1
|
Clark R, Fuller L, Platt JA, Abarbanel HDI. Reduced-Dimension, Biophysical Neuron Models Constructed From Observed Data. Neural Comput 2022; 34:1545-1587. [PMID: 35671464 DOI: 10.1162/neco_a_01515] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Accepted: 03/23/2022] [Indexed: 11/04/2022]
Abstract
Using methods from nonlinear dynamics and interpolation techniques from applied mathematics, we show how to use data alone to construct discrete time dynamical rules that forecast observed neuron properties. These data may come from simulations of a Hodgkin-Huxley (HH) neuron model or from laboratory current clamp experiments. In each case, the reduced-dimension, data-driven forecasting (DDF) models are shown to predict accurately for times after the training period. When the available observations for neuron preparations are, for example, membrane voltage V(t) only, we use the technique of time delay embedding from nonlinear dynamics to generate an appropriate space in which the full dynamics can be realized. The DDF constructions are reduced-dimension models relative to HH models as they are built on and forecast only observables such as V(t). They do not require detailed specification of ion channels, their gating variables, and the many parameters that accompany an HH model for laboratory measurements, yet all of this important information is encoded in the DDF model. As the DDF models use and forecast only voltage data, they can be used in building networks with biophysical connections. Both gap junction connections and ligand gated synaptic connections among neurons involve presynaptic voltages and induce postsynaptic voltage response. Biophysically based DDF neuron models can replace other reduced-dimension neuron models, say, of the integrate-and-fire type, in developing and analyzing large networks of neurons. When one does have detailed HH model neurons for network components, a reduced-dimension DDF realization of the HH voltage dynamics may be used in network computations to achieve computational efficiency and the exploration of larger biological networks.
Collapse
Affiliation(s)
- Randall Clark
- Department of Physics, University of California San Diego, La Jolla, CA 92093-0374, U.S.A.
| | - Lawson Fuller
- Department of Physics, University of California San Diego, La Jolla, CA 92093-0374, U.S.A.
| | - Jason A Platt
- Department of Physics, University of California San Diego, La Jolla, CA 92093-0374, U.S.A.
| | - Henry D I Abarbanel
- Marine Physical Laboratory, Scripps Institution of Oceanography, and Department of Physics, University of California San Diego, La Jolla, CA 92093-0374, U.S.A.
| |
Collapse
|
2
|
Zhou Y, Ding M, Nagel G, Konrad KR, Gao S. Advances and prospects of rhodopsin-based optogenetics in plant research. PLANT PHYSIOLOGY 2021; 187:572-589. [PMID: 35237820 PMCID: PMC8491038 DOI: 10.1093/plphys/kiab338] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 07/05/2021] [Indexed: 05/20/2023]
Abstract
Microbial rhodopsins have advanced optogenetics since the discovery of channelrhodopsins almost two decades ago. During this time an abundance of microbial rhodopsins has been discovered, engineered, and improved for studies in neuroscience and other animal research fields. Optogenetic applications in plant research, however, lagged largely behind. Starting with light-regulated gene expression, optogenetics has slowly expanded into plant research. The recently established all-trans retinal production in plants now enables the use of many microbial opsins, bringing extra opportunities to plant research. In this review, we summarize the recent advances of rhodopsin-based plant optogenetics and provide a perspective for future use, combined with fluorescent sensors to monitor physiological parameters.
