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Parker D. The functional properties of synapses made by regenerated axons across spinal cord lesion sites in lamprey. Neural Regen Res 2022; 17:2272-2277. [PMID: 35259849 PMCID: PMC9083143 DOI: 10.4103/1673-5374.335828] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
While the anatomical properties of regenerated axons across spinal cord lesion sites have been studied extensively, little is known of how the functional properties of regenerated synapses compared to those in unlesioned animals. This study aims to compare the properties of synapses made by regenerated axons with unlesioned axons using the lamprey, a model system for spinal injury research, in which functional locomotor recovery after spinal cord lesions is associated with axonal regeneration across the lesion site. Regenerated synapses below the lesion site did not differ from synapses from unlesioned axons with respect to the amplitude and duration of single excitatory postsynaptic potentials. They also showed the same activity-dependent depression over spike trains. However, regenerated synapses did differ from unlesioned synapses as the estimated number of synaptic vesicles was greater and there was evidence for increased postsynaptic quantal amplitude. For axons above the lesion site, the amplitude and duration of single synaptic inputs also did not differ significantly from unlesioned animals. However, in this case, there was evidence of a reduction in release probability and inputs facilitated rather than depressed over spike trains. Synaptic inputs from single regenerated axons below the lesion site thus do not increase in amplitude to compensate for the reduced number of descending axons after functional recovery. However, the postsynaptic input was maintained at the unlesioned level using different synaptic properties. Conversely, the facilitation from the same initial amplitude above the lesion site made the synaptic input over spike trains functionally stronger. This may help to increase propriospinal activity across the lesion site to compensate for the lesion-induced reduction in supraspinal inputs. The animal experiments were approved by the Animal Ethics Committee of Cambridge University.
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Affiliation(s)
- David Parker
- Department of Physiology, Development, and Neuroscience, University of Cambridge, Cambridge, UK
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2
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Yi F, Garrett T, Deisseroth K, Haario H, Stone E, Lawrence JJ. Septohippocampal transmission from parvalbumin-positive neurons features rapid recovery from synaptic depression. Sci Rep 2021; 11:2117. [PMID: 33483520 PMCID: PMC7822967 DOI: 10.1038/s41598-020-80245-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 12/14/2020] [Indexed: 01/30/2023] Open
Abstract
Parvalbumin-containing projection neurons of the medial-septum-diagonal band of Broca ([Formula: see text]) are essential for hippocampal rhythms and learning operations yet are poorly understood at cellular and synaptic levels. We combined electrophysiological, optogenetic, and modeling approaches to investigate [Formula: see text] neuronal properties. [Formula: see text] neurons had intrinsic membrane properties distinct from acetylcholine- and somatostatin-containing MS-DBB subtypes. Viral expression of the fast-kinetic channelrhodopsin ChETA-YFP elicited action potentials to brief (1-2 ms) 470 nm light pulses. To investigate [Formula: see text] transmission, light pulses at 5-50 Hz frequencies generated trains of inhibitory postsynaptic currents (IPSCs) in CA1 stratum oriens interneurons. Using a similar approach, optogenetic activation of local hippocampal PV ([Formula: see text]) neurons generated trains of [Formula: see text]-mediated IPSCs in CA1 pyramidal neurons. Both synapse types exhibited short-term depression (STD) of IPSCs. However, relative to [Formula: see text] synapses, [Formula: see text] synapses possessed lower initial release probability, transiently resisted STD at gamma (20-50 Hz) frequencies, and recovered more rapidly from synaptic depression. Experimentally-constrained mathematical synapse models explored mechanistic differences. Relative to the [Formula: see text] model, the [Formula: see text] model exhibited higher sensitivity to calcium accumulation, permitting a faster rate of calcium-dependent recovery from STD. In conclusion, resistance of [Formula: see text] synapses to STD during short gamma bursts enables robust long-range GABAergic transmission from MS-DBB to hippocampus.
