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Mitten EH, Souders A, Marron Fernandez de Velasco E, Wickman K. Stress-induced anxiety-related behavior in mice is driven by enhanced excitability of ventral tegmental area GABA neurons. Front Behav Neurosci 2024; 18:1425607. [PMID: 39086371 PMCID: PMC11288924 DOI: 10.3389/fnbeh.2024.1425607] [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: 04/30/2024] [Accepted: 06/24/2024] [Indexed: 08/02/2024] Open
Abstract
Introduction Stress and trauma are significant risk factors for many neuropsychiatric disorders and diseases, including anxiety disorders. Stress-induced anxiety symptoms have been attributed to enhanced excitability in circuits controlling fear, anxiety, and aversion. A growing body of evidence has implicated GABAergic neurons of the ventral tegmental area (VTA) in aversion processing and affective behavior. Methods We used an unpredictable footshock (uFS) model, together with electrophysiological and behavioral approaches, to investigate the role of VTA GABA neurons in anxiety-related behavior in mice. Results One day after a single uFS session, C57BL/6J mice exhibited elevated anxiety-related behavior and VTA GABA neuron excitability. The enhanced excitability of VTA GABA neurons was correlated with increased glutamatergic input and a reduction in postsynaptic signaling mediated via GABAA and GABAB receptors. Chemogenetic activation of VTA GABA neurons was sufficient to increase anxiety-related behavior in stress-naïve mice. In addition, chemogenetic inhibition of VTA GABA neurons suppressed anxiety-related behavior in mice exposed to uFS. Discussion These data show that VTA GABA neurons are an early substrate for stress-induced anxiety-related behavior in mice and suggest that approaches mitigating enhanced excitability of VTA GABA neurons may hold promise for the treatment of anxiety provoked by stress and trauma.
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Affiliation(s)
- Eric H. Mitten
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN, United States
| | - Anna Souders
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, United States
| | | | - Kevin Wickman
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, United States
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2
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Merkel R, Hernandez N, Weir V, Zhang Y, Rich MT, Crist RC, Reiner BC, Schmidt HD. An endogenous GLP-1 circuit engages VTA GABA neurons to regulate mesolimbic dopamine neurons and attenuate cocaine seeking. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.20.599574. [PMID: 38979354 PMCID: PMC11230186 DOI: 10.1101/2024.06.20.599574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Recent studies show that systemic administration of a glucagon-like peptide-1 receptor (GLP-1R) agonist is sufficient to attenuate the reinstatement of cocaine-seeking behavior, an animal model of relapse. However, the neural mechanisms mediating these effects and the role of endogenous central GLP-1 signaling in cocaine seeking remain unknown. Here, we show that voluntary cocaine taking decreased plasma GLP-1 levels in rats and that chemogenetic activation of GLP-1-producing neurons in the nucleus tractus solitarius (NTS) that project to the ventral tegmental area (VTA) decreased cocaine reinstatement. Single nuclei transcriptomics and FISH studies revealed GLP-1Rs are expressed primarily on GABA neurons in the VTA. Using in vivo fiber photometry, we found that the efficacy of a systemic GLP-1R agonist to attenuate cocaine seeking was associated with increased activity of VTA GABA neurons and decreased activity of VTA dopamine neurons. Together, these findings suggest that targeting central GLP-1 circuits may be an effective strategy toward reducing cocaine relapse and highlight a novel functional role of GABAergic GLP-1R-expressing midbrain neurons in drug seeking.
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3
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Groos D, Helmchen F. The lateral habenula: A hub for value-guided behavior. Cell Rep 2024; 43:113968. [PMID: 38522071 DOI: 10.1016/j.celrep.2024.113968] [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: 10/30/2023] [Revised: 01/20/2024] [Accepted: 02/29/2024] [Indexed: 03/26/2024] Open
Abstract
The habenula is an evolutionarily highly conserved diencephalic brain region divided into two major parts, medial and lateral. Over the past two decades, studies of the lateral habenula (LHb), in particular, have identified key functions in value-guided behavior in health and disease. In this review, we focus on recent insights into LHb connectivity and its functional relevance for different types of aversive and appetitive value-guided behavior. First, we give an overview of the anatomical organization of the LHb and its main cellular composition. Next, we elaborate on how distinct LHb neuronal subpopulations encode aversive and appetitive stimuli and on their involvement in more complex decision-making processes. Finally, we scrutinize the afferent and efferent connections of the LHb and discuss their functional implications for LHb-dependent behavior. A deepened understanding of distinct LHb circuit components will substantially contribute to our knowledge of value-guided behavior.
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Affiliation(s)
- Dominik Groos
- Laboratory of Neural Circuit Dynamics, Brain Research Institute, University of Zurich, Zurich, Switzerland; Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland.
| | - Fritjof Helmchen
- Laboratory of Neural Circuit Dynamics, Brain Research Institute, University of Zurich, Zurich, Switzerland; Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland; University Research Priority Program (URPP), Adaptive Brain Circuits in Development and Learning, University of Zurich, Zurich, Switzerland
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4
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Khayat A, Yaka R. Activation of nucleus accumbens projections to the ventral tegmental area alters molecular signaling and neurotransmission in the reward system. Front Mol Neurosci 2024; 17:1271654. [PMID: 38528956 PMCID: PMC10962329 DOI: 10.3389/fnmol.2024.1271654] [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: 08/02/2023] [Accepted: 02/12/2024] [Indexed: 03/27/2024] Open
Abstract
The nucleus accumbens (NAc) and the ventral tegmental area (VTA) are integral brain regions involved in reward processing and motivation, including responses to drugs of abuse. Previously, we have demonstrated that activation of NAc-VTA afferents during the acquisition of cocaine conditioned place preference (CPP) reduces the rewarding properties of cocaine and diminished the activity of VTA dopamine neurons. In the current study, we examined the impact of enhancing these inhibitory inputs on molecular changes and neurotransmission associated with cocaine exposure. Our results unveiled significant reductions in extracellular signal-regulated kinase (ERK) levels in the VTA and medial prefrontal cortex (mPFC) of both cocaine-treated groups compared with the saline control group. Furthermore, optic stimulation of NAc-VTA inputs during cocaine exposure decreased the expression of GluA1 subunit of AMPA receptor in the VTA and mPFC. Notably, in the NAc, cocaine exposure paired with optic stimulation increased ERK levels and reduced GluA1 phosphorylation at Ser845 as compared with all other groups. Additionally, both cocaine-treated groups exhibited decreased levels of GluA1 phosphorylation at Ser831 in the NAc compared with the saline control group. Moreover, cocaine exposure led to reduced ERK, GluA1, and GluA1 phosphorylation at Ser845 and Ser831 in the mPFC. Augmentation of GABAergic tone from the NAc during cocaine conditioning mitigated changes in GluA1 phosphorylation at Ser845 in the mPFC but reduced ERK, GluA1, and GluA1 phosphorylation at Ser831 compared with the saline control group. Interestingly, enhancing GABAergic tone during saline conditioning decreased GluA1 phosphorylation at Ser831 compared with the saline control group in the mPFC. Our findings highlight the influence of modulating inhibitory inputs from the NAc to the VTA on molecular signaling and glutamatergic neurotransmission in cocaine-exposed animals. Activation of these inhibitory inputs during cocaine conditioning induced alterations in key signaling molecules and AMPA receptor, providing valuable insights into the neurobiological mechanisms underlying cocaine reward and cocaine use disorder. Further exploration of these pathways may offer potential therapeutic targets for the treatment of substance use disorder.
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Affiliation(s)
| | - Rami Yaka
- Faculty of Medicine, School of Pharmacy, Institute for Drug Research, The Hebrew University of Jerusalem, Jerusalem, Israel
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5
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Khayat A, Yaka R. Activation of RMTg projections to the VTA reverse cocaine-induced molecular adaptation in the reward system. Transl Psychiatry 2024; 14:40. [PMID: 38242878 PMCID: PMC10799078 DOI: 10.1038/s41398-024-02763-9] [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: 07/16/2023] [Revised: 01/05/2024] [Accepted: 01/10/2024] [Indexed: 01/21/2024] Open
Abstract
The rostromedial tegmental nucleus (RMTg) plays a crucial role in regulating reward-related behavior by exerting inhibitory control over the ventral tegmental area (VTA). This modulation of dopamine neuron activity within the VTA is essential for maintaining homeostasis in the reward system. Recently we have shown that activation of RMTg projections to the VTA during the acquisition of cocaine-conditioned place preference (CPP) reduces the rewarding properties of cocaine and decreases VTA dopamine neuron activity. By inhibiting dopamine neurons in the VTA, we hypothesized that RMTg projections hold the potential to restore reward system homeostasis disrupted by repeated cocaine use, and attenuate molecular adaptations in the reward system, including alterations in signaling pathways. Our study demonstrates that enhancing the GABAergic inputs from the RMTg to the VTA can mitigate cocaine-induced molecular changes in key regions, namely the VTA, nucleus accumbens (NAc), and prefrontal cortex (PFC). Specifically, we found that cocaine-induced alteration in the phosphorylation state of ERK (pERK) and GluA1 on serine 845 (S845) and serine 831 (S831), that play a major role in plasticity by controlling the activity and trafficking of AMPA receptors, were significantly reversed following optic stimulation of RMTg afferents to the VTA. These findings highlight the therapeutic potential of targeting the RMTg-VTA circuitry for mitigating cocaine reward. Ultimately, this research may pave the way for novel therapeutic interventions that restore balance in the reward system and alleviate the detrimental effects of cocaine.
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Affiliation(s)
- A Khayat
- Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, 91120, Israel
| | - R Yaka
- Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, 91120, Israel.
