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Gusain P, Taketoshi M, Tominaga Y, Tominaga T. Functional Dissection of Ipsilateral and Contralateral Neural Activity Propagation Using Voltage-Sensitive Dye Imaging in Mouse Prefrontal Cortex. eNeuro 2023; 10:ENEURO.0161-23.2023. [PMID: 37977827 DOI: 10.1523/eneuro.0161-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 11/03/2023] [Accepted: 11/10/2023] [Indexed: 11/19/2023] Open
Abstract
Prefrontal cortex (PFC) intrahemispheric activity and the interhemispheric connection have a significant impact on neuropsychiatric disorder pathology. This study aimed to generate a functional map of FC intrahemispheric and interhemispheric connections. Functional dissection of mouse PFCs was performed using the voltage-sensitive dye (VSD) imaging method with high speed (1 ms/frame), high resolution (256 × 256 pixels), and a large field of view (∼10 mm). Acute serial 350 μm slices were prepared from the bregma covering the PFC and numbered 1-5 based on their distance from the bregma (i.e., 1.70, 1.34, 0.98, 0.62, and 0.26 mm) with reference to the Mouse Brain Atlas (Paxinos and Franklin, 2008). The neural response to electrical stimulation was measured at nine sites and then averaged, and a functional map of the propagation patterns was created. Intracortical propagation was observed in slices 3-5, encompassing the anterior cingulate cortex (ACC) and corpus callosum (CC). The activity reached area 33 of the ACC. Direct white matter stimulation activated area 33 in both hemispheres. Similar findings were obtained via DiI staining of the CC. Imaging analysis revealed directional biases in neural signals traveling within the ACC, whereby the signal transmission speed and probability varied based on the signal direction. Specifically, the spread of neural signals from cg2 to cg1 was stronger than that from cingulate cortex area 1(cg1) to cingulate cortex area 2(cg2), which has implications for interhemispheric functional connections. These findings highlight the importance of understanding the PFC functional anatomy in evaluating neuromodulators like serotonin and dopamine, as well as other factors related to neuropsychiatric diseases.
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Affiliation(s)
- Pooja Gusain
- Institute of Neuroscience, Tokushima Bunri University, Sanuki 769-2193, Japan
| | - Makiko Taketoshi
- Institute of Neuroscience, Tokushima Bunri University, Sanuki 769-2193, Japan
| | - Yoko Tominaga
- Institute of Neuroscience, Tokushima Bunri University, Sanuki 769-2193, Japan
| | - Takashi Tominaga
- Institute of Neuroscience, Tokushima Bunri University, Sanuki 769-2193, Japan
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki 769-2193, Japan
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2
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Mayr S, Schliep R, Elfers K, Mazzuoli-Weber G. Mechanosensitive enteric neurons in the guinea pig gastric fundus and antrum. Neurogastroenterol Motil 2023; 35:e14674. [PMID: 37702071 DOI: 10.1111/nmo.14674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 07/16/2023] [Accepted: 08/28/2023] [Indexed: 09/14/2023]
Abstract
BACKGROUND Coping with the ingested food, the gastric regions of fundus, corpus, and antrum display different motility patterns. Intrinsic components of such patterns involving mechanosensitive enteric neurons (MEN) have been described in the guinea pig gastric corpus but are poorly understood in the fundus and antrum. METHODS To elucidate mechanosensitive properties of myenteric neurons in the gastric fundus and antrum, membrane potential imaging using Di-8-ANEPPS was applied. A small-volume injection led to neuronal compression. We analyzed the number of MEN and their firing frequency in addition to the involvement of selected mechanoreceptors. To characterize the neurochemical phenotype of MEN, we performed immunohistochemistry. KEY RESULTS In the gastric fundus, 16% of the neurons reproducibly responded to mechanical stimulation and thus were MEN. Of those, 83% were cholinergic and 19% nitrergic. In the antrum, 6% of the neurons responded to the compression stimulus, equally distributed among cholinergic and nitrergic MEN. Defunctionalizing the sensory extrinsic afferents led to a significant drop in the number of MEN in both regions. CONCLUSION We provided evidence for MEN in the gastric fundus and antrum and further investigated mechanoreceptors. However, the proportions of the chemical phenotypes of the MEN differed significantly between both regions. Further investigations of synaptic connections of MEN are crucial to understand the hardwired neuronal circuits in the stomach.
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Affiliation(s)
- Sophia Mayr
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, Hannover, Germany
- Center for Systems Neuroscience (ZSN), Hannover, Germany
| | - Ronja Schliep
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Kristin Elfers
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Gemma Mazzuoli-Weber
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, Hannover, Germany
- Center for Systems Neuroscience (ZSN), Hannover, Germany
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3
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Utsumi Y, Taketoshi M, Miwa M, Tominaga Y, Tominaga T. Assessing seizure liability in vitro with voltage-sensitive dye imaging in mouse hippocampal slices. Front Cell Neurosci 2023; 17:1217368. [PMID: 37680865 PMCID: PMC10481167 DOI: 10.3389/fncel.2023.1217368] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 08/09/2023] [Indexed: 09/09/2023] Open
Abstract
Non-clinical toxicology is a major cause of drug candidate attrition during development. In particular, drug-induced seizures are the most common finding in central nervous system (CNS) toxicity. Current safety pharmacology tests for assessing CNS functions are often inadequate in detecting seizure-inducing compounds early in drug development, leading to significant delays. This paper presents an in vitro seizure liability assay using voltage-sensitive dye (VSD) imaging techniques in hippocampal brain slices, offering a powerful alternative to traditional electrophysiological methods. Hippocampal slices were isolated from mice, and VSD optical responses evoked by stimulating the Schaffer collateral pathway were recorded and analyzed in the stratum radiatum (SR) and stratum pyramidale (SP). VSDs allow for the comprehensive visualization of neuronal action potentials and postsynaptic potentials on a millisecond timescale. By employing this approach, we investigated the in vitro drug-induced seizure liability of representative pro-convulsant compounds. Picrotoxin (PiTX; 1-100 μM), gabazine (GZ; 0.1-10 μM), and 4-aminopyridine (4AP; 10-100 μM) exhibited seizure-like responses in the hippocampus, but pilocarpine hydrochloride (Pilo; 10-100 μM) did not. Our findings demonstrate the potential of VSD-based assays in identifying seizurogenic compounds during early drug discovery, thereby reducing delays in drug development and providing insights into the mechanisms underlying seizure induction and the associated risks of pro-convulsant compounds.
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Affiliation(s)
- Yuichi Utsumi
- Graduate School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki, Japan
- Institute of Neuroscience, Tokushima Bunri University, Sanuki, Japan
| | - Makiko Taketoshi
- Institute of Neuroscience, Tokushima Bunri University, Sanuki, Japan
| | - Michiko Miwa
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki, Japan
| | - Yoko Tominaga
- Institute of Neuroscience, Tokushima Bunri University, Sanuki, Japan
| | - Takashi Tominaga
- Graduate School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki, Japan
- Institute of Neuroscience, Tokushima Bunri University, Sanuki, Japan
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki, Japan
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4
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Sato K, Momose-Sato Y. Functional development of olfactory nerve-related neural circuits in the embryonic chick forebrain revealed by voltage-sensitive dye imaging. Eur J Neurosci 2022; 56:4914-4929. [PMID: 35920370 DOI: 10.1111/ejn.15788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 07/29/2022] [Accepted: 07/30/2022] [Indexed: 11/03/2022]
Abstract
Multiple-site optical recordings with NK2761, a voltage-sensitive absorption dye, were applied to the embryonic chick olfactory system, and the functional development of olfactory nerve (N.I)-related neural circuits was examined in the forebrain. The stimulation of the N. I elicited neural responses in N.I-olfactory bulb (OB)-forebrain preparations at the embryonic 8-12 day (E8-E12) stages. At the E11 stage, we functionally identified two circuits projecting from the OB to the forebrain. The first circuit passed through the ventral side of the forebrain and spread in the dorso-caudal direction, while the second circuit passed through the dorsal side to the first circuit. Pharmacological experiments showed that NMDA receptor function was more significant for the transfer of sensory information in these circuits. The functional development of N.I-related circuits was investigated, and the results obtained revealed that the ventral circuit was generated earlier than the dorsal circuit. Neural responses in the ventral circuit were detected from the E9 stage in normal physiological solution and the E8 stage in Mg2+ -free solution, which activated NMDA receptor function. At the E10 stage, neural responses in the dorsal circuit were clearly recognized in addition to ventral responses. We attempted to identify possible candidates for relay nuclei in the forebrain by comparing contour line maps of the optical signal amplitude with previously reported neuroanatomical data. The present results suggest that N.I-related neural circuits from the periphery to the subpallium functionally mature earlier than those to the pallium during ontogenesis.
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Affiliation(s)
- Katsushige Sato
- Department of Health and Nutrition Sciences, Komazawa Women's University Faculty of Human Health, Inagi-shi, Tokyo, Japan
| | - Yoko Momose-Sato
- Department of Nutrition and Dietetics, College of Nutrition, Kanto Gakuin University, Kanazawa-ku, Yokohama, Japan
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5
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Kierzek M, Deal PE, Miller EW, Mukherjee S, Wachten D, Baumann A, Kaupp UB, Strünker T, Brenker C. Simultaneous recording of multiple cellular signaling events by frequency- and spectrally-tuned multiplexing of fluorescent probes. eLife 2021; 10:e63129. [PMID: 34859780 PMCID: PMC8700268 DOI: 10.7554/elife.63129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 12/01/2021] [Indexed: 12/21/2022] Open
Abstract
Fluorescent probes that change their spectral properties upon binding to small biomolecules, ions, or changes in the membrane potential (Vm) are invaluable tools to study cellular signaling pathways. Here, we introduce a novel technique for simultaneous recording of multiple probes at millisecond time resolution: frequency- and spectrally-tuned multiplexing (FASTM). Different from present multiplexing approaches, FASTM uses phase-sensitive signal detection, which renders various combinations of common probes for Vm and ions accessible for multiplexing. Using kinetic stopped-flow fluorimetry, we show that FASTM allows simultaneous recording of rapid changes in Ca2+, pH, Na+, and Vm with high sensitivity and minimal crosstalk. FASTM is also suited for multiplexing using single-cell microscopy and genetically encoded FRET biosensors. Moreover, FASTM is compatible with optochemical tools to study signaling using light. Finally, we show that the exceptional time resolution of FASTM also allows resolving rapid chemical reactions. Altogether, FASTM opens new opportunities for interrogating cellular signaling.
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Affiliation(s)
- Michelina Kierzek
- Centre of Reproductive Medicine and Andrology, University of MünsterMünsterGermany
- CiM-IMPRS Graduate School, University of MünsterMünsterGermany
| | - Parker E Deal
- Department of Chemistry, University of California, BerkeleyBerkeleyUnited States
| | - Evan W Miller
- Department of Chemistry, University of California, BerkeleyBerkeleyUnited States
- Department of Molecular & Cell Biology, University of California, BerkeleyBerkeleyUnited States
- Helen Wills Neuroscience Institute, University of California, BerkeleyBerkeleyUnited States
| | - Shatanik Mukherjee
- Molecular Sensory Systems, Center of Advanced European Studies and ResearchBonnGermany
| | - Dagmar Wachten
- Institute of Innate Immunity, Department of Biophysical Imaging, Medical Faculty, University of BonnBonnGermany
| | - Arnd Baumann
- Institute of Biological Information Processing (IBI-1), Research Center JülichJülichGermany
| | - U Benjamin Kaupp
- Life & Medical Sciences Institute (LIMES), University of BonnBonnGermany
| | - Timo Strünker
- Centre of Reproductive Medicine and Andrology, University of MünsterMünsterGermany
- Cells in Motion Interfaculty Centre, University of MünsterMünsterGermany
| | - Christoph Brenker
- Centre of Reproductive Medicine and Andrology, University of MünsterMünsterGermany
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6
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Pak RW, Kang J, Boctor E, Kang JU. Optimization of Near-Infrared Fluorescence Voltage-Sensitive Dye Imaging for Neuronal Activity Monitoring in the Rodent Brain. Front Neurosci 2021; 15:742405. [PMID: 34776848 PMCID: PMC8582490 DOI: 10.3389/fnins.2021.742405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 10/05/2021] [Indexed: 11/13/2022] Open
Abstract
Many currently employed clinical brain functional imaging technologies rely on indirect measures of activity such as hemodynamics resulting in low temporal and spatial resolutions. To improve upon this, optical systems were developed in conjunction with methods to deliver near-IR voltage-sensitive dye (VSD) to provide activity-dependent optical contrast to establish a clinical tool to facilitate direct monitoring of neuron depolarization through the intact skull. Following the previously developed VSD delivery protocol through the blood-brain barrier, IR-780 perchlorate VSD concentrations in the brain were varied and stimulus-evoked responses were observed. In this paper, a range of optimal VSD tissue concentrations was established that maximized fluorescence fractional change for detection of membrane potential responses to external stimuli through a series of phantom, in vitro, ex vivo, and in vivo experiments in mouse models.
