levels of phosphorylated GSK3β serine 9, an inhibitory phosphorylation site, and decreased β-catenin ser33/37/thr41 phosphorylation in vitro, indicating GSK3β inhibition and reduced β-catenin degradation. GluN2A subunit levels were concurrently increased following lithium treatment. Similar alterations were also demonstrated in vivo; lithium administration increased GSK3β serine 9 phosphorylation and GluN2A levels, suggesting a reduced GSK3β activity and augmented GluN2A expression. Correspondingly, we observed that the amplitudes of evoked GluN2A-mediated excitatory postsynaptic currents in mPFC pyramidal neurons were significantly increased following lithium administration. Our data suggest that GSK3β activity negatively regulates GluN2A expression, likely by mediating upstream β-catenin phosphorylation, in prefrontal cortical neurons. Furthermore, our biochemical and electrophysiological experiments demonstrate that lithium mediates a specific increase in GluN2A subunit expression, ultimately augmenting GluN2A-mediated currents in the prefrontal cortex.
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Affiliation(s)
| | | | - Wen-Jun Gao
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, United States
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Li ML, Gulchina Y, Monaco SA, Xing B, Ferguson BR, Li YC, Li F, Hu XQ, Gao WJ. Juvenile treatment with a novel mGluR2 agonist/mGluR3 antagonist compound, LY395756, reverses learning deficits and cognitive flexibility impairments in adults in a neurodevelopmental model of schizophrenia. Neurobiol Learn Mem 2017; 140:52-61. [PMID: 28213064 DOI: 10.1016/j.nlm.2017.02.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [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: 12/09/2015] [Revised: 02/03/2017] [Accepted: 02/09/2017] [Indexed: 01/23/2023]
Abstract
Schizophrenia (SCZ) is a neurodevelopmental psychiatric disorder, in which cognitive function becomes disrupted at early stages of the disease. Although the mechanisms underlying cognitive impairments remain unclear, N-methyl-D-aspartate receptors (NMDAR) hypofunctioning in the prefrontal cortex (PFC) has been implicated. Moreover, cognitive symptoms in SCZ are usually unresponsive to treatment with current antipsychotics and by onset, disruption of the dopamine system, not NMDAR hypofunctioning, dominates the symptoms. Therefore, treating cognitive deficits at an early stage is a realistic approach. In this study, we tested whether an early treatment targeting mGluR2 would be effective in ameliorating cognitive impairments in the methylazoxymethanol acetate (MAM) model of SCZ. We investigated the effects of an mGluR2 agonist/mGluR3 antagonist, LY395756 (LY39), on the NMDAR expression and function in juveniles, as well as cognitive deficits in adult rats after juvenile treatment. We found that gestational MAM exposure induced a significant decrease in total protein levels of the NMDAR subunit, NR2B, and a significant increase of pNR2BTyr1472 in the juvenile rat PFC. Treatment with LY39 in juvenile MAM-exposed rats effectively recovered the disrupted NMDAR expression. Furthermore, a subchronic LY39 treatment in juvenile MAM-exposed rats also alleviated the learning deficits and cognitive flexibility impairments when tested with a cross-maze based set-shifting task in adults. Therefore, our study demonstrates that targeting dysfunctional NMDARs with an mGluR2 agonist during the early stage of SCZ could be an effective strategy in preventing the development and progression in addition to ameliorating cognitive impairments of SCZ.
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Affiliation(s)
- Meng-Lin Li
- Department of Rehabilitation, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou 510630, China; Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA; Department of Rehabilitation, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou 510180, China
| | - Yelena Gulchina
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA
| | - Sarah A Monaco
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA
| | - Bo Xing
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA
| | - Brielle R Ferguson
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA
| | - Yan-Chun Li
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA
| | - Feng Li
- Department of Neurobiology and Anatomy, Zhongshan School of Medicine, Sun Yat-Sen University, 510275 Guangzhou, China.
| | - Xi-Quan Hu
- Department of Rehabilitation, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou 510630, China.
| | - Wen-Jun Gao
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA.
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Monaco SA, Gulchina Y, Gao WJ. NR2B subunit in the prefrontal cortex: A double-edged sword for working memory function and psychiatric disorders. Neurosci Biobehav Rev 2015; 56:127-38. [PMID: 26143512 DOI: 10.1016/j.neubiorev.2015.06.022] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [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: 03/10/2015] [Revised: 06/27/2015] [Accepted: 06/29/2015] [Indexed: 12/23/2022]
Abstract
The prefrontal cortex (PFC) is a brain region featured with working memory function. The exact mechanism of how working memory operates within the PFC circuitry is unknown, but persistent neuronal firing recorded from prefrontal neurons during a working memory task is proposed to be the neural correlate of this mnemonic encoding. The PFC appears to be specialized for sustaining persistent firing, with N-methyl-D-aspartate (NMDA) receptors, especially slow-decay NR2B subunits, playing an essential role in the maintenance of sustained activity and normal working memory function. However, the NR2B subunit serves as a double-edged sword for PFC function. Because of its slow kinetics, NR2B endows the PFC with not only "neural psychic" properties, but also susceptibilities for neuroexcitotoxicity and psychiatric disorders. This review aims to clarify the interplay among working memory, the PFC, and NMDA receptors; demonstrate the importance of NR2B in the maintenance of persistent activity; understand the risks and vulnerabilities of how NR2B is related to the development of neuropsychiatric disorders; identify gaps that currently exist in our understanding of these processes; and provide insights regarding future directions that may clarify these issues. We conclude that the PFC is a specialized brain region with distinct delayed maturation, unique neuronal circuitry, and characteristic NMDA receptor function. The unique properties and development of NMDA receptors, especially enrichment of NR2B subunits, endow the PFC with not only the capability to generate sustained activity for working memory, but also serves as a major vulnerability to environmental insults and risk factors for psychiatric disorders.
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Affiliation(s)
- Sarah A Monaco
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, 2900 Queen Lane, Room 243, Philadelphia, PA 19129, United States
| | - Yelena Gulchina
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, 2900 Queen Lane, Room 243, Philadelphia, PA 19129, United States
| | - Wen-Jun Gao
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, 2900 Queen Lane, Room 243, Philadelphia, PA 19129, United States.
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