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6
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Pour MG, Alaei H. The reinstatement of the expression phase of morphine-induced conditioned place preference in male Wistar rats under ventral tegmental area stimulation and brief inactivation. Res Pharm Sci 2023; 18:676-695. [PMID: 39005563 PMCID: PMC11246116 DOI: 10.4103/1735-5362.389957] [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: 04/05/2023] [Revised: 08/05/2023] [Accepted: 11/18/2023] [Indexed: 07/16/2024] Open
Abstract
Background and purpose Previous research has found that the electrical stimulation of the ventral tegmental area (VTA) is involved in drug-dependent behaviors and plays a role in reward-seeking. However, the mechanisms remain unknown, especially the effect of electrical stimulation on this area. Therefore, this study aimed to investigate how the electrical stimulation and the temporary inactivation of VTA affect the morphine- dependent behavior in male rats. Experimental approach The adult Wistar male rats were anesthetized with ketamine and xylazine. The stimulation electrode (unilaterally) and the microinjection cannula (bilaterally) were implanted into the VTA, stereotaxically. Then, the rats underwent three-day of repeated conditioning with subcutaneous morphine (0.5 or 5 mg/kg) injections, in the conditioned place preference apparatus, followed by four-day forced abstinence, which altered their conditioning response to a morphine (0.5 mg/kg) priming dose on the ninth day. On that day, rats were given high- or low-intensity electrical stimulation or reversible inactivation with lidocaine (0.5 pL/site) in the VTA. Findings/Results Results showed that the electrical stimulation of the VTA with the high intensity (150 μA/rat), had a minimal effect on the expression of morphine-induced place conditioning in rats treated with a high dose (5 mg/kg) of morphine. However, the reversible inactivation of the VTA with lidocaine greatly increased place preference in rats treated with a low dose (0.5 mg/kg) of morphine. Additionally, the reinstatement of 0.5 mg/kg morphine-treated rats was observed after lidocaine infusion into the VTA. Conclusion and implications These results suggest that VTA electrical stimulation suppresses neuronal activation, but the priming dose causes reinstatement. The VTA may be a potential target for deep brain stimulation-based treatment of intractable disorders induced by substance abuse.
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Affiliation(s)
- Mozhgan Ghobadi Pour
- Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, I.R. Iran
| | - Hojjatollah Alaei
- Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, I.R. Iran
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7
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Stetsenko A, Koos T. Neuronal implementation of the temporal difference learning algorithm in the midbrain dopaminergic system. Proc Natl Acad Sci U S A 2023; 120:e2309015120. [PMID: 37903252 PMCID: PMC10636325 DOI: 10.1073/pnas.2309015120] [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: 05/29/2023] [Accepted: 09/29/2023] [Indexed: 11/01/2023] Open
Abstract
The temporal difference learning (TDL) algorithm has been essential to conceptualizing the role of dopamine in reinforcement learning (RL). Despite its theoretical importance, it remains unknown whether a neuronal implementation of this algorithm exists in the brain. Here, we provide an interpretation of the recently described signaling properties of ventral tegmental area (VTA) GABAergic neurons and show that a circuitry of these neurons implements the TDL algorithm. Specifically, we identified the neuronal mechanism of three key components of the TDL model: a sustained state value signal encoded by an afferent input to the VTA, a temporal differentiation circuit formed by two types of VTA GABAergic neurons the combined output of which computes momentary reward prediction (RP) as the derivative of the state value, and the computation of reward prediction errors (RPEs) in dopamine neurons utilizing the output of the differentiation circuit. Using computational methods, we also show that this mechanism is optimally adapted to the biophysics of RPE signaling in dopamine neurons, mechanistically links the emergence of conditioned reinforcement to RP, and can naturally account for the temporal discounting of reinforcement. Elucidating the implementation of the TDL algorithm may further the investigation of RL in biological and artificial systems.
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Affiliation(s)
- Anya Stetsenko
- Center for Molecular and Behavioral Neuroscience, Rutgers University, Newark, NJ07102
| | - Tibor Koos
- Center for Molecular and Behavioral Neuroscience, Rutgers University, Newark, NJ07102
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8
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Bouarab C, Wynalda M, Thompson BV, Khurana A, Cody CR, Kisner A, Polter AM. Sex-specific adaptations to VTA circuits following subchronic stress. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.02.551665. [PMID: 37577542 PMCID: PMC10418168 DOI: 10.1101/2023.08.02.551665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Dysregulation of the mesolimbic reward circuitry is implicated in the pathophysiology of stress-related illnesses such as depression and anxiety. These disorders are more frequently diagnosed in females, and sex differences in the response to stress are likely to be one factor that leads to enhanced vulnerability of females. In this study, we use subchronic variable stress (SCVS), a model in which females are uniquely vulnerable to behavioral disturbances, to investigate sexually divergent mechanisms of regulation of the ventral tegmental area by stress. Using slice electrophysiology, we find that female, but not male mice have a reduction in the ex vivo firing rate of VTA dopaminergic neurons following SCVS. Surprisingly, both male and female animals show an increase in inhibitory tone onto VTA dopaminergic neurons and an increase in the firing rate of VTA GABAergic neurons. In males, however, this is accompanied by a robust increase in excitatory synaptic tone onto VTA dopamine neurons. This supports a model by which SCVS recruits VTA GABA neurons to inhibit dopaminergic neurons in both male and female mice, but males are protected from diminished functioning of the dopaminergic system by a compensatory upregulation of excitatory synapses.
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Affiliation(s)
- Chloé Bouarab
- Department of Pharmacology and Physiology, George Washington University School of Medicine and Health Sciences, Washington, DC 20037
- Current address: Institut Pasteur, 25-28 rue du Docteur Roux, 75015 Paris
| | - Megan Wynalda
- Department of Pharmacology and Physiology, George Washington University School of Medicine and Health Sciences, Washington, DC 20037
| | - Brittney V. Thompson
- Department of Pharmacology and Physiology, George Washington University School of Medicine and Health Sciences, Washington, DC 20037
- Current address: Department of Psychology, Florida State University, Tallahasse, FL, 32306
| | - Ambika Khurana
- Department of Pharmacology and Physiology, George Washington University School of Medicine and Health Sciences, Washington, DC 20037
| | - Caitlyn R. Cody
- Department of Pharmacology and Physiology, George Washington University School of Medicine and Health Sciences, Washington, DC 20037
- Current address: Department of Psychology, Northeastern University, Boston, MA, 02115
| | - Alexandre Kisner
- Department of Pharmacology and Physiology, George Washington University School of Medicine and Health Sciences, Washington, DC 20037
- Current address: Department of Neuroscience, American University, Washington DC 20016
| | - Abigail M. Polter
- Department of Pharmacology and Physiology, George Washington University School of Medicine and Health Sciences, Washington, DC 20037
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9
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Si Z, Wang X, Yu Z, Ruan Y, Qian L, Lin S, Gong X, Li L, Huang J, Liu Y. EGCG attenuates METH self-administration and reinstatement of METH seeking in mice. Addict Biol 2023; 28:e13307. [PMID: 37500489 DOI: 10.1111/adb.13307] [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: 01/03/2023] [Revised: 03/31/2023] [Accepted: 06/07/2023] [Indexed: 07/29/2023]
Abstract
Methamphetamine (METH) use disorder is a chronic, relapsing disorder and involves frequent failures of self-control of drug seeking and taking. Epigallocatechin-3-gallate (EGCG) is the most abundant polyphenolic compounds of green tea, which has shown great therapeutic effectiveness in neurological disorders. However, it is still unknown whether and how EGCG affects METH seeking behaviour. Here, we show nanostructured EGCG/ascorbic acid nanoparticles (EGCG/AA NPs) dose-dependently reduced METH self-administration (SA) under fixed-ratio 1 (FR1) and progressive ratio (PR) reinforcement schedules in mice and shifted METH dose-response curves downward. Furthermore, EGCG/AA NPs decreased drug- and cue-induced METH seeking. In addition, we found that METH SA led to a decrease in inhibitory postsynaptic currents (IPSCs) and increase in the AMPAR/NMDAR ratio and excitation/inhibition (E/I) ratio in ex vivo midbrain slices from ventral tegmental area (VTA) dopamine neurons. EGCG/AA NPs enhanced Gamma-aminobutyric acid (GABA)ergic inhibition and normalized the E/I ratio. EGCG restored the balance between excitation and inhibition in VTA dopamine neurons, which may contribute to the attenuation of METH SA. These findings indicate that EGCG is a promising pharmacotherapy for METH use disorder.