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Affiliation(s)
- Feng Yi
- Department of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula, MT, 59812, USA
| | - Tavita Garrett
- Vollum Institute Neuroscience Graduate Program, Oregon Health and Science University, Portland, OR, 97239, USA
| | - Karl Deisseroth
- Department of Psychiatry and Behavioral Sciences, Department of Bioengineering, and Howard Hughes Medical Institute, Stanford University, Stanford, CA, 94305, USA
| | - Heikki Haario
- Department of Mathematics and Physics, Lappeenranta University of Technology, Lappeenranta, Finland
| | - Emily Stone
- Department of Mathematical Sciences, The University of Montana, Missoula, MT, 59812, USA
| | - J Josh Lawrence
- Department of Pharmacology and Neuroscience, Garrison Institute on Aging, and Center for Excellence in Translational Neuroscience and Therapeutics, Texas Tech University Health Sciences Center, Lubbock, TX, 79430, USA.
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3
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Francavilla R, Villette V, Luo X, Chamberland S, Muñoz-Pino E, Camiré O, Wagner K, Kis V, Somogyi P, Topolnik L. Connectivity and network state-dependent recruitment of long-range VIP-GABAergic neurons in the mouse hippocampus. Nat Commun 2018; 9:5043. [PMID: 30487571 PMCID: PMC6261953 DOI: 10.1038/s41467-018-07162-5] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 10/18/2018] [Indexed: 11/21/2022] Open
Abstract
GABAergic interneurons in the hippocampus provide for local and long-distance coordination of neurons in functionally connected areas. Vasoactive intestinal peptide-expressing (VIP+) interneurons occupy a distinct niche in circuitry as many of them specialize in innervating GABAergic cells, thus providing network disinhibition. In the CA1 hippocampus, VIP+ interneuron-selective cells target local interneurons. Here, we discover a type of VIP+ neuron whose axon innervates CA1 and also projects to the subiculum (VIP-LRPs). VIP-LRPs show specific molecular properties and target interneurons within the CA1 area but both interneurons and pyramidal cells within subiculum. They are interconnected through gap junctions but demonstrate sparse spike coupling in vitro. In awake mice, VIP-LRPs decrease their activity during theta-run epochs and are more active during quiet wakefulness but not coupled to sharp-wave ripples. Together, the data provide evidence for VIP interneuron molecular diversity and functional specialization in controlling cell ensembles along the hippocampo-subicular axis.
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Affiliation(s)
- Ruggiero Francavilla
- Neuroscience Axis, CHU de Québec Research Center, Université Laval, Quebec, QC, G1V 4G2, Canada
- Department of Biochemistry, Microbiology and Bio-informatics, Université Laval, Quebec, QC, G1V 0A6, Canada
| | - Vincent Villette
- Neuroscience Axis, CHU de Québec Research Center, Université Laval, Quebec, QC, G1V 4G2, Canada
- Department of Biochemistry, Microbiology and Bio-informatics, Université Laval, Quebec, QC, G1V 0A6, Canada
| | - Xiao Luo
- Neuroscience Axis, CHU de Québec Research Center, Université Laval, Quebec, QC, G1V 4G2, Canada
- Department of Biochemistry, Microbiology and Bio-informatics, Université Laval, Quebec, QC, G1V 0A6, Canada
| | - Simon Chamberland
- Department of Biochemistry, Microbiology and Bio-informatics, Université Laval, Quebec, QC, G1V 0A6, Canada
| | - Einer Muñoz-Pino
- Neuroscience Axis, CHU de Québec Research Center, Université Laval, Quebec, QC, G1V 4G2, Canada
- Department of Biochemistry, Microbiology and Bio-informatics, Université Laval, Quebec, QC, G1V 0A6, Canada
| | - Olivier Camiré
- Neuroscience Axis, CHU de Québec Research Center, Université Laval, Quebec, QC, G1V 4G2, Canada
- Department of Biochemistry, Microbiology and Bio-informatics, Université Laval, Quebec, QC, G1V 0A6, Canada
| | - Kristina Wagner
- Department of Pharmacology, Oxford University, Oxford, OX1 3QT, UK
| | - Viktor Kis
- Department of Pharmacology, Oxford University, Oxford, OX1 3QT, UK
| | - Peter Somogyi
- Department of Pharmacology, Oxford University, Oxford, OX1 3QT, UK
| | - Lisa Topolnik
- Neuroscience Axis, CHU de Québec Research Center, Université Laval, Quebec, QC, G1V 4G2, Canada.
