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Misiachna A, Konecny J, Kolcheva M, Ladislav M, Prchal L, Netolicky J, Kortus S, Zahumenska P, Langore E, Novak M, Hemelikova K, Hermanova Z, Hrochova M, Pelikanova A, Odvarkova J, Pejchal J, Kassa J, Zdarova Karasova J, Korabecny J, Soukup O, Horak M. Potent and reversible open-channel blocker of NMDA receptor derived from dizocilpine with enhanced membrane-to-channel inhibition. Biomed Pharmacother 2024; 178:117201. [PMID: 39053419 DOI: 10.1016/j.biopha.2024.117201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 07/16/2024] [Accepted: 07/22/2024] [Indexed: 07/27/2024] Open
Abstract
N-methyl-D-aspartate receptors (NMDARs) play a significant role in developing several central nervous system (CNS) disorders. Currently, memantine, used for treating Alzheimer's disease, and ketamine, known for its anesthetic and antidepressant properties, are two clinically used NMDAR open-channel blockers. However, despite extensive research into NMDAR modulators, many have shown either harmful side effects or inadequate effectiveness. For instance, dizocilpine (MK-801) is recognized for its powerful psychomimetic effects due to its high-affinity and nearly irreversible inhibition of the GluN1/GluN2 NMDAR subtypes. Unlike ketamine, memantine and MK-801 also act through a unique, low-affinity "membrane-to-channel inhibition" (MCI). We aimed to develop an open-channel blocker based on MK-801 with distinct inhibitory characteristics from memantine and MK-801. Our novel compound, K2060, demonstrated effective voltage-dependent inhibition in the micromolar range at key NMDAR subtypes, GluN1/GluN2A and GluN1/GluN2B, even in the presence of Mg2+. K2060 showed reversible inhibitory dynamics and a partially trapping open-channel blocking mechanism with a significantly stronger MCI than memantine. Using hippocampal slices, 30 µM K2060 inhibited excitatory postsynaptic currents in CA1 hippocampal neurons by ∼51 %, outperforming 30 µM memantine (∼21 % inhibition). K2060 exhibited No Observed Adverse Effect Level (NOAEL) of 15 mg/kg upon intraperitoneal administration in mice. Administering K2060 at a 10 mg/kg dosage resulted in brain concentrations of approximately 2 µM, with peak concentrations (Tmax) achieved within 15 minutes. Finally, applying K2060 with trimedoxime and atropine in mice exposed to tabun improved treatment outcomes. These results underscore K2060's potential as a therapeutic agent for CNS disorders linked to NMDAR dysfunction.
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Affiliation(s)
- Anna Misiachna
- Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, Prague 4 14200, Czech Republic
| | - Jan Konecny
- University Hospital Hradec Kralove, Biomedical Research Center, Sokolska 581, Hradec Kralove 500 05, Czech Republic; University of Defense, Military Faculty of Medicine, Department of Toxicology and Military Pharmacy, Trebesska 1575, Hradec Kralove 50005, Czech Republic
| | - Marharyta Kolcheva
- Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, Prague 4 14200, Czech Republic
| | - Marek Ladislav
- Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, Prague 4 14200, Czech Republic
| | - Lukas Prchal
- University Hospital Hradec Kralove, Biomedical Research Center, Sokolska 581, Hradec Kralove 500 05, Czech Republic
| | - Jakub Netolicky
- Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, Prague 4 14200, Czech Republic
| | - Stepan Kortus
- Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, Prague 4 14200, Czech Republic
| | - Petra Zahumenska
- Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, Prague 4 14200, Czech Republic
| | - Emily Langore
- Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, Prague 4 14200, Czech Republic
| | - Martin Novak
- University Hospital Hradec Kralove, Biomedical Research Center, Sokolska 581, Hradec Kralove 500 05, Czech Republic
| | - Katarina Hemelikova
- Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, Prague 4 14200, Czech Republic
| | - Zuzana Hermanova
- Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, Prague 4 14200, Czech Republic
| | - Michaela Hrochova
- Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, Prague 4 14200, Czech Republic
| | - Anezka Pelikanova
- Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, Prague 4 14200, Czech Republic
| | - Jitka Odvarkova
- University Hospital Hradec Kralove, Biomedical Research Center, Sokolska 581, Hradec Kralove 500 05, Czech Republic; University of Defense, Military Faculty of Medicine, Department of Toxicology and Military Pharmacy, Trebesska 1575, Hradec Kralove 50005, Czech Republic
| | - Jaroslav Pejchal
- University of Defense, Military Faculty of Medicine, Department of Toxicology and Military Pharmacy, Trebesska 1575, Hradec Kralove 50005, Czech Republic
| | - Jiri Kassa
- University of Defense, Military Faculty of Medicine, Department of Toxicology and Military Pharmacy, Trebesska 1575, Hradec Kralove 50005, Czech Republic
| | - Jana Zdarova Karasova
- University Hospital Hradec Kralove, Biomedical Research Center, Sokolska 581, Hradec Kralove 500 05, Czech Republic; University of Defense, Military Faculty of Medicine, Department of Toxicology and Military Pharmacy, Trebesska 1575, Hradec Kralove 50005, Czech Republic
| | - Jan Korabecny
- University Hospital Hradec Kralove, Biomedical Research Center, Sokolska 581, Hradec Kralove 500 05, Czech Republic; University of Defense, Military Faculty of Medicine, Department of Toxicology and Military Pharmacy, Trebesska 1575, Hradec Kralove 50005, Czech Republic
| | - Ondrej Soukup
- University Hospital Hradec Kralove, Biomedical Research Center, Sokolska 581, Hradec Kralove 500 05, Czech Republic; University of Defense, Military Faculty of Medicine, Department of Toxicology and Military Pharmacy, Trebesska 1575, Hradec Kralove 50005, Czech Republic.
| | - Martin Horak
- Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, Prague 4 14200, Czech Republic.
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Neuhäusel TS, Gerevich Z. Sex-specific effects of subchronic NMDA receptor antagonist MK-801 treatment on hippocampal gamma oscillations. Front Neurosci 2024; 18:1425323. [PMID: 39170673 PMCID: PMC11335629 DOI: 10.3389/fnins.2024.1425323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Accepted: 07/01/2024] [Indexed: 08/23/2024] Open
Abstract
N-methyl-D-aspartate (NMDA) receptor antagonists are widely used to pharmacologically model schizophrenia and have been recently established in the treatment of treatment-resistant major depression demonstrating that the pharmacology of this substance class is complex. Cortical gamma oscillations, a rhythmic neuronal activity associated with cognitive processes, are increased in schizophrenia and deteriorated in depressive disorders and are increasingly used as biomarker in these neuropsychiatric diseases. The opposite use of NMDA receptor antagonists in schizophrenia and depression raises the question how their effects are in accordance with the observed disease pathophysiology and if these effects show a consequent sex-specificity. In this study in rats, we investigated the effects of subchronic (14 days) intraperitoneal injections of the NMDA receptor antagonist MK-801 at a subanesthetic daily dose of 0.2 mg/kg on the behavioral phenotype of adult female and male rats and on pharmacologically induced gamma oscillations measured ex vivo from the hippocampus. We found that MK-801 treatment leads to impaired recognition memory in the novel object recognition test, increased stereotypic behavior and reduced grooming, predominantly in female rats. MK-801 also increased the peak power of hippocampal gamma oscillations induced by kainate or acetylcholine only in female rats, without affecting the peak frequency of the oscillations. The findings indicate that blockade of NMDA receptors enhances gamma oscillations predominantly in female rats and this effect is associated with behavioral changes in females. The results are in accordance with clinical electrophysiological findings and highlight the importance of hippocampal gamma oscillations as a biomarker in schizophrenia and depression.
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Affiliation(s)
| | - Zoltan Gerevich
- Institute of Neurophysiology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Berlin, Germany
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Ganesh A, Choudhury W, Coutellier L. Early spatial recognition memory deficits in 5XFAD female mice are associated with disruption of prefrontal parvalbumin neurons. Brain Res 2024; 1841:149122. [PMID: 39009061 DOI: 10.1016/j.brainres.2024.149122] [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: 06/06/2024] [Revised: 07/11/2024] [Accepted: 07/12/2024] [Indexed: 07/17/2024]
Abstract
Women have a two-fold increased risk of developing Alzheimer's disease (AD) than men, yet the underlying mechanisms of this sex-specific vulnerability remain unknown. Here, we aimed at determining in the 5XFAD mouse model whether deficits in prefrontal-dependent cognitive functions, which are impacted in the preclinical stages of AD, appear earlier in females, and whether these cognitive deficits are associated with alterations in the activity of prefrontal parvalbumin (PV)-neurons that regulate prefrontal circuits activity. We observed that 3.5-month-old 5XFAD females, but not males, display impairments in spatial short-term recognition memory, a function that relies on the integrity of the prefrontal cortex. Hippocampal-dependent cognitive functions were intact in both sexes. We then observed that 5XFAD females have more prefrontal PV neurons expressing the marker of chronic activity FosB; this was inversely correlated with prefrontal-dependent cognitive performances. Our findings show for the first time sex-specific, early deregulation of prefrontal PV neurons activity, which is associated with early appearance of prefrontal-dependent cognitive functions in 5XFAD females providing a potential novel mechanism to the increased risk to AD in females.
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Affiliation(s)
- Anish Ganesh
- Department of Psychology, The Ohio State University, Columbus, OH, USA
| | - Wajih Choudhury
- Department of Psychology, The Ohio State University, Columbus, OH, USA
| | - Laurence Coutellier
- Department of Psychology, The Ohio State University, Columbus, OH, USA; Department of Neuroscience, The Ohio State University, Columbus, OH, USA.