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Affiliation(s)
- Zizhen Si
- Department of Pharmacy, Affiliated Hospital of Ningbo University Medical School, Ningbo, People's Republic of China
- Health Science Center, Ningbo University, Ningbo, People's Republic of China
| | - Xidi Wang
- Health Science Center, Ningbo University, Ningbo, People's Republic of China
| | - Zhaoying Yu
- Department of Psychology, Collage of Teacher Education, Ningbo University, Ningbo, China
| | - Yuer Ruan
- Department of Psychology, Collage of Teacher Education, Ningbo University, Ningbo, China
| | - Liyin Qian
- Health Science Center, Ningbo University, Ningbo, People's Republic of China
| | - Shujun Lin
- Department of Psychology, Collage of Teacher Education, Ningbo University, Ningbo, China
| | - Xinshuang Gong
- Health Science Center, Ningbo University, Ningbo, People's Republic of China
| | | | - Jing Huang
- Department of Pharmacy, Affiliated Hospital of Ningbo University Medical School, Ningbo, People's Republic of China
| | - Yu Liu
- Health Science Center, Ningbo University, Ningbo, People's Republic of China
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10
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Kalamarides DJ, Singh A, Wolfman SL, Dani JA. Sex differences in VTA GABA transmission and plasticity during opioid withdrawal. Sci Rep 2023; 13:8460. [PMID: 37231124 DOI: 10.1038/s41598-023-35673-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 05/19/2023] [Indexed: 05/27/2023] Open
Abstract
The effectiveness of current treatments for opioid use disorder (OUD) varies by sex. Our understanding of the neurobiological mechanisms mediating negative states during withdrawal is lacking, particularly with regard to sex differences. Based on preclinical research in male subjects, opioid withdrawal is accompanied by increased gamma-aminobutyric acid (GABA) release probability at synapses onto dopamine neurons in the ventral tegmental area (VTA). It is unclear, however, if the physiological consequences of morphine that were originally elucidated in male rodents extend to females. The effects of morphine on the induction of future synaptic plasticity are also unknown. Here, we show that inhibitory synaptic long-term potentiation (LTPGABA) is occluded in the VTA in male mice after repeated morphine injections and 1 day of withdrawal, while morphine-treated female mice maintain the ability to evoke LTPGABA and have basal GABA activity similar to controls. Our observation of this physiological difference between male and female mice connects previous reports of sex differences in areas upstream and downstream of the GABA-dopamine synapse in the VTA during opioid withdrawal. The sex differences highlight the mechanistic distinctions between males and females that can be targeted when designing and implementing treatments for OUD.
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Affiliation(s)
- Daniel J Kalamarides
- Department of Neuroscience, Perelman School of Medicine, Mahoney Institute for Neurosciences, University of Pennsylvania, 415 Curie Blvd, Philadelphia, PA, 19104, USA
| | - Aditi Singh
- Department of Neuroscience, Perelman School of Medicine, Mahoney Institute for Neurosciences, University of Pennsylvania, 415 Curie Blvd, Philadelphia, PA, 19104, USA
| | - Shannon L Wolfman
- Department of Neuroscience, Perelman School of Medicine, Mahoney Institute for Neurosciences, University of Pennsylvania, 415 Curie Blvd, Philadelphia, PA, 19104, USA
| | - John A Dani
- Department of Neuroscience, Perelman School of Medicine, Mahoney Institute for Neurosciences, University of Pennsylvania, 415 Curie Blvd, Philadelphia, PA, 19104, USA.
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11
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Yu Z, Kisner A, Bhatt A, Polter AM, Marvar PJ. Central amygdala angiotensin type 1 receptor (Agtr1) expressing neurons contribute to fear extinction. Neuropharmacology 2023; 229:109460. [PMID: 36801399 DOI: 10.1016/j.neuropharm.2023.109460] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 01/12/2023] [Accepted: 02/08/2023] [Indexed: 02/19/2023]
Abstract
The renin-angiotensin system (RAS) has been linked to the pathophysiology of posttraumatic stress disorder (PTSD) however, the underlying neurobiological mechanism(s) remain elusive. Here we utilized angiotensin II receptor type 1 (AT1R) transgenic mice combined with neuroanatomical, behavioral, and electrophysiological approaches, to examine the role of the central amygdala (CeA) expressing AT1R neurons in fear and anxiety-related behavior. Within the major amygdala subdivisions, AT1R+ neurons were localized to gamma-aminobutyric acid (GABA) expressing neurons in the lateral division of the central amygdala (CeL), and the majority of them were identified as protein kinase C-δ positive (PKCδ+) neurons. Following CeA-AT1R deletion using cre-expressing lentiviral delivery in AT1R-Flox mice, generalized anxiety and locomotor activity as well as the acquisition of conditioned fear were unaltered while the acquisition of extinction learning, as measured by percent freezing behavior, was significantly enhanced. During electrophysiological recordings of CeL-AT1R+ neurons, the application of angiotensin II (1 μm) increased the amplitude of spontaneous inhibitory postsynaptic currents (sIPSCs) and decreased the excitability of CeL-AT1R+ neurons. Overall, these findings demonstrate that CeL-AT1R-expressing neurons play a role in fear extinction, potentially through facilitated CeL-AT1R+ GABAergic inhibition. These results provide new evidence for mechanisms of angiotensinergic neuromodulation of the CeL and its role in fear extinction and may aid in further advancing targeted novel therapies for improving maladaptive fear learning processes associated with PTSD.
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Affiliation(s)
- Zhe Yu
- Department of Pharmacology and Physiology, George Washington University, Washington, DC, USA
| | - Alexandre Kisner
- Department of Pharmacology and Physiology, George Washington University, Washington, DC, USA
| | - Amy Bhatt
- Department of Pharmacology and Physiology, George Washington University, Washington, DC, USA
| | - Abigail M Polter
- Department of Pharmacology and Physiology, George Washington University, Washington, DC, USA
| | - Paul J Marvar
- Department of Pharmacology and Physiology, George Washington University, Washington, DC, USA; Department of Psychiatry and Behavioral Sciences, George Washington University, School of Medicine and Health Sciences, Washington, DC, USA.
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12
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Engel JA, Pålsson E, Vallöf D, Jerlhag E. Ghrelin activates the mesolimbic dopamine system via nitric oxide associated mechanisms in the ventral tegmental area. Nitric Oxide 2023; 131:1-7. [PMID: 36513266 DOI: 10.1016/j.niox.2022.12.001] [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: 09/02/2022] [Revised: 11/08/2022] [Accepted: 12/05/2022] [Indexed: 12/14/2022]
Abstract
Besides enhanced feeding, the orexigenic peptide ghrelin activates the mesolimbic dopamine system to cause reward as measured by locomotor stimulation, dopamine release in nucleus accumbens shell (NAcS), and conditioned place preference. Although the ventral tegmental area (VTA) appears to be a central brain region for this ghrelin-reward, the underlying mechanisms within this area are unknown. The findings that the gaseous neurotransmitter nitric oxide (NO) modulate the ghrelin enhanced feeding, led us to hypothesize that ghrelin increases NO levels in the VTA, and thereby stimulates reward-related behaviors. We initially demonstrated that inhibition of NO synthesis blocked the ghrelin-induced activation of the mesolimbic dopamine system. We then established that antagonism of downstream signaling of NO in the VTA, namely sGC, prevents the ability of ghrelin to stimulate the mesolimbic dopamine system. The association of ghrelin to NO was further strengthened by in vivo electrochemical recordings showing that ghrelin enhances the NO release in the VTA. Besides a GABAB -receptor agonist, known to reduce NO and cGMP, blocks the stimulatory properties of ghrelin. The present series of experiments reveal that ablated NO signaling, through pharmacologically inhibiting the production of NO and/or cGMP, prevents the ability of ghrelin to induced reward-related behaviors.
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Affiliation(s)
- Jörgen A Engel
- Institute of Neuroscience and Physiology, Department of Pharmacology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Erik Pålsson
- Institute of Neuroscience and Physiology, Department of Neurochemistry and Psychiatry, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Daniel Vallöf
- Institute of Neuroscience and Physiology, Department of Pharmacology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Elisabet Jerlhag
- Institute of Neuroscience and Physiology, Department of Pharmacology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
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13
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Manning CE, Fritz M, Kauer JA. Function of Excitatory Periaqueductal Gray Synapses in the Ventral Tegmental Area following Inflammatory Injury. eNeuro 2022; 9:ENEURO.0324-22.2022. [PMID: 36635253 PMCID: PMC9797208 DOI: 10.1523/eneuro.0324-22.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 10/26/2022] [Accepted: 11/28/2022] [Indexed: 12/12/2022] Open
Abstract
Manipulating the activity of ventral tegmental area (VTA) dopamine (DA) neurons can drive nocifensive reflexes, and their firing rates are reduced following noxious stimuli. However, the pain-relevant inputs to the VTA remain incompletely understood. In this study, we used male and female mice in combination with identified dopamine and GABA neurons in the VTA that receive excitatory inputs from the periaqueductal gray (PAG), a nexus of ascending pain information. We tested whether PAG-VTA synapses undergo functional plasticity in response to a pain model using optical stimulation in conjunction with slice electrophysiology. We found that acute carrageenan inflammation does not significantly affect the strength of excitatory PAG synapses onto VTA DA neurons. However, at the PAG synapses on VTA GABA neurons, the subunit composition of NMDA receptors is altered; the complement of NR2D subunits at synaptic sites appears to be lost. Thus, our data support a model in which injury initially alters synapses on VTA GABA neurons. Over time, these alterations may increase tonic inhibition of VTA DA neurons leading to their reduced firing.
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Affiliation(s)
- Claire Elena Manning
- Nancy Pritzker Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, California 94305-5101
| | - Michael Fritz
- Nancy Pritzker Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, California 94305-5101
| | - Julie Ann Kauer
- Nancy Pritzker Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, California 94305-5101
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14
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Zhao F, Cheng Z, Piao J, Cui R, Li B. Dopamine Receptors: Is It Possible to Become a Therapeutic Target for Depression? Front Pharmacol 2022; 13:947785. [PMID: 36059987 PMCID: PMC9428607 DOI: 10.3389/fphar.2022.947785] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 06/14/2022] [Indexed: 11/13/2022] Open
Abstract
Dopamine and its receptors are currently recognized targets for the treatment of several neuropsychiatric disorders, including Parkinson’s disease, schizophrenia, some drug use addictions, as well as depression. Dopamine receptors are widely distributed in various regions of the brain, but their role and exact contribution to neuropsychiatric diseases has not yet been thoroughly studied. Based on the types of dopamine receptors and their distribution in different brain regions, this paper reviews the current research status of the molecular, cellular and circuit mechanisms of dopamine and its receptors involved in depression. Multiple lines of investigation of these mechanisms provide a new future direction for understanding the etiology and treatment of depression and potential new targets for antidepressant treatments.