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Affiliation(s)
- Rebecca W Pak
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States
| | - Jeeun Kang
- Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, United States
| | - Emad Boctor
- Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, United States
| | - Jin U Kang
- Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD, United States
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7
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Hiyoshi K, Shiraishi A, Fukuda N, Tsuda S. In vivo wide-field voltage imaging in zebrafish with voltage-sensitive dye and genetically encoded voltage indicator. Dev Growth Differ 2021; 63:417-428. [PMID: 34411280 DOI: 10.1111/dgd.12744] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 07/01/2021] [Accepted: 07/04/2021] [Indexed: 11/28/2022]
Abstract
The brain consists of neural circuits, which are assemblies of various neuron types. For understanding how the brain works, it is essential to identify the functions of each type of neuron and neuronal circuits. Recent advances in our understanding of brain function and its development have been achieved using light to detect neuronal activity. Optical measurement of membrane potentials through voltage imaging is a desirable approach, enabling fast, direct, and simultaneous detection of membrane potentials in a population of neurons. Its high speed and directness can help detect synaptic and action potentials and hyperpolarization, which encode critical information for brain function. Here, we describe in vivo voltage imaging procedures that we have recently established using zebrafish, a powerful animal model in developmental biology and neuroscience. By applying two types of voltage sensors, voltage-sensitive dyes (VSDs, Di-4-ANEPPS) and genetically encoded voltage indicators (GEVIs, ASAP1), spatiotemporal dynamics of voltage signals can be detected in the whole cerebellum and spinal cord in awake fish at single-cell and neuronal population levels. Combining this method with other approaches, such as optogenetics, behavioral analysis, and electrophysiology would facilitate a deeper understanding of the network dynamics of the brain circuitry and its development.
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Affiliation(s)
- Kanae Hiyoshi
- Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama City, Japan
| | - Asuka Shiraishi
- Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama City, Japan
| | - Narumi Fukuda
- Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama City, Japan
| | - Sachiko Tsuda
- Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama City, Japan.,Integrative Research Center for Life Sciences and Biotechnology, Saitama University, Saitama City, Japan
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8
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Ronzhina M, Stracina T, Lacinova L, Ondacova K, Pavlovicova M, Marsanova L, Smisek R, Janousek O, Fialova K, Kolarova J, Novakova M, Provaznik I. Di-4-ANEPPS Modulates Electrical Activity and Progress of Myocardial Ischemia in Rabbit Isolated Heart. Front Physiol 2021; 12:667065. [PMID: 34177617 PMCID: PMC8222999 DOI: 10.3389/fphys.2021.667065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 04/12/2021] [Indexed: 11/16/2022] Open
Abstract
Aims Although voltage-sensitive dye di-4-ANEPPS is a common tool for mapping cardiac electrical activity, reported effects on electrophysiological parameters are rather. The main goals of the study were to reveal effects of the dye on rabbit isolated heart and to verify, whether rabbit isolated heart stained with di-4-ANEPPS is a suitable tool for myocardial ischemia investigation. Methods and Results Study involved experiments on stained (n = 9) and non-stained (n = 11) Langendorff perfused rabbit isolated hearts. Electrophysiological effects of the dye were evaluated by analysis of various electrogram (EG) parameters using common paired and unpaired statistical tests. It was shown that staining the hearts with di-4-ANEPPS leads to only short-term sporadic prolongation of impulse conduction through atria and atrioventricular node. On the other hand, significant irreversible slowing of heart rate and ventricular conduction were found in stained hearts as compared to controls. In patch clamp experiments, significant inhibition of sodium current density was observed in differentiated NG108-15 cells stained by the dye. Although no significant differences in mean number of ventricular premature beats were found between the stained and the non-stained hearts in ischemia as well as in reperfusion, all abovementioned results indicate increased arrhythmogenicity. In isolated hearts during ischemia, prominent ischemic patterns appeared in the stained hearts with 3–4 min delay as compared to the non-stained ones. Moreover, the ischemic changes did not achieve the same magnitude as in controls even after 10 min of ischemia. It resulted in poor performance of ischemia detection by proposed EG parameters, as was quantified by receiver operating characteristics analysis. Conclusion Our results demonstrate significant direct irreversible effect of di-4-ANEPPS on spontaneous heart rate and ventricular impulse conduction in rabbit isolated heart model. Particularly, this should be considered when di-4-ANEPPS is used in ischemia studies in rabbit. Delayed attenuated response of such hearts to ischemia might lead to misinterpretation of obtained results.
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Affiliation(s)
- Marina Ronzhina
- Department of Biomedical Engineering, Faculty of Electrical Engineering and Communication, Brno University of Technology, Brno, Czechia
| | - Tibor Stracina
- Department of Physiology, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Lubica Lacinova
- Centre of Biosciences, Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Katarina Ondacova
- Centre of Biosciences, Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Michaela Pavlovicova
- Centre of Biosciences, Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Lucie Marsanova
- Department of Biomedical Engineering, Faculty of Electrical Engineering and Communication, Brno University of Technology, Brno, Czechia
| | - Radovan Smisek
- Department of Biomedical Engineering, Faculty of Electrical Engineering and Communication, Brno University of Technology, Brno, Czechia
| | - Oto Janousek
- Department of Biomedical Engineering, Faculty of Electrical Engineering and Communication, Brno University of Technology, Brno, Czechia
| | - Katerina Fialova
- Department of Physiology, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Jana Kolarova
- Department of Biomedical Engineering, Faculty of Electrical Engineering and Communication, Brno University of Technology, Brno, Czechia
| | - Marie Novakova
- Department of Physiology, Faculty of Medicine, Masaryk University, Brno, Czechia.,International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czechia
| | - Ivo Provaznik
- Department of Biomedical Engineering, Faculty of Electrical Engineering and Communication, Brno University of Technology, Brno, Czechia
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9
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Dorgans K, Kuhn B, Uusisaari MY. Imaging Subthreshold Voltage Oscillation With Cellular Resolution in the Inferior Olive in vitro. Front Cell Neurosci 2020; 14:607843. [PMID: 33381015 PMCID: PMC7767970 DOI: 10.3389/fncel.2020.607843] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 11/19/2020] [Indexed: 11/13/2022] Open
Abstract
Voltage imaging with cellular resolution in mammalian brain slices is still a challenging task. Here, we describe and validate a method for delivery of the voltage-sensitive dye ANNINE-6plus (A6+) into tissue for voltage imaging that results in higher signal-to-noise ratio (SNR) than conventional bath application methods. The not fully dissolved dye was injected into the inferior olive (IO) 0, 1, or 7 days prior to acute slice preparation using stereotactic surgery. We find that the voltage imaging improves after an extended incubation period in vivo in terms of labeled volume, homogeneous neuropil labeling with saliently labeled somata, and SNR. Preparing acute slices 7 days after the dye injection, the SNR is high enough to allow single-trial recording of IO subthreshold oscillations using wide-field (network-level) as well as high-magnification (single-cell level) voltage imaging with a CMOS camera. This method is easily adaptable to other brain regions where genetically-encoded voltage sensors are prohibitively difficult to use and where an ultrafast, pure electrochromic sensor, like A6+, is required. Due to the long-lasting staining demonstrated here, the method can be combined, for example, with deep-brain imaging using implantable GRIN lenses.
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Affiliation(s)
- Kevin Dorgans
- Neuronal Rhythms in Movement Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Bernd Kuhn
- Optical Neuroimaging Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Marylka Yoe Uusisaari
- Neuronal Rhythms in Movement Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
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10
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Kajiwara R, Tominaga T. Perirhinal cortex area 35 controls the functional link between the perirhinal and entorhinal-hippocampal circuitry: D-type potassium channel-mediated gating of neural propagation from the perirhinal cortex to the entorhinal-hippocampal circuitry. Bioessays 2020; 43:e2000084. [PMID: 33236360 DOI: 10.1002/bies.202000084] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 10/15/2020] [Accepted: 10/15/2020] [Indexed: 11/07/2022]
Abstract
In several experimental conditions, neuronal excitation at the perirhinal cortex (PC) does not propagate to the entorhinal cortex (EC) due to a "wall" of inhibition, which may help to create functional coupling and un-coupling of the PC and EC in the medial temporal lobe. However, little is known regarding the coupling control process. Herein, we propose that the deep layer of area 35 in the PC plays a pivotal role in opening the gate for coupling, thus allowing the activity in the PC to propagate to the EC. Using voltage-sensitive dye imaging for the brain slices of rodents, we show that a slowly inactivating potassium conductance in this area is essential to induce excitation overtaking the inhibitory control. This coupling between the distinct neural circuits persists for at least 1 h. We elucidate further implications of this network-level plastic behavior and its mechanism.
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Affiliation(s)
- Riichi Kajiwara
- Department of Electronics and Bioinformatics, School of Science and Technology, Meiji University, Kawasaki, Japan
| | - Takashi Tominaga
- Laboratory for Neural Circuit Systems, Institute of Neuroscience, Tokushima Bunri University, Sanuki, Japan
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11
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Kunori N, Takashima I. An Implantable Cranial Window Using a Collagen Membrane for Chronic Voltage-Sensitive Dye Imaging. Micromachines (Basel) 2019; 10:E789. [PMID: 31752106 PMCID: PMC6915684 DOI: 10.3390/mi10110789] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 11/08/2019] [Accepted: 11/15/2019] [Indexed: 11/22/2022]
Abstract
Incorporating optical methods into implantable neural sensing devices is a challenging approach for brain-machine interfacing. Specifically, voltage-sensitive dye (VSD) imaging is a powerful tool enabling visualization of the network activity of thousands of neurons at high spatiotemporal resolution. However, VSD imaging usually requires removal of the dura mater for dye staining, and thereafter the exposed cortex needs to be protected using an optically transparent artificial dura. This is a major disadvantage that limits repeated VSD imaging over the long term. To address this issue, we propose to use an atelocollagen membrane as the dura substitute. We fabricated a small cranial chamber device, which is a tubular structure equipped with a collagen membrane at one end of the tube. We implanted the device into rats and monitored neural activity in the frontal cortex 1 week following surgery. The results indicate that the collagen membrane was chemically transparent, allowing VSD staining across the membrane material. The membrane was also optically transparent enough to pass light; forelimb-evoked neural activity was successfully visualized through the artificial dura. Because of its ideal chemical and optical manipulation capability, this collagen membrane may be widely applicable in various implantable neural sensors.
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Affiliation(s)
| | - Ichiro Takashima
- Human Informatics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8568, Japan;
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12
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Antic SD, Baker BJ, Canepari M. Editorial: New Insights on Neuron and Astrocyte Function From Cutting-Edge Optical Techniques. Front Cell Neurosci 2019; 13:463. [PMID: 31680872 PMCID: PMC6803618 DOI: 10.3389/fncel.2019.00463] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 09/30/2019] [Indexed: 11/13/2022] Open
Affiliation(s)
- Srdjan D Antic
- Department of Neuroscience, Institute for Systems Genomics, Stem Cell Institute, UConn Health, Farmington, CT, United States
| | - Bradley James Baker
- The Center for Functional Connectomics, Korea Institute of Science and Technology, Seoul, South Korea
| | - Marco Canepari
- Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology (UST), Seoul, South Korea.,Laboratories of Excellence, Ion Channel Science and Therapeutics, Valbonne, France.,Institut National de la Santé et Recherche Médicale, Paris, France
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13
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Kang J, Zhang HK, Kadam SD, Fedorko J, Valentine H, Malla AP, Yan P, Harraz MM, Kang JU, Rahmim A, Gjedde A, Loew LM, Wong DF, Boctor EM. Transcranial Recording of Electrophysiological Neural Activity in the Rodent Brain in vivo Using Functional Photoacoustic Imaging of Near-Infrared Voltage-Sensitive Dye. Front Neurosci 2019; 13:579. [PMID: 31447622 PMCID: PMC6696882 DOI: 10.3389/fnins.2019.00579] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 05/22/2019] [Indexed: 12/27/2022] Open
Abstract
Minimally-invasive monitoring of electrophysiological neural activities in real-time-that enables quantification of neural functions without a need for invasive craniotomy and the longer time constants of fMRI and PET-presents a very challenging yet significant task for neuroimaging. In this paper, we present in vivo functional PA (fPA) imaging of chemoconvulsant rat seizure model with intact scalp using a fluorescence quenching-based cyanine voltage-sensitive dye (VSD) characterized by a lipid vesicle model mimicking different levels of membrane potential variation. The framework also involves use of a near-infrared VSD delivered through the blood-brain barrier (BBB), opened by pharmacological modulation of adenosine receptor signaling. Our normalized time-frequency analysis presented in vivo VSD response in the seizure group significantly distinguishable from those of the control groups at sub-mm spatial resolution. Electroencephalogram (EEG) recording confirmed the changes of severity and frequency of brain activities, induced by chemoconvulsant seizures of the rat brain. The findings demonstrate that the near-infrared fPA VSD imaging is a promising tool for in vivo recording of brain activities through intact scalp, which would pave a way to its future translation in real time human brain imaging.