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Karimi Tari P, Parsons CG, Collingridge GL, Rammes G. Memantine: Updating a rare success story in pro-cognitive therapeutics. Neuropharmacology 2024; 244:109737. [PMID: 37832633 DOI: 10.1016/j.neuropharm.2023.109737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 09/25/2023] [Accepted: 09/26/2023] [Indexed: 10/15/2023]
Abstract
The great potential for NMDA receptor modulators as druggable targets in neurodegenerative disorders has been met with limited success. Considered one of the rare exceptions, memantine has consistently demonstrated restorative and prophylactic properties in many AD models. In clinical trials memantine slows the decline in cognitive performance associated with AD. Here, we provide an overview of the basic properties including pharmacological targets, toxicology and cellular effects of memantine. Evidence demonstrating reductions in molecular, physiological and behavioural indices of AD-like impairments associated with memantine treatment are also discussed. This represents both an extension and homage to Dr. Chris Parson's considerable contributions to our fundamental understanding of a success story in the AD treatment landscape.
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Affiliation(s)
- Parisa Karimi Tari
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada
| | - Chris G Parsons
- Galimedix Therapeutics, Inc., 2704 Calvend Lane, Kensington, 20895, MD, USA
| | - Graham L Collingridge
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada; Department of Physiology, University of Toronto, Toronto, ON, M5S 1A8, Canada; TANZ Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, M5S 1A8, Canada.
| | - Gerhard Rammes
- Department of Anesthesiology and Intensive Care Medicine of the Technical University of Munich, School of Medicine, 22, 81675, Munich, Germany.
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Krystal JH, Kavalali ET, Monteggia LM. Ketamine and rapid antidepressant action: new treatments and novel synaptic signaling mechanisms. Neuropsychopharmacology 2024; 49:41-50. [PMID: 37488280 PMCID: PMC10700627 DOI: 10.1038/s41386-023-01629-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/29/2023] [Accepted: 06/04/2023] [Indexed: 07/26/2023]
Abstract
Ketamine is an open channel blocker of ionotropic glutamatergic N-Methyl-D-Aspartate (NMDA) receptors. The discovery of its rapid antidepressant effects in patients with depression and treatment-resistant depression fostered novel effective treatments for mood disorders. This discovery not only provided new insight into the neurobiology of mood disorders but also uncovered fundamental synaptic plasticity mechanisms that underlie its treatment. In this review, we discuss key clinical aspects of ketamine's effect as a rapidly acting antidepressant, synaptic and circuit mechanisms underlying its action, as well as how these novel perspectives in clinical practice and synapse biology form a road map for future studies aimed at more effective treatments for neuropsychiatric disorders.
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Affiliation(s)
- John H Krystal
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA
| | - Ege T Kavalali
- Department of Pharmacology and the Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, USA
| | - Lisa M Monteggia
- Department of Pharmacology and the Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, USA.
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Nuwer JL, Povysheva N, Jacob TC. Long-term α5 GABA A receptor negative allosteric modulator treatment reduces NMDAR-mediated neuronal excitation and maintains basal neuronal inhibition. Neuropharmacology 2023; 237:109587. [PMID: 37270156 PMCID: PMC10527172 DOI: 10.1016/j.neuropharm.2023.109587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 04/27/2023] [Accepted: 05/09/2023] [Indexed: 06/05/2023]
Abstract
α5 subunit-containing GABA type-A receptors (α5 GABAARs) are enriched in the hippocampus and play critical roles in neurodevelopment, synaptic plasticity, and cognition. α5 GABAAR preferring negative allosteric modulators (α5 NAMs) show promise mitigating cognitive impairment in preclinical studies of conditions characterized by excess GABAergic inhibition, including Down syndrome and memory deficits post-anesthesia. However, previous studies have primarily focused on acute application or single-dose α5 NAM treatment. Here, we measured the effects of chronic (7-day) in vitro treatment with L-655,708 (L6), a highly selective α5 NAM, on glutamatergic and GABAergic synapses in rat hippocampal neurons. We previously showed that 2-day in vitro treatment with L6 enhanced synaptic levels of the glutamate NMDA receptor (NMDAR) GluN2A subunit without modifying surface α5 GABAAR expression, inhibitory synapse function, or L6 sensitivity. We hypothesized that chronic L6 treatment would further increase synaptic GluN2A subunit levels while maintaining GABAergic inhibition and L6 efficacy, thus increasing neuronal excitation and glutamate-evoked intracellular calcium responses. Immunofluorescence experiments revealed that 7-day L6 treatment slightly increased the synaptic levels of gephyrin and surface α5 GABAARs. Functional studies showed that chronic α5 NAM treatment did not alter inhibition or α5 NAM sensitivity. Surprisingly, chronic L6 exposure decreased surface levels of GluN2A and GluN2B subunits, concurrent with reduced NMDAR-mediated neuronal excitation as seen by faster synaptic decay rates and reduced glutamate-evoked calcium responses. Together, these results show that chronic in vitro treatment with an α5 NAM leads to subtle homeostatic changes in inhibitory and excitatory synapses that suggest an overall dampening of excitability.
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Affiliation(s)
- Jessica L Nuwer
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Nadya Povysheva
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - Tija C Jacob
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
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Kim JW, Suzuki K, Kavalali ET, Monteggia LM. Bridging rapid and sustained antidepressant effects of ketamine. Trends Mol Med 2023; 29:364-375. [PMID: 36907686 PMCID: PMC10101916 DOI: 10.1016/j.molmed.2023.02.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 02/05/2023] [Accepted: 02/15/2023] [Indexed: 03/12/2023]
Abstract
Acute administration of (R,S)-ketamine (ketamine) produces rapid antidepressant effects that in some patients can be sustained for several days to more than a week. Ketamine blocks N-methyl-d-asparate (NMDA) receptors (NMDARs) to elicit specific downstream signaling that induces a novel form of synaptic plasticity in the hippocampus that has been linked to the rapid antidepressant action. These signaling events lead to subsequent downstream transcriptional changes that are involved in the sustained antidepressant effects. Here we review how ketamine triggers this intracellular signaling pathway to mediate synaptic plasticity which underlies the rapid antidepressant effects and links it to downstream signaling and the sustained antidepressant effects.
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Affiliation(s)
- Ji-Woon Kim
- Department of Pharmacology and the Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37240, USA; College of Pharmacy, Kyung Hee University, Seoul, Republic of Korea; Department of Regulatory Science, Gradaute School, Kyung Hee University, Seoul, Republic of Korea; Institute of Regulatory Innovation through Science, Kyung Hee University, Seoul, Republic of Korea
| | - Kanzo Suzuki
- Department of Pharmacology and the Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37240, USA; Department of Biological Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science, Katsushika-ku, Japan
| | - Ege T Kavalali
- Department of Pharmacology and the Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37240, USA
| | - Lisa M Monteggia
- Department of Pharmacology and the Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37240, USA.
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Kavalali ET, Monteggia LM. Rapid homeostatic plasticity and neuropsychiatric therapeutics. Neuropsychopharmacology 2023; 48:54-60. [PMID: 35995973 PMCID: PMC9700859 DOI: 10.1038/s41386-022-01411-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Revised: 07/09/2022] [Accepted: 07/23/2022] [Indexed: 11/08/2022]
Abstract
Neuronal and synaptic plasticity are widely used terms in the field of psychiatry. However, cellular neurophysiologists have identified two broad classes of plasticity. Hebbian forms of plasticity alter synaptic strength in a synapse specific manner in the same direction of the initial conditioning stimulation. In contrast, homeostatic plasticities act globally over longer time frames in a negative feedback manner to counter network level changes in activity or synaptic strength. Recent evidence suggests that homeostatic plasticity mechanisms can be rapidly engaged, particularly by fast-acting antidepressants such as ketamine to trigger behavioral effects. There is increasing evidence that several neuropsychoactive compounds either directly elicit changes in synaptic activity or indirectly tap into downstream signaling pathways to trigger homeostatic plasticity and subsequent behavioral effects. In this review, we discuss this recent work in the context of a wider paradigm where homeostatic synaptic plasticity mechanisms may provide novel targets for neuropsychiatric treatment advance.
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Affiliation(s)
- Ege T Kavalali
- Department of Pharmacology and the Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, 37240-7933, USA.
| | - Lisa M Monteggia
- Department of Pharmacology and the Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, 37240-7933, USA.
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Luessen DJ, Gallinger IM, Ferranti AS, Foster DJ, Melancon BJ, Lindsley CW, Niswender CM, Conn PJ. mGlu 1-mediated restoration of prefrontal cortex inhibitory signaling reverses social and cognitive deficits in an NMDA hypofunction model in mice. Neuropsychopharmacology 2022; 47:1826-1835. [PMID: 35643819 PMCID: PMC9372079 DOI: 10.1038/s41386-022-01350-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 05/12/2022] [Accepted: 05/20/2022] [Indexed: 11/08/2022]
Abstract
Extensive evidence supports the hypothesis that deficits in inhibitory GABA transmission in the prefrontal cortex (PFC) may drive pathophysiological changes underlying symptoms of schizophrenia that are not currently treated by available medications, including cognitive and social impairments. Recently, the mGlu1 subtype of metabotropic glutamate (mGlu) receptor has been implicated as a novel target to restore GABAergic transmission in the PFC. A recent study reported that activation of mGlu1 increases inhibitory transmission in the PFC through excitation of somatostatin-expressing GABAergic interneurons, implicating mGlu1 PAMs as a potential treatment strategy for schizophrenia. Here, we leveraged positive allosteric modulators (PAMs) of mGlu1 to examine whether mGlu1 activation might reverse physiological effects and behavioral deficits induced by MK-801, an NMDA receptor antagonist commonly used to model cortical deficits observed in schizophrenia patients. Using ex vivo whole-cell patch-clamp electrophysiology, we found that MK-801 decreased the frequency of spontaneous inhibitory postsynaptic currents onto layer V pyramidal cells of the PFC and this cortical disinhibition was reversed by mGlu1 activation. Furthermore, acute MK-801 treatment selectively induced inhibitory deficits onto layer V pyramidal cells that project to the basolateral amygdala, but not to the nucleus accumbens, and these deficits were restored by selective mGlu1 activation. Importantly, the mGlu1 PAM VU6004909 effectively reversed deficits in sociability and social novelty preference in a three-chamber assay and improved novel objection recognition following MK-801 treatment. Together, these findings provide compelling evidence that mGlu1 PAMs could serve as a novel approach to reduce social and cognitive deficits associated with schizophrenia by enhancing inhibitory transmission in the PFC, thus providing an exciting improvement over current antipsychotic medication.