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Affiliation(s)
- Fangyi Zhao
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetic, The Second Hospital of Jilin University, Changchun, China
- Engineering Laboratory for Screening of Antidepressant Drugs, Jilin Province Development and Reform Commission, Changchun, China
| | - Ziqian Cheng
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetic, The Second Hospital of Jilin University, Changchun, China
- Engineering Laboratory for Screening of Antidepressant Drugs, Jilin Province Development and Reform Commission, Changchun, China
| | - Jingjing Piao
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetic, The Second Hospital of Jilin University, Changchun, China
- Engineering Laboratory for Screening of Antidepressant Drugs, Jilin Province Development and Reform Commission, Changchun, China
| | - Ranji Cui
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetic, The Second Hospital of Jilin University, Changchun, China
- Engineering Laboratory for Screening of Antidepressant Drugs, Jilin Province Development and Reform Commission, Changchun, China
| | - Bingjin Li
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetic, The Second Hospital of Jilin University, Changchun, China
- Engineering Laboratory for Screening of Antidepressant Drugs, Jilin Province Development and Reform Commission, Changchun, China
- *Correspondence: Bingjin Li,
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15
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Zhao YN, Zhang Y, Tao SY, Huang ZL, Qu WM, Yang SR. Whole-Brain Monosynaptic Afferents to Rostromedial Tegmental Nucleus Gamma-Aminobutyric Acid-Releasing Neurons in Mice. Front Neurosci 2022; 16:914300. [PMID: 35733933 PMCID: PMC9207306 DOI: 10.3389/fnins.2022.914300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 05/16/2022] [Indexed: 12/02/2022] Open
Abstract
Increasing evidence has revealed that the rostromedial tegmental area (RMTg) mediates many behaviors, including sleep and addiction. However, presynaptic patterns governing the activity of γ-aminobutyric acid-releasing (GABAergic) neurons, the main neuronal type in the RMTg, have not been defined. Here, we used cell-type-specific retrograde trans-synaptic rabies viruses to map and quantify the monosynaptic afferents to RMTg GABAergic neurons in mouse whole brains. We identified 71 ascending projection brain regions. Sixty-eight percent of the input neurons arise from the ipsilateral and 32% from the contralateral areas of the brain. The first three strongest projection regions were the ipsilateral lateral hypothalamus, zone incerta, and contralateral pontine reticular nucleus. Immunohistochemistry imaging showed that the input neurons in the dorsal raphe, laterodorsal tegmentum, and dorsal part of zone incerta were colocalized with serotoninergic, cholinergic, and neuronal nitric oxide synthetase-expressing neurons, respectively. However, in the lateral hypothalamus, a few input neurons innervating RMTg GABAergic neurons colocalized orexinergic neurons but lacked colocalization of melanin-concentrating hormone neurons. Our findings provide anatomical evidence to understand how RMTg GABAergic neurons integrate diverse information to exert varied functions.
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16
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Mu L, Liu X, Yu H, Hu M, Friedman V, Kelly TJ, Zhao L, Liu QS. Ibudilast attenuates cocaine self-administration and prime- and cue-induced reinstatement of cocaine seeking in rats. Neuropharmacology 2021; 201:108830. [PMID: 34626665 PMCID: PMC8656241 DOI: 10.1016/j.neuropharm.2021.108830] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/30/2021] [Accepted: 10/05/2021] [Indexed: 11/21/2022]
Abstract
Ibudilast is a non-selective phosphodiesterase (PDE) inhibitor and glial cell modulator which has shown great promise for the treatment of drug and alcohol use disorders in recent clinical studies. However, it is unknown whether and how ibudilast affects cocaine seeking behavior. Here we show that systemic administration of ibudilast dose-dependently reduced cocaine self-administration under fixed- and progressive-ratio reinforcement schedules in rats and shifted cocaine dose-response curves downward. In addition, ibudilast decreased cocaine prime- and cue-induced reinstatement of cocaine seeking. These results indicate that ibudilast was effective in reducing the reinforcing effects of cocaine and relapse to cocaine seeking. Chronic cocaine exposure induces cAMP-related neuroadaptations in the reward circuitry of the brain. To investigate potential mechanisms for ibudilast-induced attenuation of cocaine self-administration, we recorded from ventral tegmental area (VTA) dopamine neurons in ex vivo midbrain slices prepared from rats that had undergone saline and cocaine self-administration. We found cocaine self-administration led to a decrease in inhibitory postsynaptic currents (IPSCs), an increase in the AMPAR/NMDAR ratio, and an increase in the excitation to inhibition (E/I) ratio. Ibudilast pretreatments enhanced GABAergic inhibition and did not further change cocaine-induced potentiation of excitation, leading to normalization of the E/I ratio. Restoration of the balance between excitation and inhibition in VTA dopamine neurons may contribute to the attenuation of cocaine self-administration by ibudilast.
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Affiliation(s)
- Lianwei Mu
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA
| | - Xiaojie Liu
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA
| | - Hao Yu
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA; Department of Exercise Physiology, Beijing Sport University, Beijing, 100084, China
| | - Mengming Hu
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA
| | - Vladislav Friedman
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA
| | - Thomas J Kelly
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA
| | - Li Zhao
- Department of Exercise Physiology, Beijing Sport University, Beijing, 100084, China
| | - Qing-Song Liu
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA.
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17
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Reactivating a positive feedback loop VTA-BLA-NAc circuit associated with positive experience ameliorates the attenuated reward sensitivity induced by chronic stress. Neurobiol Stress 2021; 15:100370. [PMID: 34381852 PMCID: PMC8334743 DOI: 10.1016/j.ynstr.2021.100370] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 07/20/2021] [Accepted: 07/22/2021] [Indexed: 12/24/2022] Open
Abstract
Both genetic predisposition and life events, particularly life stress, are thought to increase the risk for depression. Reward sensitivity appears to be attenuated in major depressive disorder (MDD), suggesting deficits in reward processing in these patients. We identified the VTA-BLA-NAc circuit as being activated by sex reward, and the VTA neurons that respond to sex reward are mostly dopaminergic. Acute or chronic reactivation of this circuit ameliorates the reward insensitivity induced by chronic restraint stress. Our histological and electrophysiological results show that the VTA neuron subpopulation responding to restraint stress, predominantly GABAergic neurons, inhibits the responsiveness of VTA dopaminergic neurons to reward stimuli, which is probably the mechanism by which stress modulates the reward processing neural circuits and subsequently disrupts reward-related behaviours. Furthermore, we found that the VTA-BLA-NAc circuit is a positive feedback loop. Blocking the projections from the BLA to the NAc associated with sex reward increases the excitability of VTA GABAergic neurons and decreases the excitability of VTA dopaminergic neurons, while activating this pathway decreases the excitability of VTA GABAergic neurons and increases the excitability of VTA dopaminergic neurons, which may be the cellular mechanism by which the VTA-BLA-NAc circuit associated with sex reward ameliorates the attenuated reward sensitivity induced by chronic stress.
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18
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Weitz M, Khayat A, Yaka R. GABAergic projections to the ventral tegmental area govern cocaine-conditioned reward. Addict Biol 2021; 26:e13026. [PMID: 33638301 DOI: 10.1111/adb.13026] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Revised: 02/09/2021] [Accepted: 02/10/2021] [Indexed: 01/20/2023]
Abstract
Elevated dopamine (DA) levels in the reward system underlie various drug-related behaviors, including addiction. As a major DA source in the reward system, the ventral tegmental area (VTA) is highly regulated by GABAergic inputs projected from different brain regions. It was previously shown that cocaine exposure reduces GABAA -mediated inhibitory postsynaptic currents (IPSCs) in VTA DA neurons; however, the specific GABAergic input underlying this inhibitory effect remains unknown. Here, using optogenetics, we separately activate and characterize different GABAergic afferents innervating the VTA, focusing on the rostromedial tegmental nucleus (RMTg) and the nucleus accumbens (NAc). GABAA -mediated IPSCs were recorded from VTA DA neurons, and the effect of DA-induced inhibition was measured in an afferent-specific manner. In addition, to examine the effect of enhanced GABAergic tone on the rewarding properties of cocaine, we exogenously activated the different GABAergic inputs during the acquisition phase of cocaine conditioned place preference (CPP). We found that acute cocaine exposure strongly attenuates GABAA -mediated IPSCs in VTA DA neurons from both inhibitory sources. Furthermore, exogenous light activation of both RMTg and NAc afferents in the VTA during the acquisition of cocaine-CPP significantly reduced the rewarding properties of cocaine. This behavioral observation was correlated with the reduction in the neuronal activity of VTA DA neurons as measured by the expression of c-fos. Together, these results emphasize the critical role of these GABAergic inputs to the VTA in modulating and potentially interrupting cocaine reward.