Collapse
Affiliation(s)
- Yang Zhou
- Institute of Physiology, Department of Neurophysiology, Biocenter, University of Wuerzburg, Wuerzburg 97070, Germany
| | - Meiqi Ding
- Institute for Molecular Plant Physiology and Biophysics, Julius-von-Sachs-Institute, Biocenter, University of Wuerzburg, Wuerzburg 97082, Germany
| | - Georg Nagel
- Institute of Physiology, Department of Neurophysiology, Biocenter, University of Wuerzburg, Wuerzburg 97070, Germany
| | - Kai R. Konrad
- Institute for Molecular Plant Physiology and Biophysics, Julius-von-Sachs-Institute, Biocenter, University of Wuerzburg, Wuerzburg 97082, Germany
| | - Shiqiang Gao
- Institute of Physiology, Department of Neurophysiology, Biocenter, University of Wuerzburg, Wuerzburg 97070, Germany
- Author for communication:
| |
Collapse
|
3
|
Ibrahim BA, Murphy CA, Yudintsev G, Shinagawa Y, Banks MI, Llano DA. Corticothalamic gating of population auditory thalamocortical transmission in mouse. eLife 2021; 10:e56645. [PMID: 34028350 PMCID: PMC8186908 DOI: 10.7554/elife.56645] [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: 03/05/2020] [Accepted: 05/23/2021] [Indexed: 12/12/2022] Open
Abstract
The mechanisms that govern thalamocortical transmission are poorly understood. Recent data have shown that sensory stimuli elicit activity in ensembles of cortical neurons that recapitulate stereotyped spontaneous activity patterns. Here, we elucidate a possible mechanism by which gating of patterned population cortical activity occurs. In this study, sensory-evoked all-or-none cortical population responses were observed in the mouse auditory cortex in vivo and similar stochastic cortical responses were observed in a colliculo-thalamocortical brain slice preparation. Cortical responses were associated with decreases in auditory thalamic synaptic inhibition and increases in thalamic synchrony. Silencing of corticothalamic neurons in layer 6 (but not layer 5) or the thalamic reticular nucleus linearized the cortical responses, suggesting that layer 6 corticothalamic feedback via the thalamic reticular nucleus was responsible for gating stochastic cortical population responses. These data implicate a corticothalamic-thalamic reticular nucleus circuit that modifies thalamic neuronal synchronization to recruit populations of cortical neurons for sensory representations.
Collapse
Affiliation(s)
- Baher A Ibrahim
- Department of Molecular and Integrative Physiology, University of IllinoisUrbana-ChampaignUnited States
- Beckman Institute for Advanced Science and Technology, University of IllinoisUrbana-ChampaignUnited States
| | - Caitlin A Murphy
- Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin-MadisonWisconsin-MadisonUnited States
- Department of Anesthesiology, School of Medicine and Public Health, University of Wisconsin-MadisonWisconsin-MadisonUnited States
| | - Georgiy Yudintsev
- Neuroscience Program, University of IllinoisUrbana-ChampaignUnited States
| | - Yoshitaka Shinagawa
- Department of Molecular and Integrative Physiology, University of IllinoisUrbana-ChampaignUnited States
| | - Matthew I Banks
- Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin-MadisonWisconsin-MadisonUnited States
- Department of Anesthesiology, School of Medicine and Public Health, University of Wisconsin-MadisonWisconsin-MadisonUnited States
| | - Daniel A Llano
- Department of Molecular and Integrative Physiology, University of IllinoisUrbana-ChampaignUnited States
- Beckman Institute for Advanced Science and Technology, University of IllinoisUrbana-ChampaignUnited States
- Neuroscience Program, University of IllinoisUrbana-ChampaignUnited States
- College of Medicine, University of IllinoisUrbana-ChampaignUnited States
| |
Collapse
|
4
|
Saleh MY, Prajapati N, DeCoster MA, Lvov Y. Tagged Halloysite Nanotubes as a Carrier for Intercellular Delivery in Brain Microvascular Endothelium. Front Bioeng Biotechnol 2020; 8:451. [PMID: 32478061 PMCID: PMC7240041 DOI: 10.3389/fbioe.2020.00451] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 04/20/2020] [Indexed: 12/29/2022] Open
Abstract
Neurological disorders that are characterized by unpredictable seizures affect people of all ages. We proposed the use of nanocarriers such as halloysite nanotubes to penetrate the blood–brain barrier and effectively deliver the payload over an extended time period. These 50-nm diameter tubes are a natural biocompatible nanomaterial available in large quantities. We proved a prolonged gradual drug delivery mechanism by the nanotube encapsulating rhodamine isothiocyanate and then ionomycin into brain microvascular endothelial cells (BMVECs). Through delayed diffusion, the nanotubes effectively delivered the drug to the primary BMVECs without killing them, by binding and penetration in time periods of 1 to 24 h.