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Affiliation(s)
- Deborah J Luessen
- Department of Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA.
- Warren Center for Neuroscience Drug Discovery, Nashville, TN, 37232, USA.
| | - Isabel M Gallinger
- Department of Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA
- Warren Center for Neuroscience Drug Discovery, Nashville, TN, 37232, USA
| | - Anthony S Ferranti
- Department of Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA
- Warren Center for Neuroscience Drug Discovery, Nashville, TN, 37232, USA
| | - Daniel J Foster
- Department of Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA
- Warren Center for Neuroscience Drug Discovery, Nashville, TN, 37232, USA
- Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Bruce J Melancon
- Department of Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA
- Warren Center for Neuroscience Drug Discovery, Nashville, TN, 37232, USA
| | - Craig W Lindsley
- Department of Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA
- Warren Center for Neuroscience Drug Discovery, Nashville, TN, 37232, USA
- Vanderbilt Center for Addiction Research, Nashville, TN, 37232, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN, 37232, USA
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, 37232, USA
| | - Colleen M Niswender
- Department of Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA
- Warren Center for Neuroscience Drug Discovery, Nashville, TN, 37232, USA
- Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, 37232, USA
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, 37232, USA
| | - P Jeffrey Conn
- Department of Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA.
- Warren Center for Neuroscience Drug Discovery, Nashville, TN, 37232, USA.
- Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN, 37232, USA.
- Vanderbilt Center for Addiction Research, Nashville, TN, 37232, USA.
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, 37232, USA.
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Zamani N, Moazedi AA, Afarinesh Khaki MR, Pourmehdi Boroujeni M. Effects of Memantine on the Spontaneous Firing Frequency of Hippocampal CA1 Pyramidal Neurons in Intact and Alzheimer Rat Model: An Electrophysiological Study. Basic Clin Neurosci 2022; 13:661-674. [PMID: 37313029 PMCID: PMC10258597 DOI: 10.32598/bcn.2021.1970.1] [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: 08/05/2019] [Revised: 02/05/2020] [Accepted: 04/19/2020] [Indexed: 11/02/2023] Open
Abstract
Introduction Memantine (MEM) is a noncompetitive N-methyl-D-aspartate receptor (NMDAR) antagonist clinically used for the treatment of Alzheimer disease (AD) in mild to severe conditions. The present study was conducted to investigate the effects of memantine on the spontaneous firing frequency of CA1 pyramidal neurons in rats caused by an electrical lesion of Nucleus Basalis Magnocellularis (NBM). Then, this model of AD rats was compared with the intact adult male rats. Methods In this study, adult male rats were divided into two groups. Group I (lesion of NBM, n=53) includes the following subgroups: lesion+saline, sham+saline, lesion+MEM 5 mg/kg, lesion+MEM 10 mg/kg, and lesion+MEM 20mg/kg. Group II (intact, n=48) includes the following subgroups: intact+saline, intact+MEM 3mg/kg, intact+MEM 5mg/kg, and intact+MEM 10mg/kg. Extracellular single-unit recording (15 min baseline+105 min after MEM or saline) was performed under urethane-anesthetized rats. Results The results showed that the mean frequency of CA1 pyramidal neurons after saline in the lesion+saline (P<0.001) group significantly decreases compared with the intact+saline and sham+saline groups. In addition, after saline and memantine, the mean frequency of CA1 pyramidal neurons in the lesion+MEM 10 mg/kg (P<0.01) and lesion+MEM 20 mg/kg (P<0.001) groups significantly increased compared with the lesion+saline group. Also, the mean frequencies of CA1 pyramidal neurons in the intact+MEM 10 mg/kg (P<0.001) group significantly decreased compared with the intact+saline group. Conclusion Results showed that memantine increases the electrical activity of CA1 pyramidal neurons in a rat model of AD. Furthermore, in the intact adult male rats, the low-dose memantine, contrary to high dose, does not decrease the electrical activity of CA1 pyramidal neurons.
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Affiliation(s)
- Nastaran Zamani
- Department of Biology, School of Science, Payame Noor University, Tehran, Iran
| | - Ahmad Ali Moazedi
- Department of Biology, School of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran
- Stem Cell and Transgenic Technology Research Center, Shahid Chamran University of Ahvaz, Ahvaz, Iran
| | - Mohamad Reza Afarinesh Khaki
- Kerman Cognitive Research Center, Kerman Neuroscience Research Center, Institute of Neuropharmachology, Kerman University of Medical Sciences, Kerman, Iran
| | - Mehdi Pourmehdi Boroujeni
- Department of Food Hygiene, School of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran
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Perry A, Hughes LE, Adams N, Naessens M, Murley AG, Rouse MA, Street D, Jones PS, Cope TE, Kocagoncu E, Rowe JB. The neurophysiological effect of NMDA-R antagonism of frontotemporal lobar degeneration is conditional on individual GABA concentration. Transl Psychiatry 2022; 12:348. [PMID: 36030249 PMCID: PMC9420128 DOI: 10.1038/s41398-022-02114-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 08/09/2022] [Accepted: 08/11/2022] [Indexed: 02/02/2023] Open
Abstract
There is a pressing need to accelerate therapeutic strategies against the syndromes caused by frontotemporal lobar degeneration, including symptomatic treatments. One approach is for experimental medicine, coupling neurophysiological studies of the mechanisms of disease with pharmacological interventions aimed at restoring neurochemical deficits. Here we consider the role of glutamatergic deficits and their potential as targets for treatment. We performed a double-blind placebo-controlled crossover pharmaco-magnetoencephalography study in 20 people with symptomatic frontotemporal lobar degeneration (10 behavioural variant frontotemporal dementia, 10 progressive supranuclear palsy) and 19 healthy age- and gender-matched controls. Both magnetoencephalography sessions recorded a roving auditory oddball paradigm: on placebo or following 10 mg memantine, an uncompetitive NMDA-receptor antagonist. Ultra-high-field magnetic resonance spectroscopy confirmed lower concentrations of GABA in the right inferior frontal gyrus of people with frontotemporal lobar degeneration. While memantine showed a subtle effect on early-auditory processing in patients, there was no significant main effect of memantine on the magnitude of the mismatch negativity (MMN) response in the right frontotemporal cortex in patients or controls. However, the change in the right auditory cortex MMN response to memantine (vs. placebo) in patients correlated with individuals' prefrontal GABA concentration. There was no moderating effect of glutamate concentration or cortical atrophy. This proof-of-concept study demonstrates the potential for baseline dependency in the pharmacological restoration of neurotransmitter deficits to influence cognitive neurophysiology in neurodegenerative disease. With changes to multiple neurotransmitters in frontotemporal lobar degeneration, we suggest that individuals' balance of excitation and inhibition may determine drug efficacy, with implications for drug selection and patient stratification in future clinical trials.
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Affiliation(s)
- Alistair Perry
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, CB2 7EF, UK.
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge, CB2 0QQ, UK.
| | - Laura E Hughes
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, CB2 7EF, UK
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Natalie Adams
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Michelle Naessens
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Alexander G Murley
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Matthew A Rouse
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, CB2 7EF, UK
| | - Duncan Street
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - P Simon Jones
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Thomas E Cope
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, CB2 7EF, UK
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Ece Kocagoncu
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, CB2 7EF, UK
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - James B Rowe
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, CB2 7EF, UK
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge, CB2 0QQ, UK
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12
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Quantitative electroencephalography parameters as neurophysiological biomarkers of schizophrenia-related deficits: A Phase II substudy of patients treated with iclepertin (BI 425809). Transl Psychiatry 2022; 12:329. [PMID: 35953474 PMCID: PMC9372178 DOI: 10.1038/s41398-022-02096-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 07/18/2022] [Accepted: 07/26/2022] [Indexed: 11/09/2022] Open
Abstract
Patients with schizophrenia experience cognitive impairment related to neural network dysfunction and deficits in sensory processing. These deficits are thought to be caused by N-methyl-D-aspartate receptor hypofunction and can be assessed in patient populations using electroencephalography (EEG). This substudy from a Phase II, randomized, double-blind, placebo-controlled, parallel-group study investigating the safety and efficacy of the novel glycine transporter-1 inhibitor, iclepertin (BI 425809), assessed the potential of EEG parameters as clinically relevant biomarkers of schizophrenia and response to iclepertin treatment. Eligible patients were randomized to once-daily add-on iclepertin (2, 5, 10, or 25 mg), or placebo (1:1:1:1:2 ratio) for 12 weeks. EEG data were recorded from a subgroup of patients (n = 79) at baseline and end of treatment (EoT). EEG parameters of interest were mismatch negativity (MMN), auditory steady-state response (ASSR), and resting state gamma power, and their correlations with clinical assessments. At baseline, MMN and ASSR exhibited consistent correlations with clinical assessments, indicating their potential value as neurophysiological biomarkers of schizophrenia-related deficits. ASSR measures were positively correlated to the MATRICS Consensus Cognitive Battery overall and neurocognitive composite scores; MMN amplitude was positively correlated with Positive and Negative Syndrome Scale scores. However, correlations between change from baseline (CfB) at EoT in clinical assessments, and baseline or CfB at EoT for EEG parameters were modest and inconsistent between dose groups, which might indicate low potential of these EEG parameters as predictive and treatment response biomarkers. Further methodological refinement is needed to establish EEG parameters as useful drug development tools for schizophrenia.
