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Nasrallah K, Berthoux C, Hashimotodani Y, Chávez AE, Gulfo MC, Luján R, Castillo PE. Retrograde adenosine/A 2A receptor signaling facilitates excitatory synaptic transmission and seizures. Cell Rep 2024; 43:114382. [PMID: 38905101 DOI: 10.1016/j.celrep.2024.114382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 12/12/2023] [Accepted: 06/03/2024] [Indexed: 06/23/2024] Open
Abstract
Retrograde signaling at the synapse is a fundamental way by which neurons communicate and neuronal circuit function is fine-tuned upon activity. While long-term changes in neurotransmitter release commonly rely on retrograde signaling, the mechanisms remain poorly understood. Here, we identified adenosine/A2A receptor (A2AR) as a retrograde signaling pathway underlying presynaptic long-term potentiation (LTP) at a hippocampal excitatory circuit critically involved in memory and epilepsy. Transient burst activity of a single dentate granule cell induced LTP of mossy cell synaptic inputs, a BDNF/TrkB-dependent form of plasticity that facilitates seizures. Postsynaptic TrkB activation released adenosine from granule cells, uncovering a non-conventional BDNF/TrkB signaling mechanism. Moreover, presynaptic A2ARs were necessary and sufficient for LTP. Lastly, seizure induction released adenosine in a TrkB-dependent manner, while removing A2ARs or TrkB from the dentate gyrus had anti-convulsant effects. By mediating presynaptic LTP, adenosine/A2AR retrograde signaling may modulate dentate gyrus-dependent learning and promote epileptic activity.
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Affiliation(s)
- Kaoutsar Nasrallah
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Coralie Berthoux
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Yuki Hashimotodani
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Andrés E Chávez
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Michelle C Gulfo
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Rafael Luján
- Instituto de Biomedicina de la UCLM (IB-UCLM), Facultad de Medicina, Universidad Castilla-La Mancha, 02008 Albacete, Spain
| | - Pablo E Castillo
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Psychiatry & Behavioral Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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2
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Lemtiri-Chlieh F, Levine ES. 2-AG and anandamide enhance hippocampal long-term potentiation via suppression of inhibition. Front Cell Neurosci 2022; 16:1023541. [PMID: 36212685 PMCID: PMC9534525 DOI: 10.3389/fncel.2022.1023541] [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: 08/19/2022] [Accepted: 09/01/2022] [Indexed: 11/13/2022] Open
Abstract
It is widely accepted that exogenous cannabinoids can impair short-term memory and cognition in humans and other animals. This is likely related to the inhibition of long-term potentiation (LTP), a form of synaptic plasticity, by the global and sustained activation of CB1 cannabinoid receptors in the presence of exogenous agonists. Conversely, the temporally and spatially restricted release of endogenous cannabinoid (eCB) ligands may enhance synaptic plasticity in a synapse-specific manner. We examined the role of eCB signaling in LTP by recording field excitatory postsynaptic potentials (fEPSPs) in the CA1 stratum radiatum in hippocampal slices from juvenile mice. LTP was induced either electrically, by theta burst stimulation (TBS), or pharmacologically, by treatment for 15 min with a solution designed to increase intracellular cAMP (chem-LTP). A stable and long-lasting potentiation in fEPSP slope following TBS was significantly reduced by blocking cannabinoid receptor activation with CB1 receptor antagonists. Chem-LTP caused a sustained 2-fold increase in fEPSP slope and was also blocked by CB1 receptor antagonists. TBS-LTP was partially reduced by inhibiting the synthesis of the endogenous ligands 2-arachidonylglycerol (2-AG) and anandamide. A similar effect was observed with chem-LTP. Blocking inhibitory synapses completely prevented the effect of CB1 receptor antagonists or inhibition of eCB synthesis on TBS-LTP and chem-LTP. These results indicate that simultaneous activation of CB1 receptors by 2-AG and anandamide enhances TBS-induced and pharmacologically-induced LTP, and this effect is mediated by the suppression of inhibition at GABAergic synapses.
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3
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Winters BL, Vaughan CW. Mechanisms of endocannabinoid control of synaptic plasticity. Neuropharmacology 2021; 197:108736. [PMID: 34343612 DOI: 10.1016/j.neuropharm.2021.108736] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 07/27/2021] [Accepted: 07/28/2021] [Indexed: 01/13/2023]
Abstract
The endogenous cannabinoid transmitter system regulates synaptic transmission throughout the nervous system. Unlike conventional transmitters, specific stimuli induce synthesis of endocannabinoids (eCBs) in the postsynaptic neuron, and these travel backwards to modulate presynaptic inputs. In doing so, eCBs can induce short-term changes in synaptic strength and longer-term plasticity. While this eCB regulation is near ubiquitous, it displays major regional and synapse specific variations with different synapse specific forms of short-versus long-term plasticity throughout the brain. These differences are due to the plethora of pre- and postsynaptic mechanisms which have been implicated in eCB signalling, the intricacies of which are only just being realised. In this review, we shall describe the current understanding and highlight new advances in this area, with a focus on the retrograde action of eCBs at CB1 receptors (CB1Rs).
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Affiliation(s)
- Bryony Laura Winters
- Pain Management Research Institute, Kolling Institute of Medical Research, Northern Clinical School, University of Sydney at Royal North Shore Hospital, NSW, Australia.
| | - Christopher Walter Vaughan
- Pain Management Research Institute, Kolling Institute of Medical Research, Northern Clinical School, University of Sydney at Royal North Shore Hospital, NSW, Australia
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4
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Multiple cannabinoid signaling cascades powerfully suppress recurrent excitation in the hippocampus. Proc Natl Acad Sci U S A 2021; 118:2017590118. [PMID: 33468648 DOI: 10.1073/pnas.2017590118] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Recurrent excitatory neural networks are unstable. In the hippocampus, excitatory mossy cells (MCs) receive strong excitatory inputs from dentate granule cells (GCs) and project back onto the proximal dendrites of GCs. By targeting the ipsi- and contralateral dentate gyrus (DG) along the dorsoventral axis of the hippocampus, MCs form an extensive recurrent excitatory circuit (GC-MC-GC) whose dysregulation can promote epilepsy. We recently reported that a physiologically relevant pattern of MC activity induces a robust form of presynaptic long-term potentiation (LTP) of MC-GC transmission which enhances GC output. Left unchecked, this LTP may interfere with DG-dependent learning, like pattern separation-which relies on sparse GC firing-and may even facilitate epileptic activity. Intriguingly, MC axons display uniquely high expression levels of type-1 cannabinoid receptors (CB1Rs), but their role at MC-GC synapses is poorly understood. Using rodent hippocampal slices, we report that constitutively active CB1Rs, presumably via βγ subunits, selectively inhibited MC inputs onto GCs but not MC inputs onto inhibitory interneurons or CB1R-sensitive inhibitory inputs onto GCs. Tonic CB1R activity also inhibited LTP and GC output. Furthermore, brief endocannabinoid release from GCs dampened MC-GC LTP in two mechanistically distinct ways: during induction via βγ signaling and before induction via αi/o signaling in a form of presynaptic metaplasticity. Lastly, a single in vivo exposure to exogenous cannabinoids was sufficient to induce this presynaptic metaplasticity. By dampening excitatory transmission and plasticity, tonic and phasic CB1R activity at MC axon terminals may preserve the sparse nature of the DG and protect against runaway excitation.
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5
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Monday HR, Bourdenx M, Jordan BA, Castillo PE. CB 1-receptor-mediated inhibitory LTD triggers presynaptic remodeling via protein synthesis and ubiquitination. eLife 2020; 9:54812. [PMID: 32902378 PMCID: PMC7521925 DOI: 10.7554/elife.54812] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 09/08/2020] [Indexed: 01/03/2023] Open
Abstract
Long-lasting forms of postsynaptic plasticity commonly involve protein synthesis-dependent structural changes of dendritic spines. However, the relationship between protein synthesis and presynaptic structural plasticity remains unclear. Here, we investigated structural changes in cannabinoid-receptor 1 (CB1)-mediated long-term depression of inhibitory transmission (iLTD), a form of presynaptic plasticity that involves a protein-synthesis-dependent long-lasting reduction in GABA release. We found that CB1-iLTD in acute rat hippocampal slices was associated with protein synthesis-dependent presynaptic structural changes. Using proteomics, we determined that CB1 activation in hippocampal neurons resulted in increased ribosomal proteins and initiation factors, but decreased levels of proteins involved in regulation of the actin cytoskeleton, such as ARPC2 and WASF1/WAVE1, and presynaptic release. Moreover, while CB1-iLTD increased ubiquitin/proteasome activity, ubiquitination but not proteasomal degradation was critical for structural and functional presynaptic CB1-iLTD. Thus, CB1-iLTD relies on both protein synthesis and ubiquitination to elicit structural changes that underlie long-term reduction of GABA release.