Collapse
Affiliation(s)
- Mahdi Yar Saleh
- Institute for Micromanufacturing and Biomedical Engineering Program, Louisiana Tech University, Ruston, LA, United States
| | - Neela Prajapati
- Institute for Micromanufacturing and Biomedical Engineering Program, Louisiana Tech University, Ruston, LA, United States
| | - Mark A DeCoster
- Institute for Micromanufacturing and Biomedical Engineering Program, Louisiana Tech University, Ruston, LA, United States
| | - Yuri Lvov
- Institute for Micromanufacturing and Biomedical Engineering Program, Louisiana Tech University, Ruston, LA, United States
| |
Collapse
|
5
|
Sceniak MP, Spitsbergen JB, Sabo SL, Yuan Y, Atchison WD. Acute neurotoxicant exposure induces hyperexcitability in mouse lumbar spinal motor neurons. J Neurophysiol 2020; 123:1448-1459. [PMID: 32159428 DOI: 10.1152/jn.00775.2019] [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] [Indexed: 12/12/2022] Open
Abstract
Spinal motor neurons (MNs) are susceptible to glutamatergic excitotoxicity, an effect associated with lumbar MN degeneration in amyotrophic lateral sclerosis (ALS). MN susceptibility to environmental toxicant exposure, one prospective contributor to sporadic ALS, has not been systematically studied. The goal of this study was to test the ability of a well-known environmental neurotoxicant to induce hyperexcitability in mouse lumbar MNs. Methylmercury (MeHg) causes neurotoxicity through mechanisms involving elevated intracellular Ca2+ concentration ([Ca2+]i), a hallmark of excitotoxicity. We tested whether acute exposure to MeHg induces hyperexcitability in MNs by altering synaptic transmission, using whole cell patch-clamp recordings of lumbar spinal MNs in vitro. Acute MeHg exposure (20 μM) led to an increase in the frequency of both spontaneous excitatory postsynaptic currents (EPSCs) and miniature EPSCs. The frequency of inhibitory postsynaptic currents (IPSCs) was also increased by MeHg. Action potential firing rates, both spontaneous and evoked, were increased by MeHg, despite increases in both EPSCs and IPSCs, indicating a shift toward hyperexcitability. Also consistent with hyperexcitability, fluo 4-AM microfluorimetry indicated that MeHg exposure induced an increase in [Ca2+]i. Spinal cord hyperexcitability is partially mediated by Ca2+-permeable AMPA receptors, as MeHg-dependent increases in EPSCs were blocked by 1-napthyl spermine. Therefore, spinal MNs appear highly susceptible to MeHg exposure, leading to significant increases in spontaneous network excitability and disruption of normal function. Prolonged hyperexcitability could lead to eventual neurodegeneration and loss of motor function as observed in spinal cord after MeHg exposure in vivo and may contribute to MeHg-induced acceleration of ALS symptoms.NEW & NOTEWORTHY Spinal motor neurons (MN) are susceptible to glutamatergic excitotoxicity, an effect associated with lumbar MN degeneration in amyotrophic lateral sclerosis (ALS). This study investigated MN susceptibility to environmental toxicant exposure, one prospective contributor to sporadic ALS. Spinal MNs appear highly susceptible to methylmercury exposure, leading to significant increases in spontaneous network excitability and disruption of normal function. Prolonged hyperexcitability could lead to neurodegeneration and loss of motor function as observed in ALS spinal cord symptoms.
Collapse
Affiliation(s)
- Michael P Sceniak
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan.,Department of Biology, Central Michigan University, Mount Pleasant, Michigan
| | - Jake B Spitsbergen
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan
| | - Shasta L Sabo
- Department of Biology, Central Michigan University, Mount Pleasant, Michigan
| | - Yukun Yuan
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan
| | - William D Atchison
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan
| |
Collapse
|
6
|
Ereifej ES, Shell CE, Schofield JS, Charkhkar H, Cuberovic I, Dorval AD, Graczyk EL, Kozai TDY, Otto KJ, Tyler DJ, Welle CG, Widge AS, Zariffa J, Moritz CT, Bourbeau DJ, Marasco PD. Neural engineering: the process, applications, and its role in the future of medicine. J Neural Eng 2019; 16:063002. [PMID: 31557730 DOI: 10.1088/1741-2552/ab4869] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
OBJECTIVE Recent advances in neural engineering have restored mobility to people with paralysis, relieved symptoms of movement disorders, reduced chronic pain, restored the sense of hearing, and provided sensory perception to individuals with sensory deficits. APPROACH This progress was enabled by the team-based, interdisciplinary approaches used by neural engineers. Neural engineers have advanced clinical frontiers by leveraging tools and discoveries in quantitative and biological sciences and through collaborations between engineering, science, and medicine. The movement toward bioelectronic medicines, where neuromodulation aims to supplement or replace pharmaceuticals to treat chronic medical conditions such as high blood pressure, diabetes and psychiatric disorders is a prime example of a new frontier made possible by neural engineering. Although one of the major goals in neural engineering is to develop technology for clinical applications, this technology may also offer unique opportunities to gain insight into how biological systems operate. MAIN RESULTS Despite significant technological progress, a number of ethical and strategic questions remain unexplored. Addressing these questions will accelerate technology development to address unmet needs. The future of these devices extends far beyond treatment of neurological impairments, including potential human augmentation applications. Our task, as neural engineers, is to push technology forward at the intersection of disciplines, while responsibly considering the readiness to transition this technology outside of the laboratory to consumer products. SIGNIFICANCE This article aims to highlight the current state of the neural engineering field, its links with other engineering and science disciplines, and the challenges and opportunities ahead. The goal of this article is to foster new ideas for innovative applications in neurotechnology.