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Affiliation(s)
- Jeeun Kang
- Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, United States
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, United States
| | - Haichong K. Zhang
- Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, United States
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, United States
| | - Shilpa D. Kadam
- Department of Neurology, Hugo W. Moser Research Institute at Kennedy Krieger, Johns Hopkins Medical Institutions, Baltimore, MD, United States
| | - Julie Fedorko
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, United States
| | - Heather Valentine
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, United States
| | - Adarsha P. Malla
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, United States
| | - Ping Yan
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health, Farmington, CT, United States
| | - Maged M. Harraz
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, United States
| | - Jin U. Kang
- Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, United States
| | - Arman Rahmim
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, United States
| | - Albert Gjedde
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, United States
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
| | - Leslie M. Loew
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health, Farmington, CT, United States
| | - Dean F. Wong
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, United States
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, United States
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, United States
- Department of Neurology, Johns Hopkins Medical Institutions, Baltimore, MD, United States
- Department of Environmental Sciences and Engineering, Johns Hopkins University, Baltimore, MD, United States
| | - Emad M. Boctor
- Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, United States
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, United States
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14
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Abstract
ANNINE-6 and ANNINE-6plus are voltage-sensitive dyes that when combined with two-photon microscopy are ideal for recording of neuronal voltages in vivo, in both bulk loaded tissue and the dendrites of single neurons. Here, we describe in detail but for a broad audience the voltage sensing mechanism of fast voltage-sensitive dyes, with a focus on ANNINE dyes, and how voltage imaging can be optimized with one-photon and two-photon excitation. Under optimized imaging conditions the key strengths of ANNINE dyes are their high sensitivity (0.5%/mV), neglectable bleaching and phototoxicity, a linear response to membrane potential, and a temporal resolution which is faster than the optical imaging devices currently used in neurobiology (order of nanoseconds). ANNINE dyes in combination with two-photon microscopy allow depth-resolved voltage imaging in bulk loaded tissue to study average membrane voltage oscillations and sensory responses. Alternatively, if ANNINE-6plus is applied internally, supra and sub threshold voltage changes can be recorded from dendrites of single neurons in awake animals. Interestingly, in our experience ANNINE-6plus labeling is impressively stable in vivo, such that voltage imaging from single Purkinje neuron dendrites can be performed for 2 weeks after a single electroporation of the neuron. Finally, to maximize their potential for neuroscience studies, voltage imaging with ANNINE dyes and two-photon microscopy can be combined with electrophysiological recording, calcium imaging, and/or pharmacology, even in awake animals.
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Affiliation(s)
- Bernd Kuhn
- Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Christopher J Roome
- Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
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15
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Kajiwara R, Tominaga Y, Tominaga T. Network Plasticity Involved in the Spread of Neural Activity Within the Rhinal Cortices as Revealed by Voltage-Sensitive Dye Imaging in Mouse Brain Slices. Front Cell Neurosci 2019; 13:20. [PMID: 30804757 PMCID: PMC6378919 DOI: 10.3389/fncel.2019.00020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Accepted: 01/16/2019] [Indexed: 11/13/2022] Open
Abstract
The rhinal cortices, such as the perirhinal cortex (PC) and the entorhinal cortex (EC), are located within the bidirectional pathway between the neocortex and the hippocampus. Physiological studies indicate that the perirhinal transmission of neocortical inputs to the EC occurs at an extremely low probability, though many anatomical studies indicated strong connections exist in the pathway. Our previous study in rat brain slices indicated that an increase in excitability in deep layers of the PC/EC border initiated the neural activity transfer from the PC to the EC. In the present study, we hypothesized that such changes in network dynamics are not incidental observations but rather due to the plastic features of the perirhinal network, which links with the EC. To confirm this idea, we analyzed the network properties of neural transmission throughout the rhinal cortices and the plastic behavior of the network by performing a single-photon wide-field optical recording technique with a voltage-sensitive dye (VSD) in mouse brain slices of the PC, the EC, and the hippocampus. The low concentration of 4-aminopyridine (4-AP; 40 μM) enhanced neural activity in the PC, which eventually propagated to the EC via the deep layers of the PC/EC border. Interestingly, washout of 4-AP was unable to reverse entorhinal activation to the previous state. This change in the network property persisted for more than 1 h. This observation was not limited to the application of 4-AP. Burst stimulation to neurons in the perirhinal deep layers also induced the same change of network property. These results indicate the long-lasting modification of physiological connection between the PC and the EC, suggesting the existence of plasticity in the perirhinal-entorhinal network.
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Affiliation(s)
- Riichi Kajiwara
- Department of Electronics and Bioinformatics, School of Science and Technology, Meiji University, Kawasaki, Japan
| | - Yoko Tominaga
- Laboratory for Neural Circuit Systems, Institute of Neuroscience, Tokushima Bunri University, Sanuki, Japan
| | - Takashi Tominaga
- Laboratory for Neural Circuit Systems, Institute of Neuroscience, Tokushima Bunri University, Sanuki, Japan
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16
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Tominaga Y, Taketoshi M, Tominaga T. Overall Assay of Neuronal Signal Propagation Pattern With Long-Term Potentiation (LTP) in Hippocampal Slices From the CA1 Area With Fast Voltage-Sensitive Dye Imaging. Front Cell Neurosci 2018; 12:389. [PMID: 30405360 PMCID: PMC6207578 DOI: 10.3389/fncel.2018.00389] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 10/10/2018] [Indexed: 12/13/2022] Open
Abstract
Activity-dependent changes in the input-output (I-O) relationship of a neural circuit are central in the learning and memory function of the brain. To understand circuit-wide adjustments, optical imaging techniques to probe the membrane potential at every component of neurons, such as dendrites, axons and somas, in the circuit are essential. We have been developing fast voltage-sensitive dye (VSD) imaging methods for quantitative measurements, especially for single-photon wide-field optical imaging. The long-term continuous measurements needed to evaluate circuit-wide modifications require stable and quantitative long-term recordings. Here, we show that VSD imaging (VSDI) can be used to record changes in circuit activity in association with theta-burst stimulation (TBS)-induced long-term potentiation (LTP) of synaptic strength in the CA1 area. Our optics, together with the fast imaging system, enabled us to measure neuronal signals from the entire CA1 area at a maximum frame speed of 0.1 ms/frame every 60 s for over 12 h. We also introduced a method to evaluate circuit activity changes by mapping the variation in recordings from the CA1 area to coordinates defined by the morphology of CA1 pyramidal cells. The results clearly showed two types of spatial heterogeneity in LTP induction. The first heterogeneity is that LTP increased with distance from the stimulation site. The second heterogeneity is that LTP is higher in the stratum pyramidale (SP)-oriens region than in the stratum radiatum (SR). We also showed that the pattern of the heterogeneity changed according to the induction protocol, such as induction by TBS or high-frequency stimulation (HFS). We further demonstrated that part of the heterogeneity depends on the I-O response of the circuit elements. The results show the usefulness of VSDI in probing the function of hippocampal circuits.
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Affiliation(s)
| | | | - Takashi Tominaga
- Laboratory for Neural Circuit Systems, Institute of Neuroscience, Tokushima Bunri University, Sanuki, Japan
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17
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Momose-Sato Y, Sato K. Optical analysis of functional development of the facial motor nucleus in the embryonic rat brainstem. Eur J Neurosci 2018; 48:3273-3287. [PMID: 30118560 DOI: 10.1111/ejn.14122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 07/29/2018] [Accepted: 08/01/2018] [Indexed: 11/28/2022]
Abstract
Facial motor neurons of the rat embryo are first generated in rhombomere 4 and then migrate in the caudo-ventral direction. This migration forms a unique axonal trajectory called the genu, a loop of facial motor axons around the abducens nucleus. It is still unclear when and how this unique structure is functionally established during ontogenesis. Using voltage-sensitive dye (VSD) recording and the DiI staining method, we identified neural responses evoked by facial nerve (N.VII) stimulation and examined developmental processes of the facial motor nucleus in E12-E17 rat brainstems. We identified two types of fast spike-like signals; a long-duration signal, which corresponded to the action potential in the N.VII soma, and a short-duration signal, which reflected the action potential in the N.VII axons. The long-duration signal was detected as early as E13, suggesting that the N.VII motor neuron is already excitable at the beginning of cell migration. The response area of the long-duration signal extended caudally at E13-E14, and shifted in a ventral direction at E15. At E16-E17, the long-duration signal was concentrated in the caudo-ventral area, which was comparable to the location of the facial motor nucleus in the adult rat brainstem. These results demonstrate that developmental processes of cell migration and nuclear organization can be visualized and identified functionally with the VSD recording. We discuss the results by comparing functiogenesis and morphogenesis of the N.VII pathway.
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Affiliation(s)
- Yoko Momose-Sato
- Department of Nutrition and Dietetics, College of Nutrition, Kanto Gakuin University, Yokohama, Japan
| | - Katsushige Sato
- Department of Health and Nutrition Sciences, Faculty of Human Health, Komazawa Women's University, Tokyo, Japan
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18
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Bermudez-Contreras E, Chekhov S, Sun J, Tarnowsky J, McNaughton BL, Mohajerani MH. High-performance, inexpensive setup for simultaneous multisite recording of electrophysiological signals and mesoscale voltage imaging in the mouse cortex. Neurophotonics 2018; 5:025005. [PMID: 29651448 PMCID: PMC5874445 DOI: 10.1117/1.nph.5.2.025005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 03/05/2018] [Indexed: 05/17/2023]
Abstract
Simultaneous recording of optical and electrophysiological signals from multiple cortical areas may provide crucial information to expand our understanding of cortical function. However, the insertion of multiple electrodes into the brain may compromise optical imaging by both restricting the field of view and interfering with the approaches used to stabilize the specimen. Existing methods that combine electrophysiological recording and optical imaging in vivo implement either multiple surface electrodes, silicon probes, or a single electrode for deeper recordings. To address such limitation, we built a microelectrode array (hyperdrive, patent US5928143 A) compatible with wide-field imaging that allows insertion of up to 12 probes into a large brain area (8 mm diameter). The hyperdrive is comprised of a circle of individual microdrives where probes are positioned at an angle leaving a large brain area unobstructed for wide-field imaging. Multiple tetrodes and voltage-sensitive dye imaging were used for acute simultaneous registration of spontaneous and evoked cortical activity in anesthetized mice. The electrophysiological signals were used to extract local field potential (LFP) traces, multiunit, and single-unit spiking activity. To demonstrate our approach, we compared LFP and VSD signals over multiple regions of the cortex and analyzed the relationship between single-unit and global cortical population activities. The study of the interactions between cortical activity at local and global scales, such as the one presented in this work, can help to expand our knowledge of brain function.
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Affiliation(s)
- Edgar Bermudez-Contreras
- University of Lethbridge, Canadian Centre for Behavioural Neuroscience, Department of Neuroscience, Lethbridge, Alberta, Canada
| | - Sergey Chekhov
- University of Lethbridge, Canadian Centre for Behavioural Neuroscience, Department of Neuroscience, Lethbridge, Alberta, Canada
| | - Jianjun Sun
- University of Lethbridge, Canadian Centre for Behavioural Neuroscience, Department of Neuroscience, Lethbridge, Alberta, Canada
| | - Jennifer Tarnowsky
- University of Lethbridge, Canadian Centre for Behavioural Neuroscience, Department of Neuroscience, Lethbridge, Alberta, Canada
| | - Bruce L. McNaughton
- University of Lethbridge, Canadian Centre for Behavioural Neuroscience, Department of Neuroscience, Lethbridge, Alberta, Canada
- University of California at Irvine, Center for the Neurobiology of Learning and Memory, Department of Neurobiology and Behavior, Irvine, California, United States
- Address all correspondence to: Bruce L. McNaughton, E-mail: ; Majid H. Mohajerani, E-mail:
| | - Majid H. Mohajerani
- University of Lethbridge, Canadian Centre for Behavioural Neuroscience, Department of Neuroscience, Lethbridge, Alberta, Canada
- Address all correspondence to: Bruce L. McNaughton, E-mail: ; Majid H. Mohajerani, E-mail:
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19
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Momose-Sato Y, Sato K. Developmental roles of the spontaneous depolarization wave in synaptic network formation in the embryonic brainstem. Neuroscience 2017; 365:33-47. [PMID: 28951326 DOI: 10.1016/j.neuroscience.2017.09.030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2017] [Revised: 08/29/2017] [Accepted: 09/18/2017] [Indexed: 01/25/2023]
Abstract
One of the earliest activities expressed within the developing central nervous system is a widely propagating wave-like activity, which we referred to as the depolarization wave. Despite considerable consensus concerning the global features of the activity, its physiological role is yet to be clarified. The depolarization wave is expressed during a specific period of functional synaptogenesis, and this developmental profile has led to the hypothesis that the wave plays some roles in synaptic network organization. In the present study, we tested this hypothesis by inhibiting the depolarization wave in ovo and examining its effects on the development of functional synapses in vagus nerve-related brainstem nuclei of the chick embryo. Chronic inhibition of the depolarization wave had no significant effect on the developmental time course, amplitude, and spatial distribution of monosynaptic excitatory postsynaptic potentials in the first-order nuclei of the vagal sensory pathway (the nucleus of the tractus solitarius (NTS) and the contralateral non-NTS region), but reduced polysynaptic responses in the higher-order nucleus (the parabrachial nucleus). These results suggest that the depolarization wave plays an important role in the initial process of functional synaptic expression in the brainstem, especially in the higher-order nucleus of the cranial sensory pathway.