- Department of Biochemistry, Microbiology and Bio-informatics, Université Laval, Quebec, QC, G1V 0A6, Canada.
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4
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Zhou FW, Puche AC, Shipley MT. Short-Term Plasticity at Olfactory Cortex to Granule Cell Synapses Requires Ca V2.1 Activation. Front Cell Neurosci 2018; 12:387. [PMID: 30416429 PMCID: PMC6212651 DOI: 10.3389/fncel.2018.00387] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 10/09/2018] [Indexed: 11/30/2022] Open
Abstract
Output projections of the olfactory bulb (OB) to the olfactory cortex (OCX) and reciprocal feedback projections from OCX provide rapid regulation of OB circuit dynamics and odor processing. Short-term synaptic plasticity (STP), a feature of many synaptic connections in the brain, can modulate the strength of feedback based on preceding network activity. We used light-gated cation channel channelrhodopsin-2 (ChR2) to investigate plasticity of excitatory synaptic currents (EPSCs) evoked at the OCX to granule cell (GC) synapse in the OB. Selective activation of OCX glutamatergic axons/terminals in OB generates strong, frequency-dependent STP in GCs. This plasticity was critically dependent on activation of CaV2.1 channels. As acetylcholine (ACh) modulates CaV2.1 channels in other brain regions and as cholinergic projections from the basal forebrain heavily target the GC layer (GCL) in OB, we investigated whether ACh modulates STP at the OCX→GC synapse. ACh decreases OCX→GC evoked EPSCs, it had no effect on STP. Thus, ACh impact on cortical feedback is independent of CaV2.1-mediated STP. Modulation of OCX feedback to the bulb by modulatory transmitters, such as ACh, or by frequency-dependent STP could regulate the precise balance of excitation and inhibition of GCs. As GCs are a major inhibitory source for OB output neurons, plasticity at the cortical feedback synapse can differentially impact OB output to higher-order networks in situations where ACh inputs are activated or by active sniff sampling of odors.
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Affiliation(s)
- Fu-Wen Zhou
- Department of Anatomy and Neurobiology, Program in Neurosciences, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Adam C Puche
- Department of Anatomy and Neurobiology, Program in Neurosciences, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Michael T Shipley
- Department of Anatomy and Neurobiology, Program in Neurosciences, University of Maryland School of Medicine, Baltimore, MD, United States
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5
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Bayat Mokhtari E, Lawrence JJ, Stone EF. Effect of Neuromodulation of Short-term Plasticity on Information Processing in Hippocampal Interneuron Synapses. JOURNAL OF MATHEMATICAL NEUROSCIENCE 2018; 8:7. [PMID: 29845383 PMCID: PMC5975118 DOI: 10.1186/s13408-018-0062-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 05/17/2018] [Indexed: 06/08/2023]
Abstract
Neurons in a micro-circuit connected by chemical synapses can have their connectivity affected by the prior activity of the cells. The number of synapses available for releasing neurotransmitter can be decreased by repetitive activation through depletion of readily releasable neurotransmitter (NT), or increased through facilitation, where the probability of release of NT is increased by prior activation. These competing effects can create a complicated and subtle range of time-dependent connectivity. Here we investigate the probabilistic properties of facilitation and depression (FD) for a presynaptic neuron that is receiving a Poisson spike train of input. We use a model of FD that is parameterized with experimental data from a hippocampal basket cell and pyramidal cell connection, for fixed frequency input spikes at frequencies in the range of theta (3-8 Hz) and gamma (20-100 Hz) oscillations. Hence our results will apply to micro-circuits in the hippocampus that are responsible for the interaction of theta and gamma rhythms associated with learning and memory. A control situation is compared with one in which a pharmaceutical neuromodulator (muscarine) is employed. We apply standard information-theoretic measures such as entropy and mutual information, and find a closed form approximate expression for the probability distribution of release probability. We also use techniques that measure the dependence of the response on the exact history of stimulation the synapse has received, which uncovers some unexpected differences between control and muscarine-added cases.
