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Sun LH, Yu L, Chan YH, Chin MH, Lee CP, Liao YH. Combining brief recall and ketamine treatment prevents stress-primed methamphetamine memory reinstatement via heightening mPFC GABA activity. Eur J Pharmacol 2024; 972:176559. [PMID: 38588768 DOI: 10.1016/j.ejphar.2024.176559] [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: 01/22/2024] [Revised: 03/20/2024] [Accepted: 04/03/2024] [Indexed: 04/10/2024]
Abstract
This study aimed to assess whether brief recall of methamphetamine (MA) memory, when combined with ketamine (KE) treatment, may prevent stress-primed MA memory reinstatement. Combining 3-min recall and KE facilitated MA memory extinction and resistance to subsequent stress-primed reinstatement. Such combination also produced glutamate metabotropic receptor 5 (mGluR5) upregulation in animals' medial prefrontal cortex (mPFC) γ-amino-butyric acid (GABA) neuron. Accordingly, chemogenetic methods were employed to bi-directionally modulate mPFC GABA activity. Following brief recall and KE-produced MA memory extinction, intra-mPFC mDlx-Gi-coupled-human-muscarinic-receptor 4 (hM4Di)-infused mice receiving compound 21 (C21) treatment showed eminent stress-primed reinstatement, while their GABA mGluR5 expression seemed to be unaltered. Intra-mPFC mDlx-Gq-coupled-human-muscarinic-receptor 3 (hM3Dq)-infused mice undergoing C21 treatment displayed MA memory extinction and resistance to stress-provoked reinstatement. These results suggest that combining a brief recall and KE treatment and exciting mPFC GABA neuron may facilitate MA memory extinction and resistance to stress-primed recall. mPFC GABA neuronal activity plays a role in mediating brief recall/KE-produced effects on curbing the stress-provoked MA seeking.
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Affiliation(s)
- Li-Han Sun
- Institute of Basic Medical Sciences, National Cheng Kung University College of Medicine, Tainan, 70101, Taiwan
| | - Lung Yu
- Institute of Basic Medical Sciences, National Cheng Kung University College of Medicine, Tainan, 70101, Taiwan; Department of Physiology, National Cheng Kung University College of Medicine, Tainan, 70101, Taiwan; Institute of Behavioral Medicine, National Cheng Kung University College of Medicine, Tainan, 70101, Taiwan
| | - Ya-Hsuan Chan
- Department of Physiology, National Cheng Kung University College of Medicine, Tainan, 70101, Taiwan
| | - Min-Han Chin
- Department of Physiology, National Cheng Kung University College of Medicine, Tainan, 70101, Taiwan
| | - Chi-Pin Lee
- Division of Cardiology, Department of Internal Medicine, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi, 600, Taiwan.
| | - Yi-Han Liao
- Department of Physiology, National Cheng Kung University College of Medicine, Tainan, 70101, Taiwan; Division of Cardiology, Department of Internal Medicine, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi, 600, Taiwan.
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Mottarlini F, Rizzi B, Targa G, Buzzelli V, Di Trapano M, Rullo L, Candeletti S, Ciccocioppo R, Fattore L, Romualdi P, Fumagalli F, Trezza V, Caffino L. Communal nesting shapes the sex-dependent glutamatergic response to early life stress in the rat prefrontal cortex. Front Psychiatry 2024; 15:1406687. [PMID: 38835543 PMCID: PMC11148342 DOI: 10.3389/fpsyt.2024.1406687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Accepted: 05/07/2024] [Indexed: 06/06/2024] Open
Abstract
Introduction Early social environment, either positive or negative, shapes the adult brain. Communal nesting (CN), a naturalistic setting in which 2-3 females keep their pups in a single nest sharing care-giving behavior, provides high level of peer interaction for pups. Early social isolation (ESI) from dam and siblings represents, instead, an adverse condition providing no peer interaction. Methods We investigated whether CN (enrichment setting) might influence the response to ESI (impoverishment setting) in terms of social behavior and glutamate system in the medial prefrontal cortex (mPFC) of adult and adolescent male and female rats. Results Pinning (a rewarding component of social play behavior) was significantly more pronounced in males than in females exposed to the combination of CN and ESI. CN sensitized the glutamate synapse in the mPFC of ESI-exposed male, but not female, rats. Accordingly, we observed (i) a potentiation of the glutamatergic neurotransmission in the mPFC of both adolescent and adult males, as shown by the recruitment of NMDA receptor subunits together with increased expression/activation of PSD95, SynCAM 1, Synapsin I and αCaMKII; (ii) a de-recruiting of NMDA receptors from active synaptic zones of same-age females, together with reduced expression/activation of the above-mentioned proteins, which might reduce the glutamate transmission. Whether similar sex-dependent glutamate homeostasis modulation occurs in other brain areas remains to be elucidated. Discussion CN and ESI interact to shape social behavior and mPFC glutamate synapse homeostasis in an age- and sex-dependent fashion, suggesting that early-life social environment may play a crucial role in regulating the risk to develop psychopathology.