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Affiliation(s)
- Yoko Momose-Sato
- Department of Nutrition and Dietetics, College of Nutrition, Kanto Gakuin University, Kanazawa-ku, Yokohama 236-8503, Japan.
| | - Katsushige Sato
- Department of Health and Nutrition Sciences, Faculty of Human Health, Komazawa Women's University, Inagi-shi, Tokyo 206-8511, Japan
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20
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Neveu CL, Costa RM, Homma R, Nagayama S, Baxter DA, Byrne JH. Unique Configurations of Compression and Truncation of Neuronal Activity Underlie l-DOPA-Induced Selection of Motor Patterns in Aplysia. eNeuro 2017; 4:ENEURO.0206-17.2017. [PMID: 29071298 PMCID: PMC5654236 DOI: 10.1523/eneuro.0206-17.2017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 09/05/2017] [Accepted: 09/28/2017] [Indexed: 12/29/2022] Open
Abstract
A key issue in neuroscience is understanding the ways in which neuromodulators such as dopamine modify neuronal activity to mediate selection of distinct motor patterns. We addressed this issue by applying either low or high concentrations of l-DOPA (40 or 250 μM) and then monitoring activity of up to 130 neurons simultaneously in the feeding circuitry of Aplysia using a voltage-sensitive dye (RH-155). l-DOPA selected one of two distinct buccal motor patterns (BMPs): intermediate (low l-DOPA) or bite (high l-DOPA) patterns. The selection of intermediate BMPs was associated with shortening of the second phase of the BMP (retraction), whereas the selection of bite BMPs was associated with shortening of both phases of the BMP (protraction and retraction). Selection of intermediate BMPs was also associated with truncation of individual neuron spike activity (decreased burst duration but no change in spike frequency or burst latency) in neurons active during retraction. In contrast, selection of bite BMPs was associated with compression of spike activity (decreased burst latency and duration and increased spike frequency) in neurons projecting through specific nerves, as well as increased spike frequency of protraction neurons. Finally, large-scale voltage-sensitive dye recordings delineated the spatial distribution of neurons active during BMPs and the modification of that distribution by the two concentrations of l-DOPA.
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Affiliation(s)
- Curtis L Neveu
- Department of Neurobiology and Anatomy, W. M. Keck Center for the Neurobiology of Learning and Memory, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, TX 77030
| | - Renan M Costa
- Department of Neurobiology and Anatomy, W. M. Keck Center for the Neurobiology of Learning and Memory, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, TX 77030
| | - Ryota Homma
- Department of Neurobiology and Anatomy, W. M. Keck Center for the Neurobiology of Learning and Memory, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, TX 77030
| | - Shin Nagayama
- Department of Neurobiology and Anatomy, W. M. Keck Center for the Neurobiology of Learning and Memory, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, TX 77030
| | - Douglas A Baxter
- Department of Neurobiology and Anatomy, W. M. Keck Center for the Neurobiology of Learning and Memory, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, TX 77030
| | - John H Byrne
- Department of Neurobiology and Anatomy, W. M. Keck Center for the Neurobiology of Learning and Memory, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, TX 77030
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21
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Short SM, Oikonomou KD, Zhou WL, Acker CD, Popovic MA, Zecevic D, Antic SD. The stochastic nature of action potential backpropagation in apical tuft dendrites. J Neurophysiol 2017; 118:1394-1414. [PMID: 28566465 DOI: 10.1152/jn.00800.2016] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 05/25/2017] [Accepted: 05/30/2017] [Indexed: 11/22/2022] Open
Abstract
In cortical pyramidal neurons, backpropagating action potentials (bAPs) supply Ca2+ to synaptic contacts on dendrites. To determine whether the efficacy of AP backpropagation into apical tuft dendrites is stable over time, we performed dendritic Ca2+ and voltage imaging in rat brain slices. We found that the amplitude of bAP-Ca2+ in apical tuft branches was unstable, given that it varied from trial to trial (termed "bAP-Ca2+ flickering"). Small perturbations in dendritic physiology, such as spontaneous synaptic inputs, channel inactivation, or temperature-induced changes in channel kinetics, can cause bAP flickering. In the tuft branches, the density of Na+ and K+ channels was sufficient to support local initiation of fast spikelets by glutamate iontophoresis. We quantified the time delay between the somatic AP burst and the peak of dendritic Ca2+ transient in the apical tuft, because this delay is important for induction of spike-timing dependent plasticity. Depending on the frequency of the somatic AP triplets, Ca2+ signals peaked in the apical tuft 20-50 ms after the 1st AP in the soma. Interestingly, at low frequency (<20 Hz), the Ca2+ peaked sooner than at high frequency, because only the 1st AP invaded tuft. Activation of dendritic voltage-gated Ca2+ channels is sensitive to the duration of the dendritic voltage transient. In apical tuft branches, small changes in the duration of bAP voltage waveforms cause disproportionately large increases in dendritic Ca2+ influx (bAP-Ca2+ flickering). The stochastic nature of bAP-Ca2+ adds a new perspective on the mechanisms by which pyramidal neurons combine inputs arriving at different cortical layers.NEW & NOTEWORTHY The bAP-Ca2+ signal amplitudes in some apical tuft branches randomly vary from moment to moment. In repetitive measurements, successful AP invasions are followed by complete failures. Passive spread of voltage from the apical trunk into the tuft occasionally reaches the threshold for local Na+ spike, resulting in stronger Ca2+ influx. During a burst of three somatic APs, the peak of dendritic Ca2+ in the apical tuft occurs with a delay of 20-50 ms depending on AP frequency.
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Affiliation(s)
- Shaina M Short
- Department of Neuroscience, UConn Health, Farmington, Connecticut
| | | | - Wen-Liang Zhou
- Department of Neuroscience, UConn Health, Farmington, Connecticut
| | - Corey D Acker
- Center for Cell Analysis and Modeling, UConn Health, Farmington, Connecticut
| | - Marko A Popovic
- Department of Cellular and Molecular Physiology, Yale University, New Haven, Connecticut
| | - Dejan Zecevic
- Department of Cellular and Molecular Physiology, Yale University, New Haven, Connecticut
| | - Srdjan D Antic
- Department of Neuroscience, UConn Health, Farmington, Connecticut; .,Stem Cell Institute, UConn Health, Farmington, Connecticut; and.,Institute for Systems Genomics, UConn Health, Farmington, Connecticut
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22
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Tang Q, Lin J, Tsytsarev V, Erzurumlu RS, Liu Y, Chen Y. Review of mesoscopic optical tomography for depth-resolved imaging of hemodynamic changes and neural activities. Neurophotonics 2017; 4:011009. [PMID: 27990452 PMCID: PMC5108095 DOI: 10.1117/1.nph.4.1.011009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 10/19/2016] [Indexed: 05/18/2023]
Abstract
Understanding the functional wiring of neural circuits and their patterns of activation following sensory stimulations is a fundamental task in the field of neuroscience. Furthermore, charting the activity patterns is undoubtedly important to elucidate how neural networks operate in the living brain. However, optical imaging must overcome the effects of light scattering in the tissue, which limit the light penetration depth and affect both the imaging quantitation and sensitivity. Laminar optical tomography (LOT) is a three-dimensional (3-D) in-vivo optical imaging technique that can be used for functional imaging. LOT can achieve both a resolution of 100 to [Formula: see text] and a penetration depth of 2 to 3 mm based either on absorption or fluorescence contrast, as well as large field-of-view and high acquisition speed. These advantages make LOT suitable for 3-D depth-resolved functional imaging of the neural functions in the brain and spinal cords. We review the basic principles and instrumentations of representative LOT systems, followed by recent applications of LOT on 3-D imaging of neural activities in the rat forepaw stimulation model and mouse whisker-barrel system.
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Affiliation(s)
- Qinggong Tang
- University of Maryland, Fischell Department of Bioengineering, 2334 Jeong H. Kim Engineering Building, College Park, Maryland 20742, United States
| | - Jonathan Lin
- University of Maryland, Fischell Department of Bioengineering, 2334 Jeong H. Kim Engineering Building, College Park, Maryland 20742, United States
| | - Vassiliy Tsytsarev
- University of Maryland School of Medicine, Department of Anatomy and Neurobiology, 20 Penn Street, HSFII S251, Baltimore, Maryland 21201, United States
| | - Reha S. Erzurumlu
- University of Maryland School of Medicine, Department of Anatomy and Neurobiology, 20 Penn Street, HSFII S251, Baltimore, Maryland 21201, United States
| | - Yi Liu
- University of Maryland, Fischell Department of Bioengineering, 2334 Jeong H. Kim Engineering Building, College Park, Maryland 20742, United States
| | - Yu Chen
- University of Maryland, Fischell Department of Bioengineering, 2334 Jeong H. Kim Engineering Building, College Park, Maryland 20742, United States
- Address all correspondence to: Yu Chen, E-mail:
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23
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Hill ES, Vasireddi SK, Wang J, Bruno AM, Frost WN. Watching a memory form-VSD imaging reveals a novel memory mechanism. Commun Integr Biol 2016; 9:e1212142. [PMID: 28003862 PMCID: PMC5154357 DOI: 10.1080/19420889.2016.1212142] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 07/06/2016] [Indexed: 11/30/2022] Open
Abstract
Studies of the mechanisms underlying memory formation have largely focused on the
synapse. However, recent evidence suggests that additional, non-synaptic, mechanisms also
play important roles in this process. We recently described a novel memory mechanism
whereby a particular class of neurons was recruited into the Tritonia
escape swim network with sensitization, a non-associative form of learning. Neurons that
in the naïve state were loosely-affiliated with the network were rapidly recruited
in, transitioning from variably bursting (VB) to reliably bursting (RB). Even after the
memory had faded some new neurons remained, and some original members had left, leaving
the network in an altered state. Further, we identified a candidate cellular mechanism
underlying these network changes. Our study supports the view that brain networks may have
surprisingly fluid functional structures and adds to the growing body of evidence that
non-synaptic mechanisms often operate synergistically with changes at the synapse to
mediate memory formation.
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Affiliation(s)
- Evan S Hill
- Department of Cell Biology and Anatomy, Rosalind Franklin University , North Chicago, IL, USA
| | - Sunil K Vasireddi
- Department of Cell Biology and Anatomy, Rosalind Franklin University , North Chicago, IL, USA
| | - Jean Wang
- Department of Cell Biology and Anatomy, Rosalind Franklin University , North Chicago, IL, USA
| | - Angela M Bruno
- Department of Cell Biology and Anatomy, Rosalind Franklin University, North Chicago, IL, USA; Department of Neuroscience, Rosalind Franklin University, North Chicago, IL, USA
| | - William N Frost
- Department of Cell Biology and Anatomy, Rosalind Franklin University , North Chicago, IL, USA
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Momose-Sato Y, Sato K. Development of synaptic networks in the mouse vagal pathway revealed by optical mapping with a voltage-sensitive dye. Eur J Neurosci 2016; 44:1906-18. [PMID: 27207499 DOI: 10.1111/ejn.13283] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Revised: 05/09/2016] [Accepted: 05/17/2016] [Indexed: 11/27/2022]
Abstract
The central issue in developmental neuroscience is when and how neural synaptic networks are established and become functional within the central nervous system (CNS). Investigations of the neural network organization have been hampered because conventional electrophysiological means have some technical limitations. In this study, the multiple-site optical recording technique with a voltage-sensitive dye was employed to survey the developmental organization of the vagal system in the mouse embryo. Stimulation of the vagus nerve in E11-E14 mouse embryos elicited optical responses in areas corresponding to the vagal sensory and motor nuclei. Postsynaptic responses in the first-order sensory nucleus, the nucleus of the tractus solitarius (NTS), were identified from E11, suggesting that sensory information becomes transferred to the brain at this stage. In addition to the NTS, optical responses were identified in the rostral and contralateral brainstem regions, which corresponded to second/higher order nuclei of the vagus nerve including the parabrachial nucleus (PBN). Postsynaptic responses in the second/higher-order nuclei were detected from E12, suggesting that polysynaptic networks were functional at this stage. We discuss the results of our optical mapping, comparing them with previous findings obtained in the chick and rat embryos, and suggest some fundamental principles in the functional organization of synaptic networks in the embryonic brain.
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Affiliation(s)
- Yoko Momose-Sato
- Department of Nutrition and Dietetics, College of Nutrition, Kanto Gakuin University, 1-50-1 Mutsuura-Higashi, Kanazawa-ku, Yokohama, 236-8503, Japan
| | - Katsushige Sato
- Department of Health and Nutrition Sciences, Faculty of Human Health, Komazawa Women's University, Tokyo, Japan
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Te Winkel JD, Gray DA, Seistrup KH, Hamoen LW, Strahl H. Analysis of Antimicrobial-Triggered Membrane Depolarization Using Voltage Sensitive Dyes. Front Cell Dev Biol 2016; 4:29. [PMID: 27148531 PMCID: PMC4829611 DOI: 10.3389/fcell.2016.00029] [Citation(s) in RCA: 167] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 03/24/2016] [Indexed: 12/14/2022] Open
Abstract
The bacterial cytoplasmic membrane is a major inhibitory target for antimicrobial compounds. Commonly, although not exclusively, these compounds unfold their antimicrobial activity by disrupting the essential barrier function of the cell membrane. As a consequence, membrane permeability assays are central for mode of action studies analysing membrane-targeting antimicrobial compounds. The most frequently used in vivo methods detect changes in membrane permeability by following internalization of normally membrane impermeable and relatively large fluorescent dyes. Unfortunately, these assays are not sensitive to changes in membrane ion permeability which are sufficient to inhibit and kill bacteria by membrane depolarization. In this manuscript, we provide experimental advice how membrane potential, and its changes triggered by membrane-targeting antimicrobials can be accurately assessed in vivo. Optimized protocols are provided for both qualitative and quantitative kinetic measurements of membrane potential. At last, single cell analyses using voltage-sensitive dyes in combination with fluorescence microscopy are introduced and discussed.