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Affiliation(s)
- Moriya Weitz
- Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine The Hebrew University of Jerusalem Jerusalem Israel
| | - Alaa Khayat
- Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine The Hebrew University of Jerusalem Jerusalem Israel
| | - Rami Yaka
- Institute for Drug Research (IDR), School of Pharmacy, Faculty of Medicine The Hebrew University of Jerusalem Jerusalem Israel
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19
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Neurochemical Signaling of Reward and Aversion to Ventral Tegmental Area Glutamate Neurons. J Neurosci 2021; 41:5471-5486. [PMID: 34001626 DOI: 10.1523/jneurosci.1419-20.2021] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 04/29/2021] [Accepted: 05/05/2021] [Indexed: 12/21/2022] Open
Abstract
Ventral tegmental area (VTA) glutamate neurons signal and participate in reward and aversion-based behaviors. However, the neurochemical mechanisms that underlie how these neurons contribute to motivated behaviors is unknown. We used a combination of optical sensors to identify how distinct neurochemical inputs to VTA glutamate neurons participate in motivated behavior within female and male transgenic mice. Activity of glutamate inputs to VTA glutamate neurons increased for both reward-predicting and aversion-predicting cues and aversive outcomes, but subpopulations of glutamate inputs were increased or decreased by reward. For both reward and aversion-based cues and outcomes, activity of GABA inputs to VTA glutamate neurons mostly decreased. GCaMP recordings showed overall population increases in VTA glutamate neuron intracellular calcium during reward and aversion-based cues and outcomes. Electrophysiological recordings of VTA VGluT2 neurons showed that glutamate receptor activation increases firing while loss of excitation via glutamate receptor blockade decreases firing. GABA-A receptor activation decreased VTA glutamate neuron firing but GABA-A receptor blockade did not significantly change VTA glutamate neuron firing. Electrophysiological recordings in coordination with our sensor data suggest that glutamate inputs strongly regulate VTA glutamate neuron participation in diverse motivated behaviors.SIGNIFICANCE STATEMENT Glutamate and GABA are the primary excitatory and inhibitory neurotransmitters of the nervous system. However, identifying how these neurotransmitters regulate motivated behavior has remained challenging because of a lack of tools (1) capable of measuring neurotransmission at the temporal scale of motivated behaviors and (2) capable of capturing chemical signaling onto genetically-distinct neuronal populations. We have overcome these obstacles by implementing genetically-encoded fluorescent indicators to monitor both glutamate and GABA input dynamics exclusively to ventral tegmental area (VTA) glutamate neurons during reward and aversion-based behaviors. We identify that glutamate and GABA inputs to VTA glutamate neurons differentially and dynamically signal reward and aversion-based cues and outcomes. This research provides foundational evidence that links distinct neurotransmitters to motivated behaviors regulated by VTA glutamate neurons.
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20
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Shields AK, Suarez M, Wakabayashi KT, Bass CE. Activation of VTA GABA neurons disrupts reward seeking by altering temporal processing. Behav Brain Res 2021; 410:113292. [PMID: 33836166 DOI: 10.1016/j.bbr.2021.113292] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 03/31/2021] [Accepted: 04/01/2021] [Indexed: 12/30/2022]
Abstract
The role of ventral tegmental area (VTA) dopamine in reward, cue processing, and interval timing is well characterized. Using a combinatorial viral approach to target activating DREADDs (Designer Receptors Exclusively Activated by Designer Drugs, hM3D) to GABAergic neurons in the VTA of male rats, we previously showed that activation disrupts responding to reward-predictive cues. Here we explored how VTA GABA neurons influence the perception of time in two fixed interval (FI) tasks, one where the reward or interval is not paired with predictive cues (Non-Cued FI), and another where the start of the FI is signaled by a constant tone that continues until the rewarded response is emitted (Cued FI). Under vehicle conditions in both tasks, responding was characterized by "scalloping" over the 30 s FI, in which responding increased towards the end of the FI. However, when VTA GABA neurons were activated in the Non-Cued FI, the time between the end of the 30 s interval and when the rats made a reinforced response increased. Additionally, post-reinforcement pauses and overall session length increased. In the Cued FI task, VTA GABA activation produced erratic responding, with a decrease in earned rewards. Thus, while both tasks were disrupted by VTA GABA activation, responding that is constrained by a cue was more sensitive to this manipulation, possibly due to convergent effects on timing and cue processing. Together these results demonstrate that VTA GABA activity disrupts the perception of interval timing, particularly when the timing is set by cues.
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Affiliation(s)
- Andrea K Shields
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, SUNY, Buffalo, NY, 14214, United States
| | - Mauricio Suarez
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, SUNY, Buffalo, NY, 14214, United States; Clinical Research Institute on Addictions, University at Buffalo, State University of New York, Buffalo, NY, 14203, United States
| | - Ken T Wakabayashi
- Department of Psychology, University of Nebraska-Lincoln, 1220 T. Street, Lincoln, NE, 68588, United States
| | - Caroline E Bass
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, SUNY, Buffalo, NY, 14214, United States; Clinical Research Institute on Addictions, University at Buffalo, State University of New York, Buffalo, NY, 14203, United States.
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21
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Morales-Puerto N, Giménez-Gómez P, Pérez-Hernández M, Abuin-Martínez C, Gil de Biedma-Elduayen L, Vidal R, Gutiérrez-López MD, O'Shea E, Colado MI. Addiction and the kynurenine pathway: A new dancing couple? Pharmacol Ther 2021; 223:107807. [PMID: 33476641 DOI: 10.1016/j.pharmthera.2021.107807] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 01/05/2021] [Indexed: 12/15/2022]
Abstract
Drug use poses a serious threat to health systems throughout the world and the number of consumers rises relentlessly every year. The kynurenine pathway, main pathway of tryptophan degradation, has drawn interest in this field due to its relationship with addictive behaviour. Recently it has been confirmed that modulation of kynurenine metabolism at certain stages of the pathway can reduce, prevent or abolish drug seeking-like behaviours in studies with several different drugs. In this review, we present an up-to-date summary of the evidences of a relationship between drug use and the kynurenine pathway, both the alterations of the pathway due to drug use as well as modulation of the pathway as a potential approach to treat drug addiction. The review discusses ethanol, nicotine, cannabis, amphetamines, cocaine and opioids and new prospects in the drug research field are proposed.
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Affiliation(s)
- Nuria Morales-Puerto
- Departamento de Farmacología y Toxicología, Facultad de Medicina, Universidad Complutense, Madrid, Spain; Instituto de Investigación Sanitaria Hospital 12 de Octubre, Madrid, Spain; Red de Trastornos Adictivos del Instituto de Salud Carlos III, Madrid, Spain; Instituto Universitario de Investigación Neuroquímica (IUIN), Facultad de Medicina, Universidad Complutense, Madrid, Spain
| | - Pablo Giménez-Gómez
- Departamento de Farmacología y Toxicología, Facultad de Medicina, Universidad Complutense, Madrid, Spain; Instituto de Investigación Sanitaria Hospital 12 de Octubre, Madrid, Spain; Red de Trastornos Adictivos del Instituto de Salud Carlos III, Madrid, Spain; Instituto Universitario de Investigación Neuroquímica (IUIN), Facultad de Medicina, Universidad Complutense, Madrid, Spain
| | - Mercedes Pérez-Hernández
- Departamento de Farmacología y Toxicología, Facultad de Medicina, Universidad Complutense, Madrid, Spain; Instituto de Investigación Sanitaria Hospital 12 de Octubre, Madrid, Spain; Red de Trastornos Adictivos del Instituto de Salud Carlos III, Madrid, Spain; Instituto Universitario de Investigación Neuroquímica (IUIN), Facultad de Medicina, Universidad Complutense, Madrid, Spain
| | - Cristina Abuin-Martínez
- Departamento de Farmacología y Toxicología, Facultad de Medicina, Universidad Complutense, Madrid, Spain; Instituto de Investigación Sanitaria Hospital 12 de Octubre, Madrid, Spain; Red de Trastornos Adictivos del Instituto de Salud Carlos III, Madrid, Spain; Instituto Universitario de Investigación Neuroquímica (IUIN), Facultad de Medicina, Universidad Complutense, Madrid, Spain
| | - Leticia Gil de Biedma-Elduayen
- Departamento de Farmacología y Toxicología, Facultad de Medicina, Universidad Complutense, Madrid, Spain; Instituto de Investigación Sanitaria Hospital 12 de Octubre, Madrid, Spain; Red de Trastornos Adictivos del Instituto de Salud Carlos III, Madrid, Spain; Instituto Universitario de Investigación Neuroquímica (IUIN), Facultad de Medicina, Universidad Complutense, Madrid, Spain
| | - Rebeca Vidal
- Departamento de Farmacología y Toxicología, Facultad de Medicina, Universidad Complutense, Madrid, Spain; Instituto de Investigación Sanitaria Hospital 12 de Octubre, Madrid, Spain; Red de Trastornos Adictivos del Instituto de Salud Carlos III, Madrid, Spain; Instituto Universitario de Investigación Neuroquímica (IUIN), Facultad de Medicina, Universidad Complutense, Madrid, Spain
| | - María Dolores Gutiérrez-López
- Departamento de Farmacología y Toxicología, Facultad de Medicina, Universidad Complutense, Madrid, Spain; Instituto de Investigación Sanitaria Hospital 12 de Octubre, Madrid, Spain; Red de Trastornos Adictivos del Instituto de Salud Carlos III, Madrid, Spain; Instituto Universitario de Investigación Neuroquímica (IUIN), Facultad de Medicina, Universidad Complutense, Madrid, Spain
| | - Esther O'Shea
- Departamento de Farmacología y Toxicología, Facultad de Medicina, Universidad Complutense, Madrid, Spain; Instituto de Investigación Sanitaria Hospital 12 de Octubre, Madrid, Spain; Red de Trastornos Adictivos del Instituto de Salud Carlos III, Madrid, Spain; Instituto Universitario de Investigación Neuroquímica (IUIN), Facultad de Medicina, Universidad Complutense, Madrid, Spain.
| | - María Isabel Colado
- Departamento de Farmacología y Toxicología, Facultad de Medicina, Universidad Complutense, Madrid, Spain; Instituto de Investigación Sanitaria Hospital 12 de Octubre, Madrid, Spain; Red de Trastornos Adictivos del Instituto de Salud Carlos III, Madrid, Spain; Instituto Universitario de Investigación Neuroquímica (IUIN), Facultad de Medicina, Universidad Complutense, Madrid, Spain.