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Affiliation(s)
| | - J. Josh Lawrence
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, Lubbock, USA
| | - Emily F. Stone
- Department of Mathematical Sciences, The University of Montana, Missoula, USA
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6
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Bayat Mokhtari E, Lawrence JJ, Stone EF. Data Driven Models of Short-Term Synaptic Plasticity. Front Comput Neurosci 2018; 12:32. [PMID: 29872388 PMCID: PMC5972196 DOI: 10.3389/fncom.2018.00032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 04/27/2018] [Indexed: 11/29/2022] Open
Abstract
Simple models of short term synaptic plasticity that incorporate facilitation and/or depression have been created in abundance for different synapse types and circumstances. The analysis of these models has included computing mutual information between a stochastic input spike train and some sort of representation of the postsynaptic response. While this approach has proven useful in many contexts, for the purpose of determining the type of process underlying a stochastic output train, it ignores the ordering of the responses, leaving an important characterizing feature on the table. In this paper we use a broader class of information measures on output only, and specifically construct hidden Markov models (HMMs) (known as epsilon machines or causal state models) to differentiate between synapse type, and classify the complexity of the process. We find that the machines allow us to differentiate between processes in a way not possible by considering distributions alone. We are also able to understand these differences in terms of the dynamics of the model used to create the output response, bringing the analysis full circle. Hence this technique provides a complimentary description of the synaptic filtering process, and potentially expands the interpretation of future experimental results.
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Affiliation(s)
- Elham Bayat Mokhtari
- Department of Mathematical Sciences, The University of Montana, Missoula, MT, United States
| | - J Josh Lawrence
- Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, Lubbock, TX, United States
| | - Emily F Stone
- Department of Mathematical Sciences, The University of Montana, Missoula, MT, United States
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7
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Pelkey KA, Chittajallu R, Craig MT, Tricoire L, Wester JC, McBain CJ. Hippocampal GABAergic Inhibitory Interneurons. Physiol Rev 2017; 97:1619-1747. [PMID: 28954853 DOI: 10.1152/physrev.00007.2017] [Citation(s) in RCA: 495] [Impact Index Per Article: 70.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 05/16/2017] [Accepted: 05/26/2017] [Indexed: 12/11/2022] Open
Abstract
In the hippocampus GABAergic local circuit inhibitory interneurons represent only ~10-15% of the total neuronal population; however, their remarkable anatomical and physiological diversity allows them to regulate virtually all aspects of cellular and circuit function. Here we provide an overview of the current state of the field of interneuron research, focusing largely on the hippocampus. We discuss recent advances related to the various cell types, including their development and maturation, expression of subtype-specific voltage- and ligand-gated channels, and their roles in network oscillations. We also discuss recent technological advances and approaches that have permitted high-resolution, subtype-specific examination of their roles in numerous neural circuit disorders and the emerging therapeutic strategies to ameliorate such pathophysiological conditions. The ultimate goal of this review is not only to provide a touchstone for the current state of the field, but to help pave the way for future research by highlighting where gaps in our knowledge exist and how a complete appreciation of their roles will aid in future therapeutic strategies.
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Affiliation(s)
- Kenneth A Pelkey
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
| | - Ramesh Chittajallu
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
| | - Michael T Craig
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
| | - Ludovic Tricoire
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
| | - Jason C Wester
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
| | - Chris J McBain
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
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8
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Fajardo-Serrano A, Liu L, Mott DD, McDonald AJ. Evidence for M 2 muscarinic receptor modulation of axon terminals and dendrites in the rodent basolateral amygdala: An ultrastructural and electrophysiological analysis. Neuroscience 2017. [PMID: 28629847 DOI: 10.1016/j.neuroscience.2017.06.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The basolateral amygdala receives a very dense cholinergic innervation from the basal forebrain that is important for memory consolidation. Although behavioral studies have shown that both M1 and M2 muscarinic receptors are critical for these mnemonic functions, there have been very few neuroanatomical and electrophysiological investigations of the localization and function of different types of muscarinic receptors in the amygdala. In the present study we investigated the subcellular localization of M2 muscarinic receptors (M2Rs) in the anterior basolateral nucleus (BLa) of the mouse, including the localization of M2Rs in parvalbumin (PV) immunoreactive interneurons, using double-labeling immunoelectron microscopy. Little if any M2R-immunoreactivity (M2R-ir) was observed in neuronal somata, but the neuropil was densely labeled. Ultrastructural analysis using a pre-embedding immunogold-silver technique (IGS) demonstrated M2R-ir in dendritic shafts, spines, and axon terminals forming asymmetrical (excitatory) or symmetrical (mostly inhibitory) synapses. In addition, about one-quarter of PV+ axon terminals and half of PV+ dendrites, localized using immunoperoxidase, were M2R+ when observed in single thin sections. In all M2R+ neuropilar structures, including those that were PV+, about one-quarter to two-thirds of M2R+ immunoparticles were plasma-membrane-associated, depending on the structure. The expression of M2Rs in PV+ and PV-negative terminals forming symmetrical synapses indicates M2R modulation of inhibitory transmission. Electrophysiological studies in mouse and rat brain slices, including paired recordings from interneurons and pyramidal projection neurons, demonstrated M2R-mediated suppression of GABA release. These findings suggest cell-type-specific functions of M2Rs and shed light on organizing principles of cholinergic modulation in the BLa.