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Affiliation(s)
- J Derk Te Winkel
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University Newcastle upon Tyne, UK
| | - Declan A Gray
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University Newcastle upon Tyne, UK
| | - Kenneth H Seistrup
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University Newcastle upon Tyne, UK
| | - Leendert W Hamoen
- Swammerdam Institute for Life Sciences, University of Amsterdam Amsterdam, Netherlands
| | - Henrik Strahl
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University Newcastle upon Tyne, UK
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Fehérvári TD, Yagi T. Population Response Propagation to Extrastriate Areas Evoked by Intracortical Electrical Stimulation in V1. Front Neural Circuits 2016; 10:6. [PMID: 26903816 PMCID: PMC4751260 DOI: 10.3389/fncir.2016.00006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 01/25/2016] [Indexed: 12/03/2022] Open
Abstract
The mouse visual system has multiple extrastriate areas surrounding V1 each with a distinct representation of the visual field and unique functional and connectivity profiles, which are believed to form two parallel processing streams, similar to the ventral and dorsal streams in primates. At the same time, mouse visual areas have a high degree of interconnectivity, in particular V1 sends input to all higher visual areas. The study of these direct connections can further our understanding of the cortical processing of visual signals in the early mammalian cortex. Several studies have been published about the anatomy of these connections, but an in vivo electrophysiological characterization and comparison of the transmission to multiple extrastriate areas has not yet been reported. We used intracortical electrical stimulation combined with RH1691 VSD imaging in adult C57BL/6 mice in urethane anesthesia to analyze interareal transmission from V1 to extrastriate areas in superficial cortical layers. We found seven extrastriate response sites (five lateral, two medial) in a spatial pattern similar to area maps of the mouse visual cortex and, by shifting the location of V1 stimulation, demonstrated that the evoked responses in LM and AL were in accordance with the visuotopic mappings of these areas known from anatomy and in vivo studies. These two sites, considered to be gateways to their processing streams, had shorter latencies and faster transmission speeds than other extrastriate response sites. Short latency differences between response sites, and that TTX injection into LM reduced but did not eliminate other extrastriate responses indicated that the evoked cortical activity was, at least partially, transmitted directly from V1 to extrastriate areas. This study reports on analysis of interareal transmission from V1 to multiple extrastriate areas in mouse using intracortical electrical stimulation in vivo.
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Affiliation(s)
- Tamás D Fehérvári
- Bio-System and Device Laboratory, Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University Osaka, Japan
| | - Tetsuya Yagi
- Bio-System and Device Laboratory, Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University Osaka, Japan
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Sato K, Hayashi S, Inaji M, Momose-Sato Y. Oscillations in the embryonic chick olfactory bulb: initial expression and development revealed by optical imaging with a voltage-sensitive dye. Eur J Neurosci 2016; 43:1111-21. [PMID: 26833763 DOI: 10.1111/ejn.13189] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2015] [Revised: 12/31/2015] [Accepted: 01/26/2016] [Indexed: 11/28/2022]
Abstract
In a previous study, we applied a multiple-site optical recording technique with a voltage-sensitive dye to the embryonic chick olfactory system and showed that functional synaptic transmission in the olfactory bulb was expressed at embryonic 6-7-day stages. It is known that oscillations, i.e. stereotyped sinusoidal neural activity, appear in the olfactory system of various species. The focus of the present study is to determine whether the oscillation is also generated in the embryonic chick olfactory bulb and, if this is the case, when the oscillation appears and how its profiles change during embryogenesis. At the early stages of development (embryonic 6- to 8-day stages), postsynaptic response-related optical signals evoked by olfactory nerve stimulation exhibited a simple monophasic waveform that lasted for a few seconds. At embryonic 9-day stage, the optical signal became multi-phasic, and the oscillatory event was detected in some preparations. The oscillation was restricted to the distal half of the olfactory bulb. As development proceeded, the incidence and duration of the oscillation gradually increased, and the waveform became complicated. In some cases at embryonic 12-day stage, the oscillation lasted for nearly a minute. The frequency of the oscillation increased slightly with development, but it remained in the range of theta oscillation during the 9- to 12-day stages. We discuss the ontogenetic dynamics of the oscillation and the significance of this activity in the developing olfactory bulb.
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Affiliation(s)
- Katsushige Sato
- Department of Health and Nutrition Sciences, Faculty of Human Health, Komazawa Women's University, Inagi-shi, Tokyo, 206-8511, Japan
| | - Shihori Hayashi
- Department of Neurosurgery, Faculty of Medicine, Tokyo Medical and Dental University Graduate School, Tokyo, Japan
| | - Motoki Inaji
- Department of Neurosurgery, Faculty of Medicine, Tokyo Medical and Dental University Graduate School, Tokyo, Japan
| | - Yoko Momose-Sato
- Department of Nutrition and Dietetics, College of Nutrition, Kanto Gakuin University, Kanazawa-ku, Yokohama, Japan
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Tominaga T, Tominaga Y. Paired Burst Stimulation Causes GABAA Receptor-Dependent Spike Firing Facilitation in CA1 of Rat Hippocampal Slices. Front Cell Neurosci 2016; 10:9. [PMID: 26858604 PMCID: PMC4731501 DOI: 10.3389/fncel.2016.00009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 01/11/2016] [Indexed: 11/24/2022] Open
Abstract
The theta oscillation (4–8 Hz) is a pivotal form of oscillatory activity in the hippocampus that is intermittently concurrent with gamma (25–100 Hz) burst events. In in vitro preparation, a stimulation protocol that mimics the theta oscillation, theta burst stimulation (TBS), is used to induce long-term potentiation. Thus, TBS is thought to have a distinct role in the neural network of the hippocampal slice preparation. However, the specific mechanisms that make TBS induce such neural circuit modifications are still unknown. Using electrophysiology and voltage-sensitive dye imaging (VSDI), we have found that TBS induces augmentation of spike firing. The augmentation was apparent in the first couple of brief burst stimulation (100 Hz four pulses) on a TBS-train in a presence of NMDA receptor blocker (APV 50 μM). In this study, we focused on the characterizes of the NMDA independent augmentation caused by a pair of the brief burst stimulation (the first pair of the TBS; paired burst stimulation-PBS). We found that PBS enhanced membrane potential responses on VSDI signal and intracellular recordings while it was absent in the current recording under whole-cell clamp condition. The enhancement of the response accompanied the augmentation of excitatory postsynaptic potential (EPSP) to spike firing (E-S) coupling. The paired burst facilitation (PBF) reached a plateau when the number of the first burst stimulation (priming burst) exceeds three. The interval between the bursts of 150 ms resulted in the maximum PBF. Gabazine (a GABAA receptor antagonist) abolished PBF. The threshold for spike generation of the postsynaptic cells measured with a current injection to cells was not lowered by the priming burst of PBS. These results indicate that PBS activates the GABAergic system to cause short-term E-S augmentation without raising postsynaptic excitability. We propose that a GABAergic system of area CA1 of the hippocampus produce the short-term E-S plasticity that could cause exaggerated spike-firing upon a theta-gamma activity distinctively, thus making the neural circuit of the CA1 act as a specific amplifier of the oscillation signal.
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Affiliation(s)
- Takashi Tominaga
- Laboratory for Neural Circuit Systems, Institute of Neuroscience, Tokushima Bunri University Sanuki, Japan
| | - Yoko Tominaga
- Laboratory for Neural Circuit Systems, Institute of Neuroscience, Tokushima Bunri University Sanuki, Japan
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Stepan J, Hladky F, Uribe A, Holsboer F, Schmidt MV, Eder M. High-Speed imaging reveals opposing effects of chronic stress and antidepressants on neuronal activity propagation through the hippocampal trisynaptic circuit. Front Neural Circuits 2015; 9:70. [PMID: 26594153 PMCID: PMC4635222 DOI: 10.3389/fncir.2015.00070] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2015] [Accepted: 10/22/2015] [Indexed: 12/11/2022] Open
Abstract
Antidepressants (ADs) are used as first-line treatment for most stress-related psychiatric disorders. The alterations in brain circuit dynamics that can arise from stress exposure and underlie therapeutic actions of ADs remain, however, poorly understood. Here, enabled by a recently developed voltage-sensitive dye imaging (VSDI) assay in mouse brain slices, we examined the impact of chronic stress and concentration-dependent effects of eight clinically used ADs (belonging to different chemical/functional classes) on evoked neuronal activity propagations through the hippocampal trisynaptic circuitry (HTC: perforant path → dentate gyrus (DG) → area CA3 → area CA1). Exposure of mice to chronic social defeat stress led to markedly weakened activity propagations (“HTC-Waves”). In contrast, at concentrations in the low micromolar range, all ADs, which were bath applied to slices, caused an amplification of HTC-Waves in CA regions (invariably in area CA1). The fast-acting “antidepressant” ketamine, the mood stabilizer lithium, and brain-derived neurotrophic factor (BDNF) exerted comparable enhancing effects, whereas the antipsychotic haloperidol and the anxiolytic diazepam attenuated HTC-Waves. Collectively, we provide direct experimental evidence that chronic stress can depress neuronal signal flow through the HTC and demonstrate shared opposing effects of ADs. Thus, our study points to a circuit-level mechanism of ADs to counteract stress-induced impairment of hippocampal network function. However, the observed effects of ADs are impossible to depend on enhanced neurogenesis.
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Affiliation(s)
- Jens Stepan
- Max Planck Institute of Psychiatry Munich, Germany ; Department Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry Munich, Germany ; Scientific Core Unit "Electrophysiology and Neuronal Network Dynamics", Max Planck Institute of Psychiatry Munich, Germany ; Clinical Department, Max Planck Institute of Psychiatry Munich, Germany
| | - Florian Hladky
- Max Planck Institute of Psychiatry Munich, Germany ; Department Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry Munich, Germany ; Scientific Core Unit "Electrophysiology and Neuronal Network Dynamics", Max Planck Institute of Psychiatry Munich, Germany
| | - Andrés Uribe
- Max Planck Institute of Psychiatry Munich, Germany ; Department Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry Munich, Germany ; Research Group "Stress Resilience", Max Planck Institute of Psychiatry Munich, Germany
| | - Florian Holsboer
- Max Planck Institute of Psychiatry Munich, Germany ; HMNC GmbH Munich, Germany
| | - Mathias V Schmidt
- Max Planck Institute of Psychiatry Munich, Germany ; Department Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry Munich, Germany ; Research Group "Stress Resilience", Max Planck Institute of Psychiatry Munich, Germany
| | - Matthias Eder
- Max Planck Institute of Psychiatry Munich, Germany ; Department Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry Munich, Germany ; Scientific Core Unit "Electrophysiology and Neuronal Network Dynamics", Max Planck Institute of Psychiatry Munich, Germany
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Nagarah JM, Stowasser A, Parker RL, Asari H, Wagenaar DA. Optically transparent multi-suction electrode arrays. Front Neurosci 2015; 9:384. [PMID: 26539078 PMCID: PMC4611137 DOI: 10.3389/fnins.2015.00384] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 10/02/2015] [Indexed: 11/17/2022] Open
Abstract
Multielectrode arrays (MEAs) allow for acquisition of multisite electrophysiological activity with submillisecond temporal resolution from neural preparations. The signal to noise ratio from such arrays has recently been improved by substrate perforations that allow negative pressure to be applied to the tissue; however, such arrays are not optically transparent, limiting their potential to be combined with optical-based technologies. We present here multi-suction electrode arrays (MSEAs) in quartz that yield a substantial increase in the detected number of units and in signal to noise ratio from mouse cortico-hippocampal slices and mouse retina explants. This enables the visualization of stronger cross correlations between the firing rates of the various sources. Additionally, the MSEA's transparency allows us to record voltage sensitive dye activity from a leech ganglion with single neuron resolution using widefield microscopy simultaneously with the electrode array recordings. The combination of enhanced electrical signals and compatibility with optical-based technologies should make the MSEA a valuable tool for investigating neuronal circuits.
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Affiliation(s)
- John M Nagarah
- Division of Biology, California Institute of Technology Pasadena, CA, USA
| | | | - Rell L Parker
- Division of Biology, California Institute of Technology Pasadena, CA, USA
| | - Hiroki Asari
- Division of Biology, California Institute of Technology Pasadena, CA, USA
| | - Daniel A Wagenaar
- Division of Biology, California Institute of Technology Pasadena, CA, USA ; Biological Sciences, University of Cincinnati Cincinnati, OH, USA
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31
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Novales Flamarique I, Wachowiak M. Functional segregation of retinal ganglion cell projections to the optic tectum of rainbow trout. J Neurophysiol 2015; 114:2703-17. [PMID: 26334009 DOI: 10.1152/jn.00440.2015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 09/01/2015] [Indexed: 11/22/2022] Open
Abstract
The interpretation of visual information relies on precise maps of retinal representation in the brain coupled with local circuitry that encodes specific features of the visual scenery. In nonmammalian vertebrates, the main target of ganglion cell projections is the optic tectum. Although the topography of retinotectal projections has been documented for several species, the spatiotemporal patterns of activity and how these depend on background adaptation have not been explored. In this study, we used a combination of electrical and optical recordings to reveal a retinotectal map of ganglion cell projections to the optic tectum of rainbow trout and characterized the spatial and chromatic distribution of ganglion cell fibers coding for increments (ON) and decrements (OFF) of light. Recordings of optic nerve activity under various adapting light backgrounds, which isolated the input of different cone mechanisms, yielded dynamic patterns of ON and OFF input characterized by segregation of these two fiber types. Chromatic adaptation decreased the sensitivity and response latency of affected cone mechanisms, revealing their variable contributions to the ON and OFF responses. Our experiments further demonstrated restricted input from a UV cone mechanism to the anterolateral optic tectum, in accordance with the limited presence of UV cones in the dorsotemporal retina of juvenile rainbow trout. Together, our findings show that retinal inputs to the optic tectum of this species are not homogeneous, exhibit highly dynamic activity patterns, and are likely determined by a combination of biased projections and specific retinal cell distributions and their activity states.