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Affiliation(s)
- Francesca Mottarlini
- Department of Pharmacological and Biomolecular Sciences 'Rodolfo Paoletti', Università degli Studi di Milano, Milan, Italy
| | - Beatrice Rizzi
- Department of Pharmacological and Biomolecular Sciences 'Rodolfo Paoletti', Università degli Studi di Milano, Milan, Italy
- Center for Neuroscience, University of Camerino, Camerino, Italy
| | - Giorgia Targa
- Department of Pharmacological and Biomolecular Sciences 'Rodolfo Paoletti', Università degli Studi di Milano, Milan, Italy
| | - Valeria Buzzelli
- Department of Science, Section of Biomedical Sciences and Technologies, Roma Tre University, Rome, Italy
| | - Melania Di Trapano
- Department of Science, Section of Biomedical Sciences and Technologies, Roma Tre University, Rome, Italy
| | - Laura Rullo
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - Sanzio Candeletti
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - Roberto Ciccocioppo
- School of Pharmacy, Center for Neuroscience, Pharmacology Unit, University of Camerino, Camerino, Italy
| | - Liana Fattore
- Research National Council (CNR) Institute of Neuroscience-Cagliari, National Research Council, Cagliari, Italy
| | - Patrizia Romualdi
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - Fabio Fumagalli
- Department of Pharmacological and Biomolecular Sciences 'Rodolfo Paoletti', Università degli Studi di Milano, Milan, Italy
| | - Viviana Trezza
- Department of Science, Section of Biomedical Sciences and Technologies, Roma Tre University, Rome, Italy
- Neuroendocrinology, Metabolism and Neuropharmacology Unit, Istituto di Ricerca e Cura di Carattere Scientifico (IRCCS) Fondazione Santa Lucia, Rome, Italy
| | - Lucia Caffino
- Department of Pharmacological and Biomolecular Sciences 'Rodolfo Paoletti', Università degli Studi di Milano, Milan, Italy
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Gokalp D, Unal G. The role of mGluR5 on the therapeutic effects of ketamine in Wistar rats. Psychopharmacology (Berl) 2024:10.1007/s00213-024-06571-3. [PMID: 38459971 DOI: 10.1007/s00213-024-06571-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 03/04/2024] [Indexed: 03/11/2024]
Abstract
RATIONALE Ketamine produces dissociative, psychomimetic, anxiolytic, antidepressant, and anesthetic effects in a dose dependent manner. It has a complex mechanism of action that involve alterations in other glutamate receptors. The metabotropic glutamate receptor 5 (mGluR5) has been investigated in relation to the psychotic and anesthetic properties of ketamine, while its role in mediating the therapeutic effects of ketamine remains unknown. OBJECTIVES We investigated the role of mGluR5 on the antidepressant, anxiolytic and fear memory-related effects of ketamine in adult male Wistar rats. METHODS Two sets of experiments were conducted. We first utilized the positive allosteric modulator CDPPB to investigate how acute mGluR5 activation regulates the therapeutic effects of ketamine (10 mg/kg). We then tested the synergistic antidepressant effect of mGluR5 antagonism and ketamine by combining MTEP with a sub-effective dose of ketamine (1 mg/kg). Behavioral despair, locomotor activity, anxiety-like behavior, and fear memory were respectively assessed in the forced swim test (FST), open field test (OFT), elevated plus maze (EPM), and auditory fear conditioning. RESULTS Enhancing mGluR5 activity via CDPPB occluded the antidepressant effect of ketamine without changing locomotor activity. Furthermore, concomitant administration of MTEP and ketamine exhibited a robust synergistic antidepressant effect. The MTEP + ketamine treatment, however, blocked the anxiolytic effect observed by sole administration of MTEP or the low dose ketamine. CONCLUSIONS These findings suggest that suppressed mGluR5 activity is required for the antidepressant effects of ketamine. Consequently, the antagonism of mGluR5 enhances the antidepressant effectiveness of low dose ketamine, but eliminates its anxiolytic effects.