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13
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Pathway-specific contribution of parvalbumin interneuron NMDARs to synaptic currents and thalamocortical feedforward inhibition. Mol Psychiatry 2022; 27:5124-5134. [PMID: 36075962 PMCID: PMC9763122 DOI: 10.1038/s41380-022-01747-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 08/08/2022] [Accepted: 08/11/2022] [Indexed: 01/19/2023]
Abstract
Prefrontal cortex (PFC) is a site of information convergence important for behaviors relevant to psychiatric disorders. Despite the importance of inhibitory GABAergic parvalbumin-expressing (PV+) interneurons to PFC circuit function and decades of interest in N-methyl-D-aspartate receptors (NMDARs) in these neurons, examples of defined circuit functions that depend on PV+ interneuron NMDARs have been elusive. Indeed, it remains controversial whether all PV+ interneurons contain functional NMDARs in adult PFC, which has major consequences for hypotheses of the pathogenesis of psychiatric disorders. Using a combination of fluorescent in situ hybridization, pathway-specific optogenetics, cell-type-specific gene ablation, and electrophysiological recordings from PV+ interneurons, here we resolve this controversy. We found that nearly 100% of PV+ interneurons in adult medial PFC (mPFC) express transcripts encoding GluN1 and GluN2B, and they have functional NMDARs. By optogenetically stimulating corticocortical and thalamocortical inputs to mPFC, we show that synaptic NMDAR contribution to PV+ interneuron EPSCs is pathway-specific, which likely explains earlier reports of PV+ interneurons without synaptic NMDAR currents. Lastly, we report a major contribution of NMDARs in PV+ interneurons to thalamus-mediated feedforward inhibition in adult mPFC circuits, suggesting molecular and circuit-based mechanisms for cognitive impairment under conditions of reduced NMDAR function. These findings represent an important conceptual advance that has major implications for hypotheses of the pathogenesis of psychiatric disorders.
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14
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Lie E, Yeo Y, Lee EJ, Shin W, Kim K, Han KA, Yang E, Choi TY, Bae M, Lee S, Um SM, Choi SY, Kim H, Ko J, Kim E. SALM4 negatively regulates NMDA receptor function and fear memory consolidation. Commun Biol 2021; 4:1138. [PMID: 34588597 PMCID: PMC8481232 DOI: 10.1038/s42003-021-02656-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 09/09/2021] [Indexed: 02/08/2023] Open
Abstract
Many synaptic adhesion molecules positively regulate synapse development and function, but relatively little is known about negative regulation. SALM4/Lrfn3 (synaptic adhesion-like molecule 4/leucine rich repeat and fibronectin type III domain containing 3) inhibits synapse development by suppressing other SALM family proteins, but whether SALM4 also inhibits synaptic function and specific behaviors remains unclear. Here we show that SALM4-knockout (Lrfn3-/-) male mice display enhanced contextual fear memory consolidation (7-day post-training) but not acquisition or 1-day retention, and exhibit normal cued fear, spatial, and object-recognition memory. The Lrfn3-/- hippocampus show increased currents of GluN2B-containing N-methyl-D-aspartate (NMDA) receptors (GluN2B-NMDARs), but not α-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptors (AMPARs), which requires the presynaptic receptor tyrosine phosphatase PTPσ. Chronic treatment of Lrfn3-/- mice with fluoxetine, a selective serotonin reuptake inhibitor used to treat excessive fear memory that directly inhibits GluN2B-NMDARs, normalizes NMDAR function and contextual fear memory consolidation in Lrfn3-/- mice, although the GluN2B-specific NMDAR antagonist ifenprodil was not sufficient to reverse the enhanced fear memory consolidation. These results suggest that SALM4 suppresses excessive GluN2B-NMDAR (not AMPAR) function and fear memory consolidation (not acquisition).
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Affiliation(s)
- Eunkyung Lie
- grid.410720.00000 0004 1784 4496Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, 34141 Korea ,grid.255168.d0000 0001 0671 5021Department of Chemistry, Dongguk University, Seoul, 04620 Korea
| | - Yeji Yeo
- grid.37172.300000 0001 2292 0500Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, 34141 Korea
| | - Eun-Jae Lee
- grid.267370.70000 0004 0533 4667Department of Neurology, Asan Medical Center, University of Ulsan, College of Medicine, Seoul, 05505 Korea
| | - Wangyong Shin
- grid.410720.00000 0004 1784 4496Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, 34141 Korea
| | - Kyungdeok Kim
- grid.410720.00000 0004 1784 4496Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, 34141 Korea
| | - Kyung Ah Han
- grid.417736.00000 0004 0438 6721Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Hyeonpoong-Eup, Dalseong-Gun, Daegu, 42988 Korea
| | - Esther Yang
- grid.222754.40000 0001 0840 2678Department of Anatomy and Division of Brain Korea 21, Biomedical Science, College of Medicine, Korea University, Seoul, 02841 Korea
| | - Tae-Yong Choi
- grid.31501.360000 0004 0470 5905Department of Physiology and Neuroscience, Dental Research Institute, Seoul National University School of Dentistry, Seoul, 03080 Korea
| | - Mihyun Bae
- grid.410720.00000 0004 1784 4496Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, 34141 Korea
| | - Suho Lee
- grid.410720.00000 0004 1784 4496Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, 34141 Korea
| | - Seung Min Um
- grid.37172.300000 0001 2292 0500Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon, 34141 Korea
| | - Se-Young Choi
- grid.31501.360000 0004 0470 5905Department of Physiology and Neuroscience, Dental Research Institute, Seoul National University School of Dentistry, Seoul, 03080 Korea
| | - Hyun Kim
- grid.222754.40000 0001 0840 2678Department of Anatomy and Division of Brain Korea 21, Biomedical Science, College of Medicine, Korea University, Seoul, 02841 Korea
| | - Jaewon Ko
- grid.417736.00000 0004 0438 6721Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Hyeonpoong-Eup, Dalseong-Gun, Daegu, 42988 Korea
| | - Eunjoon Kim
- grid.410720.00000 0004 1784 4496Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, 34141 Korea ,grid.267370.70000 0004 0533 4667Department of Neurology, Asan Medical Center, University of Ulsan, College of Medicine, Seoul, 05505 Korea
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15
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Nuwer JL, Brady ML, Povysheva NV, Coyne A, Jacob TC. Sustained treatment with an α5 GABA A receptor negative allosteric modulator delays excitatory circuit development while maintaining GABAergic neurotransmission. Neuropharmacology 2021; 197:108724. [PMID: 34284042 DOI: 10.1016/j.neuropharm.2021.108724] [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: 04/01/2021] [Revised: 07/01/2021] [Accepted: 07/14/2021] [Indexed: 01/02/2023]
Abstract
α5 subunit GABA type A receptor (GABAAR) preferring negative allosteric modulators (NAMs) are cognitive enhancers with antidepressant-like effects. α5-NAM success in treating mouse models of neurodevelopmental disorders with excessive inhibition have led to Phase 2 clinical trials for Down syndrome. Despite in vivo efficacy, no study has examined the effects of continued α5-NAM treatment on inhibitory and excitatory synapse plasticity to identify mechanisms of action. Here we used L-655,708, an imidazobenzodiazepine that acts as a highly selective but weak α5-NAM, to investigate the impact of sustained treatment on hippocampal neuron synapse and dendrite development. We show that 2-day pharmacological reduction of α5-GABAAR signaling from DIV12-14, when GABAARs contribute to depolarization, delays dendritic spine maturation and the NMDA receptor (NMDAR) GluN2B/GluN2A developmental shift. In contrast, α5-NAM treatment from DIV19-21, when hyperpolarizing GABAAR signaling predominates, enhances surface synaptic GluN2A while decreasing GluN2B. Despite changes in NMDAR subtype surface levels and localization, total levels of key excitatory synapse proteins were largely unchanged, and mEPSCs were unaltered. Importantly, 2-day α5-NAM treatment does not alter the total surface levels or distribution of α5-GABAARs, reduce the gephyrin inhibitory synaptic scaffold, or impair phasic or tonic inhibition. Furthermore, α5-NAM inhibition of the GABAAR tonic current in mature neurons is maintained after 2-day α5-NAM treatment, suggesting reduced tolerance liability, in contrast to other clinically relevant GABAAR-targeting drugs such as benzodiazepines. Together, these results show that α5-GABAARs contribute to dendritic spine maturation and excitatory synapse development via a NMDAR dependent mechanism without perturbing overall neuronal excitability.
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Affiliation(s)
- Jessica L Nuwer
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Megan L Brady
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Nadya V Povysheva
- Department of Neuroscience and Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - Amanda Coyne
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Tija C Jacob
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
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16
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Epileptic Mechanisms Shared by Alzheimer's Disease: Viewed via the Unique Lens of Genetic Epilepsy. Int J Mol Sci 2021; 22:ijms22137133. [PMID: 34281185 PMCID: PMC8268161 DOI: 10.3390/ijms22137133] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 06/14/2021] [Accepted: 06/15/2021] [Indexed: 12/18/2022] Open
Abstract
Our recent work on genetic epilepsy (GE) has identified common mechanisms between GE and neurodegenerative diseases including Alzheimer's disease (AD). Although both disorders are seemingly unrelated and occur at opposite ends of the age spectrum, it is likely there are shared mechanisms and studies on GE could provide unique insights into AD pathogenesis. Neurodegenerative diseases are typically late-onset disorders, but the underlying pathology may have already occurred long before the clinical symptoms emerge. Pathophysiology in the early phase of these diseases is understudied but critical for developing mechanism-based treatment. In AD, increased seizure susceptibility and silent epileptiform activity due to disrupted excitatory/inhibitory (E/I) balance has been identified much earlier than cognition deficit. Increased epileptiform activity is likely a main pathology in the early phase that directly contributes to impaired cognition. It is an enormous challenge to model the early phase of pathology with conventional AD mouse models due to the chronic disease course, let alone the complex interplay between subclinical nonconvulsive epileptiform activity, AD pathology, and cognition deficit. We have extensively studied GE, especially with gene mutations that affect the GABA pathway such as mutations in GABAA receptors and GABA transporter 1. We believe that some mouse models developed for studying GE and insights gained from GE could provide unique opportunity to understand AD. These include the pathology in early phase of AD, endoplasmic reticulum (ER) stress, and E/I imbalance as well as the contribution to cognitive deficit. In this review, we will focus on the overlapping mechanisms between GE and AD, the insights from mutations affecting GABAA receptors, and GABA transporter 1. We will detail mechanisms of E/I imbalance and the toxic epileptiform generation in AD, and the complex interplay between ER stress, impaired membrane protein trafficking, and synaptic physiology in both GE and AD.