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Affiliation(s)
- Iñigo Novales Flamarique
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada; Department of Biology, University of Victoria, Victoria, British Columbia, Canada; and Marine Biological Laboratory, Woods Hole, Massachusetts
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Momose-Sato Y, Sato K. Voltage-sensitive dye imaging during functional development of the embryonic nervous system: a brief review with special thanks to Professor Larry Cohen. Neurophotonics 2015; 2:021009. [PMID: 26157999 PMCID: PMC4478868 DOI: 10.1117/1.nph.2.2.021009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 12/31/2014] [Indexed: 06/04/2023]
Abstract
Investigating the developmental organization of the embryonic nervous system is one of the major challenges in the field of neuroscience. Despite their significance, functional studies on the vertebrate embryonic central nervous system (CNS) have been hampered by the technical limitations associated with conventional electrophysiological methods. The advent of optical techniques using voltage-sensitive dyes, which were developed by Dr. Cohen and his colleagues, has enabled electrical activity in living cells to be monitored noninvasively and also facilitated the simultaneous recording of neural responses from multiple regions. Using optical recording techniques, it is now possible to follow the functional organization of the embryonic CNS and image the spatiotemporal dynamics involved in the formation of this neural network. We herein briefly reviewed optical studies on the embryonic CNS with a special emphasis on methodological considerations and the study of neuronal circuit formation, which demonstrates the utility of fast voltage-sensitive dye imaging as a powerful tool for elucidating the functional organization of the embryonic CNS.
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Affiliation(s)
- Yoko Momose-Sato
- Kanto Gakuin University, College of Human and Environmental Studies, Department of Health and Nutrition, 1-50-1 Mutsuura-higashi, Kanazawa-ku, Yokohama 236-8503, Japan
| | - Katsushige Sato
- Komazawa Women’s University Faculty of Human Health, Department of Health and Nutrition Sciences, 238 Sakahama, Inagi-shi, Tokyo 206-8511, Japan
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Zhou WL, Short SM, Rich MT, Oikonomou KD, Singh MB, Sterjanaj EV, Antic SD. Branch specific and spike-order specific action potential invasion in basal, oblique, and apical dendrites of cortical pyramidal neurons. Neurophotonics 2015; 2:021006. [PMID: 26157997 PMCID: PMC4478750 DOI: 10.1117/1.nph.2.2.021006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2014] [Accepted: 11/10/2014] [Indexed: 06/04/2023]
Abstract
In neocortical pyramidal neurons, action potentials (APs) propagate from the axon into the dendritic tree to influence distal synapses. Traditionally, AP backpropagation was studied in the thick apical trunk. Here, we used the principles of optical imaging developed by Cohen to investigate AP invasion into thin dendritic branches (basal, oblique, and tuft) of prefrontal cortical L5 pyramidal neurons. Multisite optical recordings from neighboring dendrites revealed a clear dichotomy between two seemingly equal dendritic branches belonging to the same cell ("sister branches"). We documented the variable efficacy of AP invasion in basal and oblique branches by revealing their AP voltage waveforms. Using fast multisite calcium imaging, we found that trains of APs are filtered differently between two apical tuft branches. Although one dendritic branch passes all spikes in an AP train, another branch belonging to the same neuron, same cortical layer, and same path distance from the cell body, experiences only one spike. Our data indicate that the vast differences in dendritic voltage and calcium transients, detected in dendrites of pyramidal neurons, arise from a nonuniform distribution of A-type [Formula: see text] conductance, an aggregate number of branch points in the path of the AP propagation and minute differences in dendritic diameter.
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Affiliation(s)
- Wen-Liang Zhou
- University of Connecticut, Stem Cell Institute, Institute for Systems Genomics, UConn Health, Department of Neuroscience, 263 Farmington Avenue, Farmington, Connecticut 06030-3401, United States
| | - Shaina M. Short
- University of Connecticut, Stem Cell Institute, Institute for Systems Genomics, UConn Health, Department of Neuroscience, 263 Farmington Avenue, Farmington, Connecticut 06030-3401, United States
| | - Matthew T. Rich
- University of Connecticut, Stem Cell Institute, Institute for Systems Genomics, UConn Health, Department of Neuroscience, 263 Farmington Avenue, Farmington, Connecticut 06030-3401, United States
| | - Katerina D. Oikonomou
- University of Connecticut, Stem Cell Institute, Institute for Systems Genomics, UConn Health, Department of Neuroscience, 263 Farmington Avenue, Farmington, Connecticut 06030-3401, United States
| | - Mandakini B. Singh
- University of Connecticut, Stem Cell Institute, Institute for Systems Genomics, UConn Health, Department of Neuroscience, 263 Farmington Avenue, Farmington, Connecticut 06030-3401, United States
| | - Enas V. Sterjanaj
- University of Connecticut, Stem Cell Institute, Institute for Systems Genomics, UConn Health, Department of Neuroscience, 263 Farmington Avenue, Farmington, Connecticut 06030-3401, United States
| | - Srdjan D. Antic
- University of Connecticut, Stem Cell Institute, Institute for Systems Genomics, UConn Health, Department of Neuroscience, 263 Farmington Avenue, Farmington, Connecticut 06030-3401, United States
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Lo SQ, Koh DXP, Sng JCG, Augustine GJ. All-optical mapping of barrel cortex circuits based on simultaneous voltage-sensitive dye imaging and channelrhodopsin-mediated photostimulation. Neurophotonics 2015; 2:021013. [PMID: 26158003 PMCID: PMC4478985 DOI: 10.1117/1.nph.2.2.021013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2014] [Accepted: 03/04/2015] [Indexed: 05/25/2023]
Abstract
We describe an experimental approach that uses light to both control and detect neuronal activity in mouse barrel cortex slices: blue light patterned by a digital micromirror array system allowed us to photostimulate specific layers and columns, while a red-shifted voltage-sensitive dye was used to map out large-scale circuit activity. We demonstrate that such all-optical mapping can interrogate various circuits in somatosensory cortex by sequentially activating different layers and columns. Further, mapping in slices from whisker-deprived mice demonstrated that chronic sensory deprivation did not significantly alter feedforward inhibition driven by layer 5 pyramidal neurons. Further development of voltage-sensitive optical probes should allow this all-optical mapping approach to become an important and high-throughput tool for mapping circuit interactions in the brain.
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Affiliation(s)
- Shun Qiang Lo
- National University of Singapore, Yong Loo Lin School of Medicine, Department of Physiology, Singapore 117597, Singapore
- Nanyang Technological University, Lee Kong Chian School of Medicine, Proteos, Biopolis, Level 4, 61 Biopolis Drive, #04-06/07, Singapore 138673, Singapore
- Institute of Molecular and Cell Biology, A*STAR, Proteos, 61 Biopolis Drive, Proteos, Singapore 138673, Singapore
- Marine Biological Laboratory, 7 MBL Street, Woods Hole, Massachusetts 02543, United States
| | - Dawn X. P. Koh
- National University of Singapore, Graduate School of Integrative Sciences and Engineering, Singapore 117456, Singapore
- National University of Singapore, Yong Loo Lin School of Medicine, Department of Pharmacology, Singapore 117599, Singapore
- Singapore Institute of Clinical Sciences (SICS), A*STAR, Brenner Centre for Molecular Medicine, 30 Medical Drive, Singapore 117609, Singapore
| | - Judy C. G. Sng
- National University of Singapore, Yong Loo Lin School of Medicine, Department of Pharmacology, Singapore 117599, Singapore
- Singapore Institute of Clinical Sciences (SICS), A*STAR, Brenner Centre for Molecular Medicine, 30 Medical Drive, Singapore 117609, Singapore
| | - George J. Augustine
- National University of Singapore, Yong Loo Lin School of Medicine, Department of Physiology, Singapore 117597, Singapore
- Nanyang Technological University, Lee Kong Chian School of Medicine, Proteos, Biopolis, Level 4, 61 Biopolis Drive, #04-06/07, Singapore 138673, Singapore
- Institute of Molecular and Cell Biology, A*STAR, Proteos, 61 Biopolis Drive, Proteos, Singapore 138673, Singapore
- Marine Biological Laboratory, 7 MBL Street, Woods Hole, Massachusetts 02543, United States
- Korea Institute of Science and Technology, Center for Functional Connectomics, 39-1 Hawolgokdong, Seongbukgu, Seoul 136-791, Republic of Korea
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35
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Johnson BN, Palmer CP, Bourgeois EB, Elkind JA, Putnam BJ, Cohen AS. Augmented Inhibition from Cannabinoid-Sensitive Interneurons Diminishes CA1 Output after Traumatic Brain Injury. Front Cell Neurosci 2014; 8:435. [PMID: 25565968 PMCID: PMC4271495 DOI: 10.3389/fncel.2014.00435] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 12/02/2014] [Indexed: 11/15/2022] Open
Abstract
The neurological impairments associated with traumatic brain injury include learning and memory deficits and increased risk of seizures. The hippocampus is critically involved in both of these phenomena and highly susceptible to damage by traumatic brain injury. To examine network activity in the hippocampal CA1 region after lateral fluid percussion injury, we used a combination of voltage-sensitive dye, field potential, and patch clamp recording in mouse hippocampal brain slices. When the stratum radiatum (SR) was stimulated in slices from injured mice, we found decreased depolarization in SR and increased hyperpolarization in stratum oriens (SO), together with a decrease in the percentage of pyramidal neurons firing stimulus-evoked action potentials. Increased hyperpolarization in SO persisted when glutamatergic transmission was blocked. However, we found no changes in SO responses when the alveus was stimulated to directly activate SO. These results suggest that the increased SO hyperpolarization evoked by SR stimulation was mediated by interneurons that have cell bodies and/or axons in SR, and form synapses in stratum pyramidale and SO. A low concentration (100 nM) of the synthetic cannabinoid WIN55,212-2, restored CA1 output in slices from injured animals. These findings support the hypothesis that increased GABAergic signaling by cannabinoid-sensitive interneurons contributes to the reduced CA1 output following traumatic brain injury.
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Affiliation(s)
- Brian N Johnson
- Children's Hospital of Philadelphia Research Institute, Children's Hospital of Philadelphia , Philadelphia, PA , USA
| | - Chris P Palmer
- Department of Neuroscience, University of Pennsylvania School of Medicine , Philadelphia, PA , USA
| | - Elliot B Bourgeois
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School , Boston, MA , USA
| | - Jaclynn A Elkind
- Children's Hospital of Philadelphia Research Institute, Children's Hospital of Philadelphia , Philadelphia, PA , USA
| | - Brendan J Putnam
- Children's Hospital of Philadelphia Research Institute, Children's Hospital of Philadelphia , Philadelphia, PA , USA
| | - Akiva S Cohen
- Children's Hospital of Philadelphia Research Institute, Children's Hospital of Philadelphia , Philadelphia, PA , USA ; Department of Pediatrics, University of Pennsylvania School of Medicine , Philadelphia, PA , USA
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Momose-Sato Y, Sato K. Maintenance of the large-scale depolarization wave in the embryonic chick brain against deprivation of the rhythm generator. Neuroscience 2014; 266:186-96. [PMID: 24568731 DOI: 10.1016/j.neuroscience.2014.02.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 02/11/2014] [Accepted: 02/12/2014] [Indexed: 11/24/2022]
Abstract
Widely correlated spontaneous activity in the developing nervous system is transiently expressed and is considered to play a fundamental role in neural circuit formation. The depolarization wave, which spreads over a long distance along the neuraxis, maximally extending to the lumbosacral cord and forebrain, is an example of this spontaneous activity. Although the depolarization wave is typically initiated in the spinal cord in intact preparations, spontaneous discharges have also been detected in the isolated brainstem. Although this suggests that the brainstem has the ability to generate spontaneous activity, but is paced by a caudal rhythm generator of higher excitability, a number of questions remains. Does brainstem activity simply appear as a passive consequence, or does any active change occur in the brainstem network to compensate for this activity? If the latter is the case, does this compensation occur equally at different developmental stages? Where is the new rhythm generator in the isolated brainstem? To answer these questions, we optically analyzed spatio-temporal patterns of activity detected from the chick brainstem before and after transection at the obex. The results revealed that the depolarization wave was homeostatically maintained, which was characterized by an increase in excitability and/or the number of neurons recruited to the wave. The wave was more easily maintained in younger embryos. Furthermore, we demonstrated that the ability of brainstem neurons to perform such an active compensation was not lost even at the stage when the depolarization wave was no longer observed in the intact brainstem.
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Affiliation(s)
- Y Momose-Sato
- Department of Health and Nutrition, College of Human Environmental Studies, Kanto Gakuin University, Kanazawa-ku, Yokohama 236-8503, Japan.
| | - K Sato
- Department of Health and Nutrition Sciences, Faculty of Human Health, Komazawa Women's University, Inagi-shi, Tokyo 206-8511, Japan.
