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Depannemaecker D, Canton Santos LE, Rodrigues AM, Scorza CA, Scorza FA, Almeida ACGD. Realistic spiking neural network: Non-synaptic mechanisms improve convergence in cell assembly. Neural Netw 2019; 122:420-433. [PMID: 31841876 DOI: 10.1016/j.neunet.2019.09.038] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 09/17/2019] [Accepted: 09/23/2019] [Indexed: 01/26/2023]
Abstract
Learning in neural networks inspired by brain tissue has been studied for machine learning applications. However, existing works primarily focused on the concept of synaptic weight modulation, and other aspects of neuronal interactions, such as non-synaptic mechanisms, have been neglected. Non-synaptic interaction mechanisms have been shown to play significant roles in the brain, and four classes of these mechanisms can be highlighted: (i) electrotonic coupling; (ii) ephaptic interactions; (iii) electric field effects; and iv) extracellular ionic fluctuations. In this work, we proposed simple rules for learning inspired by recent findings in machine learning adapted to a realistic spiking neural network. We show that the inclusion of non-synaptic interaction mechanisms improves cell assembly convergence. By including extracellular ionic fluctuation represented by the extracellular electrodiffusion in the network, we showed the importance of these mechanisms to improve cell assembly convergence. Additionally, we observed a variety of electrophysiological patterns of neuronal activity, particularly bursting and synchronism when the convergence is improved.
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Affiliation(s)
- Damien Depannemaecker
- Laboratório de Neurociência Experimental e Computacional, Departamento de Engenharia de Biossistemas, Universidade Federal de São João del-Rei (UFSJ), Brazil; Disciplina de Neurociência, Departamento de Neurologia e Neurocirurgia, Universidade Federal de São Paulo (UNIFESP), São Paulo, Brazil
| | - Luiz Eduardo Canton Santos
- Laboratório de Neurociência Experimental e Computacional, Departamento de Engenharia de Biossistemas, Universidade Federal de São João del-Rei (UFSJ), Brazil; Disciplina de Neurociência, Departamento de Neurologia e Neurocirurgia, Universidade Federal de São Paulo (UNIFESP), São Paulo, Brazil
| | - Antônio Márcio Rodrigues
- Laboratório de Neurociência Experimental e Computacional, Departamento de Engenharia de Biossistemas, Universidade Federal de São João del-Rei (UFSJ), Brazil
| | - Carla Alessandra Scorza
- Laboratório de Neurociência Experimental e Computacional, Departamento de Engenharia de Biossistemas, Universidade Federal de São João del-Rei (UFSJ), Brazil
| | - Fulvio Alexandre Scorza
- Disciplina de Neurociência, Departamento de Neurologia e Neurocirurgia, Universidade Federal de São Paulo (UNIFESP), São Paulo, Brazil
| | - Antônio-Carlos Guimarães de Almeida
- Laboratório de Neurociência Experimental e Computacional, Departamento de Engenharia de Biossistemas, Universidade Federal de São João del-Rei (UFSJ), Brazil.
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Queenan BN, Dunn RL, Santos VR, Feng Y, Huizenga MN, Hammack RJ, Vicini S, Forcelli PA, Pak DTS. Kappa opioid receptors regulate hippocampal synaptic homeostasis and epileptogenesis. Epilepsia 2017; 59:106-122. [PMID: 29114861 DOI: 10.1111/epi.13941] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/10/2017] [Indexed: 12/13/2022]
Abstract
OBJECTIVE Homeostatic synaptic plasticity (HSP) serves as a gain control mechanism at central nervous system (CNS) synapses, including those between the dentate gyrus (DG) and CA3. Improper circuit control of DG-CA3 synapses is hypothesized to underlie epileptogenesis. Here, we sought to (1) identify compounds that preferentially modulate DG-CA3 synapses in primary neuronal culture and (2) determine if these compounds would delay or prevent epileptogenesis in vivo. METHODS We previously developed and validated an in vitro assay to visualize the behavior of DG-CA3 synapses and predict functional changes. We used this "synapse-on-chip" assay (quantification of synapse size, number, and type using immunocytochemical markers) to dissect the mechanisms of HSP at DG-CA3 synapses. Using chemogenetic constructs and pharmacological agents we determined the signaling cascades necessary for gain control at DG-CA3 synapses. Finally, we tested the implicated cascades (using kappa opioid receptor (OR) agonists and antagonists) in two models of epileptogenesis: electrical amygdala kindling in the mouse and chemical (pentylenetetrazole) kindling in the rat. RESULTS In vitro, synapses between DG mossy fibers (MFs) and CA3 neurons are the primary homeostatic responders during sustained periods of activity change. Kappa OR signaling is both necessary and sufficient for the homeostatic elaboration of DG-CA3 synapses, induced by presynaptic DG activity levels. Blocking kappa OR signaling in vivo attenuates the development of seizures in both mouse and rat models of epilepsy. SIGNIFICANCE This study elucidates mechanisms by which synapses between DG granule cells and CA3 pyramidal neurons undergo activity-dependent homeostatic compensation, via OR signaling in vitro. Modulation of kappa OR signaling in vivo alters seizure progression, suggesting that breakdown of homeostatic closed-loop control at DG-CA3 synapses contributes to seizures, and that targeting endogenous homeostatic mechanisms at DG-CA3 synapses may prove useful in combating epileptogenesis.