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Affiliation(s)
- Hannah R Monday
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, United States
| | - Mathieu Bourdenx
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, United States.,Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, United States
| | - Bryen A Jordan
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, United States.,Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, United States
| | - Pablo E Castillo
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, United States.,Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, United States
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6
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Piette C, Cui Y, Gervasi N, Venance L. Lights on Endocannabinoid-Mediated Synaptic Potentiation. Front Mol Neurosci 2020; 13:132. [PMID: 32848597 PMCID: PMC7399367 DOI: 10.3389/fnmol.2020.00132] [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: 05/04/2020] [Accepted: 06/26/2020] [Indexed: 12/15/2022] Open
Abstract
The endocannabinoid (eCB) system is a lipid-based neurotransmitter complex that plays crucial roles in the neural control of learning and memory. The current model of eCB-mediated retrograde signaling is that eCBs released from postsynaptic elements travel retrogradely to presynaptic axon terminals, where they activate cannabinoid type-1 receptors (CB1Rs) and ultimately decrease neurotransmitter release on a short- or long-term scale. An increasing body of evidence has enlarged this view and shows that eCBs, besides depressing synaptic transmission, are also able to increase neurotransmitter release at multiple synapses of the brain. This indicates that eCBs act as bidirectional regulators of synaptic transmission and plasticity. Recently, studies unveiled links between the expression of eCB-mediated long-term potentiation (eCB-LTP) and learning, and between its dysregulation and several pathologies. In this review article, we first distinguish the various forms of eCB-LTP based on their mechanisms, resulting from homosynaptically or heterosynaptically-mediated processes. Next, we consider the neuromodulation of eCB-LTP, its behavioral impact on learning and memory, and finally, eCB-LTP disruptions in various pathologies and its potential as a therapeutic target in disorders such as stress coping, addiction, Alzheimer’s and Parkinson’s disease, and pain. Cannabis is gaining popularity as a recreational substance as well as a medicine, and multiple eCB-based drugs are under development. In this context, it is critical to understand eCB-mediated signaling in its multi-faceted complexity. Indeed, the bidirectional nature of eCB-based neuromodulation may offer an important key to interpret the functions of the eCB system and how it is impacted by cannabis and other drugs.
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Affiliation(s)
- Charlotte Piette
- Center for Interdisciplinary Research in Biology, College de France, INSERM U1050, CNRS UMR7241, Labex Memolife, Paris, France
| | - Yihui Cui
- Department of Neurobiology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Nicolas Gervasi
- Center for Interdisciplinary Research in Biology, College de France, INSERM U1050, CNRS UMR7241, Labex Memolife, Paris, France
| | - Laurent Venance
- Center for Interdisciplinary Research in Biology, College de France, INSERM U1050, CNRS UMR7241, Labex Memolife, Paris, France
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7
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Capogna M, Castillo PE, Maffei A. The ins and outs of inhibitory synaptic plasticity: Neuron types, molecular mechanisms and functional roles. Eur J Neurosci 2020; 54:6882-6901. [PMID: 32663353 DOI: 10.1111/ejn.14907] [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: 01/30/2020] [Revised: 06/30/2020] [Accepted: 07/08/2020] [Indexed: 01/05/2023]
Abstract
GABAergic interneurons are highly diverse, and their synaptic outputs express various forms of plasticity. Compelling evidence indicates that activity-dependent changes of inhibitory synaptic transmission play a significant role in regulating neural circuits critically involved in learning and memory and circuit refinement. Here, we provide an updated overview of inhibitory synaptic plasticity with a focus on the hippocampus and neocortex. To illustrate the diversity of inhibitory interneurons, we discuss the case of two highly divergent interneuron types, parvalbumin-expressing basket cells and neurogliaform cells, which support unique roles on circuit dynamics. We also present recent progress on the molecular mechanisms underlying long-term, activity-dependent plasticity of fast inhibitory transmission. Lastly, we discuss the role of inhibitory synaptic plasticity in neuronal circuits' function. The emerging picture is that inhibitory synaptic transmission in the CNS is extremely diverse, undergoes various mechanistically distinct forms of plasticity and contributes to a much more refined computational role than initially thought. Both the remarkable diversity of inhibitory interneurons and the various forms of plasticity expressed by GABAergic synapses provide an amazingly rich inhibitory repertoire that is central to a variety of complex neural circuit functions, including memory.
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Affiliation(s)
- Marco Capogna
- Department of Biomedicine, Danish National Research Foundation Center of Excellence PROMEMO, Aarhus University, Aarhus, Denmark
| | - Pablo E Castillo
- Dominck P Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA.,Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Arianna Maffei
- Center for Neural Circuit Dynamics and Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, USA
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8
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Hu HY, Kruijssen DLH, Frias CP, Rózsa B, Hoogenraad CC, Wierenga CJ. Endocannabinoid Signaling Mediates Local Dendritic Coordination between Excitatory and Inhibitory Synapses. Cell Rep 2020; 27:666-675.e5. [PMID: 30995465 DOI: 10.1016/j.celrep.2019.03.078] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 12/21/2018] [Accepted: 03/21/2019] [Indexed: 01/01/2023] Open
Abstract
Dendritic inhibitory synapses are most efficient in modulating excitatory inputs localized on the same dendrite, but it is unknown whether their location is random or regulated. Here, we show that the formation of inhibitory synapses can be directed by excitatory synaptic activity on the same dendrite. We stimulated dendritic spines close to a GABAergic axon crossing by pairing two-photon glutamate uncaging with postsynaptic depolarization in CA1 pyramidal cells. We found that repeated spine stimulation promoted growth of a GABAergic bouton onto the same dendrite. The dendritic feedback signal required postsynaptic activation of DAGL, which produces the endocannabinoid 2-AG, and was mediated by CB1 receptors. We could also induce inhibitory bouton growth by local, brief applications of 2-AG. Our findings reveal a dendritic signaling mechanism to trigger growth of an inhibitory bouton at dendritic locations with strong excitatory synaptic activity, and this mechanism may serve to ensure inhibitory control over clustered excitatory inputs.
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Affiliation(s)
- Hai Yin Hu
- Department of Biology, Science for Life, Utrecht University, 3584CH Utrecht, the Netherlands
| | - Dennis L H Kruijssen
- Department of Biology, Science for Life, Utrecht University, 3584CH Utrecht, the Netherlands
| | - Cátia P Frias
- Department of Biology, Science for Life, Utrecht University, 3584CH Utrecht, the Netherlands
| | - Balázs Rózsa
- Laboratory of 3D Functional Network and Dendritic Imaging, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest 1083, Hungary; Faculty of Information Technology, Pázmány Péter Catholic University, Budapest 1083, Hungary
| | - Casper C Hoogenraad
- Department of Biology, Science for Life, Utrecht University, 3584CH Utrecht, the Netherlands
| | - Corette J Wierenga
- Department of Biology, Science for Life, Utrecht University, 3584CH Utrecht, the Netherlands.
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9
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Disrupted inhibitory plasticity and homeostasis in Fragile X syndrome. Neurobiol Dis 2020; 142:104959. [PMID: 32512151 PMCID: PMC7959200 DOI: 10.1016/j.nbd.2020.104959] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 05/28/2020] [Accepted: 06/03/2020] [Indexed: 12/21/2022] Open
Abstract
Fragile X Syndrome (FXS) is a neurodevelopmental disorder instigated by the absence of a key translation regulating protein, Fragile X Mental Retardation Protein (FMRP). The loss of FMRP in the CNS leads to abnormal synaptic development, disruption of critical periods of plasticity, and an overall deficiency in proper sensory circuit coding leading to hyperexcitable sensory networks. However, little is known about how this hyperexcitable environment affects inhibitory synaptic plasticity. Here, we show that in vivo layer 2/3 of the primary somatosensory cortex of the Fmr1 KO mouse exhibits basal hyperexcitability and an increase in neuronal firing rate suppression during whisker activation. This aligns with our in vitro data that indicate an increase in GABAergic spontaneous activity, a faulty mGluR-mediated inhibitory input and impaired inhibitory plasticity processes. Specifically, we find that mGluR activation sensitivity is overall diminished in the Fmr1 KO mouse leading to both a decreased spontaneous inhibitory postsynaptic input to principal cells and a disrupted form of inhibitory long-term depression (I-LTD). These data suggest an adaptive mechanism that acts to homeostatically counterbalance the cortical hyperexcitability observed in FXS.
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10
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Morgan PJ, Bourboulou R, Filippi C, Koenig-Gambini J, Epsztein J. Kv1.1 contributes to a rapid homeostatic plasticity of intrinsic excitability in CA1 pyramidal neurons in vivo. eLife 2019; 8:49915. [PMID: 31774395 PMCID: PMC6881145 DOI: 10.7554/elife.49915] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 11/08/2019] [Indexed: 12/12/2022] Open
Abstract
In area CA1 of the hippocampus, the selection of place cells to represent a new environment is biased towards neurons with higher excitability. However, different environments are represented by orthogonal cell ensembles, suggesting that regulatory mechanisms exist. Activity-dependent plasticity of intrinsic excitability, as observed in vitro, is an attractive candidate. Here, using whole-cell patch-clamp recordings of CA1 pyramidal neurons in anesthetized rats, we have examined how inducing theta-bursts of action potentials affects their intrinsic excitability over time. We observed a long-lasting, homeostatic depression of intrinsic excitability which commenced within minutes, and, in contrast to in vitro observations, was not mediated by dendritic Ih. Instead, it was attenuated by the Kv1.1 channel blocker dendrotoxin K, suggesting an axonal origin. Analysis of place cells’ out-of-field firing in mice navigating in virtual reality further revealed an experience-dependent reduction consistent with decreased excitability. We propose that this mechanism could reduce memory interference.