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Moshtagh-Khorasani M, Miller EW, Torre V. The spontaneous electrical activity of neurons in leech ganglia. Physiol Rep 2013; 1:e00089. [PMID: 24303164 PMCID: PMC3841027 DOI: 10.1002/phy2.89] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 08/15/2013] [Accepted: 08/19/2013] [Indexed: 11/17/2022] Open
Abstract
Using the newly developed voltage-sensitive dye VF2.1.Cl, we monitored simultaneously the spontaneous electrical activity of ∼80 neurons in a leech ganglion, representing around 20% of the entire neuronal population. Neurons imaged on the ventral surface of the ganglion either fired spikes regularly at a rate of 1–5 Hz or fired sparse spikes irregularly. In contrast, neurons imaged on the dorsal surface, fired spikes in bursts involving several neurons. The overall degree of correlated electrical activity among leech neurons was limited in control conditions but increased in the presence of the neuromodulator serotonin. The spontaneous electrical activity in a leech ganglion is segregated in three main groups: neurons comprising Retzius cells, Anterior Pagoda, and Annulus Erector motoneurons firing almost periodically, a group of neurons firing sparsely and randomly, and a group of neurons firing bursts of spikes of varying durations. These three groups interact and influence each other only weakly.
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Affiliation(s)
- Majid Moshtagh-Khorasani
- Neuroscience Area, International School for Advanced Studies (SISSA) via Bonomea, 265, Trieste, 34136, Italy
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Mullah SHER, Komuro R, Yan P, Hayashi S, Inaji M, Momose-Sato Y, Loew LM, Sato K. Evaluation of voltage-sensitive fluorescence dyes for monitoring neuronal activity in the embryonic central nervous system. J Membr Biol 2013; 246:679-88. [PMID: 23975337 PMCID: PMC4096138 DOI: 10.1007/s00232-013-9584-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Accepted: 08/04/2013] [Indexed: 11/29/2022]
Abstract
Using an optical imaging technique with voltage-sensitive dyes (VSDs), we investigated the functional organization and architecture of the central nervous system (CNS) during embryogenesis. In the embryonic nervous system, a merocyanine-rhodanine dye, NK2761, has proved to be the most useful absorption dye for detecting neuronal activity because of its high signal-to-noise ratio (S/N), low toxicity and small dye bleaching. In the present study, we evaluated the suitability of fluorescence VSDs for optical recording in the embryonic CNS. We screened eight styryl (hemicyanine) dyes in isolated brainstem-spinal cord preparations from 7-day-old chick embryos. Measurements of voltage-related optical signals were made using a multiple-site optical recording system. The signal size, S/N, photobleaching, effects of perfusion and recovery of neural responses after staining were compared. We also evaluated optical responses with various magnifications. Although the S/N was lower than with the absorption dye, clear optical responses were detected with several fluorescence dyes, including di-2-ANEPEQ, di-4-ANEPPS, di-3-ANEPPDHQ, di-4-AN(F)EPPTEA, di-2-AN(F)EPPTEA and di-2-ANEPPTEA. Di-2-ANEPEQ showed the largest S/N, whereas its photobleaching was faster and the recovery of neural responses after staining was slower. Di-4-ANEPPS and di-3-ANEPPDHQ also exhibited a large S/N but required a relatively long time for recovery of neural activity. Di-4-AN(F)EPPTEA, di-2-AN(F)EPPTEA and di-2-ANEPPTEA showed smaller S/Ns than di-2-ANEPEQ, di-4-ANEPPS and di-3-ANEPPDHQ; but the recovery of neural responses after staining was faster. This study demonstrates the potential utility of these styryl dyes in optical monitoring of voltage changes in the embryonic CNS.
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Affiliation(s)
- Saad Habib-E-Rasul Mullah
- Department of Health and Nutrition Sciences, Komazawa Women’s University Faculty of Human Health, Tokyo 206-8511, Japan
| | - Ryo Komuro
- Department of Health and Nutrition, Kanto Gakuin University, College of Human and Environmental Studies, Yokohama 236-8501, Japan
| | - Ping Yan
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, CT 06030-6406, USA
| | - Shihori Hayashi
- Department of Neurosurgery, Tokyo Medical and Dental University Graduate School and Faculty of Medicine, Tokyo 113-8519, Japan
| | - Motoki Inaji
- Department of Neurosurgery, Tokyo Medical and Dental University Graduate School and Faculty of Medicine, Tokyo 113-8519, Japan
| | - Yoko Momose-Sato
- Department of Health and Nutrition, Kanto Gakuin University, College of Human and Environmental Studies, Yokohama 236-8501, Japan
| | - Leslie M. Loew
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, CT 06030-6406, USA
| | - Katsushige Sato
- Department of Health and Nutrition Sciences, Komazawa Women’s University Faculty of Human Health, Tokyo 206-8511, Japan
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Tominaga T, Tominaga Y. A new nonscanning confocal microscopy module for functional voltage-sensitive dye and Ca2+ imaging of neuronal circuit activity. J Neurophysiol 2013; 110:553-61. [PMID: 23615547 DOI: 10.1152/jn.00856.2012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Recent advances in fluorescent confocal microscopy and voltage-sensitive and Ca(2+) dyes have vastly improved our ability to image neuronal circuits. However, existing confocal systems are not fast enough or too noisy for many live-cell functional imaging studies. Here, we describe and demonstrate the function of a novel, nonscanning confocal microscopy module. The optics, which are designed to fit the standard camera port of the Olympus BX51WI epifluorescent microscope, achieve a high signal-to-noise ratio (SNR) at high temporal resolution, making this configuration ideal for functional imaging of neuronal activities such as the voltage-sensitive dye (VSD) imaging. The optics employ fixed 100- × 100-pinhole arrays at the back focal plane (optical conjugation plane), above the tube lens of a usual upright microscope. The excitation light travels through these pinholes, and the fluorescence signal, emitted from subject, passes through corresponding pinholes before exciting the photodiodes of the imager: a 100- × 100-pixel metal-oxide semiconductor (MOS)-type pixel imager with each pixel corresponding to a single 100- × 100-μm photodiode. This design eliminated the need for a scanning device; therefore, acquisition rate of the imager (maximum rate of 10 kHz) is the only factor limiting acquisition speed. We tested the application of the system for VSD and Ca(2+) imaging of evoked neuronal responses on electrical stimuli in rat hippocampal slices. The results indicate that, at least for these applications, the new microscope maintains a high SNR at image acquisition rates of ≤0.3 ms per frame.
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Affiliation(s)
- Takashi Tominaga
- Laboratory for Neural Circuit Systems, Institute of Neuroscience, Tokushima Bunri University, Shido, Sanuki, Kagawa, Japan.
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Abstract
Recovery from stroke is rarely complete as humans and experimental animals typically show lingering deficits in sensory function. One explanation for limited recovery could be that rewired cortical networks do not process sensory stimuli with the same temporal precision as they normally would. To examine how well peri-infarct and more distant cortical networks process successive vibro-tactile stimulations of the affected forepaw (a measure of temporal fidelity), we imaged cortical depolarizations with millisecond temporal resolution using voltage-sensitive dyes. In control mice, paired forepaw stimulations (ranging from 50 to 200 milliseconds apart) induced temporally distinct depolarizations in primary forelimb somatosensory (FLS1) cortex, and to a lesser extent in secondary FLS (FLS2) cortex. For mice imaged 3 months after stroke, the first forepaw stimulus reliably evoked a strong depolarization in the surviving region of FLS1 and FLS2 cortex. However, depolarizations to subsequent forepaw stimuli were significantly reduced or completely absent (for stimuli ≤100 milliseconds apart) in the FLS1 cortex, whereas FLS2 responses were relatively unaffected. Our data reveal that stroke induces long-lasting impairments in how well the rewired FLS1 cortex processes temporal aspects of sensory stimuli. Future therapies directed at enhancing the temporal fidelity of cortical circuits may be necessary for achieving full recovery of sensory functions.
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Stepan J, Dine J, Fenzl T, Polta SA, von Wolff G, Wotjak CT, Eder M. Entorhinal theta-frequency input to the dentate gyrus trisynaptically evokes hippocampal CA1 LTP. Front Neural Circuits 2012; 6:64. [PMID: 22988432 PMCID: PMC3439738 DOI: 10.3389/fncir.2012.00064] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Accepted: 08/27/2012] [Indexed: 01/01/2023] Open
Abstract
There exists substantial evidence that some forms of explicit learning in mammals require long-term potentiation (LTP) at hippocampal CA3-CA1 synapses. While CA1 LTP has been well characterized at the monosynaptic level, it still remains unclear how the afferent systems to the hippocampus can initiate formation of this neuroplastic phenomenon. Using voltage-sensitive dye imaging (VSDI) in a mouse brain slice preparation, we show that evoked entorhinal cortical (EC) theta-frequency input to the dentate gyrus highly effectively generates waves of neuronal activity which propagate through the entire trisynaptic circuit of the hippocampus (“HTC-Waves”). This flow of activity, which we also demonstrate in vivo, critically depends on frequency facilitation of mossy fiber to CA3 synaptic transmission. The HTC-Waves are rapidly boosted by the cognitive enhancer caffeine (5 μM) and the stress hormone corticosterone (100 nM). They precisely follow the rhythm of the EC input, involve high-frequency firing (>100 Hz) of CA3 pyramidal neurons, and induce NMDA receptor-dependent CA1 LTP within a few seconds. Our study provides the first experimental evidence that synchronous theta-rhythmical spiking of EC stellate cells, as occurring during EC theta oscillations, has the capacity to drive induction of CA1 LTP via the hippocampal trisynaptic pathway. Moreover, we present data pointing to a basic filter mechanism of the hippocampus regarding EC inputs and describe a methodology to reveal alterations in the “input–output relationship” of the hippocampal trisynaptic circuit.
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Affiliation(s)
- Jens Stepan
- Research Group Neuronal Network Dynamics, Max Planck Institute of Psychiatry Munich, Germany
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Oikonomou KD, Short SM, Rich MT, Antic SD. Extrasynaptic glutamate receptor activation as cellular bases for dynamic range compression in pyramidal neurons. Front Physiol 2012; 3:334. [PMID: 22934081 PMCID: PMC3429100 DOI: 10.3389/fphys.2012.00334] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Accepted: 07/30/2012] [Indexed: 12/02/2022] Open
Abstract
Repetitive synaptic stimulation overcomes the ability of astrocytic processes to clear glutamate from the extracellular space, allowing some dendritic segments to become submerged in a pool of glutamate, for a brief period of time. This dynamic arrangement activates extrasynaptic NMDA receptors located on dendritic shafts. We used voltage-sensitive and calcium-sensitive dyes to probe dendritic function in this glutamate-rich location. An excess of glutamate in the extrasynaptic space was achieved either by repetitive synaptic stimulation or by glutamate iontophoresis onto the dendrites of pyramidal neurons. Two successive activations of synaptic inputs produced a typical NMDA spike, whereas five successive synaptic inputs produced characteristic plateau potentials, reminiscent of cortical UP states. While NMDA spikes were coupled with brief calcium transients highly restricted to the glutamate input site, the dendritic plateau potentials were accompanied by calcium influx along the entire dendritic branch. Once initiated, the glutamate-mediated dendritic plateau potentials could not be interrupted by negative voltage pulses. Activation of extrasynaptic NMDA receptors in cellular compartments void of spines is sufficient to initiate and support plateau potentials. The only requirement for sustained depolarizing events is a surplus of free glutamate near a group of extrasynaptic receptors. Highly non-linear dendritic spikes (plateau potentials) are summed in a highly sublinear fashion at the soma, revealing the cellular bases of signal compression in cortical circuits. Extrasynaptic NMDA receptors provide pyramidal neurons with a function analogous to a dynamic range compression in audio engineering. They limit or reduce the volume of “loud sounds” (i.e., strong glutamatergic inputs) and amplify “quiet sounds” (i.e., glutamatergic inputs that barely cross the dendritic threshold for local spike initiation). Our data also explain why consecutive cortical UP states have uniform amplitudes in a given neuron.
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Affiliation(s)
- Katerina D Oikonomou
- Department of Neuroscience, University of Connecticut Health Center Farmington, CT, USA
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Watanabe H, Ai H, Yokohari F. Spatio-temporal activity patterns of odor-induced synchronized potentials revealed by voltage-sensitive dye imaging and intracellular recording in the antennal lobe of the cockroach. Front Syst Neurosci 2012; 6:55. [PMID: 22848191 PMCID: PMC3404411 DOI: 10.3389/fnsys.2012.00055] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2012] [Accepted: 07/08/2012] [Indexed: 11/13/2022] Open
Abstract
In animals, odor qualities are represented as both spatial activity patterns of glomeruli and temporal patterns of synchronized oscillatory signals in the primary olfactory centers. By optical imaging of a voltage-sensitive dye (VSD) and intracellular recording from secondary olfactory interneurons, we examined possible neural correlates of the spatial and temporal odor representations in the primary olfactory center, the antennal lobe (AL), of the cockroach Periplaneta americana. Voltage-sensitive dye imaging revealed that all used odorants induced odor-specific temporal patterns of depolarizing potentials in specific combinations of anterior glomeruli of the AL. The depolarizing potentials evoked by different odorants were temporally synchronized across glomeruli and were termed "synchronized potentials." These observations suggest that odor qualities are represented by spatio-temporal activity patterns of the synchronized potentials across glomeruli. We also performed intracellular recordings and stainings from secondary olfactory interneurons, namely projection neurons and local interneurons. We analyzed the temporal structures of enanthic acid-induced action potentials of secondary olfactory interneurons using simultaneous paired intracellular recording from two given neurons. Our results indicated that the multiple local interneurons synchronously fired in response to the olfactory stimulus. In addition, all stained enanthic acid-responsive projection neurons exhibited dendritic arborizations within the glomeruli where the synchronized potentials were evoked. Since multiple local interneurons are known to synapse to a projection neuron in each glomerulus in the cockroach AL, converging inputs from local interneurons to the projection neurons appear to contribute the odorant specific spatio-temporal activity patterns of the synchronized potentials.