Collapse
Affiliation(s)
- Evon S Ereifej
- Veteran Affairs Ann Arbor Healthcare System, Ann Arbor, MI, United States of America. Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America. Department of Neurology, University of Michigan, Ann Arbor, MI, United States of America. Advanced Platform Technology Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, United States of America
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Osaki T, Shin Y, Sivathanu V, Campisi M, Kamm RD. In Vitro Microfluidic Models for Neurodegenerative Disorders. Adv Healthc Mater 2018; 7. [PMID: 28881425 DOI: 10.1002/adhm.201700489] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 07/18/2017] [Indexed: 01/09/2023]
Abstract
Microfluidic devices enable novel means of emulating neurodegenerative disease pathophysiology in vitro. These organ-on-a-chip systems can potentially reduce animal testing and substitute (or augment) simple 2D culture systems. Reconstituting critical features of neurodegenerative diseases in a biomimetic system using microfluidics can thereby accelerate drug discovery and improve our understanding of the mechanisms of several currently incurable diseases. This review describes latest advances in modeling neurodegenerative diseases in the central nervous system and the peripheral nervous system. First, this study summarizes fundamental advantages of microfluidic devices in the creation of compartmentalized cell culture microenvironments for the co-culture of neurons, glial cells, endothelial cells, and skeletal muscle cells and in their recapitulation of spatiotemporal chemical gradients and mechanical microenvironments. Then, this reviews neurodegenerative-disease-on-a-chip models focusing on Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. Finally, this study discusses about current drawbacks of these models and strategies that may overcome them. These organ-on-chip technologies can be useful to be the first line of testing line in drug development and toxicology studies, which can contribute significantly to minimize the phase of animal testing steps.
Collapse
Affiliation(s)
- Tatsuya Osaki
- Department of Mechanical EngineeringMassachusetts Institutes of Technology 500 Technology Square MIT Building, Room NE47‐321 Cambridge MA 02139 USA
| | - Yoojin Shin
- Department of Mechanical EngineeringMassachusetts Institutes of Technology 500 Technology Square MIT Building, Room NE47‐321 Cambridge MA 02139 USA
| | - Vivek Sivathanu
- Department of Mechanical EngineeringMassachusetts Institutes of Technology 500 Technology Square MIT Building, Room NE47‐321 Cambridge MA 02139 USA
| | - Marco Campisi
- Department of Mechanical and Aerospace EngineeringPolitecnico di Torino Corso Duca degli Abruzzi 24 10129 Torino Italy
| | - Roger D. Kamm
- Department of Mechanical EngineeringMassachusetts Institutes of Technology 500 Technology Square MIT Building, Room NE47‐321 Cambridge MA 02139 USA
- Department of Biological EngineeringMassachusetts Institutes of Technology 500 Technology Square, MIT Building, Room NE47‐321 Cambridge MA 02139 USA
| |
Collapse
|
8
|
Roncacè V, Polli FS, Zojicic M, Kohlmeier KA. Neuropeptide S (NPS) is a neuropeptide with cellular actions in arousal and anxiety-related nuclei: Functional implications for effects of NPS on wakefulness and mood. Neuropharmacology 2017; 126:292-317. [PMID: 28655610 DOI: 10.1016/j.neuropharm.2017.06.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 06/02/2017] [Accepted: 06/23/2017] [Indexed: 12/27/2022]
Abstract
Neuropeptide S (NPS) is a peptide recently recognized to be present in the CNS, and believed to play a role in vigilance and mood control, as behavioral studies have shown it promotes arousal and has an anxiolytic effect. Although NPS precursor is found in very few neurons, NPS positive fibers are present throughout the brain stem. Given the behavioral actions of this peptide and the wide innervation pattern, we examined the cellular effects of NPS within two brain stem nuclei known to play a critical role in anxiety and arousal: the dorsal raphe (DR) and laterodorsal tegmentum (LDT). In mouse brain slices, NPS increased cytoplasmic levels of calcium in DR and LDT cells. Calcium rises were independent of action potential generation, reduced by low extracellular levels of calcium, attenuated by IP3 - and ryanodine (RyR)-dependent intracellular calcium store depletion, and eliminated by the receptor (NPSR) selective antagonist, SHA 68. NPS also exerted an effect on the membrane of DR and LDT cells inducing inward and outward currents, which were driven by an increase in conductance, and eliminated by SHA 68. Membrane actions of NPS were found to be dependent on store-mediated calcium as depletion of IP3 and RyR stores eliminated NPS-induced currents. Finally, NPS also had actions on synaptic events, suggesting facilitation of glutamatergic and GABAergic presynaptic transmission. When taken together, actions of NPS influenced the excitability of DR and LDT neurons, which could play a role in the anxiolytic and arousal-promoting effects of this peptide.