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22
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Fotio Y, Borruto AM, Benvenuti F, Demopulos G, Gaitanaris G, Roberto M, Ciccocioppo R. Activation of peroxisome proliferator-activated receptor γ reduces alcohol drinking and seeking by modulating multiple mesocorticolimbic regions in rats. Neuropsychopharmacology 2021; 46:360-367. [PMID: 32610339 PMCID: PMC7852659 DOI: 10.1038/s41386-020-0754-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 06/24/2020] [Indexed: 11/09/2022]
Abstract
Peroxisome proliferator-activated receptor γ (PPARγ) is an intracellular transcription factor whose signaling activation by the selective agonist pioglitazone reduces alcohol drinking and alcohol-seeking behavior in rats. The present study utilized the two-bottle choice and operant self-administration procedures to investigate neuroanatomical substrates that mediate the effects of PPARγ agonism on alcohol drinking and seeking in msP rats. Bilateral infusions of pioglitazone (0, 5, and 10 μg/μl) in the rostromedial tegmental nucleus (RMTg) decreased voluntary alcohol drinking and alcohol self-administration. Microinjections of pioglitazone in the ventral tegmental area (VTA), central amygdala (CeA), and nucleus accumbens (NAc) shell had no such effect. Notably, water, food, and saccharin consumption was unaltered by either treatment. The yohimbine-induced reinstatement of alcohol seeking was prevented by infusions of pioglitazone (0, 2.5, 5, and 10 μg/μl) in the CeA, VTA, and RMTg but not in the NAc shell. These results emphasize the involvement of mesocorticolimbic circuitries in mediating the effects of PPARγ agonists on alcohol drinking and seeking. These results will facilitate future studies that investigate the pathophysiological role of PPARγ in alcohol use disorder and help clarify the mechanisms by which the activation of this receptor decreases the motivation for drinking.
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Affiliation(s)
- Yannick Fotio
- grid.5602.10000 0000 9745 6549School of Pharmacy, Pharmacology Unit, University of Camerino, 62032 Camerino, Italy ,grid.266093.80000 0001 0668 7243Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA 92617 USA
| | - Anna Maria Borruto
- grid.5602.10000 0000 9745 6549School of Pharmacy, Pharmacology Unit, University of Camerino, 62032 Camerino, Italy
| | - Federica Benvenuti
- grid.5602.10000 0000 9745 6549School of Pharmacy, Pharmacology Unit, University of Camerino, 62032 Camerino, Italy
| | | | | | - Marisa Roberto
- grid.214007.00000000122199231Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037 USA
| | - Roberto Ciccocioppo
- School of Pharmacy, Pharmacology Unit, University of Camerino, 62032, Camerino, Italy.
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23
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Turecek J, Regehr WG. Cerebellar and vestibular nuclear synapses in the inferior olive have distinct release kinetics and neurotransmitters. eLife 2020; 9:e61672. [PMID: 33259288 PMCID: PMC7707816 DOI: 10.7554/elife.61672] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 11/12/2020] [Indexed: 01/16/2023] Open
Abstract
The inferior olive (IO) is composed of electrically-coupled neurons that make climbing fiber synapses onto Purkinje cells. Neurons in different IO subnuclei are inhibited by synapses with wide ranging release kinetics. Inhibition can be exclusively synchronous, asynchronous, or a mixture of both. Whether the same boutons, neurons or sources provide these kinetically distinct types of inhibition was not known. We find that in mice the deep cerebellar nuclei (DCN) and vestibular nuclei (VN) are two major sources of inhibition to the IO that are specialized to provide inhibitory input with distinct kinetics. DCN to IO synapses lack fast synaptotagmin isoforms, release neurotransmitter asynchronously, and are exclusively GABAergic. VN to IO synapses contain fast synaptotagmin isoforms, release neurotransmitter synchronously, and are mediated by combined GABAergic and glycinergic transmission. These findings indicate that VN and DCN inhibitory inputs to the IO are suited to control different aspects of IO activity.
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Affiliation(s)
- Josef Turecek
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
| | - Wade G Regehr
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
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24
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Shepard RD, Nugent FS. Early Life Stress- and Drug-Induced Histone Modifications Within the Ventral Tegmental Area. Front Cell Dev Biol 2020; 8:588476. [PMID: 33102491 PMCID: PMC7554626 DOI: 10.3389/fcell.2020.588476] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 09/14/2020] [Indexed: 12/11/2022] Open
Abstract
Psychiatric illnesses are a major public health concern due to their prevalence and heterogeneity of symptom presentation resulting from a lack of efficacious treatments. Although dysregulated dopamine (DA) signaling has been observed in a myriad of psychiatric conditions, different pathophysiological mechanisms have been implicated which impede the development of adequate treatments that work across all patient populations. The ventral tegmental area (VTA), a major source of DA neurons in the brain reward pathway, has been shown to have altered activity that contributes to reward dysregulation in mental illnesses and drug addiction. It has now become better appreciated that epigenetic mechanisms contribute to VTA DA dysfunction, such as through histone modifications, which dynamically regulate transcription rates of critical genes important in synaptic plasticity underlying learning and memory. Here, we provide a focused review on differential histone modifications within the VTA observed in both humans and animal models, as well as their relevance to disease-based phenotypes, specifically focusing on epigenetic dysregulation of histones in the VTA associated with early life stress (ELS) and drugs of abuse. Locus- and cell-type-specific targeting of individual histone modifications at specific genes within the VTA presents novel therapeutic targets which can result in greater efficacy and better long-term health outcomes in susceptible individuals that are at increased risk for substance use and psychiatric disorders.
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Affiliation(s)
- Ryan D Shepard
- Department of Pharmacology, Edward Hebert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Fereshteh S Nugent
- Department of Pharmacology, Edward Hebert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
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25
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Lee C, Lavoie A, Liu J, Chen SX, Liu BH. Light Up the Brain: The Application of Optogenetics in Cell-Type Specific Dissection of Mouse Brain Circuits. Front Neural Circuits 2020; 14:18. [PMID: 32390806 PMCID: PMC7193678 DOI: 10.3389/fncir.2020.00018] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 03/31/2020] [Indexed: 11/13/2022] Open
Abstract
The exquisite intricacies of neural circuits are fundamental to an animal’s diverse and complex repertoire of sensory and motor functions. The ability to precisely map neural circuits and to selectively manipulate neural activity is critical to understanding brain function and has, therefore been a long-standing goal for neuroscientists. The recent development of optogenetic tools, combined with transgenic mouse lines, has endowed us with unprecedented spatiotemporal precision in circuit analysis. These advances greatly expand the scope of tractable experimental investigations. Here, in the first half of the review, we will present applications of optogenetics in identifying connectivity between different local neuronal cell types and of long-range projections with both in vitro and in vivo methods. We will then discuss how these tools can be used to reveal the functional roles of these cell-type specific connections in governing sensory information processing, and learning and memory in the visual cortex, somatosensory cortex, and motor cortex. Finally, we will discuss the prospect of new optogenetic tools and how their application can further advance modern neuroscience. In summary, this review serves as a primer to exemplify how optogenetics can be used in sophisticated modern circuit analyses at the levels of synapses, cells, network connectivity and behaviors.
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Affiliation(s)
- Candice Lee
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Andreanne Lavoie
- Department of Biology, University of Toronto Mississauga, Mississauga, ON, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Jiashu Liu
- Department of Biology, University of Toronto Mississauga, Mississauga, ON, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Simon X Chen
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.,Brain and Mind Research Institute, University of Ottawa, Ottawa, ON, Canada.,Center for Neural Dynamics, University of Ottawa, Ottawa, ON, Canada
| | - Bao-Hua Liu
- Department of Biology, University of Toronto Mississauga, Mississauga, ON, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
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26
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St Laurent R, Martinez Damonte V, Tsuda AC, Kauer JA. Periaqueductal Gray and Rostromedial Tegmental Inhibitory Afferents to VTA Have Distinct Synaptic Plasticity and Opiate Sensitivity. Neuron 2020; 106:624-636.e4. [PMID: 32191871 DOI: 10.1016/j.neuron.2020.02.029] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 10/01/2019] [Accepted: 02/25/2020] [Indexed: 12/16/2022]
Abstract
The ventral tegmental area (VTA) is a major target of addictive drugs and receives multiple GABAergic projections originating outside the VTA. We describe differences in synaptic plasticity and behavior when optogenetically driving two opiate-sensitive GABAergic inputs to the VTA, the rostromedial tegmental nucleus (RMTg), and the periaqueductal gray (PAG). Activation of GABAergic RMTg terminals in the VTA in vivo is aversive, and low-frequency stimulation induces long-term depression in vitro. Low-frequency stimulation of PAG afferents in vitro unexpectedly causes long-term potentiation. Opioid receptor activation profoundly depresses PAG and RMTg inhibitory synapses but prevents synaptic plasticity only at PAG synapses. Activation of the GABAergic PAG terminals in the VTA promotes immobility, and optogenetically-driven immobility is blocked by morphine. Our data reveal the PAG as a source of highly opioid-sensitive GABAergic afferents and support the idea that different GABAergic pathways to the VTA control distinct behaviors.
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Affiliation(s)
- Robyn St Laurent
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94035, USA
| | - Valentina Martinez Damonte
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94035, USA
| | - Ayumi C Tsuda
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, RI 02912, USA
| | - Julie A Kauer
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94035, USA.