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Affiliation(s)
- Dilan Gokalp
- Behavioral Neuroscience Laboratory, Department of Psychology, Boğaziçi University, 34342, Istanbul, Turkey
| | - Gunes Unal
- Behavioral Neuroscience Laboratory, Department of Psychology, Boğaziçi University, 34342, Istanbul, Turkey.
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Pintori N, Piva A, Mottarlini F, Díaz FC, Maggi C, Caffino L, Fumagalli F, Chiamulera C. Brief exposure to enriched environment rapidly shapes the glutamate synapses in the rat brain: A metaplastic fingerprint. Eur J Neurosci 2024; 59:982-995. [PMID: 38378276 DOI: 10.1111/ejn.16279] [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: 07/06/2023] [Revised: 09/22/2023] [Accepted: 01/27/2024] [Indexed: 02/22/2024]
Abstract
Environmental enrichment (EE) has been shown to produce beneficial effects in addiction disorders; however, due to its configurational complexity, the underlying mechanisms are not yet fully elucidated. Recent evidence suggests that EE, acting as a metaplastic agent, may affect glutamatergic mechanisms underlying appetitive memory and, in turn, modulate reward-seeking behaviours: here, we have investigated such a possibility following a brief EE exposure. Adult male Sprague-Dawley rats were exposed to EE for 22 h and the expression of critical elements of the glutamate synapse was measured 2 h after the end of EE in the medial prefrontal cortex (mPFC), nucleus accumbens (NAc) and hippocampus (Hipp) brain areas, which are critical for reward and memory. We focused our investigation on the expression of NMDA and AMPA receptor subunits, their scaffolding proteins SAP102 and SAP97, vesicular and membrane glutamate transporters vGluT1 and GLT-1, and critical structural components such as proteins involved in morphology and function of glutamatergic synapses, PSD95 and Arc/Arg3.1. Our findings demonstrate that a brief EE exposure induces metaplastic changes in glutamatergic mPFC, NAc and Hipp. Such changes are area-specific and involve postsynaptic NMDA/AMPA receptor subunit composition, as well as changes in the expression of their main scaffolding proteins, thus influencing the retention of such receptors at synaptic sites. Our data indicate that brief EE exposure is sufficient to dynamically modulate the glutamatergic synapses in mPFC-NAc-Hipp circuits, which may modulate rewarding and memory processes.