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Affiliation(s)
- Ana Fajardo-Serrano
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, USA
| | - Lei Liu
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, USA
| | - David D Mott
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, USA
| | - Alexander J McDonald
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, USA.
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Gray M, Daudelin DH, Golowasch J. Activation mechanism of a neuromodulator-gated pacemaker ionic current. J Neurophysiol 2017; 118:595-609. [PMID: 28446585 DOI: 10.1152/jn.00743.2016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 04/19/2017] [Accepted: 04/19/2017] [Indexed: 02/04/2023] Open
Abstract
The neuromodulator-gated current (IMI) found in the crab stomatogastric ganglion is activated by neuromodulators that are essential to induce the rhythmic activity of the pyloric network in this system. One of these neuromodulators is also known to control the correlated expression of voltage-gated ionic currents in pyloric neurons, as well as synaptic plasticity and strength. Thus understanding the mechanism by which neuromodulator receptors activate IMI should provide insights not only into how oscillations are initiated but also into how other processes, and currents not directly activated by them, are regulated. To determine what specific signaling molecules are implicated in this process, we used a battery of agonists and antagonists of common signal transduction pathways. We found that the G protein inhibitor GDPβS and the G protein activator GTPγS significantly affect IMI amplitude, suggesting that its activation is mediated by G proteins. Interestingly, when using the more specific G protein blocker pertussis toxin, we observed the expected inhibition of IMI amplitude but, unexpectedly, in a calcium-dependent fashion. We also found that antagonists of calcium- and calmodulin-associated signaling significantly reduce IMI amplitude. In contrast, we found little evidence for the role of cyclic nucleotide signaling, phospholipase C (PLC), or kinases and phosphatases, except two calmodulin-dependent kinases. In sum, these results suggest that proctolin-induced IMI is mediated by a G protein whose pertussis toxin sensitivity is altered by external calcium concentration and appears to depend on intracellular calcium, calmodulin, and calmodulin-activated kinases. In contrast, we found no support for IMI being mediated by PLC signaling or cyclic nucleotides.NEW & NOTEWORTHY Neuronal rhythmic activity is generated by either network-based or cell-autonomous mechanisms. In the pyloric network of decapod crustaceans, the activation of a neuromodulator-gated pacemaker current is crucial for the generation of rhythmic activity. This current is activated by several neuromodulators, including peptides and acetylcholine, presumably via metabotropic receptors. We have previously demonstrated a novel extracellular calcium-sensitive voltage-dependence mechanism of this current. We presently report that the activation mechanism depends on intracellular and extracellular calcium-sensitive components.