Collapse
Affiliation(s)
- Vincenzo Roncacè
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, 2100 Copenhagen Ø, Denmark
| | - Filip Souza Polli
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, 2100 Copenhagen Ø, Denmark
| | - Minella Zojicic
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, 2100 Copenhagen Ø, Denmark
| | - Kristi A Kohlmeier
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, 2100 Copenhagen Ø, Denmark.
| |
Collapse
|
9
|
Lambert MØ, Ipsen TH, Kohlmeier KA. Acute cocaine exposure elicits rises in calcium in arousal-related laterodorsal tegmental neurons. Pharmacol Res Perspect 2016; 5:e00282. [PMID: 28596834 PMCID: PMC5461641 DOI: 10.1002/prp2.282] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 10/25/2016] [Indexed: 12/17/2022] Open
Abstract
Cocaine has strong reinforcing properties, which underlie its high addiction potential. Reinforcement of use of addictive drugs is associated with rises in dopamine (DA) in mesoaccumbal circuitry. Excitatory afferent input to mesoaccumbal circuitry sources from the laterodorsal tegmental nucleus (LDT). Chronic, systemic cocaine exposure has been shown to have cellular effects on LDT cells, but acute actions of local application have never been demonstrated. Using calcium imaging, we show that acute application of cocaine to mouse brain slices induces calcium spiking in cells of the LDT. Spiking was attenuated by tetrodotoxin (TTX) and low calcium solutions, and abolished by prior exhaustion of intracellular calcium stores. Further, DA receptor antagonists reduced these transients, whereas DA induced rises with similar spiking kinetics. Amphetamine, which also results in elevated levels of synaptic DA, but via a different pharmacological action than cocaine, induced calcium spiking with similar profiles. Although large differences in spiking were not noted in an animal model associated with a heightened proclivity of acquiring addiction‐related behavior, the prenatal nicotine exposed mouse (PNE), subtle differences in cocaine's effect on calcium spiking were noted, indicative of a reduction in action of cocaine in the LDT associated with exposure to nicotine during gestation. When taken together, our data indicate that acute actions of cocaine do include effects on LDT cells. Considering the role of intracellular calcium in cellular excitability, and of the LDT in addiction circuitry, our data suggest that cocaine effects in this nucleus may contribute to the high addiction potential of this drug.
Collapse
Affiliation(s)
- Mads Ødum Lambert
- Department of Drug Design and Pharmacology Faculty of Health Sciences Universitetsparken 2 University of Copenhagen Copenhagen 2100 Denmark
| | - Theis Højland Ipsen
- Department of Drug Design and Pharmacology Faculty of Health Sciences Universitetsparken 2 University of Copenhagen Copenhagen 2100 Denmark
| | - Kristi Anne Kohlmeier
- Department of Drug Design and Pharmacology Faculty of Health Sciences Universitetsparken 2 University of Copenhagen Copenhagen 2100 Denmark
| |
Collapse
|
10
|
Renault R, Sukenik N, Descroix S, Malaquin L, Viovy JL, Peyrin JM, Bottani S, Monceau P, Moses E, Vignes M. Combining microfluidics, optogenetics and calcium imaging to study neuronal communication in vitro. PLoS One 2015; 10:e0120680. [PMID: 25901914 PMCID: PMC4406441 DOI: 10.1371/journal.pone.0120680] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 02/05/2015] [Indexed: 11/19/2022] Open
Abstract
In this paper we report the combination of microfluidics, optogenetics and calcium imaging as a cheap and convenient platform to study synaptic communication between neuronal populations in vitro. We first show that Calcium Orange indicator is compatible in vitro with a commonly used Channelrhodopsine-2 (ChR2) variant, as standard calcium imaging conditions did not alter significantly the activity of transduced cultures of rodent primary neurons. A fast, robust and scalable process for micro-chip fabrication was developed in parallel to build micro-compartmented cultures. Coupling optical fibers to each micro-compartment allowed for the independent control of ChR2 activation in the different populations without crosstalk. By analyzing the post-stimuli activity across the different populations, we finally show how this platform can be used to evaluate quantitatively the effective connectivity between connected neuronal populations.