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17
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Swain O, Romano SK, Miryala R, Tsai J, Parikh V, Umanah GKE. SARS-CoV-2 Neuronal Invasion and Complications: Potential Mechanisms and Therapeutic Approaches. J Neurosci 2021; 41:5338-5349. [PMID: 34162747 PMCID: PMC8221594 DOI: 10.1523/jneurosci.3188-20.2021] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 04/12/2021] [Accepted: 05/02/2021] [Indexed: 12/15/2022] Open
Abstract
Clinical reports suggest that the coronavirus disease-19 (COVID-19) pandemic caused by severe acute respiratory syndrome (SARS)-coronavirus-2 (CoV-2) has not only taken millions of lives, but has also created a major crisis of neurologic complications that persist even after recovery from the disease. Autopsies of patients confirm the presence of the coronaviruses in the CNS, especially in the brain. The invasion and transmission of SARS-CoV-2 in the CNS is not clearly defined, but, because the endocytic pathway has become an important target for the development of therapeutic strategies for COVID-19, it is necessary to understand endocytic processes in the CNS. In addition, mitochondria and mechanistic target of rapamycin (mTOR) signaling pathways play a critical role in the antiviral immune response, and may also be critical for endocytic activity. Furthermore, dysfunctions of mitochondria and mTOR signaling pathways have been associated with some high-risk conditions such as diabetes and immunodeficiency for developing severe complications observed in COVID-19 patients. However, the role of these pathways in SARS-CoV-2 infection and spread are largely unknown. In this review, we discuss the potential mechanisms of SARS-CoV-2 entry into the CNS and how mitochondria and mTOR pathways might regulate endocytic vesicle-mitochondria interactions and dynamics during SARS-CoV-2 infection. The mechanisms that plausibly account for severe neurologic complications with COVID-19 and potential treatments with Food and Drug Administration-approved drugs targeting mitochondria and the mTOR pathways are also addressed.
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Affiliation(s)
- Olivia Swain
- Neuroscience Department, Krieger School of Arts and Sciences, The Johns Hopkins University, Baltimore, Maryland 21205
| | - Sofia K Romano
- Neuroscience Department, Krieger School of Arts and Sciences, The Johns Hopkins University, Baltimore, Maryland 21205
| | - Ritika Miryala
- Neuroscience Department, Krieger School of Arts and Sciences, The Johns Hopkins University, Baltimore, Maryland 21205
| | - Jocelyn Tsai
- Neuroscience Department, Krieger School of Arts and Sciences, The Johns Hopkins University, Baltimore, Maryland 21205
| | - Vinnie Parikh
- Neuroscience Department, Krieger School of Arts and Sciences, The Johns Hopkins University, Baltimore, Maryland 21205
| | - George K E Umanah
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
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18
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Tikhonov DB. Channel Blockers of Ionotropic Glutamate
Receptors. J EVOL BIOCHEM PHYS+ 2021. [DOI: 10.1134/s0022093021020149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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19
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Youn H, Lee KJ, Kim SG, Cho SJ, Kim WJ, Lee WJ, Hwang JY, Han C, Shin C, Jung HY. The Behavioral Effects of Combination Therapy of Memantine and Acetylcholinesterase Inhibitors Compared with Acetylcholinesterase Inhibitors Alone in Patients with Moderate Alzheimer's Dementia: A Double-Blind Randomized Placebo-Controlled Trial. Psychiatry Investig 2021; 18:233-240. [PMID: 33685036 PMCID: PMC8016683 DOI: 10.30773/pi.2020.0329] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 01/13/2021] [Indexed: 12/03/2022] Open
Abstract
OBJECTIVE This study aimed to investigate treatment effects of combination therapy of memantine and acetylcholinesterase inhibitors (AchEIs) compared with AchEIs alone on behavioral and psychological symptoms of dementia (BPSD) in patients with moderate Alzheimer's dementia (AD). METHODS This was a 12-week, double-blind, randomized, placebo-controlled trial. A total of 148 patients with moderate AD participated in this study. Mini-Mental State Examination, Neuropsychiatric Inventory (NPI), Clinician's Interview-Based Impression of Change plus caregiver input, Gottfries-Bråne-Steen Scale, and Zarit Burden Interview were used as assessment scales. RESULTS There were no significant differences in age, sex, or education between AChEIs alone and combination groups. The combination group showed significantly more improvement of NPI-disinhibition score (0.76±2.15) than the AChEIs alone group (-0.14±1.71) after 12 weeks. CONCLUSION Our findings suggest that the combination therapy of memantine and AchEIs might be a beneficial option for reducing disinhibition symptoms of patients with moderate AD compared with AchEIs alone. We believe that clinicians need to consider additional memantine treatment when patients with moderate AD complain disinhibition symptom. A larger clinical trial is needed to further determine the efficacy and advantages of such combination therapy of memantine and AchEIs for treating BPSD of patients with moderate AD.
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Affiliation(s)
- HyunChul Youn
- Department of Psychiatry, Soonchunhyang University Bucheon Hospital, Bucheon, Republic of Korea
| | - Kang Joon Lee
- Department of Psychiatry, Ilsanpaik Hospital, Inje University College of Medicine, Goyang, Republic of Korea
| | - Shin-Gyeom Kim
- Department of Psychiatry, Soonchunhyang University Bucheon Hospital, Bucheon, Republic of Korea
| | - Seong-Jin Cho
- Department of Psychiatry, Gil Medical Center, Gachon University College of Medicine, Incheon, Republic of Korea
| | - Woo Jung Kim
- Department of Psychiatry, Yongin Severance Hospital, Yonsei University College of Medicine, Yongin, Republic of Korea
| | - Won Joon Lee
- Department of Psychiatry, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Republic of Korea
| | - Jae Yeon Hwang
- Department of Psychiatry, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Republic of Korea
| | - Changsu Han
- Department of Psychiatry, Korea University College of Medicine, Seoul, Republic of Korea
| | - Cheolmin Shin
- Department of Psychiatry, Korea University College of Medicine, Seoul, Republic of Korea
| | - Han-Yong Jung
- Department of Psychiatry, Soonchunhyang University Bucheon Hospital, Bucheon, Republic of Korea
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20
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Swerdlow NR, Kotz JE, Joshi YB, Talledo J, Sprock J, Molina JL, Huisa B, Huege SF, Romero JA, Walsh MJ, Delano-Wood L, Light GA. Using Biomarkers to Predict Memantine Effects in Alzheimer's Disease: A Proposal and Proof-Of-Concept Demonstration. J Alzheimers Dis 2021; 84:1431-1438. [PMID: 34690144 PMCID: PMC8881988 DOI: 10.3233/jad-215029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Memantine's benefits in Alzheimer's disease (AD) are modest and heterogeneous. We tested the feasibility of using sensitivity to acute memantine challenge to predict an individual's clinical response. Eight participants completed a double-blind challenge study of memantine (placebo versus 20 mg) effects on autonomic, subjective, cognitive, and neurophysiological measures, followed by a 24-week unblinded active-dose therapeutic trial (10 mg bid). Study participation was well tolerated. Subgroups based on memantine sensitivity on specific laboratory measures differed in their clinical response to memantine, some by large effect sizes. It appears feasible to use biomarkers to predict clinical sensitivity to memantine.
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Affiliation(s)
- Neal R. Swerdlow
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Juliana E. Kotz
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Yash B. Joshi
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA
- VISN-22 Mental Illness, Research, Education and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA, USA
| | - Jo Talledo
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Joyce Sprock
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA
- VISN-22 Mental Illness, Research, Education and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA, USA
| | - Juan L. Molina
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA
- VISN-22 Mental Illness, Research, Education and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA, USA
| | - Branko Huisa
- Department of Neurosciences, School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Steven F. Huege
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Jairo Alberto Romero
- Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Michael J. Walsh
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Lisa Delano-Wood
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Gregory A. Light
- Department of Psychiatry, School of Medicine, University of California, San Diego, La Jolla, CA, USA
- VISN-22 Mental Illness, Research, Education and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA, USA
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21
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Molecular mechanisms of action determine inhibition of paroxysmal depolarizing shifts by NMDA receptor antagonists in rat cortical neurons. Neuropharmacology 2020; 184:108443. [PMID: 33345828 DOI: 10.1016/j.neuropharm.2020.108443] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 12/03/2020] [Accepted: 12/15/2020] [Indexed: 01/28/2023]
Abstract
N-methyl-d-aspartate glutamate receptors (NMDARs) are involved in numerous central nervous system (CNS) processes, including epileptiform activity. We used a picrotoxin-induced epileptiform activity model to compare the action of different types of NMDAR antagonists in rat brain slices. Paroxysmal depolarizing shifts (PDS) were evoked by external stimulation in the medial prefrontal cortex (mPFC) slices and recorded in pyramidal cells (PC) and in fast-spiking interneurons (FSI). The NMDAR antagonists APV and memantine reduced the duration of PDS. However, the competitive antagonist APV caused similar effects on the PC and FSI, while the open-channel blocker memantine had a much stronger effect on the PDS in the FSI than in the PC. This difference cannot be explained by a corresponding difference in NMDAR sensitivity to memantine because the drug inhibited the excitatory postsynaptic current (EPSC) similarly in both cell types. Importantly, the PDS were significantly longer in the FSI than in the PC. The degree of PDS inhibition by memantine correlated with individual PDS durations in each cell type. Computer modeling of a synaptic network in the mPFC suggests that the different effects of memantine on the PDS in the PC and FSI can be explained by use dependence of its action. An open-channel blocking mechanism and competition with Mg2+ ions for the binding site result in pronounced inhibition of the long PDS, whereas the short PDS are weakly sensitive. Our results show that peculiarities of kinetics and the mechanism of action largely determine the effects of NMDAR antagonists on physiological and/or pathological processes.