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27
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Simmons SJ, Gentile TA. Cocaine abuse and midbrain circuits: Functional anatomy of hypocretin/orexin transmission and therapeutic prospect. Brain Res 2020; 1731:146164. [PMID: 30796894 PMCID: PMC6702109 DOI: 10.1016/j.brainres.2019.02.026] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 01/09/2019] [Accepted: 02/12/2019] [Indexed: 12/18/2022]
Abstract
Cocaine abuse remains a pervasive public health problem, and treatments thus far have proven ineffective for long-term abstinence maintenance. Intensive research on the neurobiology underlying drug abuse has led to the consideration of many candidate transmitter systems to target for intervention. Among these, the hypocretin/orexin (hcrt/ox) neuropeptide system holds largely untapped yet clinically viable therapeutic potential. Hcrt/ox originates from the hypothalamus and projects widely across the mammalian central nervous system to produce neuroexcitatory actions via two excitatory G-protein coupled receptor subtypes. Functionally, hcrt/ox promotes arousal/wakefulness and facilitates energy homeostasis. In the early 2000s, hcrt/ox transmission was shown to underlie mating behavior in male rats suggesting a novel role in reward-seeking. Soon thereafter, hcrt/ox neurons were shown to respond to drug-associated stimuli, and hcrt/ox transmission was found to facilitate motivated responding for intravenous cocaine. Notably, blocking hcrt/ox transmission using systemic or site-directed pharmacological antagonists markedly reduced motivated drug-taking as well as drug-seeking in tests of relapse. This review will unfold the current state of knowledge implicating hcrt/ox receptor transmission in the context of cocaine abuse and provide detailed background on animal models and underlying midbrain circuits. Specifically, attention will be paid to the mesoaccumbens, tegmental, habenular, pallidal and preoptic circuits. The review will conclude with discussion of recent preclinical studies assessing utility of suvorexant - the first and only FDA-approved hcrt/ox receptor antagonist - against cocaine-associated behaviors.
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Affiliation(s)
- Steven J Simmons
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia Research Institute, Philadelphia, PA, USA; Center for Substance Abuse Research, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA.
| | - Taylor A Gentile
- Center for Substance Abuse Research, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
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28
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Velasquez-Martinez MC, Santos-Vera B, Velez-Hernandez ME, Vazquez-Torres R, Jimenez-Rivera CA. Alpha-1 Adrenergic Receptors Modulate Glutamate and GABA Neurotransmission onto Ventral Tegmental Dopamine Neurons during Cocaine Sensitization. Int J Mol Sci 2020; 21:E790. [PMID: 31991781 PMCID: PMC7036981 DOI: 10.3390/ijms21030790] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 01/16/2020] [Accepted: 01/20/2020] [Indexed: 12/25/2022] Open
Abstract
The ventral tegmental area (VTA) plays an important role in the reward and motivational processes that facilitate the development of drug addiction. Presynaptic α1-AR activation modulates glutamate and Gamma-aminobutyric acid (GABA) release. This work elucidates the role of VTA presynaptic α1-ARs and their modulation on glutamatergic and GABAergic neurotransmission during cocaine sensitization. Excitatory and inhibitory currents (EPSCs and IPSCs) measured by a whole cell voltage clamp show that α1-ARs activation increases EPSCs amplitude after 1 day of cocaine treatment but not after 5 days of cocaine injections. The absence of a pharmacological response to an α1-ARs agonist highlights the desensitization of the receptor after repeated cocaine administration. The desensitization of α1-ARs persists after a 7-day withdrawal period. In contrast, the modulation of α1-ARs on GABA neurotransmission, shown by decreases in IPSCs' amplitude, is not affected by acute or chronic cocaine injections. Taken together, these data suggest that α1-ARs may enhance DA neuronal excitability after repeated cocaine administration through the reduction of GABA inhibition onto VTA dopamine (DA) neurons even in the absence of α1-ARs' function on glutamate release and protein kinase C (PKC) activation. α1-AR modulatory changes in cocaine sensitization increase our knowledge of the role of the noradrenergic system in cocaine addiction and may provide possible avenues for therapeutics.
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Affiliation(s)
- Maria Carolina Velasquez-Martinez
- Grupo de Neurociencias y Comportamiento, Departamento de Ciencias Básicas, Facultad de Salud, Universidad Industrial de Santander, Bucaramanga 680006, Colombia;
| | - Bermary Santos-Vera
- Department of Biology, Cayey Campus, University of Puerto Rico, Cayey, PR 00737, USA;
| | - Maria E. Velez-Hernandez
- Department of Biological and Health Sciences, Texas A&M University-Kingsville, Kingsville, TX 78363, USA;
| | - Rafael Vazquez-Torres
- Department of Physiology, Medical Sciences Campus, University of Puerto Rico, San Juan, PR 00925, USA;
| | - Carlos A. Jimenez-Rivera
- Department of Physiology, Medical Sciences Campus, University of Puerto Rico, San Juan, PR 00925, USA;
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29
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Li X, Slesinger PA. GABA B Receptors and Drug Addiction: Psychostimulants and Other Drugs of Abuse. Curr Top Behav Neurosci 2020; 52:119-155. [PMID: 33442842 DOI: 10.1007/7854_2020_187] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Metabotropic GABAB receptors (GABABRs) mediate slow inhibition and modulate synaptic plasticity throughout the brain. Dysfunction of GABABRs has been associated with psychiatric illnesses and addiction. Drugs of abuse alter GABAB receptor (GABABR) signaling in multiple brain regions, which partly contributes to the development of drug addiction. Recently, GABABR ligands and positive allosteric modulators (PAMs) have been shown to attenuate the initial rewarding effect of addictive substances, inhibit seeking and taking of these drugs, and in some cases, ameliorate drug withdrawal symptoms. The majority of the anti-addiction effects seen with GABABR modulation can be localized to ventral tegmental area (VTA) dopamine neurons, which receive complex inhibitory and excitatory inputs that are modified by drugs of abuse. Preclinical research suggests that GABABR PAMs are emerging as promising candidates for the treatment of drug addiction. Clinical studies on drug dependence have shown positive results with GABABR ligands but more are needed, and compounds with better pharmacokinetics and fewer side effects are critically needed.
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Affiliation(s)
- Xiaofan Li
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Paul A Slesinger
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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30
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Bouarab C, Thompson B, Polter AM. VTA GABA Neurons at the Interface of Stress and Reward. Front Neural Circuits 2019; 13:78. [PMID: 31866835 PMCID: PMC6906177 DOI: 10.3389/fncir.2019.00078] [Citation(s) in RCA: 99] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 11/18/2019] [Indexed: 01/20/2023] Open
Abstract
The ventral tegmental area (VTA) is best known for its robust dopaminergic projections to forebrain regions and their critical role in regulating reward, motivation, cognition, and aversion. However, the VTA is not only made of dopamine (DA) cells, as approximately 30% of cells in the VTA are GABA neurons. These neurons play a dual role, as VTA GABA neurons provide both local inhibition of VTA DA neurons and long-range inhibition of several distal brain regions. VTA GABA neurons have increasingly been recognized as potent mediators of reward and aversion in their own right, as well as potential targets for the treatment of addiction, depression, and other stress-linked disorders. In this review article, we dissect the circuit architecture, physiology, and behavioral roles of VTA GABA neurons and suggest critical gaps to be addressed.
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Affiliation(s)
- Chloé Bouarab
- Department of Pharmacology and Physiology, Institute for Neuroscience, George Washington University School of Medicine and Health Sciences, Washington, DC, United States
| | - Brittney Thompson
- Department of Pharmacology and Physiology, Institute for Neuroscience, George Washington University School of Medicine and Health Sciences, Washington, DC, United States
| | - Abigail M Polter
- Department of Pharmacology and Physiology, Institute for Neuroscience, George Washington University School of Medicine and Health Sciences, Washington, DC, United States
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31
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Synaptic Plasticity at Inhibitory Synapses in the Ventral Tegmental Area Depends upon Stimulation Site. eNeuro 2019; 6:ENEURO.0137-19.2019. [PMID: 31619451 PMCID: PMC6860988 DOI: 10.1523/eneuro.0137-19.2019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 09/16/2019] [Accepted: 10/04/2019] [Indexed: 01/04/2023] Open
Abstract
Drug exposure induces cell and synaptic plasticity within the brain reward pathway that could be a catalyst for progression to addiction. Several cellular adaptations have been described in the ventral tegmental area (VTA), a central component of the reward pathway that is the major source of dopamine release. For example, administration of morphine induces long-term potentiation (LTP) of excitatory synapses on VTA dopamine cells and blocks LTP at inhibitory synapses. Drug-induced synaptic changes have a common endpoint of increasing dopamine cell firing and dopamine release. However, gaining a complete picture of synaptic plasticity in the VTA is hindered by its complex circuitry of efferents and afferents. Most studies of synaptic plasticity in the VTA activated a mixed population of afferents, potentially yielding an incomplete and perhaps misleading view of how drugs of abuse modify VTA synapses. Here, we use midbrain slices from mice and find that electrical stimulation in two different regions induces different forms of plasticity, including two new forms of LTP at inhibitory synapses. High-frequency stimulation (HFS) induces LTP independently of NMDA receptor (NMDAR) activation, and surprisingly, some inhibitory inputs to the VTA also undergo NMDAR-independent LTP after a low-frequency stimulation (LFS) pairing protocol.