Collapse
Affiliation(s)
- Renaud Renault
- MSC (Université Paris-Diderot, CNRS-UMR 7057), 5 Rue Thomas Mann, 75013 Paris, France
- Physicochimie Curie (Institut Curie, CNRS-UMR 168, UPMC), Institut Curie, Centre de Recherche, 26 rue d’Ulm, 75248 Paris Cedex 05, France
- Department of Complex Systems, Weizmann Institute, Rehovot, Israel
| | - Nirit Sukenik
- Department of Complex Systems, Weizmann Institute, Rehovot, Israel
| | - Stéphanie Descroix
- Physicochimie Curie (Institut Curie, CNRS-UMR 168, UPMC), Institut Curie, Centre de Recherche, 26 rue d’Ulm, 75248 Paris Cedex 05, France
| | - Laurent Malaquin
- Physicochimie Curie (Institut Curie, CNRS-UMR 168, UPMC), Institut Curie, Centre de Recherche, 26 rue d’Ulm, 75248 Paris Cedex 05, France
| | - Jean-Louis Viovy
- Physicochimie Curie (Institut Curie, CNRS-UMR 168, UPMC), Institut Curie, Centre de Recherche, 26 rue d’Ulm, 75248 Paris Cedex 05, France
| | - Jean-Michel Peyrin
- Biological Adaptation and Ageing (CNRS, UMR 8256), F-75005, Paris, France
- Sorbonne Universités, UPMC Univ Paris 06, UMR 8256, B2A, Institut de Biologie Paris Seine, F-75005, Paris, France
| | - Samuel Bottani
- MSC (Université Paris-Diderot, CNRS-UMR 7057), 5 Rue Thomas Mann, 75013 Paris, France
| | - Pascal Monceau
- MSC (Université Paris-Diderot, CNRS-UMR 7057), 5 Rue Thomas Mann, 75013 Paris, France
| | - Elisha Moses
- Department of Complex Systems, Weizmann Institute, Rehovot, Israel
| | - Maéva Vignes
- Physicochimie Curie (Institut Curie, CNRS-UMR 168, UPMC), Institut Curie, Centre de Recherche, 26 rue d’Ulm, 75248 Paris Cedex 05, France
- Biological Adaptation and Ageing (CNRS, UMR 8256), F-75005, Paris, France
- Sorbonne Universités, UPMC Univ Paris 06, UMR 8256, B2A, Institut de Biologie Paris Seine, F-75005, Paris, France
- * E-mail: (MV)
| |
Collapse
|
11
|
Sceniak MP, Lang M, Enomoto AC, James Howell C, Hermes DJ, Katz DM. Mechanisms of Functional Hypoconnectivity in the Medial Prefrontal Cortex of Mecp2 Null Mice. Cereb Cortex 2015; 26:1938-1956. [PMID: 25662825 DOI: 10.1093/cercor/bhv002] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Frontal cortical dysfunction is thought to contribute to cognitive and behavioral features of autism spectrum disorders; however, underlying mechanisms are poorly understood. The present study sought to define how loss of Mecp2, the gene mutated in Rett syndrome (RTT), disrupts function in the murine medial prefrontal cortex (mPFC) using acute brain slices and behavioral testing. Compared with wildtype, pyramidal neurons in the Mecp2 null mPFC exhibit significant reductions in excitatory postsynaptic currents, the duration of excitatory UP-states, evoked population activity, and the ratio of NMDA:AMPA currents, as well as an increase in the relative fraction of NR2B currents. These functional changes are associated with reductions in the density of excitatory dendritic spines, the ratio of vesicular glutamate to GABA transporters and GluN1 expression. In contrast to recent reports on circuit defects in other brain regions, we observed no effect of Mecp2 loss on inhibitory synaptic currents or expression of the inhibitory marker parvalbumin. Consistent with mPFC hypofunction, Mecp2 nulls exhibit respiratory dysregulation in response to behavioral arousal. Our data highlight functional hypoconnectivity in the mPFC as a potential substrate for behavioral disruption in RTT and other disorders associated with reduced expression of Mecp2 in frontal cortical regions.