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Affiliation(s)
- Peter James Morgan
- Institute of Neurobiology of the Mediterranean Sea (INMED), Turing Center for Living Systems (CENTURI), Aix-Marseille University, INSERM, Marseille, France
| | - Romain Bourboulou
- Institute of Neurobiology of the Mediterranean Sea (INMED), Turing Center for Living Systems (CENTURI), Aix-Marseille University, INSERM, Marseille, France
| | - Caroline Filippi
- Institute of Neurobiology of the Mediterranean Sea (INMED), Turing Center for Living Systems (CENTURI), Aix-Marseille University, INSERM, Marseille, France
| | - Julie Koenig-Gambini
- Institute of Neurobiology of the Mediterranean Sea (INMED), Turing Center for Living Systems (CENTURI), Aix-Marseille University, INSERM, Marseille, France.,Institut Universitaire de France, Paris, France
| | - Jérôme Epsztein
- Institute of Neurobiology of the Mediterranean Sea (INMED), Turing Center for Living Systems (CENTURI), Aix-Marseille University, INSERM, Marseille, France
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11
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Xiang Z, Lv X, Maksymetz J, Stansley BJ, Ghoshal A, Gogliotti RG, Niswender CM, Lindsley CW, Conn PJ. mGlu 5 Positive Allosteric Modulators Facilitate Long-Term Potentiation via Disinhibition Mediated by mGlu 5-Endocannabinoid Signaling. ACS Pharmacol Transl Sci 2019; 2:198-209. [PMID: 31259318 PMCID: PMC6591772 DOI: 10.1021/acsptsci.9b00017] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Indexed: 11/29/2022]
Abstract
Metabotropic glutamate (mGlu) receptor type 5 (mGlu5) positive allosteric modulators (PAMs) enhance hippocampal long-term potentiation (LTP) and have cognition-enhancing effects in animal models. These effects were initially thought to be mediated by potentiation of mGlu5 modulation of N-methyl-d-aspartate receptor (NMDAR) currents. However, a biased mGlu5 PAM that potentiates Gαq-dependent mGlu5 signaling, but not mGlu5 modulation of NMDAR currents, retains cognition-enhancing effects in animal models, suggesting that potentiation of NMDAR currents is not required for these in vivo effects of mGlu5 PAMs. However, it is not clear whether the potentiation of NMDAR currents is critical for the ability of mGlu5 PAMs to enhance hippocampal LTP. We now report the characterization of effects of two structurally distinct mGlu5 PAMs, VU-29 and VU0092273, on NMDAR currents and hippocampal LTP. As with other mGlu5 PAMs that do not display observable bias for potentiation of NMDAR currents, VU0092273 enhanced both mGlu5 modulation of NMDAR currents and induction of LTP at the hippocampal Schaffer collateral (SC)-CA1 synapse. In contrast, VU-29 did not potentiate mGlu5 modulation of NMDAR currents but induced robust potentiation of hippocampal LTP. Interestingly, both VU-29 and VU0092273 suppressed evoked inhibitory postsynaptic currents (eIPSCs) in CA1 pyramidal cells, and this effect was blocked by the cannabinoid receptor type 1 (CB1) antagonist AM251. Furthermore, AM251 blocked the ability of both mGlu5 PAMs to enhance LTP. Finally, both PAMs failed to enhance LTP in mice with the restricted genetic deletion of mGlu5 in CA1 pyramidal cells. Taken together with previous findings, these results suggest that enhancement of LTP by mGlu5 PAMs does not depend on mGlu5 modulation of NMDAR currents but is mediated by a previously established mechanism in which mGlu5 in CA1 pyramidal cells induces endocannabinoid release and CB1-dependent disinhibition.
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Affiliation(s)
- Zixiu Xiang
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery,Department of Chemistry, Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Xiaohui Lv
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery,Department of Chemistry, Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - James Maksymetz
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery,Department of Chemistry, Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Branden J Stansley
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery,Department of Chemistry, Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Ayan Ghoshal
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery,Department of Chemistry, Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Rocco G Gogliotti
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery,Department of Chemistry, Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Colleen M Niswender
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery,Department of Chemistry, Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Craig W Lindsley
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery,Department of Chemistry, Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - P Jeffrey Conn
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery,Department of Chemistry, Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
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12
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Djurisic M, Brott BK, Saw NL, Shamloo M, Shatz CJ. Activity-dependent modulation of hippocampal synaptic plasticity via PirB and endocannabinoids. Mol Psychiatry 2019; 24:1206-1219. [PMID: 29670176 PMCID: PMC6372352 DOI: 10.1038/s41380-018-0034-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 01/21/2018] [Accepted: 01/31/2018] [Indexed: 12/18/2022]
Abstract
The threshold for Hebbian synaptic plasticity in the CNS is modulated by prior synaptic activity. At adult CA3-CA1 synapses, endocannabinoids play a role in this process, but how activity engages and maintains this retrograde signaling system is not well understood. Here we show that conditional deletion of Paired Immunoglobulin-like receptor B (PirB) from pyramidal neurons in adult mouse hippocampus results in deficient LTD at CA3-CA1 synapses over a range of stimulation frequencies, accompanied by an increase in LTP. This finding can be fully explained by the disengagement of retrograde endocannabinoid signaling selectively at excitatory synapses. In the absence of PirB, the NMDAR-dependent regulation of endocannabinoid signaling is lost, while CB1R-dependent and group I mGluR-dependent regulation are intact. Moreover, mEPSC frequency in mutant CA1 pyramidal cells is elevated, consistent with a higher density of excitatory synapses and altered synapse pruning. Mice lacking PirB also perform better than WT in learning and memory tasks. These observations suggest that PirB is an integral part of an NMDA receptor-mediated synaptic mechanism that maintains bidirectional Hebbian plasticity and learning via activity-dependent endocannabinoid signaling.
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Affiliation(s)
- Maja Djurisic
- Departments of Biology and Neurobiology, and Bio-X, Stanford University, Stanford, CA, 94305, USA.
| | - Barbara K. Brott
- 0000000419368956grid.168010.eDepartments of Biology and Neurobiology, and Bio-X, Stanford University, Stanford, CA 94305 USA
| | - Nay L. Saw
- 0000000419368956grid.168010.eBehavioral and Functional Neuroscience Laboratory, Stanford University School of Medicine, Stanford, CA 94305 USA
| | - Mehrdad Shamloo
- 0000000419368956grid.168010.eBehavioral and Functional Neuroscience Laboratory, Stanford University School of Medicine, Stanford, CA 94305 USA ,0000000419368956grid.168010.eBehavioral and Functional Neuroscience Laboratory and Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA 94305 USA
| | - Carla J. Shatz
- 0000000419368956grid.168010.eDepartments of Biology and Neurobiology, and Bio-X, Stanford University, Stanford, CA 94305 USA
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13
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Ramirez-Villegas JF, Willeke KF, Logothetis NK, Besserve M. Dissecting the Synapse- and Frequency-Dependent Network Mechanisms of In Vivo Hippocampal Sharp Wave-Ripples. Neuron 2018; 100:1224-1240.e13. [DOI: 10.1016/j.neuron.2018.09.041] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 06/25/2018] [Accepted: 09/24/2018] [Indexed: 01/14/2023]
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14
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Association of mGluR-Dependent LTD of Excitatory Synapses with Endocannabinoid-Dependent LTD of Inhibitory Synapses Leads to EPSP to Spike Potentiation in CA1 Pyramidal Neurons. J Neurosci 2018; 39:224-237. [PMID: 30459224 DOI: 10.1523/jneurosci.2935-17.2018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 10/16/2018] [Accepted: 11/08/2018] [Indexed: 01/10/2023] Open
Abstract
The input-output relationships in neural circuits are determined not only by synaptic efficacy but also by neuronal excitability. Activity-dependent alterations of synaptic efficacy have been extensively investigated, but relatively less is known about how the neuronal output is modulated when synaptic efficacy changes are associated with neuronal excitability changes. In this study, we demonstrate that paired pulses of low-frequency stimulation (PP-LFS) induced metabotropic glutamate receptor (mGluR)-dependent LTD at Schaffer collateral (SC)-CA1 synapses in Sprague Dawley rats (both sexes), and this LTD was associated with EPSP to spike (E-S) potentiation, leading to the increase in action potential (AP) outputs. Threshold voltage (Vth) for APs evoked by synaptic stimulation and that by somatic current injection were hyperpolarized significantly after PP-LFS. Blockers of GABA receptors mimicked and occluded PP-LFS effects on E-S potentiation and Vth hyperpolarization, suggesting that suppression of GABAergic mechanisms is involved in E-S potentiation after PP-LFS. Indeed, IPSCs and tonic inhibitory currents were reduced after PP-LFS. The IPSC reduction was accompanied by increased paired-pulse ratio, and abolished by AM251, a blocker for Type 1 cannabinoid receptors, suggesting that PP-LFS suppresses presynaptic GABA release by mGluR-dependent endocannabinoids signaling. By contrast, a Group 1 mGluR agonist, 3, 5-dihydroxyphenylglycine, induced LTD at SC-CA1 synapses but failed to induce significant IPSC reduction and AP output increase. We propose that mGluR signaling that induces LTD coexpression at excitatory and inhibitory synapses regulates an excitation-inhibition balance to increase neuronal output in CA1 neurons.SIGNIFICANCE STATEMENT Long-lasting forms of synaptic plasticity are usually associated with excitability changes, the ability to fire action potentials. However, excitability changes have been regarded to play subsidiary roles to synaptic plasticity in modifying neuronal output. We demonstrate that, when metabotropic glutamate receptor-dependent LTD is induced by paired pulses of low-frequency stimulation, the action potential output in response to a given input paradoxically increases, indicating that increased excitability is more powerful than synaptic depression. This increase is mediated by the suppression of a presynaptic GABA release via metabotropic glutamate receptor-dependent endocannabinoid signaling. Our study shows that neuronal output changes do not always follow the direction of synaptic plasticity at excitatory synapses, highlighting the importance of regulating inhibitory tone via endocannabinoid signaling.