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Widman AJ, McMahon LL. Effects of ketamine and other rapidly acting antidepressants on hippocampal excitatory and inhibitory transmission. ADVANCES IN PHARMACOLOGY 2020; 89:3-41. [PMID: 32616211 DOI: 10.1016/bs.apha.2020.05.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A single sub-anesthetic intravascular dose of the use-dependent NMDAR antagonist, ketamine, improves mood in patients with treatment resistant depression within hours that can last for days, creating an entirely new treatment strategy for the most seriously ill patients. However, the psychomimetic effects and abuse potential of ketamine require that new therapies be developed that maintain the rapid antidepressant effects of ketamine without the unwanted side effects. This necessitates a detailed understanding of what cellular and synaptic mechanisms are immediately activated once ketamine reaches the brain that triggers the needed changes to elicit the improved behavior. Intense research has centered on the effects of ketamine, and the other rapidly acting antidepressants, on excitatory and inhibitory circuits in hippocampus and medial prefrontal cortex to determine common mechanisms, including key modifications in synaptic transmission and the precise location of the NMDARs that mediate the rapid and sustained antidepressant response. We review data comparing the effects of ketamine with other NMDAR receptor modulators and the muscarinic M1 acetylcholine receptor antagonist, scopolamine, together with evidence supporting the disinhibition hypothesis and the direct inhibition hypothesis of ketamine's mechanism of action on synaptic circuits using preclinical models.
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Affiliation(s)
- Allie J Widman
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Lori L McMahon
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, United States.
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Molina JL, Voytek B, Thomas ML, Joshi YB, Bhakta SG, Talledo JA, Swerdlow NR, Light GA. Memantine Effects on Electroencephalographic Measures of Putative Excitatory/Inhibitory Balance in Schizophrenia. BIOLOGICAL PSYCHIATRY. COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2020; 5:562-568. [PMID: 32340927 PMCID: PMC7286803 DOI: 10.1016/j.bpsc.2020.02.004] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 02/07/2020] [Accepted: 02/11/2020] [Indexed: 12/20/2022]
Abstract
BACKGROUND Abnormalities in cortical excitation and inhibition (E/I) balance are thought to underlie sensory and information processing deficits in schizophrenia. Deficits in early auditory information processing mediate both neurocognitive and functional impairment and appear to be normalized by acute pharmacologic challenge with the NMDA antagonist memantine (MEM). METHODS Thirty-six subjects with a diagnosis of schizophrenia and 31 healthy control subjects underwent electroencephalographic recordings. Subjects ingested either placebo or MEM (10 or 20 mg) in a double-blind, within-subject, crossover, randomized design. The aperiodic, 1/f-like scaling property of the neural power spectra, which is thought to index relative E/I balance, was estimated using a robust linear regression algorithm. RESULTS Patients with schizophrenia had greater aperiodic components compared with healthy control subjects (p < .01, d = 0.64), which was normalized after 20 mg MEM. Analysis revealed a significant dose × diagnosis interaction (p < .0001, d = 0.82). Furthermore, the MEM effect (change in aperiodic component in MEM vs. placebo conditions) was associated with baseline attention and vigilance (r = .54, p < .05) and MEM-induced enhancements in gamma power (r = -.60, p < .01). CONCLUSIONS Findings confirmed E/I balance abnormalities in schizophrenia that were normalized with acute MEM administration and suggest that neurocognitive profiles may predict treatment response based on E/I sensitivity. These data provide proof-of-concept evidence for the utility of E/I balance indices as metrics of acute pharmacologic sensitivity for central nervous system therapeutics.
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Affiliation(s)
- Juan L Molina
- Department of Psychiatry, University of California, San Diego, La Jolla, California
| | - Bradley Voytek
- Department of Cognitive Sciences, Halicioğlu Data Science Institute, and Neurosciences Graduate Program, University of California, San Diego, La Jolla, California
| | - Michael L Thomas
- Department of Psychiatry, University of California, San Diego, La Jolla, California; Department of Psychology, Colorado State University, Fort Collins, Colorado
| | - Yash B Joshi
- Department of Psychiatry, University of California, San Diego, La Jolla, California; VA Desert Pacific Mental Illness Research, Education and Clinical Center, VA San Diego Healthcare System, San Diego, California
| | - Savita G Bhakta
- Department of Psychiatry, University of California, San Diego, La Jolla, California
| | - Jo A Talledo
- Department of Psychiatry, University of California, San Diego, La Jolla, California
| | - Neal R Swerdlow
- Department of Psychiatry, University of California, San Diego, La Jolla, California.
| | - Gregory A Light
- Department of Psychiatry, University of California, San Diego, La Jolla, California; VA Desert Pacific Mental Illness Research, Education and Clinical Center, VA San Diego Healthcare System, San Diego, California
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Effects of Antagonists of Different Types of NMDA Receptor on Evoked Responses of Pyramidal Neurons in Rat Cerebral Cortex Slices. ACTA ACUST UNITED AC 2020. [DOI: 10.1007/s11055-020-00925-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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25
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Fu Y, Li L, Wang Y, Chu G, Kong X, Wang J. Role of GABAA receptors in EEG activity and spatial recognition memory in aged APP and PS1 double transgenic mice. Neurochem Int 2019; 131:104542. [DOI: 10.1016/j.neuint.2019.104542] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 09/02/2019] [Accepted: 09/02/2019] [Indexed: 10/26/2022]
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26
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Kokhan VS, Anokhin PK, Belov OV, Gulyaev MV. Cortical Glutamate/GABA Imbalance after Combined Radiation Exposure: Relevance to Human Deep-Space Missions. Neuroscience 2019; 416:295-308. [DOI: 10.1016/j.neuroscience.2019.08.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 07/01/2019] [Accepted: 08/03/2019] [Indexed: 12/22/2022]
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Povysheva N, Nigam A, Brisbin AK, Johnson JW, Barrionuevo G. Oxygen-Glucose Deprivation Differentially Affects Neocortical Pyramidal Neurons and Parvalbumin-Positive Interneurons. Neuroscience 2019; 412:72-82. [PMID: 31152933 DOI: 10.1016/j.neuroscience.2019.05.042] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 05/02/2019] [Accepted: 05/21/2019] [Indexed: 11/28/2022]
Abstract
Stroke is a devastating brain disorder. The pathophysiology of stroke is associated with an impaired excitation-inhibition balance in the area that surrounds the infarct core after the insult, the peri-infarct zone. Here we exposed slices from adult mouse prefrontal cortex to oxygen-glucose deprivation and reoxygenation (OGD-RO) to study ischemia-induced changes in the activity of excitatory pyramidal neurons and inhibitory parvalbumin (PV)-positive interneurons. We found that during current-clamp recordings, PV-positive interneurons were more vulnerable to OGD-RO than pyramidal neurons as indicated by the lower percentage of recovery of PV-positive interneurons. However, neither the amplitude of OGD-induced depolarization observed in current-clamp mode nor the OGD-associated current observed in voltage-clamp mode differed between the two cell types. Large amplitude, presumably action-potential dependent, spontaneous postsynaptic inhibitory currents recorded from pyramidal neurons were less frequent after OGD-RO than in control condition. Disynaptic inhibitory postsynaptic currents (dIPSCs) in pyramidal neurons produced predominantly by PV-positive interneurons were reduced by OGD-RO. Following OGD-RO, dendrites of PV-positive interneurons exhibited more pathological beading than those of pyramidal neurons. Our data support the hypothesis that the differential vulnerability to ischemia-like conditions of excitatory and inhibitory neurons leads to the altered excitation-inhibition balance associated with stroke pathophysiology.
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Affiliation(s)
- Nadya Povysheva
- Department of Neuroscience and Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, 15260, USA.
| | - Aparna Nigam
- Department of Neuroscience and Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Alyssa K Brisbin
- Department of Neuroscience and Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Jon W Johnson
- Department of Neuroscience and Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, 15260, USA; Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Germán Barrionuevo
- Department of Neuroscience and Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, 15260, USA; Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, 15213, USA
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Fang Q, Li Z, Huang GD, Zhang HH, Chen YY, Zhang LB, Ding ZB, Shi J, Lu L, Yang JL. Traumatic Stress Produces Distinct Activations of GABAergic and Glutamatergic Neurons in Amygdala. Front Neurosci 2018; 12:387. [PMID: 30186100 PMCID: PMC6110940 DOI: 10.3389/fnins.2018.00387] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 05/22/2018] [Indexed: 12/12/2022] Open
Abstract
Posttraumatic stress disorder (PTSD) is an anxiety disorder characterized by intrusive recollections of a severe traumatic event and hyperarousal following exposure to the event. Human and animal studies have shown that the change of amygdala activity after traumatic stress may contribute to occurrences of some symptoms or behaviors of the patients or animals with PTSD. However, it is still unknown how the neuronal activation of different sub-regions in amygdala changes during the development of PTSD. In the present study, we used single prolonged stress (SPS) procedure to obtain the animal model of PTSD, and found that 1 day after SPS, there were normal anxiety behavior and extinction of fear memory in rats which were accompanied by a reduced proportion of activated glutamatergic neurons and increased proportion of activated GABAergic neurons in basolateral amygdala (BLA). About 10 days after SPS, we observed enhanced anxiety and impaired extinction of fear memory with increased activated both glutamatergic and GABAergic neurons in BLA and increased activated GABAergic neurons in central amygdala (CeA). These results indicate that during early and late phase after traumatic stress, distinct patterns of activation of glutamatergic neurons and GABAergic neurons are displayed in amygdala, which may be implicated in the development of PTSD.