Collapse
Affiliation(s)
- Michael P Sceniak
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Min Lang
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Addison C Enomoto
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - C James Howell
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Douglas J Hermes
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - David M Katz
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| |
Collapse
|
12
|
Extracellular pH and neuronal depolarization serve as dynamic switches to rapidly mobilize trkA to the membrane of adult sensory neurons. J Neurosci 2013; 33:8202-15. [PMID: 23658159 DOI: 10.1523/jneurosci.4408-12.2013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Activation of the nerve growth factor (NGF) receptor trkA and tissue acidosis are critically linked to inflammation-associated nociceptor sensitization. This study explored how increased acidity is linked to sensory neuron sensitization to NGF. Adult Wistar rat primary sensory neurons grown at physiological pH 7.4, then either kept at pH 7.4 or challenged for 30 min in pH 6.5 medium, provided a model of acidosis. Nonpermeabilizing trkA immunofluorescence revealed a significant increase in trkA mobilization to the plasma membrane from intracellular stores in response to proton challenge. This was confirmed using a surface protein biotinylation assay and Brefeldin A disruption of the rough endoplasmic reticulum-Golgi-trans-Golgi network. Mobilization of trkA to the membrane at pH 6.5 was abolished in neurons treated with the acid-sensitive ion channel blocker, amiloride. While elevated levels of NGF-independent trkA phosphorylation occurred at pH 6.5 alone, the level of activation was significantly increased in response to NGF challenge. Exposure of sensory neurons to pH 6.5 medium also resulted in strong calcium (Ca(2+)) transients that were reversible upon reintroduction to physiological pH. The pH 6.5-induced mobilization of trkA to the membrane was Ca(2+) dependent, as BAPTA-AM Ca(2+) chelation abrogated the response. Interestingly, KCl-induced depolarization was sufficient to induce mobilization of trkA to the cell surface at pH 7.4, but did not augment the response to pH 6.5. In conclusion, increased mobilization of trkA to neuronal membranes in response to either acidosis or neuronal depolarization provides two novel mechanisms by which sensory neurons can rapidly sensitize to NGF and has important implications for inflammatory pain states.
Collapse
|
13
|
Idoux E, Mertz J. Control of local intracellular calcium concentration with dynamic-clamp controlled 2-photon uncaging. PLoS One 2011; 6:e28685. [PMID: 22216105 PMCID: PMC3247215 DOI: 10.1371/journal.pone.0028685] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Accepted: 11/13/2011] [Indexed: 11/18/2022] Open
Abstract
The variations of the intracellular concentration of calcium ion ([Ca(2+)](i)) are at the heart of intracellular signaling, and their imaging is therefore of enormous interest. However, passive [Ca(2+)](i) imaging provides no control over these variations, meaning that a full exploration of the functional consequences of [Ca(2+)](i) changes is difficult to attain. The tools designed so far to modify [Ca(2+)](i), even qualitatively, suffer drawbacks that undermine their widespread use. Here, we describe an electro-optical technique to quantitatively set [Ca(2+)](i), in real time and with sub-cellular resolution, using two-photon Ca(2+) uncaging and dynamic-clamp. We experimentally demonstrate, on neurons from acute olfactory bulb slices of Long Evans rats, various capabilities of this technique previously difficult to achieve, such as the independent control of the membrane potential and [Ca(2+)](i) variations, the functional knocking-in of user-defined virtual voltage-dependent Ca(2+) channels, and the standardization of [Ca(2+)](i) patterns across different cells. Our goal is to lay the groundwork for this technique and establish it as a new and versatile tool for the study of cell signaling.
Collapse
Affiliation(s)
- Erwin Idoux
- Biomedical Engineering Department, Boston University, Boston, Massachusetts, USA.