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Affiliation(s)
- Nicholas Pintori
- Section of Pharmacology, Department of Diagnostic & Public Health, University of Verona, Verona, Italy
- Current Affiliation: Department of Biomedical Sciences, University of Cagliari, Cittadella Universitaria di Monserrato, Cagliari, Italy
| | - Alessandro Piva
- Section of Pharmacology, Department of Diagnostic & Public Health, University of Verona, Verona, Italy
| | - Francesca Mottarlini
- Department of Pharmacological and Biomolecular Sciences 'Rodolfo Paoletti', University of Milan, Milan, Italy
| | - Fernando Castillo Díaz
- Department of Pharmacological and Biomolecular Sciences 'Rodolfo Paoletti', University of Milan, Milan, Italy
| | - Coralie Maggi
- Department of Pharmacological and Biomolecular Sciences 'Rodolfo Paoletti', University of Milan, Milan, Italy
| | - Lucia Caffino
- Department of Pharmacological and Biomolecular Sciences 'Rodolfo Paoletti', University of Milan, Milan, Italy
| | - Fabio Fumagalli
- Department of Pharmacological and Biomolecular Sciences 'Rodolfo Paoletti', University of Milan, Milan, Italy
| | - Cristiano Chiamulera
- Section of Pharmacology, Department of Diagnostic & Public Health, University of Verona, Verona, Italy
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Elmeseiny OSA, Müller HK. A molecular perspective on mGluR5 regulation in the antidepressant effect of ketamine. Pharmacol Res 2024; 200:107081. [PMID: 38278430 DOI: 10.1016/j.phrs.2024.107081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 01/16/2024] [Accepted: 01/23/2024] [Indexed: 01/28/2024]
Abstract
Ketamine, a non-competitive N-methyl-D-aspartate receptor (NMDAR) antagonist, has received much attention for its rapid antidepressant effects. A single administration of ketamine elicits rapid and sustained antidepressant effects in both humans and animals. Current efforts are focused on uncovering molecular mechanisms responsible for ketamine's antidepressant activity. Ketamine primarily acts via the glutamatergic pathway, and increasing evidence suggests that ketamine induces synaptic and structural plasticity through increased translation and release of neurotrophic factors, activation of mammalian target of rapamycin (mTOR), and α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor (AMPAR)-mediated synaptic potentiation. However, the initial events triggering activation of intracellular signaling cascades and the mechanisms responsible for the sustained antidepressant effects of ketamine remain poorly understood. Over the last few years, it has become apparent that in addition to the fast actions of the ligand-gated AMPARs and NMDARs, metabotropic glutamate receptors (mGluRs), and particularly mGluR5, may also play a role in the antidepressant action of ketamine. Although research on mGluR5 in relation to the beneficial actions of ketamine is still in its infancy, a careful evaluation of the existing literature can identify converging trends and provide new interpretations. Here, we review the current literature on mGluR5 regulation in response to ketamine from a molecular perspective and propose a possible mechanism linking NMDAR inhibition to mGluR5 modulation.
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Affiliation(s)
- Ola Sobhy A Elmeseiny
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Heidi Kaastrup Müller
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
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Postsynaptic Proteins at Excitatory Synapses in the Brain—Relationship with Depressive Disorders. Int J Mol Sci 2022; 23:ijms231911423. [PMID: 36232725 PMCID: PMC9569598 DOI: 10.3390/ijms231911423] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 09/21/2022] [Accepted: 09/22/2022] [Indexed: 11/17/2022] Open
Abstract
Depressive disorders (DDs) are an increasingly common health problem that affects all age groups. DDs pathogenesis is multifactorial. However, it was proven that stress is one of the most important environmental factors contributing to the development of these conditions. In recent years, there has been growing interest in the role of the glutamatergic system in the context of pharmacotherapy of DDs. Thus, it has become increasingly important to explore the functioning of excitatory synapses in pathogenesis and pharmacological treatment of psychiatric disorders (including DDs). This knowledge may lead to the description of new mechanisms of depression and indicate new potential targets for the pharmacotherapy of illness. An excitatory synapse is a highly complex and very dynamic structure, containing a vast number of proteins. This review aimed to discuss in detail the role of the key postsynaptic proteins (e.g., NMDAR, AMPAR, mGluR5, PSD-95, Homer, NOS etc.) in the excitatory synapse and to systematize the knowledge about changes that occur in the clinical course of depression and after antidepressant treatment. In addition, a discussion on the potential use of ligands and/or modulators of postsynaptic proteins at the excitatory synapse has been presented.