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Affiliation(s)
- Hidehiro Watanabe
- Division of Biology, Department of Earth System Science, Fukuoka University Fukuoka, Japan
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Pagès S, Côté D, De Koninck P. Optophysiological approach to resolve neuronal action potentials with high spatial and temporal resolution in cultured neurons. Front Cell Neurosci 2011; 5:20. [PMID: 22016723 PMCID: PMC3191737 DOI: 10.3389/fncel.2011.00020] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Accepted: 09/15/2011] [Indexed: 12/02/2022] Open
Abstract
Cell to cell communication in the central nervous system is encoded into transient and local membrane potential changes (ΔVm). Deciphering the rules that govern synaptic transmission and plasticity entails to be able to perform Vm recordings throughout the entire neuronal arborization. Classical electrophysiology is, in most cases, not able to do so within small and fragile neuronal subcompartments. Thus, optical techniques based on the use of fluorescent voltage-sensitive dyes (VSDs) have been developed. However, reporting spontaneous or small ΔVm from neuronal ramifications has been challenging, in part due to the limited sensitivity and phototoxicity of VSD-based optical measurements. Here we demonstrate the use of water soluble VSD, ANNINE-6plus, with laser-scanning microscopy to optically record ΔVm in cultured neurons. We show that the sensitivity (>10% of fluorescence change for 100 mV depolarization) and time response (sub millisecond) of the dye allows the robust detection of action potentials (APs) even without averaging, allowing the measurement of spontaneous neuronal firing patterns. In addition, we show that back-propagating APs can be recorded, along distinct dendritic sites and within dendritic spines. Importantly, our approach does not induce any detectable phototoxic effect on cultured neurons. This optophysiological approach provides a simple, minimally invasive, and versatile optical method to measure electrical activity in cultured neurons with high temporal (ms) resolution and high spatial (μm) resolution.
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Affiliation(s)
- Stéphane Pagès
- Centre de Recherche Université Laval Robert-Giffard, Université Laval Québec, QC, Canada
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Chavane F, Sharon D, Jancke D, Marre O, Frégnac Y, Grinvald A. Lateral Spread of Orientation Selectivity in V1 is Controlled by Intracortical Cooperativity. Front Syst Neurosci 2011; 5:4. [PMID: 21629708 PMCID: PMC3100672 DOI: 10.3389/fnsys.2011.00004] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Accepted: 01/14/2011] [Indexed: 11/13/2022] Open
Abstract
Neurons in the primary visual cortex receive subliminal information originating from the periphery of their receptive fields (RF) through a variety of cortical connections. In the cat primary visual cortex, long-range horizontal axons have been reported to preferentially bind to distant columns of similar orientation preferences, whereas feedback connections from higher visual areas provide a more diverse functional input. To understand the role of these lateral interactions, it is crucial to characterize their effective functional connectivity and tuning properties. However, the overall functional impact of cortical lateral connections, whatever their anatomical origin, is unknown since it has never been directly characterized. Using direct measurements of postsynaptic integration in cat areas 17 and 18, we performed multi-scale assessments of the functional impact of visually driven lateral networks. Voltage-sensitive dye imaging showed that local oriented stimuli evoke an orientation-selective activity that remains confined to the cortical feedforward imprint of the stimulus. Beyond a distance of one hypercolumn, the lateral spread of cortical activity gradually lost its orientation preference approximated as an exponential with a space constant of about 1 mm. Intracellular recordings showed that this loss of orientation selectivity arises from the diversity of converging synaptic input patterns originating from outside the classical RF. In contrast, when the stimulus size was increased, we observed orientation-selective spread of activation beyond the feedforward imprint. We conclude that stimulus-induced cooperativity enhances the long-range orientation-selective spread.
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Affiliation(s)
- Frédéric Chavane
- Department of Neurobiology, Weizmann Institute of Science Rehovot, Israel
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Mapelli J, Gandolfi D, D'Angelo E. High-Pass Filtering and Dynamic Gain Regulation Enhance Vertical Bursts Transmission along the Mossy Fiber Pathway of Cerebellum. Front Cell Neurosci 2010; 4:14. [PMID: 20577586 PMCID: PMC2889686 DOI: 10.3389/fncel.2010.00014] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Accepted: 04/16/2010] [Indexed: 11/18/2022] Open
Abstract
Signal elaboration in the cerebellum mossy fiber input pathway presents controversial aspects, especially concerning gain regulation and the spot-like (rather than beam-like) appearance of granular to molecular layer transmission. By using voltage-sensitive dye imaging in rat cerebellar slices (Mapelli et al., 2010), we found that mossy fiber bursts optimally excited the granular layer above ∼50 Hz and the overlaying molecular layer above ∼100 Hz, thus generating a cascade of high-pass filters. NMDA receptors enhanced transmission in the granular, while GABA-A receptors depressed transmission in both the granular and molecular layer. Burst transmission gain was controlled through a dynamic frequency-dependent involvement of these receptors. Moreover, while high-frequency transmission was enhanced along vertical lines connecting the granular to molecular layer, no high-frequency enhancement was observed along the parallel fiber axis in the molecular layer. This was probably due to the stronger effect of Purkinje cell GABA-A receptor-mediated inhibition occurring along the parallel fibers than along the granule cell axon ascending branch. The consequent amplification of burst responses along vertical transmission lines could explain the spot-like activation of Purkinje cells observed following punctuate stimulation in vivo.
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Kanlop N, Sakai T. Optical mapping study of blebbistatin-induced chaotic electrical activities in isolated rat atrium preparations. J Physiol Sci 2010; 60:109-17. [PMID: 20013327 PMCID: PMC10717695 DOI: 10.1007/s12576-009-0074-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2009] [Accepted: 11/17/2009] [Indexed: 11/30/2022]
Abstract
We have studied the spatiotemporal pattern of blebbistatin-induced anomalous electrical activities in isolated rat atrial preparations using the optical mapping of excitation spread. Atrial preparations including the right or left auricle were dissected from adult rat hearts. Each preparation was then stained with a fast merocyanine-rhodanine voltage-sensitive dye (NK2761). Using a multi-element (16 x 16) photodiode array, we assessed the spread of excitation optically by timing the initiation of the action potential-related extrinsic absorption changes. The contraction-related optical signals were suppressed by adding (S)-(-)-blebbistatin (10-100 miocroM) to the bathing solution. Blebbistatin had an effective delay time of about 1.5 h following its application, at which time anomalous electrical activities occurred. These took the form of triggered activities and rhythmical spontaneous excitations. We optically mapped the spatiotemporal patterns of the excitation spread during these anomalous electrical activities. When the triggered activities occurred, the site of ectopic focus, where the triggered action potential first appeared, and the area of excitation spread varied in every event. When the rhythmical spontaneous excitations occurred, the excitation spread from the anomalous pacemaker and, occasionally, their spatial shift was observed. In addition, the combination pattern of the spontaneous excitations and triggered activities was also observed. We suggest that these phenomena are due to the disturbed intracellular calcium dynamics induced by the application of blebbistatin.
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Affiliation(s)
- Natnicha Kanlop
- Department of Physiology, University of the Ryukyus School of Medicine, 207 Uehara, Nishihara, Okinawa 903-0215 Japan
- Present Address: Cardiac Electrophysiology Unit, Department of Physiology, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200 Thailand
| | - Tetsuro Sakai
- Department of Physiology, University of the Ryukyus School of Medicine, 207 Uehara, Nishihara, Okinawa 903-0215 Japan
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Masumiya H, Oku Y, Okada Y. Inhomogeneous distribution of action potential characteristics in the rabbit sino-atrial node revealed by voltage imaging. J Physiol Sci 2009; 59:227-41. [PMID: 19340533 PMCID: PMC10717393 DOI: 10.1007/s12576-009-0032-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2008] [Accepted: 02/03/2009] [Indexed: 11/25/2022]
Abstract
The sino-atrial node (SAN) is the natural pacemaker of the heart. Mechanisms of the leading pacemaker site generation and dynamic pacemaker shifts in the SAN have been so far studied with an electrophysiological technique, but the detailed spatial distribution of action potential characteristics in the SAN has not been analyzed due to the limited number of simultaneously recorded sites in microelectrode recording. To elucidate the mechanism of leading pacemaker site generation in the SAN, we applied a voltage imaging technique and analyzed the spatial distribution of action potential characteristics in the rabbit SAN. Action potential parameters, i.e., action potential duration at 50% repolarization level, the slope of upstroke, and the slope of the linearly depolarizing early phase of pacemaker activity (phase-4), were calculated from optical signals. Action potential parameter values derived from intracellular recording with a microelectrode and those from optical recording were significantly correlated. The leading pacemaker site occurred in the region of either globally or locally maximum phase-4 slope in 7 of 12 preparations, however, it did not coincide with the region of the early maximum phase-4 slope in the other 5 preparations. Carbenoxolone, a gap junction blocker, changed action potential properties and caused pacemaker shifts. Model simulation, assuming an inhomogeneous distribution of intrinsic properties of SAN cells, reproduced the experimental results. We conclude that the functional structure of the SAN is more inhomogeneous than that dictated by previous models. Besides intrinsic cellular properties, cell-to-cell interaction through gap junctions influences action potential characteristics and leading pacemaker site generation.
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Affiliation(s)
- Haruko Masumiya
- Division of Physiome, Department of Physiology, Hyogo College of Medicine, Nishinomiya, Hyogo 663-8501 Japan
| | - Yoshitaka Oku
- Division of Physiome, Department of Physiology, Hyogo College of Medicine, Nishinomiya, Hyogo 663-8501 Japan
| | - Yasumasa Okada
- Department of Medicine, Keio University Tsukigase Rehabilitation Center, Izu, Shizuoka 410-3215 Japan
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Tsytsarev V, Fukuyama H, Pope D, Pumbo E, Kimura M. Optical imaging of interaural time difference representation in rat auditory cortex. Front Neuroeng 2009; 2:2. [PMID: 19277218 PMCID: PMC2654020 DOI: 10.3389/neuro.16.002.2009] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2008] [Accepted: 01/31/2009] [Indexed: 11/30/2022]
Abstract
We used in vivo voltage-sensitive dye optical imaging to examine the cortical representation of interaural time difference (ITD), which is believed to be involved in sound source localization. We found that acoustic stimuli with dissimilar ITD activate various localized domains in the auditory cortex. The main loci of the activation pattern shift up to 1 mm during the first 40 ms of the response period. We suppose that some of the neurons in each pool are sensitive to the definite ITD and involved in the transduction of information about sound source localization, based on the ITD. This assumption gives a reasonable fit to the Jeffress model in which the neural network calculates the ITD to define the direction of the sound source. Such calculation forms the basis for the cortex's ability to detect the azimuth of the sound source.
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Affiliation(s)
- Vassiliy Tsytsarev
- Washington University, Department of Biomedical Engineering St Louis, MO, USA
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Farkas E, Pratt R, Sengpiel F, Obrenovitch TP. Direct, live imaging of cortical spreading depression and anoxic depolarisation using a fluorescent, voltage-sensitive dye. J Cereb Blood Flow Metab 2008; 28:251-62. [PMID: 17971792 DOI: 10.1038/sj.jcbfm.9600569] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Perilesion depolarisations, whether transient anoxic depolarisation (AD) or spreading depression (SD), occur in stroke models and in patients with acute brain ischaemia, but their contribution to lesion progression remains unclear. As these phenomena correspond to waves of cellular depolarisation, we have developed a technique for their live imaging with a fluorescent voltage-sensitive (VS) dye (RH-1838). Method development and validation were performed in two different preparations: chicken retina, to avoid any vascular interference; and cranial window exposing the cortical surface of anaesthetised rats. Spreading depression was produced by high-K medium, and AD by complete terminal ischaemia in rats. After dye loading, the preparation was illuminated at its excitation wavelength and fluorescence changes were recorded sequentially with a charge-coupled device camera. No light was recorded when the VS dye was omitted, ruling out the contribution of any endogenous fluorophore. With both preparations, the changes in VS dye fluorescence with SD were analogous to those of the DC (direct current) potential recorded with glass electrodes. Although some blood quenching of the emitted light was identified, the VS dye signatures of SD had a good signal-to-noise ratio and were reproducible. The changes in VS dye fluorescence associated with AD were more complex because of additional interferents, especially transient brain swelling with subsequent shrinkage. However, the kinetics of the AD-associated changes in VS dye fluorescence was also analogous to that of the DC potential. In conclusion, this method provides the imaging equivalent of electrical extracellular DC potential recording, with the SD and AD negative shifts translating directly to fluorescence increase.
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