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15
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Artinian J, Lacaille JC. Disinhibition in learning and memory circuits: New vistas for somatostatin interneurons and long-term synaptic plasticity. Brain Res Bull 2018; 141:20-26. [DOI: 10.1016/j.brainresbull.2017.11.012] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 11/08/2017] [Accepted: 11/20/2017] [Indexed: 12/21/2022]
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16
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Monday HR, Younts TJ, Castillo PE. Long-Term Plasticity of Neurotransmitter Release: Emerging Mechanisms and Contributions to Brain Function and Disease. Annu Rev Neurosci 2018; 41:299-322. [PMID: 29709205 DOI: 10.1146/annurev-neuro-080317-062155] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Long-lasting changes of brain function in response to experience rely on diverse forms of activity-dependent synaptic plasticity. Chief among them are long-term potentiation and long-term depression of neurotransmitter release, which are widely expressed by excitatory and inhibitory synapses throughout the central nervous system and can dynamically regulate information flow in neural circuits. This review article explores recent advances in presynaptic long-term plasticity mechanisms and contributions to circuit function. Growing evidence indicates that presynaptic plasticity may involve structural changes, presynaptic protein synthesis, and transsynaptic signaling. Presynaptic long-term plasticity can alter the short-term dynamics of neurotransmitter release, thereby contributing to circuit computations such as novelty detection, modifications of the excitatory/inhibitory balance, and sensory adaptation. In addition, presynaptic long-term plasticity underlies forms of learning and its dysregulation participates in several neuropsychiatric conditions, including schizophrenia, autism, intellectual disabilities, neurodegenerative diseases, and drug abuse.
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Affiliation(s)
- Hannah R Monday
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461, USA;
| | - Thomas J Younts
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, United Kingdom
| | - Pablo E Castillo
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461, USA;
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17
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Busquets-Garcia A, Bains J, Marsicano G. CB 1 Receptor Signaling in the Brain: Extracting Specificity from Ubiquity. Neuropsychopharmacology 2018; 43:4-20. [PMID: 28862250 PMCID: PMC5719111 DOI: 10.1038/npp.2017.206] [Citation(s) in RCA: 190] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 07/22/2017] [Accepted: 08/14/2017] [Indexed: 02/07/2023]
Abstract
Endocannabinoids (eCBs) are amongst the most ubiquitous signaling molecules in the nervous system. Over the past few decades, observations based on a large volume of work, first examining the pharmacological effects of exogenous cannabinoids, and then the physiological functions of eCBs, have directly challenged long-held and dogmatic views about communication, plasticity and behavior in the central nervous system (CNS). The eCBs and their cognate cannabinoid receptors exhibit a number of unique properties that distinguish them from the widely studied classical amino-acid transmitters, neuropeptides, and catecholamines. Although we now have a loose set of mechanistic rules based on experimental findings, new studies continue to reveal that our understanding of the eCB system (ECS) is continuously evolving and challenging long-held conventions. Here we will briefly summarize findings on the current canonical view of the 'ECS' and will address novel aspects that reveal how a nearly ubiquitous system can determine highly specific functions in the brain. In particular, we will focus on findings that push for an expansion of our ideas around long-held beliefs about eCB signaling that, while clearly true, may be contributing to an oversimplified perspective on how cannabinoid signaling at the microscopic level impacts behavior at the macroscopic level.
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Affiliation(s)
- Arnau Busquets-Garcia
- INSERM U1215, NeuroCentre Magendie, Team ‘Endocannabinoids and Neuroadaptation’, Bordeaux, France
- Université de Bordeaux, Bordeaux, France
| | - Jaideep Bains
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Giovanni Marsicano
- INSERM U1215, NeuroCentre Magendie, Team ‘Endocannabinoids and Neuroadaptation’, Bordeaux, France
- Université de Bordeaux, Bordeaux, France
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18
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Younts TJ, Monday HR, Dudok B, Klein ME, Jordan BA, Katona I, Castillo PE. Presynaptic Protein Synthesis Is Required for Long-Term Plasticity of GABA Release. Neuron 2017; 92:479-492. [PMID: 27764673 DOI: 10.1016/j.neuron.2016.09.040] [Citation(s) in RCA: 131] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 07/29/2016] [Accepted: 09/20/2016] [Indexed: 12/16/2022]
Abstract
Long-term changes of neurotransmitter release are critical for proper brain function. However, the molecular mechanisms underlying these changes are poorly understood. While protein synthesis is crucial for the consolidation of postsynaptic plasticity, whether and how protein synthesis regulates presynaptic plasticity in the mature mammalian brain remain unclear. Here, using paired whole-cell recordings in rodent hippocampal slices, we report that presynaptic protein synthesis is required for long-term, but not short-term, plasticity of GABA release from type 1 cannabinoid receptor (CB1)-expressing axons. This long-term depression of inhibitory transmission (iLTD) involves cap-dependent protein synthesis in presynaptic interneuron axons, but not somata. Translation is required during the induction, but not maintenance, of iLTD. Mechanistically, CB1 activation enhances protein synthesis via the mTOR pathway. Furthermore, using super-resolution STORM microscopy, we revealed eukaryotic ribosomes in CB1-expressing axon terminals. These findings suggest that presynaptic local protein synthesis controls neurotransmitter release during long-term plasticity in the mature mammalian brain.
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Affiliation(s)
- Thomas J Younts
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY 10461, USA.
| | - Hannah R Monday
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Barna Dudok
- Momentum Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest 1051, Hungary; School of Ph.D. Studies, Semmelweis University, Budapest 1085, Hungary
| | - Matthew E Klein
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Bryen A Jordan
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY 10461, USA; Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - István Katona
- Momentum Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest 1051, Hungary
| | - Pablo E Castillo
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY 10461, USA.
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19
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Taketo M, Matsuda H. Short-term inhibition of GABAergic IPSCs induced by association of pre- and postsynaptic activation in the neonatal hippocampus. Neuropharmacology 2017; 121:39-48. [DOI: 10.1016/j.neuropharm.2017.04.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 03/19/2017] [Accepted: 04/13/2017] [Indexed: 10/19/2022]
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20
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Araque A, Castillo PE, Manzoni OJ, Tonini R. Synaptic functions of endocannabinoid signaling in health and disease. Neuropharmacology 2017. [PMID: 28625718 DOI: 10.1016/j.neuropharm.2017.06.017] [Citation(s) in RCA: 147] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Endocannabinoids (eCBs) are a family of lipid molecules that act as key regulators of synaptic transmission and plasticity. They are synthetized "on demand" following physiological and/or pathological stimuli. Once released from postsynaptic neurons, eCBs typically act as retrograde messengers to activate presynaptic type 1 cannabinoid receptors (CB1) and induce short- or long-term depression of neurotransmitter release. Besides this canonical mechanism of action, recent findings have revealed a number of less conventional mechanisms by which eCBs regulate neural activity and synaptic function, suggesting that eCB-mediated plasticity is mechanistically more diverse than anticipated. These mechanisms include non-retrograde signaling, signaling via astrocytes, participation in long-term potentiation, and the involvement of mitochondrial CB1. Focusing on paradigmatic brain areas, such as hippocampus, striatum, and neocortex, we review typical and novel signaling mechanisms, and discuss the functional implications in normal brain function and brain diseases. In summary, eCB signaling may lead to different forms of synaptic plasticity through activation of a plethora of mechanisms, which provide further complexity to the functional consequences of eCB signaling. This article is part of the Special Issue entitled "A New Dawn in Cannabinoid Neurobiology".
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Affiliation(s)
- Alfonso Araque
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Pablo E Castillo
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY 10461, USA.
| | - Olivier J Manzoni
- Institut National de la Santé et et de la Recherche Médicale U901 Marseille, France, Université de la Méditerranée UMR S901 Aix-Marseille Marseille, France, INMED Marseille, France.
| | - Raffaella Tonini
- Neuroscience and Brain Technologies Department, Istituto Italiano di Tecnologia, Genova, Italy.
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21
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Tatti R, Haley MS, Swanson O, Tselha T, Maffei A. Neurophysiology and Regulation of the Balance Between Excitation and Inhibition in Neocortical Circuits. Biol Psychiatry 2017; 81:821-831. [PMID: 27865453 PMCID: PMC5374043 DOI: 10.1016/j.biopsych.2016.09.017] [Citation(s) in RCA: 105] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 08/25/2016] [Accepted: 09/15/2016] [Indexed: 12/18/2022]
Abstract
Brain function relies on the ability of neural networks to maintain stable levels of activity, while experiences sculpt them. In the neocortex, the balance between activity and stability relies on the coregulation of excitatory and inhibitory inputs onto principal neurons. Shifts of excitation or inhibition result in altered excitability impaired processing of incoming information. In many neurodevelopmental and neuropsychiatric disorders, the excitability of local circuits is altered, suggesting that their pathophysiology may involve shifts in synaptic excitation, inhibition, or both. Most studies focused on identifying the cellular and molecular mechanisms controlling network excitability to assess whether they may be altered in animal models of disease. The impact of changes in excitation/inhibition balance on local circuit and network computations is not clear. Here we report findings on the integration of excitatory and inhibitory inputs in healthy cortical circuits and discuss how shifts in excitation/inhibition balance may relate to pathological phenotypes.