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Pintori N, Piva A, Guardiani V, Decimo I, Chiamulera C. Brief Environmental Enrichment exposure enhances contextual-induced sucrose-seeking with and without memory reactivation in rats. Behav Brain Res 2022; 416:113556. [PMID: 34474039 DOI: 10.1016/j.bbr.2021.113556] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 07/21/2021] [Accepted: 08/23/2021] [Indexed: 12/16/2022]
Abstract
Chronic Environmental Enrichment (EE) has been shown to prevent the relapse to addictive behaviours, such as drug-taking and -seeking. Recently, acute EE was shown to reduce cue-induced sucrose-seeking, but its effects on contextual (Cx)-induced sucrose-seeking is still unknown. Here we report the effects of brief EE exposure on Cx-induced sucrose-seeking with and without prior Cx-memory reactivation. Adult male Sprague-Dawley rats were trained to sucrose self-administration associated to a specific conditioning Cx (CxA), followed by a 7-day extinction in a different Cx (CxB). Afterwards, rats were exposed for 22 h to EE, and 1 h later to either i) Cx-induced sucrose-seeking (1 h, renewal without Cx-memory reactivation), ii) or two different Cx-memory reactivations: short (2-min) and long (15-min) CxA-retrieval session (Cx-Ret). In Cx-Ret experiments, CxA-induced sucrose-seeking test (1 h) was done after a subsequent 3-day extinction phase. The assessment of molecular markers of memory reactivation/reconsolidation, Zif-268 and rpS6P, was performed 2 h after Cx-Ret. Brief EE exposure enhanced Cx-induced sucrose-seeking without and with short but not long Cx-retrieval. Moreover, EE impaired discriminative responding at test prior to long, whereas improved it with or without short Cx-retrieval. Different changes in Zif-268 and rpS6P expression induced by short vs. long Cx-Ret were correlated to behavioural data, suggesting the occurrence of different memory processes affected by EE. Our data show that brief EE exposure may differently affect subsequent appetitive relapse depending on the modality of re-exposure to conditioned context. This finding suggests caution and further studies to understand the proper conditions for the use of EE against appetitive and addiction disorders.
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Affiliation(s)
- N Pintori
- Section of Pharmacology, Dept. Diagnostic & Public Health, University of Verona, Verona, Italy.
| | - A Piva
- Section of Pharmacology, Dept. Diagnostic & Public Health, University of Verona, Verona, Italy
| | - V Guardiani
- Section of Pharmacology, Dept. Diagnostic & Public Health, University of Verona, Verona, Italy
| | - I Decimo
- Section of Pharmacology, Dept. Diagnostic & Public Health, University of Verona, Verona, Italy
| | - C Chiamulera
- Section of Pharmacology, Dept. Diagnostic & Public Health, University of Verona, Verona, Italy
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Pintori N, Piva A, Guardiani V, Marzo CM, Decimo I, Chiamulera C. The interaction between Environmental Enrichment and fluoxetine in inhibiting sucrose-seeking renewal in mice depend on social living condition. Psychopharmacology (Berl) 2022; 239:2351-2361. [PMID: 35353203 PMCID: PMC9205808 DOI: 10.1007/s00213-022-06124-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 03/17/2022] [Indexed: 12/01/2022]
Abstract
RATIONALE Several single or combined therapeutic approaches have been developed to treat addiction, however with partial efficacy in preventing relapse. Recently, the living environment has been suggested as a critical intervening factor determining the treatment outcomes. Despite accumulating evidence confirming a role of living conditions in the vulnerability to addictive behaviours, their impact on single or integrative therapeutic strategies preventing relapse is yet to be identified. OBJECTIVES Here, we explore the possible interaction between brief Environmental Enrichment (EE) exposure and acute fluoxetine administration in inhibiting sucrose-seeking behaviours, and whether this effect could be affected by living environment. METHODS Social and isolated adult male C57BL/6 mice were trained to sucrose self-administration associated to a specific conditioning context (CxA), followed by a 7-day extinction in a different context (CxB). Afterwards, mice were exposed for 22 h to EE and then injected with fluoxetine (10 mg/kg, i.p.) 1 h before a CxA-induced sucrose-seeking test. RESULTS Brief EE exposure and acute fluoxetine administration alone inhibited context-induced sucrose-seeking in both housing conditions; however, they exhibited additive properties only in social condition. CONCLUSIONS Our data show that social environment may influence the EE/fluoxetine interaction in inhibiting relapse to sucrose. These findings suggest that setting up proper living conditions to boost the efficacy of therapeutic approaches may represent a fundamental strategy to treat addiction disorders.