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Affiliation(s)
- Michael Gray
- Behavioral and Neural Science Graduate Program, Rutgers University-Newark, Newark, New Jersey; and.,Federated Department of Biological Sciences, New Jersey Institute of Technology, Newark, New Jersey
| | - Daniel H Daudelin
- Federated Department of Biological Sciences, New Jersey Institute of Technology, Newark, New Jersey
| | - Jorge Golowasch
- Federated Department of Biological Sciences, New Jersey Institute of Technology, Newark, New Jersey
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10
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Fasulo L, Brandi R, Arisi I, La Regina F, Berretta N, Capsoni S, D'Onofrio M, Cattaneo A. ProNGF Drives Localized and Cell Selective Parvalbumin Interneuron and Perineuronal Net Depletion in the Dentate Gyrus of Transgenic Mice. Front Mol Neurosci 2017; 10:20. [PMID: 28232789 PMCID: PMC5299926 DOI: 10.3389/fnmol.2017.00020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 01/16/2017] [Indexed: 01/12/2023] Open
Abstract
ProNGF, the precursor of mature Nerve Growth Factor (NGF), is the most abundant NGF form in the brain and increases markedly in the cortex in Alzheimer's Disease (AD), relative to mature NGF. A large body of evidence shows that the actions of ProNGF and mature NGF are often conflicting, depending on the receptors expressed in target cells. TgproNGF#3 mice, expressing furin-cleavage resistant proNGF in CNS neurons, directly reveal consequences of increased proNGF levels on brain homeostasis. Their phenotype clearly indicates that proNGF can be a driver of neurodegeneration, including severe learning and memory behavioral deficits, cholinergic deficits, and diffuse immunoreactivity for A-beta and A-beta-oligomers. In aged TgproNGF#3 mice spontaneous epileptic-like events are detected in entorhinal cortex-hippocampal slices, suggesting occurrence of excitatory/inhibitory (E/I) imbalance. In this paper, we investigate the molecular events linking increased proNGF levels to the epileptiform activity detected in hippocampal slices. The occurrence of spontaneous epileptiform discharges in the hippocampal network in TgproNGF#3 mice suggests an impaired inhibitory interneuron homeostasis. In the present study, we detect the onset of hippocampal epileptiform events at 1-month of age. Later, we observe a regional- and cellular-selective Parvalbumin interneuron and perineuronal net (PNN) depletion in the dentate gyrus (DG), but not in other hippocampal regions of TgproNGF#3 mice. These results demonstrate that, in the hippocampus, the DG is selectively vulnerable to altered proNGF/NGF signaling. Parvalbumin interneuron depletion is also observed in the amygdala, a region strongly connected to the hippocampus and likewise receiving cholinergic afferences. Transcriptome analysis of TgproNGF#3 hippocampus reveals a proNGF signature with broad down-regulation of transcription. The most affected mRNAs modulated at early times belong to synaptic transmission and plasticity and extracellular matrix (ECM) gene families. Moreover, alterations in the expression of selected BDNF splice variants were observed. Our results provide further mechanistic insights into the vicious negative cycle linking proNGF and neurodegeneration, confirming the regulation of E/I homeostasis as a crucial mediating mechanism.
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Affiliation(s)
- Luisa Fasulo
- Bio@SNS Laboratory, Scuola Normale SuperiorePisa, Italy; European Brain Research Institute Rita Levi-MontalciniRome, Italy
| | - Rossella Brandi
- European Brain Research Institute Rita Levi-Montalcini Rome, Italy
| | - Ivan Arisi
- European Brain Research Institute Rita Levi-Montalcini Rome, Italy
| | | | - Nicola Berretta
- Department of Experimental Neurology, Fondazione Santa Lucia IRCCS Rome, Italy
| | - Simona Capsoni
- Bio@SNS Laboratory, Scuola Normale Superiore Pisa, Italy
| | - Mara D'Onofrio
- European Brain Research Institute Rita Levi-Montalcini Rome, Italy
| | - Antonino Cattaneo
- Bio@SNS Laboratory, Scuola Normale SuperiorePisa, Italy; European Brain Research Institute Rita Levi-MontalciniRome, Italy
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11
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Maier P, Kaiser ME, Grinevich V, Draguhn A, Both M. Differential effects of oxytocin on mouse hippocampal oscillationsin vitro. Eur J Neurosci 2016; 44:2885-2898. [DOI: 10.1111/ejn.13412] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 09/09/2016] [Accepted: 09/20/2016] [Indexed: 12/11/2022]
Affiliation(s)
- Pia Maier