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Affiliation(s)
- Roberta Tatti
- Dept. of Neurobiology and Behavior, SUNY-Stony Brook, Stony Brook, NY 11794
| | - Melissa S. Haley
- Dept. of Neurobiology and Behavior, SUNY-Stony Brook, Stony Brook, NY 11794
| | - Olivia Swanson
- Dept. of Neurobiology and Behavior, SUNY-Stony Brook, Stony Brook, NY 11794
| | - Tenzin Tselha
- Dept. of Neurobiology and Behavior, SUNY-Stony Brook, Stony Brook, NY 11794
| | - Arianna Maffei
- Department of Neurobiology and Behavior, Stony Brook University, The State University of New York, Stony Brook, New York.
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22
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Rangaraju V, Tom Dieck S, Schuman EM. Local translation in neuronal compartments: how local is local? EMBO Rep 2017; 18:693-711. [PMID: 28404606 DOI: 10.15252/embr.201744045] [Citation(s) in RCA: 110] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 03/15/2017] [Accepted: 03/15/2017] [Indexed: 12/18/2022] Open
Abstract
Efficient neuronal function depends on the continued modulation of the local neuronal proteome. Local protein synthesis plays a central role in tuning the neuronal proteome at specific neuronal regions. Various aspects of translation such as the localization of translational machinery, spatial spread of the newly translated proteins, and their site of action are carried out in specialized neuronal subcompartments to result in a localized functional outcome. In this review, we focus on the various aspects of these local translation compartments such as size, biochemical and organelle composition, structural boundaries, and temporal dynamics. We also discuss the apparent absence of definitive components of translation in these local compartments and the emerging state-of-the-art tools that could help dissecting these conundrums in greater detail in the future.
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Affiliation(s)
- Vidhya Rangaraju
- Max Planck Institute for Brain Research, Frankfurt am Main, Germany
| | | | - Erin M Schuman
- Max Planck Institute for Brain Research, Frankfurt am Main, Germany
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23
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Senter RK, Ghoshal A, Walker AG, Xiang Z, Niswender CM, Conn PJ. The Role of mGlu Receptors in Hippocampal Plasticity Deficits in Neurological and Psychiatric Disorders: Implications for Allosteric Modulators as Novel Therapeutic Strategies. Curr Neuropharmacol 2017; 14:455-73. [PMID: 27296640 PMCID: PMC4983746 DOI: 10.2174/1570159x13666150421003225] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 03/18/2015] [Accepted: 04/09/2015] [Indexed: 11/22/2022] Open
Abstract
Long-term potentiation (LTP) and long-term depression (LTD) are two distinct forms of synaptic plasticity that have been extensively characterized at the Schaffer collateral-CA1 (SCCA1) synapse and the mossy fiber (MF)-CA3 synapse within the hippocampus, and are postulated to be the molecular underpinning for several cognitive functions. Deficits in LTP and LTD have been implicated in the pathophysiology of several neurological and psychiatric disorders. Therefore, there has been a large effort focused on developing an understanding of the mechanisms underlying these forms of plasticity and novel therapeutic strategies that improve or rescue these plasticity deficits. Among many other targets, the metabotropic glutamate (mGlu) receptors show promise as novel therapeutic candidates for the treatment of these disorders. Among the eight distinct mGlu receptor subtypes (mGlu1-8), the mGlu1,2,3,5,7 subtypes are expressed throughout the hippocampus and have been shown to play important roles in the regulation of synaptic plasticity in this brain area. However, development of therapeutic agents that target these mGlu receptors has been hampered by a lack of subtype-selective compounds. Recently, discovery of allosteric modulators of mGlu receptors has provided novel ligands that are highly selective for individual mGlu receptor subtypes. The mGlu receptors modulate the multiple forms of synaptic plasticity at both SC-CA1 and MF synapses and allosteric modulators of mGlu receptors have emerged as potential therapeutic agents that may rescue plasticity deficits and improve cognitive function in patients suffering from multiple neurological and psychiatric disorders.
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Affiliation(s)
| | | | | | | | | | - P Jeffrey Conn
- Department of Pharmacology, Faculty of Vanderbilt University Medical Center, 1205 Light Hall, Nashville, TN 37232, USA.
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24
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Younts TJ, Monday HR, Dudok B, Klein ME, Jordan BA, Katona I, Castillo PE. Presynaptic Protein Synthesis Is Required for Long-Term Plasticity of GABA Release. Neuron 2016. [PMID: 27764673 DOI: 10.1016/j.neuron.2016.09.040.] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Long-term changes of neurotransmitter release are critical for proper brain function. However, the molecular mechanisms underlying these changes are poorly understood. While protein synthesis is crucial for the consolidation of postsynaptic plasticity, whether and how protein synthesis regulates presynaptic plasticity in the mature mammalian brain remain unclear. Here, using paired whole-cell recordings in rodent hippocampal slices, we report that presynaptic protein synthesis is required for long-term, but not short-term, plasticity of GABA release from type 1 cannabinoid receptor (CB1)-expressing axons. This long-term depression of inhibitory transmission (iLTD) involves cap-dependent protein synthesis in presynaptic interneuron axons, but not somata. Translation is required during the induction, but not maintenance, of iLTD. Mechanistically, CB1 activation enhances protein synthesis via the mTOR pathway. Furthermore, using super-resolution STORM microscopy, we revealed eukaryotic ribosomes in CB1-expressing axon terminals. These findings suggest that presynaptic local protein synthesis controls neurotransmitter release during long-term plasticity in the mature mammalian brain.
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Affiliation(s)
- Thomas J Younts
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY 10461, USA.
| | - Hannah R Monday
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Barna Dudok
- Momentum Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest 1051, Hungary; School of Ph.D. Studies, Semmelweis University, Budapest 1085, Hungary
| | - Matthew E Klein
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Bryen A Jordan
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY 10461, USA; Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - István Katona
- Momentum Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest 1051, Hungary
| | - Pablo E Castillo
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY 10461, USA.
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25
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Balu DT, Li Y, Takagi S, Presti KT, Ramikie TS, Rook JM, Jones CK, Lindsley CW, Conn PJ, Bolshakov VY, Coyle JT. An mGlu5-Positive Allosteric Modulator Rescues the Neuroplasticity Deficits in a Genetic Model of NMDA Receptor Hypofunction in Schizophrenia. Neuropsychopharmacology 2016; 41:2052-61. [PMID: 26741285 PMCID: PMC4908650 DOI: 10.1038/npp.2016.2] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 12/01/2015] [Accepted: 01/02/2016] [Indexed: 12/13/2022]
Abstract
There is substantial evidence that NMDA receptor (NMDAR) hypofunction contributes to the pathophysiology of schizophrenia (SCZ). A recent large-scale genome-wide association study identified serine racemase (SR), the enzyme that produces the NMDAR co-agonist D-serine, as a risk gene for SCZ. Serine racemase knockout (SR-/-) mice, which lack D-serine, exhibit many of the neurochemical and behavioral abnormalities observed in SCZ. Metabotropic glutamate receptor 5 (mGlu5)-positive allosteric modulators (PAMs) are currently being developed to treat cognitive dysfunction. We used in vitro electrophysiology to determine whether the mGlu5 PAM VU0409551 directly enhances NMDAR function in hippocampal slices from adult male SR-/- mice. We administered VU0409551 systemically for 5 days to adult male wild-type C57BL/6 animals to determine the optimal dose to test in SR-/- mice. We used western blot analyses and trace-fear conditioning to determine whether 5 days of VU0409551 treatment could reverse the neuroplasticity and learning deficits, respectively, in SR-/- mice. We show that VU0409551 enhances NMDAR function and rescues long-term potentiation in hippocampal slices obtained from SR-/- mice. Systemic treatment with VU0409551 (10 and 30 mg/kg) to wild-type mice causes a dose-dependent increase in the Akt/GS3Kα/β signaling pathway, which is reduced in SR-/- mice and in SCZ. Furthermore, the administration of VU0409551 to SR-/- mice reverses their deficits in several neuroplasticity signaling pathways and improves their contextual fear memory. These results support positive allosteric modulation of mGlu5, particularly with VU0409551, as a viable mechanism to reverse the deficits in NMDAR function, synaptic plasticity, and memory that are known to be impaired in SCZ.