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Affiliation(s)
- Qing Fang
- Department of Psychiatry, Tianjin Medical University, Tianjin, China.,National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence, Peking University, Beijing, China.,Psychiatric Department, Tianjin Anding Hospital, Tianjin, China
| | - Zhe Li
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence, Peking University, Beijing, China.,Cangzhou Medical College, Cangzhou, China
| | - Geng-Di Huang
- Department of Psychiatry, Tianjin Medical University, Tianjin, China.,National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence, Peking University, Beijing, China
| | - Huan-Huan Zhang
- Department of Psychiatry, Tianjin Medical University, Tianjin, China.,National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence, Peking University, Beijing, China
| | - Ya-Yun Chen
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence, Peking University, Beijing, China
| | - Li-Bo Zhang
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence, Peking University, Beijing, China
| | - Zeng-Bo Ding
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence, Peking University, Beijing, China
| | - Jie Shi
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence, Peking University, Beijing, China
| | - Lin Lu
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence, Peking University, Beijing, China.,Peking University Sixth Hospital/Peking University Institute of Mental Health, Peking University, Beijing, China
| | - Jian-Li Yang
- Department of Psychiatry, Tianjin Medical University, Tianjin, China.,Tianjin Medical University General Hospital, Tianjin, China
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Glasgow NG, Wilcox MR, Johnson JW. Effects of Mg 2+ on recovery of NMDA receptors from inhibition by memantine and ketamine reveal properties of a second site. Neuropharmacology 2018; 137:344-358. [PMID: 29793153 PMCID: PMC6050087 DOI: 10.1016/j.neuropharm.2018.05.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 04/18/2018] [Accepted: 05/11/2018] [Indexed: 01/19/2023]
Abstract
Memantine and ketamine are NMDA receptor (NMDAR) open channel blockers that are thought to act via similar mechanisms at NMDARs, but exhibit divergent clinical effects. Both drugs act by entering open NMDARs and binding at a site deep within the ion channel (the deep site) at which the endogenous NMDAR channel blocker Mg2+ also binds. Under physiological conditions, Mg2+ increases the IC50s of memantine and ketamine through competition for binding at the deep site. Memantine also can inhibit NMDARs after associating with a second site accessible in the absence of agonist, a process termed second site inhibition (SSI) that is not observed with ketamine. Here we investigated the effects of 1 mM Mg2+ on recovery from inhibition by memantine and ketamine, and on memantine SSI, of the four main diheteromeric NMDAR subtypes. We found that: recovery from memantine inhibition depended strongly on the concentration of memantine used to inhibit the NMDAR response; Mg2+ accelerated recovery from memantine and ketamine inhibition through distinct mechanisms and in an NMDAR subtype-dependent manner; and Mg2+ occupation of the deep site disrupted memantine SSI in a subtype-dependent manner. Our results support the hypothesis that memantine associates with, but does not inhibit at the second site. After associating with the second site, memantine can either slowly dissociate directly to the extracellular solution, or transit to the deep site, resulting in typical channel block. Memantine's relatively slow dissociation from the second site underlies the dependence of NMDAR recovery from inhibition on both memantine concentration and on Mg2+.
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Affiliation(s)
- Nathan G Glasgow
- Department of Neuroscience and Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Madeleine R Wilcox
- Department of Neuroscience and Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Jon W Johnson
- Department of Neuroscience and Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA; Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA.
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Newman EL, Terunuma M, Wang TL, Hewage N, Bicakci MB, Moss SJ, DeBold JF, Miczek KA. A Role for Prefrontal Cortical NMDA Receptors in Murine Alcohol-Heightened Aggression. Neuropsychopharmacology 2018; 43:1224-1234. [PMID: 29052618 PMCID: PMC5916347 DOI: 10.1038/npp.2017.253] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 10/03/2017] [Accepted: 10/15/2017] [Indexed: 11/09/2022]
Abstract
Alcohol is associated with nearly half of all violent crimes committed in the United States; yet, a potential neural basis for this type of pathological aggression remains elusive. Alcohol may act on N-methyl-d-aspartate receptors (NMDARs) within cortical circuits to impede processing and to promote aggression. Here, male mice were characterized as alcohol-heightened (AHAs) or alcohol non-heightened aggressors (ANAs) during resident-intruder confrontations after self-administering 1.0 g/kg alcohol (6% w/v) or water. Alcohol produced a pathological-like pattern of aggression in AHAs; these mice shifted their bites to more vulnerable locations on the body of a submissive animal, including the anterior back and ventrum after consuming alcohol. In addition, through immunoblotting, we found that AHAs overexpressed the NMDAR GluN2D subunit in the prefrontal cortex (PFC) as compared to ANAs while the two phenotypes expressed similar levels of GluN1, GluN2A and GluN2B. After identifying several behavioral and molecular characteristics that distinguish AHAs from ANAs, we tested additional mice for their aggression following preferential antagonism of GluN2D-containing NMDARs. In these experiments, groups of AHAs and ANAs self-administered 1.0 g/kg alcohol (6% w/v) or water before receiving intraperitoneal (i.p.) doses of ketamine or memantine, or infusions of memantine directly into the prelimbic (PLmPFC) or infralimbic medial PFC (ILmPFC). Moderate doses of IP ketamine, IP memantine, or intra-PLmPFC memantine increased aggression in AHAs, but only in the absence of alcohol. Prior alcohol intake blocked the pro-aggressive effects of ketamine or memantine. In contrast, only memantine, administered systemically or intra-PLmPFC, interacted with prior alcohol intake to escalate aggression in ANAs. Intra-ILmPFC memantine had no effect on aggression in either AHAs or ANAs. In sum, this work illustrates a potential role of GluN2D-containing NMDARs in the PLmPFC in alcohol-heightened aggression. GluN2D-containing NMDARs are highly expressed on cortical parvalbumin-containing interneurons, suggesting that, in a subset of individuals, alcohol may functionally alter signal integration within cortical microcircuits to dysregulate threat reactivity and promote aggression. This work suggests that targeting GluN2D-NMDARs may be of use in reducing the impact of alcohol-related violence in the human population.
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Affiliation(s)
- Emily L Newman
- Psychology Department, Tufts University, Medford, MA, USA
| | - Miho Terunuma
- Division of Oral Biochemistry, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Tiffany L Wang
- Psychology Department, Tufts University, Medford, MA, USA
| | - Nishani Hewage
- Psychology Department, Tufts University, Medford, MA, USA
| | | | - Stephen J Moss
- Department of Neuroscience, Sackler School of Graduate Biomedical Sciences, Boston, MA, USA
| | | | - Klaus A Miczek
- Psychology Department, Tufts University, Medford, MA, USA
- Department of Neuroscience, Sackler School of Graduate Biomedical Sciences, Boston, MA, USA
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Torregrossa MM. A Role for Prefrontal Cortical NMDA Receptors in Murine Alcohol-Heightened Aggression. Neuropsychopharmacology 2018; 43:1199-1200. [PMID: 29317778 PMCID: PMC5916359 DOI: 10.1038/npp.2017.286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Mary M Torregrossa
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA,Department of Psychiatry, University of Pittsburgh, Bridgeside Point II, Room 228, 450 Technology Drive, Pittsburgh, PA 15219, USA, Tel: 412 624 5723, Fax: 412 624 5280, E-mail:
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Disinhibition of CA1 pyramidal cells by low-dose ketamine and other antagonists with rapid antidepressant efficacy. Proc Natl Acad Sci U S A 2018. [PMID: 29531088 DOI: 10.1073/pnas.1718883115] [Citation(s) in RCA: 147] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Low-dose ketamine, an open-channel N-methyl d-aspartate receptor (NMDAR) antagonist, mediates rapid antidepressant effects in humans that are mimicked in preclinical rodent models. Disinhibition of pyramidal cells via decreased output of fast-spiking GABAergic interneurons has been proposed as a key mechanism that triggers the antidepressant response. Unfortunately, to date, disinhibition has not been directly demonstrated. Furthermore, whether disinhibition is a common mechanism shared among other antagonists with rapid antidepressant properties in humans has not been investigated. Using in vitro electrophysiology in acute slices of dorsal hippocampus from adult male Sprague-Dawley rats, we examined the immediate effects of a clinically relevant concentration of ketamine to directly test the disinhibition hypothesis. As a mechanistic comparison, we also tested the effects of the glycine site NMDAR partial agonist/antagonist GLYX-13 (rapastinel), the GluN2B subunit-selective NMDAR antagonist Ro 25-6981, and the muscarinic acetylcholine receptor (mAChR) antagonist scopolamine. Low-dose ketamine, GLYX-13, and scopolamine reduced inhibitory input onto pyramidal cells and increased synaptically driven pyramidal cell excitability measured at the single-cell and population levels. Conversely, Ro 25-6981 increased the strength of inhibitory transmission and did not change pyramidal cell excitability. These results show a decrease in the inhibition/excitation balance that supports disinhibition as a common mechanism shared among those antagonists with rapid antidepressant properties. These data suggest that pyramidal cell disinhibition downstream of NMDAR antagonism could serve as a possible biomarker for the efficacy of rapid antidepressant therapy.
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Single-Dose Memantine Improves Cortical Oscillatory Response Dynamics in Patients with Schizophrenia. Neuropsychopharmacology 2017; 42:2633-2639. [PMID: 28425497 PMCID: PMC5686499 DOI: 10.1038/npp.2017.81] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 04/10/2017] [Accepted: 04/11/2017] [Indexed: 01/25/2023]
Abstract
Aberrant gamma-band (30-80 Hz) oscillations may underlie cognitive deficits in schizophrenia (SZ). Gamma oscillations and their regulation by NMDA receptors can be studied via their evoked power (γEP) and phase locking (γPL) in response to auditory steady-state stimulation; these auditory steady-state responses (ASSRs) may be biomarkers for target engagement and early therapeutic effects. We previously reported that memantine, an NMDA receptor antagonist, enhanced two biomarkers of early auditory information processing: prepulse inhibition and mismatch negativity (MMN) in SZ patients and healthy subjects (HS). Here, we describe memantine effects on γEP and γPL in those subjects. SZ patients (n=18) and HS (n=14) received memantine 20 mg (p.o.) and placebo over 2 test days in a double-blind, randomized, counterbalanced, cross-over design. The ASSR paradigm (1 ms, 85 dB clicks in 250-0.5 s trains at a frequency of 40 Hz; 0.5 s inter-train interval) was used to assess γEP and γPL. SZ patients had reduced γEP and γPL; memantine enhanced γEP and γPL (p<0.025 and 0.002, respectively) in both SZ and HS. In patients, significant correlations between age and memantine effects were detected for γEP and γPL: greater memantine sensitivity on γEP and γPL were present in younger SZ patients, similar to our reported findings with MMN. Memantine acutely normalized cortical oscillatory dynamics associated with NMDA receptor dysfunction in SZ patients. Ongoing studies will clarify whether these acute changes predict beneficial clinical, neurocognitive and functional outcomes. These data support the use of gamma-band ASSR as a translational end point in pro-cognitive drug discovery and early-phase clinical trials.
