The Experts below are selected from a list of 6591 Experts worldwide ranked by ideXlab platform
Alfredo Kirkwood - One of the best experts on this subject based on the ideXlab platform.
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pull push neuromodulation of cortical plasticity enables rapid bi directional shifts in ocular dominance
eLife, 2020Co-Authors: Su Z Hong, Shiyong Huang, Daniel Severin, Alfredo KirkwoodAbstract:Neuromodulatory systems are essential for remodeling glutamatergic connectivity during experience-dependent cortical plasticity. This permissive/enabling function of Neuromodulators has been associated with their capacity to facilitate the induction of Hebbian forms of long-term potentiation (LTP) and depression (LTD) by affecting cellular and network excitability. In vitro studies indicate that Neuromodulators also affect the expression of Hebbian plasticity in a pull-push manner: receptors coupled to the G-protein Gs promote the expression of LTP at the expense of LTD, and Gq-coupled receptors promote LTD at the expense of LTP. Here we show that pull-push mechanisms can be recruited in vivo by pairing brief monocular stimulation with pharmacological or chemogenetical activation of Gs- or Gq-coupled receptors to respectively enhance or reduce neuronal responses in primary visual cortex. These changes were stable, inducible in adults after the termination of the critical period for ocular dominance plasticity, and can rescue deficits induced by prolonged monocular deprivation.
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pull push neuromodulation of cortical plasticity enables rapid bi directional shifts in ocular dominance
bioRxiv, 2019Co-Authors: Su Z Hong, Shiyong Huang, Daniel Severin, Alfredo KirkwoodAbstract:Neuromodulatory systems are essential for remodeling glutamatergic connectivity during experience-dependent cortical plasticity. This permissive/enabling function of Neuromodulators has been associated with their capacity to facilitate the induction of Hebbian forms of long-term potentiation (LTP) and depression (LTD) by affecting cellular and network excitability. In vitro studies indicate that Neuromodulators can also affect the expression of Hebbian plasticity in a pull-push manner: receptors coupled to the G-protein Gs promote the expression of LTP at the expense of LTD, and Gq-coupled receptors promote LTD at the expense of LTD. Here we show that the pull-push mechanism can be recruited in vivo by pairing brief monocular stimulation with pharmacological or chemogenetical activation of Gs- or Gq-coupled receptors to respectively enhance or reduce visual cortical responses. These changes were stable, can be induced in adults after the termination of the critical period for juvenile ocular dominance plasticity, and can rescue deficits induced by prolonged monocular deprivation.
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timing is not everything neuromodulation opens the stdp gate
Frontiers in Synaptic Neuroscience, 2010Co-Authors: Verena Pawlak, Jeffery R Wickens, Alfredo Kirkwood, Jason N D KerrAbstract:Spike timing dependent plasticity (STDP) is a temporally specific extension of Hebbian associative plasticity that has tied together the timing of presynaptic inputs relative to the postsynaptic single spike. However, it is difficult to translate this mechanism to in vivo conditions where there is an abundance of presynaptic activity constantly impinging upon the dendritic tree as well as ongoing postsynaptic spiking activity that backpropagates along the dendrite. Theoretical studies have proposed that, in addition to this pre- and postsynaptic activity, a ‘third factor’ would enable the association of specific inputs to specific outputs. Experimentally, the picture that is beginning to emerge, is that in addition to the precise timing of pre- and postsynaptic spikes, this third factor involves Neuromodulators that have a distinctive influence on STDP rules. Specifically, neuromodulatory systems can influence STDP rules by acting via dopaminergic, noradrenergic, muscarinic and nicotinic receptors. Neuromodulator actions can enable STDP induction or - by increasing or decreasing the threshold - can change the conditions for plasticity induction. Because some of the Neuromodulators are also involved in reward, a link between STDP and reward-mediated learning is emerging. However, many outstanding questions concerning the relationship between neuromodulatory systems and STDP rules remain, that once solved, will help make the crucial link from timing-based synaptic plasticity rules to behaviorally-based learning.
Su Z Hong - One of the best experts on this subject based on the ideXlab platform.
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pull push neuromodulation of cortical plasticity enables rapid bi directional shifts in ocular dominance
eLife, 2020Co-Authors: Su Z Hong, Shiyong Huang, Daniel Severin, Alfredo KirkwoodAbstract:Neuromodulatory systems are essential for remodeling glutamatergic connectivity during experience-dependent cortical plasticity. This permissive/enabling function of Neuromodulators has been associated with their capacity to facilitate the induction of Hebbian forms of long-term potentiation (LTP) and depression (LTD) by affecting cellular and network excitability. In vitro studies indicate that Neuromodulators also affect the expression of Hebbian plasticity in a pull-push manner: receptors coupled to the G-protein Gs promote the expression of LTP at the expense of LTD, and Gq-coupled receptors promote LTD at the expense of LTP. Here we show that pull-push mechanisms can be recruited in vivo by pairing brief monocular stimulation with pharmacological or chemogenetical activation of Gs- or Gq-coupled receptors to respectively enhance or reduce neuronal responses in primary visual cortex. These changes were stable, inducible in adults after the termination of the critical period for ocular dominance plasticity, and can rescue deficits induced by prolonged monocular deprivation.