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Affiliation(s)
- N. Pintori
- Section of Pharmacology, Department of Diagnostic and Public Health, Policlinico ‘GB Rossi’, P.le Scuro 10, University of Verona, 37134 Verona, Italy ,Department of Biomedical Sciences, Cittadella Universitaria Di Monserrato, University of Cagliari, S.P.8 km 0, 700-09042 Monserrato, Cagliari Italy
| | - A. Piva
- Section of Pharmacology, Department of Diagnostic and Public Health, Policlinico ‘GB Rossi’, P.le Scuro 10, University of Verona, 37134 Verona, Italy
| | - V. Guardiani
- Section of Pharmacology, Department of Diagnostic and Public Health, Policlinico ‘GB Rossi’, P.le Scuro 10, University of Verona, 37134 Verona, Italy
| | - C. M. Marzo
- Department of Biotechnology, University of Verona, Verona, Italy
| | - I. Decimo
- Section of Pharmacology, Department of Diagnostic and Public Health, Policlinico ‘GB Rossi’, P.le Scuro 10, University of Verona, 37134 Verona, Italy
| | - C. Chiamulera
- Section of Pharmacology, Department of Diagnostic and Public Health, Policlinico ‘GB Rossi’, P.le Scuro 10, University of Verona, 37134 Verona, Italy
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Castillo Díaz F, Caffino L, Fumagalli F. Bidirectional role of dopamine in learning and memory-active forgetting. Neurosci Biobehav Rev 2021; 131:953-963. [PMID: 34655655 DOI: 10.1016/j.neubiorev.2021.10.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 10/05/2021] [Accepted: 10/11/2021] [Indexed: 12/15/2022]
Abstract
Dopaminergic neurons projecting from the Substantia Nigra to the Striatum play a critical role in motor functions while dopaminergic neurons originating in the Ventral Tegmental Area (VTA) and projecting to the Nucleus Accumbens, Hippocampus and other cortical structures regulate rewarding learning. While VTA mainly consists of dopaminergic neurons, excitatory (glutamate) and inhibitory (GABA) VTA-neurons have also been described: these neurons may also modulate and contribute to shape the final dopaminergic response, which is critical for memory formation. However, given the large amount of information that is handled daily by our brain, it is essential that irrelevant information be deleted. Recently, apart from the well-established role of dopamine (DA) in learning, it has been shown that DA plays a critical role in the intrinsic active forgetting mechanisms that control storage information, contributing to the deletion of a consolidated memory. These new insights may be instrumental to identify therapies for those disorders that involve memory alterations.
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Affiliation(s)
- Fernando Castillo Díaz
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Via Balzaretti 9, 20133 Milano, Italy.
| | - Lucia Caffino
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Via Balzaretti 9, 20133 Milano, Italy
| | - Fabio Fumagalli
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Via Balzaretti 9, 20133 Milano, Italy
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Synaptic metaplasticity for image processing enhancement in convolutional neural networks. Neurocomputing 2021. [DOI: 10.1016/j.neucom.2021.08.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Guinjoan SM, Bär KJ, Camprodon JA. Cognitive effects of rapid-acting treatments for resistant depression: Just adverse, or contributing to clinical efficacy? J Psychiatr Res 2021; 140:512-521. [PMID: 34157590 PMCID: PMC8319118 DOI: 10.1016/j.jpsychires.2021.06.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 06/07/2021] [Accepted: 06/13/2021] [Indexed: 12/28/2022]
Abstract
Major Depressive Disorder is a major public health problem and has a high rate of treatment resistance. Fear conditioning has been proposed as a potential mechanism sustaining negative affect in mood disorders. With the aim of exploring cognitive effects of rapid-acting antidepressant treatments as a potential mechanism of action that can be targeted by neuromodulation, we performed a narrative review of the extant literature on effects of electroconvulsive therapy, ketamine or esketamine, and sleep deprivation on emotional/fear memory retrieval-reconsolidation. We explore interference with reconsolidation as a potential common pathway that explains in part the efficacy of rapid-acting antidepressant treatments with disparate mechanisms of action. We propose the testable hypothesis that fear learning circuits can be specifically targeted by neuromodulation to attempt rapid amelioration of depressive symptoms (especially repetitive negative thinking) while limiting unspecific, untoward cognitive side effects.