| | | |
Collapse
|
14
|
Sapap3 deletion anomalously activates short-term endocannabinoid-mediated synaptic plasticity. J Neurosci 2011; 31:9563-73. [PMID: 21715621 DOI: 10.1523/jneurosci.1701-11.2011] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Retrograde synaptic signaling by endocannabinoids (eCBs) is a widespread mechanism for activity-dependent inhibition of synaptic strength in the brain. Although prevalent, the conditions for eliciting eCB-mediated synaptic depression vary among brain circuits. As yet, relatively little is known about the molecular mechanisms underlying this variation, although the initial signaling events are likely dictated by postsynaptic proteins. SAP90/PSD-95-associated proteins (SAPAPs) are a family of postsynaptic proteins unique to excitatory synapses. Using Sapap3 knock-out (KO) mice, we find that, in the absence of SAPAP3, striatal medium spiny neuron (MSN) excitatory synapses exhibit eCB-mediated synaptic depression under conditions that do not normally activate this process. The anomalous synaptic plasticity requires type 5 metabotropic glutamate receptors (mGluR5s), which we find are dysregulated in Sapap3 KO MSNs. Both surface expression and activity of mGluR5s are increased in Sapap3 KO MSNs, suggesting that enhanced mGluR5 activity may drive the anomalous synaptic plasticity. In direct support of this possibility, we find that, in wild-type (WT) MSNs, pharmacological enhancement of mGluR5 by a positive allosteric modulator is sufficient to reproduce the increased synaptic depression seen in Sapap3 KO MSNs. The same pharmacologic treatment, however, fails to elicit further depression in KO MSNs. Under conditions that are sufficient to engage eCB-mediated synaptic depression in WT MSNs, Sapap3 deletion does not alter the magnitude of the response. These results identify a role for SAPAP3 in the regulation of postsynaptic mGluRs and eCB-mediated synaptic plasticity. SAPAPs, through their effect on mGluR activity, may serve as regulatory molecules gating the threshold for inducing eCB-mediated synaptic plasticity.
Collapse
|
15
|
Shew WL, Bellay T, Plenz D. Simultaneous multi-electrode array recording and two-photon calcium imaging of neural activity. J Neurosci Methods 2010; 192:75-82. [PMID: 20659501 DOI: 10.1016/j.jneumeth.2010.07.023] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2010] [Revised: 07/16/2010] [Accepted: 07/19/2010] [Indexed: 11/17/2022]
Abstract
A complete understanding of how brain circuits function will require measurement techniques which monitor large-scale network activity simultaneously with the activity of local neural populations at a small scale. Here we present a useful step towards achieving this aim: simultaneous two-photon calcium imaging and multi-electrode array (MEA) recordings. The primary challenge of this method is removing an electrical artifact from the MEA signals that is caused by the imaging laser. Here we show that artifact removal can be achieved with a simple filtering scheme. As a demonstration of this technique we compare large-scale local field potential signals to single-neuron activity in a small-scale group of cells recorded from rat acute slices under two conditions: suppressed vs. intact inhibitory interactions between neurons.
Collapse
Affiliation(s)
- Woodrow L Shew
- Section on Critical Brain Dynamics National Institute of Mental Health, Bethesda, MD 20892, USA.
| | | | | |
Collapse
|
16
|
Kalmbach A, Kullmann PHM, Kandler K. NMDAR-Mediated Calcium Transients Elicited by Glutamate Co-Release at Developing Inhibitory Synapses. Front Synaptic Neurosci 2010; 2:27. [PMID: 21423513 PMCID: PMC3059663 DOI: 10.3389/fnsyn.2010.00027] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2010] [Accepted: 06/11/2010] [Indexed: 11/13/2022] Open
Abstract
Before hearing onset, the topographic organization of the inhibitory sound localization pathway from the medial nucleus of the trapezoid body (MNTB) to the lateral superior olive (LSO) is refined by means of synaptic silencing and strengthening. During this refinement period MNTB-LSO synapses not only release GABA and glycine but also release glutamate. This co-released glutamate can elicit postsynaptic currents that are predominantly mediated by NMDA receptors (NMDARs). To gain a better understanding of how glutamate contributes to synaptic signaling at developing MNTB-LSO inhibitory synapses, we investigated to what degree and under what conditions NMDARs contribute to postsynaptic calcium responses. Our results demonstrate that MNTB-LSO synapses can elicit compartmentalized calcium responses along aspiny LSO dendrites. These responses are significantly attenuated by the NMDAR antagonist APV. APV, however, had no effect on somatically recorded electrical postsynaptic responses, indicating little, if any, contribution of NMDARs to spike generation. NMDAR-mediated calcium responses were decreased when increasing extracellular magnesium concentrations to physiological levels indicating that MNTB-LSO synapses activate magnesium sensitive NMDAR on immature LSO dendrites. In Fura-2 AM loaded neurons, blocking GABAA and glycine receptors increased NMDAR contribution to somatic calcium responses suggesting that GABA and glycine, perhaps by shunting backpropagating action potentials, decrease the level of NMDAR activation under strong stimulus conditions.
Collapse
Affiliation(s)
- Abigail Kalmbach
- Department of Neurobiology, School of Medicine, University of Pittsburgh Pittsburgh, PA, USA
| | | | | |
Collapse
|