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pull push neuromodulation of cortical plasticity enables rapid bi directional shifts in ocular dominance
bioRxiv, 2019Co-Authors: Su Z Hong, Shiyong Huang, Daniel Severin, Alfredo KirkwoodAbstract:Neuromodulatory systems are essential for remodeling glutamatergic connectivity during experience-dependent cortical plasticity. This permissive/enabling function of Neuromodulators has been associated with their capacity to facilitate the induction of Hebbian forms of long-term potentiation (LTP) and depression (LTD) by affecting cellular and network excitability. In vitro studies indicate that Neuromodulators can also affect the expression of Hebbian plasticity in a pull-push manner: receptors coupled to the G-protein Gs promote the expression of LTP at the expense of LTD, and Gq-coupled receptors promote LTD at the expense of LTD. Here we show that the pull-push mechanism can be recruited in vivo by pairing brief monocular stimulation with pharmacological or chemogenetical activation of Gs- or Gq-coupled receptors to respectively enhance or reduce visual cortical responses. These changes were stable, can be induced in adults after the termination of the critical period for juvenile ocular dominance plasticity, and can rescue deficits induced by prolonged monocular deprivation.
Eve Marder - One of the best experts on this subject based on the ideXlab platform.
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neuromodulation of neuronal circuits back to the future
Neuron, 2012Co-Authors: Eve MarderAbstract:All nervous systems are subject to neuromodulation. Neuromodulators can be delivered as local hormones, as cotransmitters in projection neurons, and through the general circulation. Because Neuromodulators can transform the intrinsic firing properties of circuit neurons and alter effective synaptic strength, neuromodulatory substances reconfigure neuronal circuits, often massively altering their output. Thus, the anatomical connectome provides a minimal structure and the neuromodulatory environment constructs and specifies the functional circuits that give rise to behavior.
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developmental regulation of neuromodulator function in the stomatogastric ganglion of the lobster homarus americanus
The Journal of Neuroscience, 2008Co-Authors: Kristina J Rehm, Katherine E Deeg, Eve MarderAbstract:Neuromodulatory substances have profound effects on the two motor patterns generated by the adult crustacean stomatogastric ganglion (STG), the gastric mill rhythm and the pyloric rhythm. Developmentally regulated changes in the modulatory functions of Neuromodulators could therefore play an important role in the maturation of the output from the developing STG. We compared the effects of Neuromodulators on isolated embryonic and adult STG of the lobster, Homarus americanus . Bath application of Val 1 -SIFamide, a peptide whose expression is different in embryos and adults, activated different neuron classes in embryos and adults. Cancer borealis tachykinin-related peptide 1a, a peptide that does not appear in the terminals of modulatory neurons in the STG until after embryonic development, also produced different motor patterns in embryos and adults. In contrast, red pigment concentrating hormone, a peptide with a similar distribution in the STNS across development, produced similar motor patterns in embryonic and adult STG. Proctolin, serotonin, and allatostatin were also physiologically active on the isolated embryonic STG. Together, these results demonstrate that receptors to many Neuromodulators are present and functional on STG neurons before the motor patterns of the stomatogastric nervous system are mature. Moreover, neuromodulator responses change during development, perhaps contributing to the maturation of the output from the stomatogastric nervous system.
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profiling of neuropeptides released at the stomatogastric ganglion of the crab cancer borealis with mass spectrometry
Journal of Neurochemistry, 2005Co-Authors: Cyrus P Billimoria, Lingjun Li, Eve MarderAbstract:Studies of release under physiological conditions provide more direct data about the identity of neuromodulatory signaling molecules than studies of tissue localization that cannot distinguish between processing precursors and biologically active neuropeptides. We have identified neuropeptides released by electrical stimulation of nerves that contain the axons of the modulatory projection neurons to the stomatogastric ganglion of the crab, Cancer borealis. Preparations were bathed in saline containing a cocktail of peptidase inhibitors to minimize peptide degradation. Both electrical stimulation of projection nerves and depolarization with high K+ saline were used to evoke release. Releasates were desalted and then identified by mass using MALDI–TOF (matrix-assisted laser desorption/ionization–time-of-flight) mass spectrometry. Both previously known and novel peptides were detected. Subsequent to electrical stimulation proctolin, Cancer borealis tachykinin-related peptide (CabTRP), FVNSRYa, carcinustatin-8, allatostatin-3 (AST-3), red pigment concentrating hormone, NRNFLRFa, AST-5, SGFYANRYa, TNRNFLRFa, AST-9, orcomyotropin-related peptide, corazonin, Ala13-orcokinin, and Ser9-Val13-orcokinin were detected. Some of these were also detected after high K+ depolarization. Release was calcium dependent. In summary, we have shown release of the neuropeptides thought to play an important neuromodulatory role in the stomatogastric ganglion, as well as numerous other candidate Neuromodulators that remain to be identified.
Yasushi Kobayashi - One of the best experts on this subject based on the ideXlab platform.