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Affiliation(s)
- Darrick T Balu
- Department of Psychiatry, Harvard Medical School, Boston, MA, USA,Laboratory for Psychiatric and Molecular Neuroscience, McLean Hospital, Belmont, MA, USA,Laboratory for Psychiatric and Molecular Neuroscience, McLean Hospital, 115 Mill Street, Belmont, MA 02478, USA, Tel: +617 855 2329, Fax: +617 855 2705, E-mail:
| | - Yan Li
- Department of Psychiatry, Harvard Medical School, Boston, MA, USA
| | - Shunsuke Takagi
- Laboratory for Psychiatric and Molecular Neuroscience, McLean Hospital, Belmont, MA, USA,Department of Psychiatry and Behavioral Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Kendall Taylor Presti
- Laboratory for Psychiatric and Molecular Neuroscience, McLean Hospital, Belmont, MA, USA
| | - Teniel S Ramikie
- Department of Psychiatry, Harvard Medical School, Boston, MA, USA
| | - Jerri M Rook
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Carrie K Jones
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Craig W Lindsley
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - P Jeffrey Conn
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN, USA
| | | | - Joseph T Coyle
- Department of Psychiatry, Harvard Medical School, Boston, MA, USA,Laboratory for Psychiatric and Molecular Neuroscience, McLean Hospital, Belmont, MA, USA
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26
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Cannabinoid Type 2 Receptors Mediate a Cell Type-Specific Plasticity in the Hippocampus. Neuron 2016; 90:795-809. [PMID: 27133464 DOI: 10.1016/j.neuron.2016.03.034] [Citation(s) in RCA: 203] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 01/20/2016] [Accepted: 03/18/2016] [Indexed: 02/07/2023]
Abstract
Endocannabinoids (eCBs) exert major control over neuronal activity by activating cannabinoid receptors (CBRs). The functionality of the eCB system is primarily ascribed to the well-documented retrograde activation of presynaptic CB1Rs. We find that action potential-driven eCB release leads to a long-lasting membrane potential hyperpolarization in hippocampal principal cells that is independent of CB1Rs. The hyperpolarization, which is specific to CA3 and CA2 pyramidal cells (PCs), depends on the activation of neuronal CB2Rs, as shown by a combined pharmacogenetic and immunohistochemical approach. Upon activation, they modulate the activity of the sodium-bicarbonate co-transporter, leading to a hyperpolarization of the neuron. CB2R activation occurred in a purely self-regulatory manner, robustly altered the input/output function of CA3 PCs, and modulated gamma oscillations in vivo. To conclude, we describe a cell type-specific plasticity mechanism in the hippocampus that provides evidence for the neuronal expression of CB2Rs and emphasizes their importance in basic neuronal transmission.
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27
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Jappy D, Valiullina F, Draguhn A, Rozov A. GABABR-Dependent Long-Term Depression at Hippocampal Synapses between CB1-Positive Interneurons and CA1 Pyramidal Cells. Front Cell Neurosci 2016; 10:4. [PMID: 26858602 PMCID: PMC4729905 DOI: 10.3389/fncel.2016.00004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 01/04/2016] [Indexed: 12/31/2022] Open
Abstract
Activity induced long lasting modifications of synaptic efficacy have been extensively studied in excitatory synapses, however, long term plasticity is also a property of inhibitory synapses. Inhibitory neurons in the hippocampal CA1 region can be subdivided according to the compartment they target on the pyramidal cell. Some interneurons preferentially innervate the perisomatic area and axon hillock of the pyramidal cells while others preferentially target dendritic branches and spines. Another characteristic feature allowing functional classification of interneurons is cell type specific expression of different neurochemical markers and receptors. In the hippocampal CA1 region, nearly 90% of the interneurons expressing cannabinoid type 1 receptors (CB1R) also express cholecystokinin (CCK). Therefore, the functional presence of CB1 receptors can be used for identification of the inhibitory input from CCK positive (CCK+) interneurons to CA1 pyramidal cells. The goal of this study was to explore the nature of long term plasticity at the synapses between interneurons expressing CB1Rs (putative CCK+) and pyramidal neurons in the CA1 region of the hippocampus in vitro. We found that theta burst stimulation triggered robust long-term depression (LTD) at this synapse. The locus of LTD induction was postsynaptic and required activation of GABAB receptors. We also showed that LTD at this synaptic connection involves GABABR-dependent suppression of adenylyl cyclase and consequent reduction of PKA activity. In this respect, CB1+ to pyramidal cell synapses differ from the majority of the other hippocampal inhibitory connections where theta burst stimulation results in long-term potentiation.
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Affiliation(s)
- Dave Jappy
- OpenLab of Neurobiology, Kazan Federal University Kazan, Russia
| | | | - Andreas Draguhn
- Department of Physiology and Pathophysiology, University of Heidelberg Heidelberg, Germany
| | - Andrei Rozov
- OpenLab of Neurobiology, Kazan Federal UniversityKazan, Russia; Department of Physiology and Pathophysiology, University of HeidelbergHeidelberg, Germany
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28
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Basu J, Zaremba JD, Cheung SK, Hitti FL, Zemelman BV, Losonczy A, Siegelbaum SA. Gating of hippocampal activity, plasticity, and memory by entorhinal cortex long-range inhibition. Science 2016; 351:aaa5694. [PMID: 26744409 PMCID: PMC4920085 DOI: 10.1126/science.aaa5694] [Citation(s) in RCA: 167] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The cortico-hippocampal circuit is critical for storage of associational memories. Most studies have focused on the role in memory storage of the excitatory projections from entorhinal cortex to hippocampus. However, entorhinal cortex also sends inhibitory projections, whose role in memory storage and cortico-hippocampal activity remains largely unexplored. We found that these long-range inhibitory projections enhance the specificity of contextual and object memory encoding. At the circuit level, these γ-aminobutyric acid (GABA)-releasing projections target hippocampal inhibitory neurons and thus act as a disinhibitory gate that transiently promotes the excitation of hippocampal CA1 pyramidal neurons by suppressing feedforward inhibition. This enhances the ability of CA1 pyramidal neurons to fire synaptically evoked dendritic spikes and to generate a temporally precise form of heterosynaptic plasticity. Long-range inhibition from entorhinal cortex may thus increase the precision of hippocampal-based long-term memory associations by assessing the salience of mnemonormation to the immediate sensory input.
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Affiliation(s)
- Jayeeta Basu
- Department of Neuroscience, Kavli Brain Institute, Columbia University Medical Center, 1051 Riverside Drive, New York, NY 10032, USA.
| | - Jeffrey D Zaremba
- Department of Neuroscience, Kavli Brain Institute, Columbia University Medical Center, 1051 Riverside Drive, New York, NY 10032, USA
| | - Stephanie K Cheung
- Department of Neuroscience, Kavli Brain Institute, Columbia University Medical Center, 1051 Riverside Drive, New York, NY 10032, USA
| | - Frederick L Hitti
- Department of Neuroscience, Kavli Brain Institute, Columbia University Medical Center, 1051 Riverside Drive, New York, NY 10032, USA
| | | | - Attila Losonczy
- Department of Neuroscience, Kavli Brain Institute, Columbia University Medical Center, 1051 Riverside Drive, New York, NY 10032, USA
| | - Steven A Siegelbaum
- Department of Neuroscience, Kavli Brain Institute, Columbia University Medical Center, 1051 Riverside Drive, New York, NY 10032, USA.
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Martin HGS, Bernabeu A, Lassalle O, Bouille C, Beurrier C, Pelissier-Alicot AL, Manzoni OJ. Endocannabinoids Mediate Muscarinic Acetylcholine Receptor-Dependent Long-Term Depression in the Adult Medial Prefrontal Cortex. Front Cell Neurosci 2015; 9:457. [PMID: 26648844 PMCID: PMC4664641 DOI: 10.3389/fncel.2015.00457] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 11/09/2015] [Indexed: 12/31/2022] Open
Abstract
Cholinergic inputs into the prefrontal cortex (PFC) are associated with attention and cognition; however there is evidence that acetylcholine also has a role in PFC dependent learning and memory. Muscarinic acetylcholine receptors (mAChR) in the PFC can induce synaptic plasticity, but the underlying mechanisms remain either opaque or unresolved. We have characterized a form of mAChR mediated long-term depression (LTD) at glutamatergic synapses of layer 5 principal neurons in the adult medial PFC. This mAChR LTD is induced with the mAChR agonist carbachol and inhibited by selective M1 mAChR antagonists. In contrast to other cortical regions, we find that this M1 mAChR mediated LTD is coupled to endogenous cannabinoid (eCB) signaling. Inhibition of the principal eCB CB1 receptor blocked carbachol induced LTD in both rats and mice. Furthermore, when challenged with a sub-threshold carbachol application, LTD was induced in slices pretreated with the monoacylglycerol lipase (MAGL) inhibitor JZL184, suggesting that the eCB 2-arachidonylglyerol (2-AG) mediates M1 mAChR LTD. Yet, when endogenous acetylcholine was released from local cholinergic afferents in the PFC using optogenetics, it failed to trigger eCB-LTD. However coupling patterned optical and electrical stimulation to generate local synaptic signaling allowed the reliable induction of LTD. The light—electrical pairing induced LTD was M1 mAChR and CB1 receptor mediated. This shows for the first time that connecting excitatory synaptic activity with coincident endogenously released acetylcholine controls synaptic gain via eCB signaling. Together these results shed new light on the mechanisms of synaptic plasticity in the adult PFC and expand on the actions of endogenous cholinergic signaling.