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García-Pardo MP, De la Rubia Ortí JE, Aguilar Calpe MA. Differential effects of MDMA and cocaine on inhibitory avoidance and object recognition tests in rodents. Neurobiol Learn Mem 2017; 146:1-11. [PMID: 29081371 DOI: 10.1016/j.nlm.2017.10.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 10/23/2017] [Accepted: 10/24/2017] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Drug addiction continues being a major public problem faced by modern societies with different social, health and legal consequences for the consumers. Consumption of psychostimulants, like cocaine or MDMA (known as ecstasy) are highly prevalent and cognitive and memory impairments have been related with the abuse of these drugs. AIM The aim of this work was to review the most important data of the literature in the last 10 years about the effects of cocaine and MDMA on inhibitory avoidance and object recognition tests in rodents. DEVELOPMENT The object recognition and the inhibitory avoidance tests are popular procedures used to assess different types of memory. We compare the effects of cocaine and MDMA administration in these tests, taking in consideration different factors such as the period of life development of the animals (prenatal, adolescence and adult age), the presence of polydrug consumption or the role of environmental variables. Brain structures involved in the effects of cocaine and MDMA on memory are also described. CONCLUSIONS Cocaine and MDMA induced similar impairing effects on the object recognition test during critical periods of lifetime or after abstinence of prolonged consumption in adulthood. Deficits of inhibitory avoidance memory are observed only in adult rodents exposed to MDMA. Psychostimulant abuse is a potential factor to induce memory impairments and could facilitate the development of future neurodegenerative disorders.
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Memantine and Ketamine Differentially Alter NMDA Receptor Desensitization. J Neurosci 2017; 37:9686-9704. [PMID: 28877967 DOI: 10.1523/jneurosci.1173-17.2017] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Revised: 08/07/2017] [Accepted: 08/30/2017] [Indexed: 11/21/2022] Open
Abstract
Memantine and ketamine are clinically useful NMDA receptor (NMDAR) open channel blockers that inhibit NMDARs with similar potency and kinetics, but display vastly different clinical profiles. This discrepancy has been hypothesized to result from inhibition by memantine and ketamine of overlapping but distinct NMDAR subpopulations. For example, memantine but not ketamine may inhibit extrasynaptic NMDARs more effectively than synaptic NMDARs. However, the basis for preferential NMDAR inhibition depending on subcellular location has not been investigated systematically. We integrated recordings from heterologously expressed single NMDAR subtypes, kinetic modeling, and recordings of synaptically evoked NMDAR responses in acute brain slices to investigate mechanisms by which channel blockers may distinguish NMDAR subpopulations. We found that memantine and ketamine differentially alter NMDAR desensitization and that memantine stabilizes a Ca2+-dependent desensitized state. As a result, inhibition by memantine of GluN1/2A receptors in tsA201 cells and of native synaptic NMDARs in cortical pyramidal neurons from mice of either sex increased in conditions that enhanced intracellular Ca2+ accumulation. Therefore, differential inhibition by memantine and ketamine based on NMDAR location is likely to result from location dependence of the intensity and duration of NMDAR activation. Modulation of Ca2+-dependent NMDAR desensitization is an unexplored mechanism of inhibitory action with the potential to endow drugs with NMDAR selectivity that leads to superior clinical profiles. Our results suggest that designing compounds to target specific receptor states, rather than specific receptor types, may be a viable strategy for future drug development.SIGNIFICANCE STATEMENT Memantine and ketamine are NMDA receptor (NMDAR) channel-blocking drugs with divergent clinical effects. Understanding mechanistically their differential actions may advance our understanding of nervous system disorders and suggest strategies for the design of more effective drugs. Here, we show that memantine and ketamine have contrasting effects on NMDAR desensitization. Ketamine binding decreases occupancy of desensitized states of the GluN1/2B NMDAR subtype. In contrast, memantine binding increases occupancy of GluN1/2A and native NMDAR desensitized states entered after accumulation of intracellular Ca2+, a novel inhibitory mechanism. These properties may contribute to inhibition of distinct NMDAR subpopulations by memantine and ketamine and help to explain their differential clinical effects. Our results suggest stabilization of Ca2+-dependent desensitized states as a new strategy for pharmaceutical neuroprotection.
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Maezawa I, Zou B, Di Lucente J, Cao WS, Pascual C, Weerasekara S, Zhang M, Xie XS, Hua DH, Jin LW. The Anti-Amyloid-β and Neuroprotective Properties of a Novel Tricyclic Pyrone Molecule. J Alzheimers Dis 2017; 58:559-574. [PMID: 28482635 PMCID: PMC5438482 DOI: 10.3233/jad-161175] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/15/2017] [Indexed: 12/17/2022]
Abstract
There is an urgent unmet need for new therapeutics for Alzheimer's disease (AD), the most common cause of dementia in the elderly. Therapeutic approaches targeting amyloid-β (Aβ) and its downstream toxicities have become major strategies in AD drug development. We have taken a rational design approach and synthesized a class of tricyclic pyrone (TP) compounds that show anti-Aβ and other neuroprotective actions. The in vivo efficacy of a lead TP named CP2 to ameliorate AD-like pathologies has been shown in mouse models. Here we report the selection and initial characterization of a new lead TP70, which exhibited an anti-Aβ therapeutic index even higher than CP2. Moreover, TP70 was able to reduce oxidative stress, inhibit acyl-coenzyme A:cholesterol acyltransferase (ACAT), and upregulate the expression of ATP-binding cassette subfamily A, member 1 (ABCA1), actions considered neuroprotective in AD. TP70 further showed excellent pharmacokinetic properties, including brain penetration and oral availability. When administered to 5xFAD mice via intraperitoneal or oral route, TP70 enhanced the overall solubility and decreased the level of cerebral Aβ, including both fibrillary and soluble Aβ species. Interestingly, TP70 enhanced N-methyl-D-aspartate (NMDA) receptor-mediated excitatory post-synaptic potential (EPSP) in the hippocampal CA1 area, increased the magnitude of NMDA-dependent hippocampal long-term potentiation (LTP), a cellular model of learning and memory, and prevented the Aβ oligomer-impaired LTP. Significantly, a single dose of TP70 administered to aged 5xFAD mice was effective in mitigating the impaired LTP induction, recorded at 24 h after administration. Our results support a potential of TP70 in clinical development for AD in view of its synergistic neuroprotective actions, ability to positively modulate NMDA receptor-mediated hippocampal plasticity, and favorable pharmacokinetic properties in rodents.
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Affiliation(s)
- Izumi Maezawa
- Department of Pathology and Laboratory Medicine, University of California Davis Medical Center, Sacramento, CA, USA
| | - Bende Zou
- AfaSci Research Laboratory, Redwood City, CA, USA
| | - Jacopo Di Lucente
- Department of Pathology and Laboratory Medicine, University of California Davis Medical Center, Sacramento, CA, USA
| | | | | | | | - Man Zhang
- Department of Chemistry, Kansas State University, Manhattan, KS, USA
| | | | - Duy H. Hua
- Department of Chemistry, Kansas State University, Manhattan, KS, USA
| | - Lee-Way Jin
- Department of Pathology and Laboratory Medicine, University of California Davis Medical Center, Sacramento, CA, USA
- Alzheimer’s Disease Center, University of California Davis Medical Center, Sacramento, CA, USA
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Swanger SA, Chen W, Wells G, Burger PB, Tankovic A, Bhattacharya S, Strong KL, Hu C, Kusumoto H, Zhang J, Adams DR, Millichap JJ, Petrovski S, Traynelis SF, Yuan H. Mechanistic Insight into NMDA Receptor Dysregulation by Rare Variants in the GluN2A and GluN2B Agonist Binding Domains. Am J Hum Genet 2016; 99:1261-1280. [PMID: 27839871 PMCID: PMC5142120 DOI: 10.1016/j.ajhg.2016.10.002] [Citation(s) in RCA: 133] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Accepted: 10/03/2016] [Indexed: 12/30/2022] Open
Abstract
Epilepsy and intellectual disability are associated with rare variants in the GluN2A and GluN2B (encoded by GRIN2A and GRIN2B) subunits of the N-methyl-D-aspartate receptor (NMDAR), a ligand-gated ion channel with essential roles in brain development and function. By assessing genetic variation across GluN2 domains, we determined that the agonist binding domain, transmembrane domain, and the linker regions between these domains were particularly intolerant to functional variation. Notably, the agonist binding domain of GluN2B exhibited significantly more variation intolerance than that of GluN2A. To understand the ramifications of missense variation in the agonist binding domain, we investigated the mechanisms by which 25 rare variants in the GluN2A and GluN2B agonist binding domains dysregulated NMDAR activity. When introduced into recombinant human NMDARs, these rare variants identified in individuals with neurologic disease had complex, and sometimes opposing, consequences on agonist binding, channel gating, receptor biogenesis, and forward trafficking. Our approach combined quantitative assessments of these effects to estimate the overall impact on synaptic and non-synaptic NMDAR function. Interestingly, similar neurologic diseases were associated with both gain- and loss-of-function variants in the same gene. Most rare variants in GluN2A were associated with epilepsy, whereas GluN2B variants were associated with intellectual disability with or without seizures. Finally, discerning the mechanisms underlying NMDAR dysregulation by these rare variants allowed investigations of pharmacologic strategies to correct NMDAR function.
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Affiliation(s)
- Sharon A Swanger
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Wenjuan Chen
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Gordon Wells
- Department of Chemistry, Emory University, Atlanta, GA 30322, USA
| | - Pieter B Burger
- Department of Chemistry, Emory University, Atlanta, GA 30322, USA
| | - Anel Tankovic
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | | | - Katie L Strong
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Chemistry, Emory University, Atlanta, GA 30322, USA
| | - Chun Hu
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Hirofumi Kusumoto
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Jing Zhang
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - David R Adams
- Undiagnosed Diseases Network, National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA
| | - John J Millichap
- Departments of Pediatrics and Neurology, Northwestern University Feinberg School of Medicine and Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL 60611, USA
| | - Slavé Petrovski
- Department of Medicine, The University of Melbourne, Austin Health and Royal Melbourne Hospital, Melbourne, VIC 3050, Australia
| | - Stephen F Traynelis
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA; Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, GA 30322, USA.
| | - Hongjie Yuan
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA; Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, GA 30322, USA.
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