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Raphe Nucleus during Saccade Tasks
2013Co-Authors: Information Monkey, Kenichi Okada, Kae Nakamura, Pedunculopontine Tegmental, Yasushi KobayashiAbstract:Copyright © 2011 Ken-ichi Okada et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Dopamine, acetylcholine, and serotonin, the main modulators of the central nervous system, have been proposed to play important roles in the execution of movement, control of several forms of attentional behavior, and reinforcement learning. While the response pattern of midbrain dopaminergic neurons and its specific role in reinforcement learning have been revealed, the role of the other Neuromodulators remains rather elusive. Here, we review our recent studies using extracellular recording from neurons in the pedunculopontine tegmental nucleus, where many cholinergic neurons exist, and the dorsal raphe nucleus, where many serotonergic neurons exist, while monkeys performed eye movement tasks to obtain different reward values. The firing patterns of these neurons are often tonic throughout the task period, while dopaminergic neurons exhibited a phasic activity pattern to the task event. The different modulation patterns, together with the activity of dopaminergic neurons, reveal dynamic information processing between these different neuromodulator systems. 1
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a neural correlate of predicted and actual reward value information in monkey pedunculopontine tegmental and dorsal raphe nucleus during saccade tasks
Neural Plasticity, 2011Co-Authors: Kenichi Okada, Kae Nakamura, Yasushi KobayashiAbstract:Dopamine, acetylcholine, and serotonin, the main modulators of the central nervous system, have been proposed to play important roles in the execution of movement, control of several forms of attentional behavior, and reinforcement learning. While the response pattern of midbrain dopaminergic neurons and its specific role in reinforcement learning have been revealed, the role of the other Neuromodulators remains rather elusive. Here, we review our recent studies using extracellular recording from neurons in the pedunculopontine tegmental nucleus, where many cholinergic neurons exist, and the dorsal raphe nucleus, where many serotonergic neurons exist, while monkeys performed eye movement tasks to obtain different reward values. The firing patterns of these neurons are often tonic throughout the task period, while dopaminergic neurons exhibited a phasic activity pattern to the task event. The different modulation patterns, together with the activity of dopaminergic neurons, reveal dynamic information processing between these different neuromodulator systems.
Markita P. Landry - One of the best experts on this subject based on the ideXlab platform.
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stochastic simulation of dopamine neuromodulation for implementation of fluorescent neurochemical probes in the striatal extracellular space
ACS Chemical Neuroscience, 2017Co-Authors: Abraham G Beyene, Rebecca L. Pinals, Ian R Mcfarlane, Markita P. LandryAbstract:Imaging the dynamic behavior of neuromodulatory neurotransmitters in the extracelluar space that arise from individual quantal release events would constitute a major advance in neurochemical imaging. Spatial and temporal resolution of these highly stochastic neuromodulatory events requires concurrent advances in the chemical development of optical nanosensors selective for Neuromodulators in concert with advances in imaging methodologies to capture millisecond neurotransmitter release. Herein, we develop and implement a stochastic model to describe dopamine dynamics in the extracellular space (ECS) of the brain dorsal striatum to guide the design and implementation of fluorescent neurochemical probes that record neurotransmitter dynamics in the ECS. Our model is developed from first-principles and simulates release, diffusion, and reuptake of dopamine in a 3D simulation volume of striatal tissue. We find that in vivo imaging of neuromodulation requires simultaneous optimization of dopamine nanosensor rev...
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stochastic simulation of dopamine neuromodulation for implementation of fluorescent neurochemical probes in the striatal extracellular space
bioRxiv, 2017Co-Authors: Abraham G Beyene, Rebecca L. Pinals, Ian R Mcfarlane, Markita P. LandryAbstract:Imaging the dynamic behavior of neuromodulatory neurotransmitters in the extracelluar space arising from individual quantal releases would constitute a major advance in neurochemical imaging. Spatial and temporal resolution of these highly stochastic neuromodulatory events requires concurrent advances in the chemical development of optical nanosensors selective for Neuromodulators in concert with advances in imaging methodologies to capture millisecond neurotransmitter release. Herein, we develop and implement a stochastic model to describe dopamine dynamics in the extracellular space (ECS) of the brain dorsal striatum. Our model is developed from first principles and simulates release, diffusion, and reuptake of dopamine in a 3D simulation volume of striatal tissue. We find that in vivo imaging of neuromodulation requires simultaneous optimization of dopamine nanosensor reversibility and sensitivity: dopamine imaging in the striatum or nucleus accumbens requires nanosensors with an optimal dopamine dissociation constant (Kd) of 1 μM, whereas Kd above 10 μM are required for dopamine imaging in the prefrontal cortex. Furthermore, our model reveals that imaging frame rates of 20 Hz are optimal for imaging temporally-resolved dopamine release events based on the probabilistic nature of dopaminergic terminal activity in the striatum. Our work provides a modeling platform to probe how complex neuromodulatory processes can be studied with fluorescent nanosensors and enables direct evaluation of nanosensor chemistry and imaging hardware parameters. Our stochastic model is generic for evaluating fluorescent neurotransmission probes, and is broadly applicable to the design of other neurotransmitter fluorophores and their optimization for implementation in vivo.