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Affiliation(s)
- Henry G S Martin
- Aix-Marseille Université Marseille, France ; Institut de Neurobiologie de la Méditerranée UMR_S 901 Marseille, France ; INMED UMR_S 901 Marseille, France
| | - Axel Bernabeu
- Aix-Marseille Université Marseille, France ; Institut de Neurobiologie de la Méditerranée UMR_S 901 Marseille, France ; INMED UMR_S 901 Marseille, France ; APHM, CHU Conception, Service de Psychiatrie Marseille, France
| | - Olivier Lassalle
- Aix-Marseille Université Marseille, France ; Institut de Neurobiologie de la Méditerranée UMR_S 901 Marseille, France ; INMED UMR_S 901 Marseille, France
| | - Clément Bouille
- Aix-Marseille Université Marseille, France ; Institut de Neurobiologie de la Méditerranée UMR_S 901 Marseille, France ; INMED UMR_S 901 Marseille, France
| | - Corinne Beurrier
- Aix-Marseille Université Marseille, France ; Centre National de la Recherche Scientifique, Institut de Biologie du Développement de Marseille UMR 7288 Marseille, France
| | - Anne-Laure Pelissier-Alicot
- Aix-Marseille Université Marseille, France ; Institut de Neurobiologie de la Méditerranée UMR_S 901 Marseille, France ; INMED UMR_S 901 Marseille, France ; APHM, CHU Timone Adultes, Service de Médecine Légale Marseille, France
| | - Olivier J Manzoni
- Aix-Marseille Université Marseille, France ; Institut de Neurobiologie de la Méditerranée UMR_S 901 Marseille, France ; INMED UMR_S 901 Marseille, France
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30
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Abstract
UNLABELLED The possibility that mechanisms of synaptic modulation differ between males and females has far-reaching implications for understanding brain disorders that vary between the sexes. We found recently that 17β-estradiol (E2) acutely suppresses GABAergic inhibition in the hippocampus of female rats through a sex-specific estrogen receptor α (ERα), mGluR, and endocannabinoid-dependent mechanism. Here, we define the intracellular signaling that links ERα, mGluRs, and endocannabinoids in females and identify where in this pathway males and females differ. Using a combination of whole-cell patch-clamp recording and biochemical analyses in hippocampal slices from young adult rats, we show that E2 acutely suppresses inhibition in females through mGluR1 stimulation of phospholipase C, leading to inositol triphosphate (IP3) generation, activation of the IP3 receptor (IP3R), and postsynaptic endocannabinoid release, likely of anandamide. Analysis of sex differences in this pathway showed that E2 stimulates a much greater increase in IP3 levels in females than males, whereas the group I mGluR agonist DHPG increases IP3 levels equivalently in each sex. Coimmunoprecipitation showed that ERα-mGluR1 and mGluR1-IP3R complexes exist in both sexes but are regulated by E2 only in females. Independently of E2, a fatty acid amide hydrolase inhibitor, which blocks breakdown of anandamide, suppressed >50% of inhibitory synapses in females with no effect in males, indicating tonic endocannabinoid release in females that is absent in males. Together, these studies demonstrate sex differences in both E2-dependent and E2-independent regulation of the endocannabinoid system and suggest that manipulation of endocannabinoids in vivo could affect physiological and behavioral responses differently in each sex. SIGNIFICANCE STATEMENT Many brain disorders vary between the sexes, yet the degree to which this variation arises from differential experience versus intrinsic biological sex differences is unclear. In this study, we demonstrate intrinsic sex differences in molecular regulation of a key neuromodulatory system, the endocannabinoid system, in the hippocampus. Endocannabinoids are involved in diverse aspects of physiology and behavior that involve the hippocampus, including cognitive and motivational state, responses to stress, and neurological disorders such as epilepsy. Our finding that molecular regulation of the endocannabinoid system differs between the sexes suggests mechanisms through which experiences or therapeutics that engage endocannabinoids could affect males and females differently.
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Basu J, Siegelbaum SA. The Corticohippocampal Circuit, Synaptic Plasticity, and Memory. Cold Spring Harb Perspect Biol 2015; 7:7/11/a021733. [PMID: 26525152 DOI: 10.1101/cshperspect.a021733] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Synaptic plasticity serves as a cellular substrate for information storage in the central nervous system. The entorhinal cortex (EC) and hippocampus are interconnected brain areas supporting basic cognitive functions important for the formation and retrieval of declarative memories. Here, we discuss how information flow in the EC-hippocampal loop is organized through circuit design. We highlight recently identified corticohippocampal and intrahippocampal connections and how these long-range and local microcircuits contribute to learning. This review also describes various forms of activity-dependent mechanisms that change the strength of corticohippocampal synaptic transmission. A key point to emerge from these studies is that patterned activity and interaction of coincident inputs gives rise to associational plasticity and long-term regulation of information flow. Finally, we offer insights about how learning-related synaptic plasticity within the corticohippocampal circuit during sensory experiences may enable adaptive behaviors for encoding spatial, episodic, social, and contextual memories.
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Affiliation(s)
- Jayeeta Basu
- Department of Neuroscience and Physiology, NYU Neuroscience Institute, New York University School of Medicine, New York, New York 10016
| | - Steven A Siegelbaum
- Kavli Institute for Brain Science, Columbia University, New York, New York 10032 Department of Neuroscience, Columbia University, New York, New York 10032 Department of Pharmacology, Columbia University, New York, New York 10032
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Allene C, Lourenço J, Bacci A. The neuronal identity bias behind neocortical GABAergic plasticity. Trends Neurosci 2015; 38:524-34. [PMID: 26318208 DOI: 10.1016/j.tins.2015.07.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 07/28/2015] [Accepted: 07/29/2015] [Indexed: 12/18/2022]
Abstract
In the neocortex, different types of excitatory and inhibitory neurons connect to one another following a detailed blueprint, defining functionally-distinct subnetworks, whose activity and modulation underlie complex cognitive functions. We review the cell-autonomous plasticity of perisomatic inhibition onto principal excitatory neurons. We propose that the tendency of different cortical layers to exhibit depression or potentiation of perisomatic inhibition is dictated by the specific identities of principal neurons (PNs). These are mainly defined by their projection targets and by their preference to be innervated by specific perisomatic-targeting basket cell types. Therefore, principal neurons responsible for relaying information to subcortical nuclei are differentially inhibited and show specific forms of plasticity compared to other PNs that are specialized in more associative functions.
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Affiliation(s)
- Camille Allene
- Sorbonne Universités, Université Pierre et Marie Curie (UPMC Paris 6), Unité Mixte de Recherche S 1127; Institut National de la Santé et de la Recherche Médicale (INSERM) Unité 1127; Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche 7225; Institut du Cerveau et de la Moelle épinière (ICM), 75013 Paris, France
| | - Joana Lourenço
- Sorbonne Universités, Université Pierre et Marie Curie (UPMC Paris 6), Unité Mixte de Recherche S 1127; Institut National de la Santé et de la Recherche Médicale (INSERM) Unité 1127; Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche 7225; Institut du Cerveau et de la Moelle épinière (ICM), 75013 Paris, France
| | - Alberto Bacci
- Sorbonne Universités, Université Pierre et Marie Curie (UPMC Paris 6), Unité Mixte de Recherche S 1127; Institut National de la Santé et de la Recherche Médicale (INSERM) Unité 1127; Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche 7225; Institut du Cerveau et de la Moelle épinière (ICM), 75013 Paris, France.
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33
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Sun W, Wang L, Li S, Tie X, Jiang B. Layer-specific endocannabinoid-mediated long-term depression of GABAergic neurotransmission onto principal neurons in mouse visual cortex. Eur J Neurosci 2015; 42:1952-65. [PMID: 25997857 DOI: 10.1111/ejn.12958] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 05/15/2015] [Accepted: 05/17/2015] [Indexed: 11/29/2022]
Abstract
Visually induced endocannabinoid-mediated long-term depression of GABAergic neurotransmission (iLTD) mediates the maturation of GABAergic release in layer 2/3 of visual cortex. Here we examined whether the maturation of GABAergic transmission in other layers of visual cortex also requires endocannabinoids. The developmental plasticity of GABAergic neurotransmission onto the principal neurons in different layers of mouse visual cortex was examined in cortical slices by whole-cell recordings of inhibitory postsynaptic currents evoked by presynaptic inhibitory inputs. Theta burst stimulation of GABAergic inputs induced an endocannabinoid-mediated long-term depression of GABAergic neurotransmission onto pyramidal cells in layer 2/3 from postnatal day (P)10 to 30 and in layer 5 from P10 to 40, whereas that of GABAergic inputs did not induce iLTD onto star pyramidal neurons in layer 4 at any time postnatally, indicating that this plasticity is laminar-specific. The developmental loss of iLTD paralleled the maturation of GABAergic inhibition in both layer 2/3 and layer 5. Visual deprivation delayed the developmental loss of iLTD in layers 3 and 5 during a critical period, while 2 days of light exposure eliminated iLTD in both layers. Furthermore, the GABAergic synapses in layers 2/3 and 5 did not normally mature in the type 1 cannabinoid receptor knock-out mice, whereas those in layer 4 did not require endocannabinoid receptor for maturation. These results suggest that visually induced endocannabinoid-dependent iLTD mediates the maturation of GABAergic release in extragranular layer rather than in granular layer of mouse visual cortex.