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32
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Nitric Oxide-Mediated Plasticity of Interconnections Between T-Stellate cells of the Ventral Cochlear Nucleus Generate Positive Feedback and Constitute a Central Gain Control in the Auditory System. J Neurosci 2019; 39:6095-6107. [PMID: 31160538 DOI: 10.1523/jneurosci.0177-19.2019] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 05/24/2019] [Accepted: 05/30/2019] [Indexed: 12/21/2022] Open
Abstract
T-stellate cells in the ventral cochlear nucleus (VCN) form an ascending pathway that conveys spectral information from the cochlea to brainstem nuclei, the inferior colliculi, and the thalamus. The tonotopic array of T-stellate cells enhances the encoding of spectral peaks relative to their auditory nerve fiber inputs. The alignment of local collaterals and T-stellate cell dendrites within the isofrequency lamina suggests that the cells make connections within the isofrequency lamina in which they reside. Recordings from pairs of T-stellate cells in mice of both sexes revealed that firing in the presynaptic cell evoked responses in the postsynaptic cell when presynaptic firing was paired with depolarization of the postsynaptic cell. After such experimental coactivation, presynaptic firing evoked EPSCs of uniform amplitude whose frequency depended on the duration of depolarization and diminished over minutes. Nitric oxide (NO) donors evoked EPSCs in T-stellate cells but not in the other types of principal cells. Blockers of neuronal nitric oxide synthase (nNOS) and of NMDA receptors blocked potentiation, indicating that NO mediates potentiation. nNOS and its receptor, guanylate cyclase (NO-GC), are expressed in somata of T-stellate cells. Excitatory interconnections were bidirectional and polysynaptic, indicating that T-stellate cells connect in networks. Positive feedback provided by temporarily potentiated interconnections between T-stellate cells could enhance the gain of auditory nerve excitation in proportion to the excitation, generating a form of short-term central gain control that could account for the ability of T-stellate cells to enhance the encoding of spectral peaks.SIGNIFICANCE STATEMENT T-stellate cells are interconnected through synapses that have a previously undescribed form of temporary, nitric oxide-mediated plasticity. Coactivation of neighboring cells enhances the activation of an excitatory network that feeds back on itself by enhancing the probability of EPSCs. Although there remain gaps in our understanding of how the interconnections revealed in slices contribute to hearing, our findings have interesting implications. Positive feedback through a network of interconnections could account for how T-stellate cells are able to encode spectral peaks over a wider range of intensities than many of their auditory nerve inputs (Blackburn and Sachs, 1990; May et al., 1998). The magnitude of the gain may itself be plastic because neuronal nitric oxide synthase increases when animals have tinnitus (Coomber et al., 2015).
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33
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Li Y, Li CY, Xi W, Jin S, Wu ZH, Jiang P, Dong P, He XB, Xu FQ, Duan S, Zhou YD, Li XM. Rostral and Caudal Ventral Tegmental Area GABAergic Inputs to Different Dorsal Raphe Neurons Participate in Opioid Dependence. Neuron 2019; 101:748-761.e5. [PMID: 30638902 DOI: 10.1016/j.neuron.2018.12.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 10/26/2018] [Accepted: 12/07/2018] [Indexed: 12/14/2022]
Abstract
Both the ventral tegmental area (VTA) and dorsal raphe nucleus (DRN) are involved in affective control and reward-related behaviors. Moreover, the neuronal activities of the VTA and DRN are modulated by opioids. However, the precise circuits from the VTA to DRN and how opioids modulate these circuits remain unknown. Here, we found that neurons projecting from the VTA to DRN are primarily GABAergic. Rostral VTA (rVTA) GABAergic neurons preferentially innervate DRN GABAergic neurons, thus disinhibiting DRN serotonergic neurons. Optogenetic activation of this circuit induces aversion. In contrast, caudal VTA (cVTA) GABAergic neurons mainly target DRN serotonergic neurons, and activation of this circuit promotes reward. Importantly, μ-opioid receptors (MOPs) are selectively expressed at rVTA→DRN GABAergic synapses, and morphine depresses the synaptic transmission. Chronically elevating the activity of the rVTA→DRN pathway specifically interrupts morphine-induced conditioned place preference. This opioid-modulated inhibitory circuit may yield insights into morphine reward and dependence pathogenesis.
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Affiliation(s)
- Yue Li
- Center for Neuroscience and Department of Neurology of Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Joint Institute for Genetics and Genome Medicine between Zhejiang University and University of Toronto, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Chun-Yue Li
- Center for Neuroscience and Department of Neurology of Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Joint Institute for Genetics and Genome Medicine between Zhejiang University and University of Toronto, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Wang Xi
- Center for Neuroscience and Department of Neurology of Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Joint Institute for Genetics and Genome Medicine between Zhejiang University and University of Toronto, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Sen Jin
- CAS Center for Excellence in Brain Science, Chinese Academy of Sciences, Wuhan Institute of Physics and Mathematics, Wuhan 430071, China
| | - Zuo-Hang Wu
- Center for Neuroscience and Department of Neurology of Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Joint Institute for Genetics and Genome Medicine between Zhejiang University and University of Toronto, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Ping Jiang
- Center for Neuroscience and Department of Neurology of Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Joint Institute for Genetics and Genome Medicine between Zhejiang University and University of Toronto, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Ping Dong
- Center for Neuroscience and Department of Neurology of Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Joint Institute for Genetics and Genome Medicine between Zhejiang University and University of Toronto, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Xiao-Bin He
- CAS Center for Excellence in Brain Science, Chinese Academy of Sciences, Wuhan Institute of Physics and Mathematics, Wuhan 430071, China
| | - Fu-Qiang Xu
- CAS Center for Excellence in Brain Science, Chinese Academy of Sciences, Wuhan Institute of Physics and Mathematics, Wuhan 430071, China
| | - Shumin Duan
- Center for Neuroscience and Department of Neurology of Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Joint Institute for Genetics and Genome Medicine between Zhejiang University and University of Toronto, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Yu-Dong Zhou
- Center for Neuroscience and Department of Neurology of Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Joint Institute for Genetics and Genome Medicine between Zhejiang University and University of Toronto, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Xiao-Ming Li
- Center for Neuroscience and Department of Neurology of Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Joint Institute for Genetics and Genome Medicine between Zhejiang University and University of Toronto, Zhejiang University School of Medicine, Hangzhou 310058, China.
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Ostroumov A, Dani JA. Inhibitory Plasticity of Mesocorticolimbic Circuits in Addiction and Mental Illness. Trends Neurosci 2018; 41:898-910. [PMID: 30149979 PMCID: PMC6252277 DOI: 10.1016/j.tins.2018.07.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 07/12/2018] [Accepted: 07/31/2018] [Indexed: 12/19/2022]
Abstract
Behavioral adaptations occur through remodeling of brain circuits, as arising, for instance, from experience-dependent synaptic plasticity. Drugs of abuse and aversive stimuli, such as stress, act on the mesocorticolimbic system, dysregulating adaptive mechanisms and leading to a variety of aberrant behaviors associated with neuropsychiatric disorders. Until recently, research in the field has commonly focused on experience-dependent synaptic plasticity at excitatory synapses. However, there is growing evidence that synaptic plasticity within inhibitory circuits is an important contributor to maladaptive behaviors. We speculate that restoring normal inhibitory synaptic transmission is a promising therapeutic target for correcting some of the circuit abnormalities underlying neuropsychiatric disorders.
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Affiliation(s)
- Alexey Ostroumov
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School for Medicine, Philadelphia, PA 19104, USA.
| | - John A Dani
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School for Medicine, Philadelphia, PA 19104, USA.
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35
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Langlois LD, Dacher M, Nugent FS. Dopamine Receptor Activation Is Required for GABAergic Spike Timing-Dependent Plasticity in Response to Complex Spike Pairing in the Ventral Tegmental Area. Front Synaptic Neurosci 2018; 10:32. [PMID: 30297996 PMCID: PMC6160785 DOI: 10.3389/fnsyn.2018.00032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 08/30/2018] [Indexed: 01/06/2023] Open
Abstract
One of the most influential synaptic learning rules explored in the past decades is activity dependent spike-timing-dependent plasticity (STDP). In STDP, synapses are either potentiated or depressed based on the order of pre- and postsynaptic neuronal activation within narrow, milliseconds-long, time intervals. STDP is subject to neuromodulation by dopamine (DA), a potent neurotransmitter that significantly impacts synaptic plasticity and reward-related behavioral learning. Previously, we demonstrated that GABAergic synapses onto ventral tegmental area (VTA) DA neurons are able to express STDP (Kodangattil et al., 2013), however it is still unclear whether DA modulates inhibitory STDP in the VTA. Here, we used whole-cell recordings in rat midbrain slices to investigate whether DA D1-like and/or D2-like receptor (D1R/D2R) activation is required for induction of STDP in response to a complex pattern of spiking. We found that VTA but not Substantia nigra pars compact (SNc) DA neurons exhibit long-term depression (LTDGABA) in response to a combination of positive (pre-post) and negative (post-pre) timing of spiking (a complex STDP protocol). Blockade of either D1Rs or D2Rs prevented the induction of LTDGABA while activation of D1Rs did not affect the plasticity in response to this complex STDP protocol in VTA DA neurons.Our data suggest that this DA-dependent GABAergic STDP is selectively expressed at GABAergic synapses onto VTA DA neurons which could be targeted by drugs of abuse to mediate drug-induced modulation of DA signaling within the VTA, as well as in VTA-projection areas, thereby affecting reward-related learning and drug-associated memories.
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Affiliation(s)
- Ludovic D Langlois
- Department of Pharmacology, F. Edward Hebert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Matthieu Dacher
- Department of Pharmacology, F. Edward Hebert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Fereshteh S Nugent
- Department of Pharmacology, F. Edward Hebert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
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36
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Quraishi SA, Paladini CA. Could GABA, with a side of glycine, control glutamate receptors? Eur J Neurosci 2018; 47:1206-1207. [PMID: 29729221 DOI: 10.1111/ejn.13929] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Salma A Quraishi
- Department of Biology, UTSA Neurosciences Institute, University of Texas at San Antonio, San Antonio, TX, USA
| | - Carlos A Paladini
- Department of Biology, UTSA Neurosciences Institute, University of Texas at San Antonio, San Antonio, TX, USA
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