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Affiliation(s)
- Bridget N Queenan
- Department of Pharmacology & Physiology, Georgetown University Medical Center, Washington, DC, USA.,Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, DC, USA.,Department of Mechanical Engineering, Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Raymond L Dunn
- Department of Pharmacology & Physiology, Georgetown University Medical Center, Washington, DC, USA.,Georgetown Hughes Scholars Program, Department of Biology, Georgetown University, Washington, DC, USA
| | - Victor R Santos
- Department of Pharmacology & Physiology, Georgetown University Medical Center, Washington, DC, USA
| | - Yang Feng
- Department of Pharmacology & Physiology, Georgetown University Medical Center, Washington, DC, USA
| | - Megan N Huizenga
- Department of Pharmacology & Physiology, Georgetown University Medical Center, Washington, DC, USA
| | - Robert J Hammack
- Department of Pharmacology & Physiology, Georgetown University Medical Center, Washington, DC, USA
| | - Stefano Vicini
- Department of Pharmacology & Physiology, Georgetown University Medical Center, Washington, DC, USA.,Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, DC, USA
| | - Patrick A Forcelli
- Department of Pharmacology & Physiology, Georgetown University Medical Center, Washington, DC, USA.,Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, DC, USA
| | - Daniel T S Pak
- Department of Pharmacology & Physiology, Georgetown University Medical Center, Washington, DC, USA.,Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, DC, USA
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Félix-Oliveira A, Dias RB, Colino-Oliveira M, Rombo DM, Sebastião AM. Homeostatic plasticity induced by brief activity deprivation enhances long-term potentiation in the mature rat hippocampus. J Neurophysiol 2014; 112:3012-22. [PMID: 25210161 DOI: 10.1152/jn.00058.2014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Different forms of plasticity occur concomitantly in the nervous system. Whereas homeostatic plasticity monitors and maintains neuronal activity within a functional range, Hebbian changes such as long-term potentiation (LTP) modify the relative strength of specific synapses after discrete changes in activity and are thought to provide the cellular basis for learning and memory. Here, we assessed whether homeostatic plasticity could influence subsequent LTP in acute hippocampal slices that had been briefly deprived of activity by blocking action potential generation and N-methyl-D-aspartate (NMDA) receptor activation for 3 h. Activity deprivation enhanced the frequency and the amplitude of spontaneous miniature excitatory postsynaptic currents and enhanced basal synaptic transmission in the absence of significant changes in intrinsic excitability. Changes in the threshold for Hebbian plasticity were evaluated by inducing LTP with stimulation protocols of increasing strength. We found that activity-deprived slices consistently showed higher LTP magnitude compared with control conditions even when using subthreshold theta-burst stimulation. Enhanced LTP in activity-deprived slices was also observed when picrotoxin was used to prevent the modulation of GABAergic transmission. Finally, we observed that consecutive LTP inductions attained a higher magnitude of facilitation in activity-deprived slices, suggesting that the homeostatic plasticity mechanisms triggered by a brief period of neuronal silencing can both lower the threshold and raise the ceiling for Hebbian modifications. We conclude that even brief periods of altered activity are able to shape subsequent synaptic transmission and Hebbian plasticity in fully developed hippocampal circuits.
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Affiliation(s)
- A Félix-Oliveira
- Instituto de Farmacologia e Neurociencias, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal; and
| | - R B Dias
- Instituto de Farmacologia e Neurociencias, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal; and Unidade de Neurociencias, Instituto de Medicina Molecular, Universidade de Lisboa, Lisbon, Portugal
| | - M Colino-Oliveira
- Instituto de Farmacologia e Neurociencias, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal; and Unidade de Neurociencias, Instituto de Medicina Molecular, Universidade de Lisboa, Lisbon, Portugal
| | - D M Rombo
- Instituto de Farmacologia e Neurociencias, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal; and Unidade de Neurociencias, Instituto de Medicina Molecular, Universidade de Lisboa, Lisbon, Portugal
| | - A M Sebastião
- Instituto de Farmacologia e Neurociencias, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal; and Unidade de Neurociencias, Instituto de Medicina Molecular, Universidade de Lisboa, Lisbon, Portugal
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