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Affiliation(s)
- Salvador M. Guinjoan
- Principal Investigator, Laureate Institute for Brain Research, Tulsa, Oklahoma, United States of America,Schools of Medicine and Psychology, University of Buenos Aires, CONICET, Argentina,Mailing Address: Salvador M. Guinjoan, Laureate Institute for Brain Research, 6655 South Yale Avenue, Tulsa, Oklahoma 74136-3326, United States of America,
| | - Karl-Jürgen Bär
- Chief, Departments of Psychosomatic Medicine and Gerontopsychiatry and Psychotherapy, University Hospital Jena, Jena, Germany
| | - Joan A. Camprodon
- Director, Division of Neuropsychiatry, Massachusetts General Hospital and Harvard Medical School
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Vives-Boix V, Ruiz-Fernández D. Diabetic retinopathy detection through convolutional neural networks with synaptic metaplasticity. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2021; 206:106094. [PMID: 34010801 DOI: 10.1016/j.cmpb.2021.106094] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 04/02/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND AND OBJECTIVES Diabetic retinopathy is a type of diabetes that causes vascular changes that can lead to blindness. The ravages of this disease cannot be reversed, so early detection is essential. This work presents an automated method for early detection of this disease using fundus colored images. METHODS A bio-inspired approach is proposed on synaptic metaplasticity in convolutional neural networks. This biological phenomenon is known to directly interfere in both learning and memory by reinforcing less common occurrences during the learning process. Synaptic metaplasticity has been included in the backpropagation stage of a convolution operation for every convolutional layer. RESULTS The proposed method has been evaluated by using a public small diabetic retinopathy dataset from Kaggle with four award-winning convolutional neural network architectures. Results show that convolutional neural network architectures including synaptic metaplasticity improve both learning rate and accuracy. Furthermore, obtained results outperform other methods in current literature, even using smaller datasets for training. Best results have been obtained for the InceptionV3 architecture with synaptic metaplasticity with a 95.56% accuracy, 94.24% F1-score, 98.9% precision and 90% recall, using 3662 images for training. CONCLUSIONS Convolutional neural networks with synaptic metaplasticity are suitable for early detection of diabetic retinopathy due to their fast convergence rate, training simplicity and high performance.
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Affiliation(s)
- Víctor Vives-Boix
- Department of Computer Science and Technology, University of Alicante, Ctra. San Vicente del Raspeig s/n, 03690, San Vicente del Raspeig, Spain.
| | - Daniel Ruiz-Fernández
- Department of Computer Science and Technology, University of Alicante, Ctra. San Vicente del Raspeig s/n, 03690, San Vicente del Raspeig, Spain.