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Affiliation(s)
- Wenjuan Sun
- Neuroscience Research Center, Department of Physiology, Zhongshan School of Medicine, Sun Yat-Sen University, 74, Zhongshan Road 2, Guangzhou, 510080, China
| | - Laijian Wang
- Neuroscience Research Center, Department of Physiology, Zhongshan School of Medicine, Sun Yat-Sen University, 74, Zhongshan Road 2, Guangzhou, 510080, China
| | - Shuo Li
- Neuroscience Research Center, Department of Physiology, Zhongshan School of Medicine, Sun Yat-Sen University, 74, Zhongshan Road 2, Guangzhou, 510080, China
| | - Xiaoxiu Tie
- Neuroscience Research Center, Department of Physiology, Zhongshan School of Medicine, Sun Yat-Sen University, 74, Zhongshan Road 2, Guangzhou, 510080, China
| | - Bin Jiang
- Neuroscience Research Center, Department of Physiology, Zhongshan School of Medicine, Sun Yat-Sen University, 74, Zhongshan Road 2, Guangzhou, 510080, China
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34
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Soltesz I, Alger BE, Kano M, Lee SH, Lovinger DM, Ohno-Shosaku T, Watanabe M. Weeding out bad waves: towards selective cannabinoid circuit control in epilepsy. Nat Rev Neurosci 2015; 16:264-77. [PMID: 25891509 PMCID: PMC10631555 DOI: 10.1038/nrn3937] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Endocannabinoids are lipid-derived messengers, and both their synthesis and breakdown are under tight spatiotemporal regulation. As retrograde signalling molecules, endocannabinoids are synthesized postsynaptically but activate presynaptic cannabinoid receptor 1 (CB1) receptors to inhibit neurotransmitter release. In turn, CB1-expressing inhibitory and excitatory synapses act as strategically placed control points for activity-dependent regulation of dynamically changing normal and pathological oscillatory network activity. Here, we highlight emerging principles of cannabinoid circuit control and plasticity, and discuss their relevance for epilepsy and related comorbidities. New insights into cannabinoid signalling may facilitate the translation of the recent interest in cannabis-related substances as antiseizure medications to evidence-based treatment strategies.
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Affiliation(s)
- Ivan Soltesz
- Department of Anatomy and Neurobiology, University of California, Irvine, California 92697, USA
| | - Bradley E Alger
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
| | - Masanobu Kano
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Sang-Hun Lee
- Department of Anatomy and Neurobiology, University of California, Irvine, California 92697, USA
| | - David M Lovinger
- Section on Synaptic Pharmacology, Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, US National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Takako Ohno-Shosaku
- Department of Impairment Study, Graduate School of Medical Science, Kanazawa University, Kanazawa 920-0942, Japan
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan
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35
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Abstract
Exogenous cannabinoids can limit seizures and neurodegeneration, and their actions are largely mimicked by endogenous cannabinoids (endocannabinoids). Endocannabinoids are mobilized by epileptiform activity and in turn influence this activity by inhibiting synaptic transmission; both excitatory and some inhibitory synapses can be suppressed, leading to potentially complex outcomes. Moreover, the endocannabinoid system is not a fixed entity, and its strength can be enhanced or reduced. Endocannabinoids and their receptors are altered by epileptic seizures in ways that can reduce the efficacy of both exogenous and endogenous cannabinoids in sometimes unexpected ways.
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36
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Postsynaptic activity reverses the sign of the acetylcholine-induced long-term plasticity of GABAA inhibition. Proc Natl Acad Sci U S A 2014; 111:E2741-50. [PMID: 24938789 DOI: 10.1073/pnas.1321777111] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Acetylcholine (ACh) regulates forms of plasticity that control cognitive functions but the underlying mechanisms remain largely unknown. ACh controls the intrinsic excitability, as well as the synaptic excitation and inhibition of CA1 hippocampal pyramidal cells (PCs), cells known to participate in circuits involved in cognition and spatial navigation. However, how ACh regulates inhibition in function of postsynaptic activity has not been well studied. Here we show that in rat PCs, a brief pulse of ACh or a brief stimulation of cholinergic septal fibers combined with repeated depolarization induces strong long-term enhancement of GABAA inhibition (GABAA-LTP). Indeed, this enhanced inhibition is due to the increased activation of α5βγ2 subunit-containing GABAA receptors by the GABA released. GABAA-LTP requires the activation of M1-muscarinic receptors and an increase in cytosolic Ca(2+). In the absence of PC depolarization ACh triggered a presynaptic depolarization-induced suppression of inhibition (DSI), revealing that postsynaptic activity gates the effects of ACh from presynaptic DSI to postsynaptic LTP. These results provide key insights into mechanisms potentially linked with cognitive functions, spatial navigation, and the homeostatic control of abnormal hyperexcitable states.
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37
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Ohno-Shosaku T, Kano M. Endocannabinoid-mediated retrograde modulation of synaptic transmission. Curr Opin Neurobiol 2014; 29:1-8. [PMID: 24747340 DOI: 10.1016/j.conb.2014.03.017] [Citation(s) in RCA: 162] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 03/10/2014] [Accepted: 03/20/2014] [Indexed: 10/25/2022]
Abstract
One of the two major endocannabinoids, 2-arachidonoylglycerol (2-AG), serves as a retrograde messenger at various types of synapses throughout the brain. Upon postsynaptic activation, 2-AG is released immediately after de novo synthesis, activates presynaptic CB1 cannabinoid receptors, and transiently suppresses neurotransmitter release. When CB1 receptor activation is combined with some other factors such as presynaptic activity, the suppression is converted to a long-lasting form. Whereas 2-AG primarily transmits a rapid, transient, point-to-point retrograde signal, the other major endocannabinoid, anandamide, may function as a relatively slow retrograde or non-retrograde signal or as an agonist of the vanilloid receptor. The endocannabinoid system can be up- or down-regulated by a variety of physiological and environmental factors including stress, which might be clinically important.
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Affiliation(s)
- Takako Ohno-Shosaku
- Department of Impairment Study, Graduate School of Medical Science, Kanazawa University, Kanazawa 920-0942, Japan
| | - Masanobu Kano
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
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38
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Chevaleyre V, Piskorowski R. Modulating excitation through plasticity at inhibitory synapses. Front Cell Neurosci 2014; 8:93. [PMID: 24734003 PMCID: PMC3975092 DOI: 10.3389/fncel.2014.00093] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 03/13/2014] [Indexed: 01/18/2023] Open
Abstract
Learning is believed to depend on lasting changes in synaptic efficacy such as long-term potentiation and long-term depression. As a result, a profusion of studies has tried to elucidate the mechanisms underlying these forms of plasticity. Traditionally, experience-dependent changes at excitatory synapses were assumed to underlie learning and memory formation. However, with the relatively more recent investigation of inhibitory transmission, it had become evident that inhibitory synapses are not only plastic, but also provide an additional way to modulate excitatory transmission and the induction of plasticity at excitatory synapses. Thanks to recent technological advances, progress has been made in understanding synaptic transmission and plasticity from particular interneuron subtypes. In this review article, we will describe various forms of synaptic plasticity that have been ascribed to two fairly well characterized populations of interneurons in the hippocampus, those expressing cholecystokinin (CCK) and parvalbumin (PV). We will discuss the resulting changes in the strength and plasticity of excitatory transmission that occur in the local circuit as a result of the modulation of inhibitory transmission. We will focus on the hippocampus because this region has a relatively well-understood circuitry, numerous forms of activity-dependent plasticity and a multitude of identified interneuron subclasses.
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Affiliation(s)
- Vivien Chevaleyre
- Centre National de la Recherche Scientifique, UMR8118, Université Paris Descartes Paris, France
| | - Rebecca Piskorowski
- Centre National de la Recherche Scientifique, UMR8118, Université Paris Descartes Paris, France
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39
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KANO M. Control of synaptic function by endocannabinoid-mediated retrograde signaling. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2014; 90:235-250. [PMID: 25169670 PMCID: PMC4237895 DOI: 10.2183/pjab.90.235] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2014] [Accepted: 05/30/2014] [Indexed: 06/03/2023]
Abstract
Since the first reports in 2001, great advances have been made towards the understanding of endocannabinoid-mediated synaptic modulation. Electrophysiological studies have revealed that one of the two major endocannabinoids, 2-arachidonoylglycerol (2-AG), is produced from membrane lipids upon postsynaptic Ca(2+) elevation and/or activation of Gq/11-coupled receptors, and released from postsynaptic neurons. The released 2-AG then acts retrogradely onto presynaptic cannabinoid CB1 receptors and induces suppression of neurotransmitter release either transiently or persistently. These forms of 2-AG-mediated retrograde synaptic modulation are functional throughout the brain. The other major endocannabinoid, anandamide, mediates a certain form of endocannabinoid-mediated long-term depression (LTD). Anandamide also functions as an agonist for transient receptor potential vanilloid receptor type 1 (TRPV1) and mediates endocannabinoid-independent and TRPV1-dependent forms of LTD. It has also been demonstrated that the endocannabinoid system itself is plastic, which can be either up- or down-regulated by experimental or environmental conditions. In this review, I will make an overview of the mechanisms underlying endocannabinoid-mediated synaptic modulation.
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Affiliation(s)
- Masanobu KANO
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
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40
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Younts TJ, Castillo PE. Endogenous cannabinoid signaling at inhibitory interneurons. Curr Opin Neurobiol 2013; 26:42-50. [PMID: 24650503 DOI: 10.1016/j.conb.2013.12.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 12/02/2013] [Accepted: 12/04/2013] [Indexed: 11/15/2022]
Abstract
Significant progress has been made in our understanding of how endogenous cannabinoids (eCBs) signal at excitatory and inhibitory synapses in the central nervous system (CNS). This review discusses how eCBs regulate inhibitory interneurons, their synapses, and the networks in which they are embedded. eCB signaling plays a pivotal role in brain physiology by means of their synaptic signal transduction, spatiotemporal signaling profile, routing of information through inhibitory microcircuits, and experience-dependent plasticity. Understanding the normal processes underlying eCB signaling is beginning to shed light on how their dysregulation contributes to disease.
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Affiliation(s)
- Thomas J Younts
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, United States
| | - Pablo E Castillo
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, United States.
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