- Institute of Physiology and Pathophysiology; University of Heidelberg; Im Neuenheimer Feld 326 69120 Heidelberg Germany
| | - Martin E. Kaiser
- Institute of Physiology and Pathophysiology; University of Heidelberg; Im Neuenheimer Feld 326 69120 Heidelberg Germany
| | - Valery Grinevich
- Schaller Research Group on Neuropeptides; German Cancer Research Center (DKFZ) and Network Cluster of Excellence; University of Heidelberg; Heidelberg Germany
| | - Andreas Draguhn
- Institute of Physiology and Pathophysiology; University of Heidelberg; Im Neuenheimer Feld 326 69120 Heidelberg Germany
| | - Martin Both
- Institute of Physiology and Pathophysiology; University of Heidelberg; Im Neuenheimer Feld 326 69120 Heidelberg Germany
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Voltage Dependence of a Neuromodulator-Activated Ionic Current. eNeuro 2016; 3:eN-NWR-0038-16. [PMID: 27257619 PMCID: PMC4874538 DOI: 10.1523/eneuro.0038-16.2016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 04/18/2016] [Accepted: 04/25/2016] [Indexed: 02/07/2023] Open
Abstract
The neuromodulatory inward current (IMI) generated by crab Cancer borealis stomatogastric ganglion neurons is an inward current whose voltage dependence has been shown to be crucial in the activation of oscillatory activity of the pyloric network of this system. It has been previously shown that IMI loses its voltage dependence in conditions of low extracellular calcium, but that this effect appears to be regulated by intracellular calmodulin. Voltage dependence is only rarely regulated by intracellular signaling mechanisms. Here we address the hypothesis that the voltage dependence of IMI is mediated by intracellular signaling pathways activated by extracellular calcium. We demonstrate that calmodulin inhibitors and a ryanodine antagonist can reduce IMI voltage dependence in normal Ca(2+), but that, in conditions of low Ca(2+), calmodulin activators do not restore IMI voltage dependence. Further, we show evidence that CaMKII alters IMI voltage dependence. These results suggest that calmodulin is necessary but not sufficient for IMI voltage dependence. We therefore hypothesize that the Ca(2+)/calmodulin requirement for IMI voltage dependence is due to an active sensing of extracellular calcium by a GPCR family calcium-sensing receptor (CaSR) and that the reduction in IMI voltage dependence by a calmodulin inhibitor is due to CaSR endocytosis. Supporting this, preincubation with an endocytosis inhibitor prevented W7 (N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide hydrochloride)-induced loss of IMI voltage dependence, and a CaSR antagonist reduced IMI voltage dependence. Additionally, myosin light chain kinase, which is known to act downstream of the CaSR, seems to play a role in regulating IMI voltage dependence. Finally, a Gβγ-subunit inhibitor also affects IMI voltage dependence, in support of the hypothesis that this process is regulated by a G-protein-coupled CaSR.
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Stone E, Haario H, Lawrence JJ. A kinetic model for the frequency dependence of cholinergic modulation at hippocampal GABAergic synapses. Math Biosci 2014; 258:162-75. [PMID: 25445738 DOI: 10.1016/j.mbs.2014.09.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 09/25/2014] [Accepted: 09/26/2014] [Indexed: 01/31/2023]
Abstract
In this paper we use a simple model of presynaptic neuromodulation of GABA signaling to decipher paired whole-cell recordings of frequency dependent cholinergic neuromodulation at CA1 parvalbumin-containing basket cell (PV BC)-pyramidal cell synapses. Variance-mean analysis is employed to normalize the data, which is then used to estimate parameters in the mathematical model. Various parameterizations and hidden parameter dependencies are investigated using Markov Chain Monte Carlo (MCMC) parameter estimation techniques. This analysis reveals that frequency dependence of cholinergic modulation requires both calcium-dependent recovery from depression and mAChR-induced inhibition of presynaptic calcium entry. A reduction in calcium entry into the presynaptic terminal in the kinetic model accounted for the frequency-dependent effects of mAChR activation.
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Affiliation(s)
- Emily Stone
- Department of Mathematical Sciences, The University of Montana Missoula, MT 59812, USA.
| | - Heikki Haario
- Department of Mathematics and Physics, Lappeenranta University of Technology, Lappeenranta, Finland
| | - J Josh Lawrence
- Department of Biomedical and Pharmaceutical Sciences, The University of Montana Missoula, MT 59812, USA
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