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Piva A, Caffino L, Mottarlini F, Pintori N, Castillo Díaz F, Fumagalli F, Chiamulera C. Metaplastic Effects of Ketamine and MK-801 on Glutamate Receptors Expression in Rat Medial Prefrontal Cortex and Hippocampus. Mol Neurobiol 2021; 58:3443-3456. [PMID: 33723767 PMCID: PMC8257545 DOI: 10.1007/s12035-021-02352-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 03/05/2021] [Indexed: 12/16/2022]
Abstract
Ketamine and MK-801 by blocking NMDA receptors may induce reinforcing effects as well as schizophrenia-like symptoms. Recent results showed that ketamine can also effectively reverse depressive signs in patients' refractory to standard therapies. This evidence clearly points to the need of characterization of effects of these NMDARs antagonists on relevant brain areas for mood disorders. The aim of the present study was to investigate the molecular changes occurring at glutamatergic synapses 24 h after ketamine or MK-801 treatment in the rat medial prefrontal cortex (mPFC) and hippocampus (Hipp). In particular, we analyzed the levels of the glutamate transporter-1 (GLT-1), NMDA receptors, AMPA receptors subunits, and related scaffolding proteins. In the homogenate, we found a general decrease of protein levels, whereas their changes in the post-synaptic density were more complex. In fact, ketamine in the mPFC decreased the level of GLT-1 and increased the level of GluN2B, GluA1, GluA2, and scaffolding proteins, likely indicating a pattern of enhanced excitability. On the other hand, MK-801 only induced sparse changes with apparently no correlation to functional modification. Differently from mPFC, in Hipp, both substances reduced or caused no changes of glutamate receptors and scaffolding proteins expression. Ketamine decreased NMDA receptors while increased AMPA receptors subunit ratios, an effect indicative of permissive metaplastic modulation; conversely, MK-801 only decreased the latter, possibly representing a blockade of further synaptic plasticity. Taken together, these findings indicate a fine tuning of glutamatergic synapses by ketamine compared to MK-801 both in the mPFC and Hipp.
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Affiliation(s)
- Alessandro Piva
- Neuropsychopharmacology Lab, Section Pharmacology, Department Diagnostic & Public Health, University of Verona, Policlinico GB Rossi, P.le Scuro 10, 37134, Verona, Italy.
| | - Lucia Caffino
- Department of Pharmacological and Biomolecular Sciences, University of Milano, Via Balzaretti 9, 20133, Milano, Italy
| | - Francesca Mottarlini
- Department of Pharmacological and Biomolecular Sciences, University of Milano, Via Balzaretti 9, 20133, Milano, Italy
| | - Nicholas Pintori
- Neuropsychopharmacology Lab, Section Pharmacology, Department Diagnostic & Public Health, University of Verona, Policlinico GB Rossi, P.le Scuro 10, 37134, Verona, Italy
| | - Fernando Castillo Díaz
- Department of Pharmacological and Biomolecular Sciences, University of Milano, Via Balzaretti 9, 20133, Milano, Italy
| | - Fabio Fumagalli
- Department of Pharmacological and Biomolecular Sciences, University of Milano, Via Balzaretti 9, 20133, Milano, Italy
| | - Cristiano Chiamulera
- Neuropsychopharmacology Lab, Section Pharmacology, Department Diagnostic & Public Health, University of Verona, Policlinico GB Rossi, P.le Scuro 10, 37134, Verona, Italy
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Chiamulera C, Piva A, Abraham WC. Glutamate receptors and metaplasticity in addiction. Curr Opin Pharmacol 2020; 56:39-45. [PMID: 33128937 DOI: 10.1016/j.coph.2020.09.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 09/10/2020] [Accepted: 09/10/2020] [Indexed: 12/12/2022]
Abstract
Chronic drug use is a neuroadaptive disorder characterized by strong and persistent plasticity in the mesocorticolimbic reward system. Long-lasting effects of drugs of abuse rely on their ability to hijack glutamate receptor activity and long-term synaptic plasticity processes like long-term potentiation and depression. Importantly, metaplasticity-based modulation of synaptic plasticity contributes to durable neurotransmission changes in mesocorticolimbic pathways including the ventral tegmental area and the nucleus accumbens, causing 'maladaptive' drug memory and higher risk for drug-seeking relapse. On the other hand, drug-induced metaplasticity can make appetitive memories more malleable to modification, offering a potential target mechanism for intervention. Here we review the literature on the role of glutamate receptors in addiction-related metaplasticity phenomena.
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Affiliation(s)
- Cristiano Chiamulera
- Neuropsychopharmacology Lab, Section Pharmacology, Department Diagnostic & Public Health, University of Verona, Verona, Italy.
| | - Alessandro Piva
- Neuropsychopharmacology Lab, Section Pharmacology, Department Diagnostic & Public Health, University of Verona, Verona, Italy
| | - Wickliffe C Abraham
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Dunedin, New Zealand
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