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Barioni NO, Beduschi RS, da Silva AV, Martins MG, Almeida-Francia CCD, Rodrigues SA, López DE, Gómez-Nieto R, Horta-Júnior JAC. The role of the Ventral Nucleus of the Trapezoid Body in the auditory prepulse inhibition of the acoustic startle reflex. Hear Res 2024; 450:109070. [PMID: 38972084 DOI: 10.1016/j.heares.2024.109070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 05/28/2024] [Accepted: 06/13/2024] [Indexed: 07/09/2024]
Abstract
Cholinergic signaling is essential to mediate the auditory prepulse inhibition (PPI), an operational measure of sensorimotor gating, that refers to the reduction of the acoustic startle reflex (ASR) when a low-intensity, non-startling acoustic stimulus (the prepulse) is presented just before the onset of the acoustic startle stimulus. The cochlear root neurons (CRNs) are the first cells of the ASR circuit to receive cholinergic inputs from non-olivocochlear neurons of the ventral nucleus of the trapezoid body (VNTB) and subsequently decrease their neuronal activity in response to auditory prepulses. Yet, the contribution of the VNTB-CRNs pathway to the mediation of PPI has not been fully elucidated. In this study, we used the immunotoxin anti-choline acetyltransferase (ChAT)-saporin as well as electrolytic lesions of the medial olivocochlear bundle to selectively eliminate cholinergic VNTB neurons, and then assessed the ASR and PPI paradigms. Retrograde track-tracing experiments were conducted to precisely determine the site of lesioning VNTB neurons projecting to the CRNs. Additionally, the effects of VNTB lesions and the integrity of the auditory pathway were evaluated via auditory brain responses tests, ChAT- and FOS-immunohistochemistry. Consequently, we established three experimental groups: 1) intact control rats (non-lesioned), 2) rats with bilateral lesions of the olivocochlear bundle (OCB-lesioned), and 3) rats with bilateral immunolesions affecting both the olivocochlear bundle and the VNTB (OCB/VNTB-lesioned). All experimental groups underwent ASR and PPI tests at several interstimulus intervals before the lesion and 7, 14, and 21 days after it. Our results show that the ASR amplitude remained unaffected both before and after the lesion across all experimental groups, suggesting that the VNTB does not contribute to the ASR. The%PPI increased across the time points of evaluation in the control and OCB-lesioned groups but not in the OCB/VNTB-lesioned group. At the ISI of 50 ms, the OCB-lesioned group exhibited a significant increase in%PPI (p < 0.01), which did not occur in the OCB/VNTB-lesioned group. Therefore, the ablation of cholinergic non-olivocochlear neurons in the OCB/VNTB-lesioned group suggests that these neurons contribute to the mediation of auditory PPI at the 50 ms ISI through their cholinergic projections to CRNs. Our study strongly reinforces the notion that auditory PPI encompasses a complex mechanism of top-down cholinergic modulation, effectively attenuating the ASR across different interstimulus intervals within multiple pathways.
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Affiliation(s)
- N O Barioni
- Department of Functional and Structural Biology - Anatomy Division, Institute of Biosciences of Botucatu, São Paulo State University-UNESP, Botucatu, São Paulo, Brazil
| | - R S Beduschi
- Department of Functional and Structural Biology - Anatomy Division, Institute of Biosciences of Botucatu, São Paulo State University-UNESP, Botucatu, São Paulo, Brazil
| | - A V da Silva
- Medicine School, Federal University of Mato Grosso do Sul, UFMS-CPTL, Três Lagoas, Mato Grosso do Sul, Brazil
| | - M G Martins
- Department of Functional and Structural Biology - Anatomy Division, Institute of Biosciences of Botucatu, São Paulo State University-UNESP, Botucatu, São Paulo, Brazil
| | - C C D Almeida-Francia
- Department of Functional and Structural Biology - Anatomy Division, Institute of Biosciences of Botucatu, São Paulo State University-UNESP, Botucatu, São Paulo, Brazil
| | - S A Rodrigues
- Department of Bioprocesses and Biotechnology - Faculty of Agricultural Sciences, São Paulo State University-UNESP, Botucatu, São Paulo, Brazil
| | - D E López
- Neuroscience Institute of Castilla y León (INCyL), Salamanca, Spain; Institute of Biomedical Research of Salamanca (IBSAL), University of Salamanca, Salamanca, Spain; Department of Cell Biology and Pathology, University of Salamanca, Salamanca, Spain
| | - R Gómez-Nieto
- Neuroscience Institute of Castilla y León (INCyL), Salamanca, Spain; Institute of Biomedical Research of Salamanca (IBSAL), University of Salamanca, Salamanca, Spain; Department of Cell Biology and Pathology, University of Salamanca, Salamanca, Spain.
| | - J A C Horta-Júnior
- Department of Functional and Structural Biology - Anatomy Division, Institute of Biosciences of Botucatu, São Paulo State University-UNESP, Botucatu, São Paulo, Brazil.
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Yagishita H, Sasaki T. Integrating physiological and transcriptomic analyses at the single-neuron level. Neurosci Res 2024:S0168-0102(24)00065-8. [PMID: 38821412 DOI: 10.1016/j.neures.2024.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2024] [Revised: 04/30/2024] [Accepted: 05/12/2024] [Indexed: 06/02/2024]
Abstract
Neurons generate various spike patterns to execute different functions. Understanding how these physiological neuronal spike patterns are related to their molecular characteristics is a long-standing issue in neuroscience. Herein, we review the results of recent studies that have addressed this issue by integrating physiological and transcriptomic techniques. A sequence of experiments, including in vivo recording and/or labeling, brain tissue slicing, cell collection, and transcriptomic analysis, have identified the gene expression profiles of brain neurons at the single-cell level, with activity patterns recorded in living animals. Although these techniques are still in the early stages, this methodological idea is principally applicable to various brain regions and neuronal activity patterns. Accumulating evidence will contribute to a deeper understanding of neuronal characteristics by integrating insights from molecules to cells, circuits, and behaviors.
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Affiliation(s)
- Haruya Yagishita
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aramaki-Aoba, Aoba-Ku, Sendai 980-8578, Japan
| | - Takuya Sasaki
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aramaki-Aoba, Aoba-Ku, Sendai 980-8578, Japan; Department of Neuropharmacology, Tohoku University School of Medicine, 4-1 Seiryo-machi, Aoba-Ku, Sendai 980-8575, Japan.
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Yagishita H, Go Y, Okamoto K, Arimura N, Ikegaya Y, Sasaki T. A method to analyze gene expression profiles from hippocampal neurons electrophysiologically recorded in vivo. Front Neurosci 2024; 18:1360432. [PMID: 38694898 PMCID: PMC11061373 DOI: 10.3389/fnins.2024.1360432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Accepted: 03/26/2024] [Indexed: 05/04/2024] Open
Abstract
Hippocampal pyramidal neurons exhibit diverse spike patterns and gene expression profiles. However, their relationships with single neurons are not fully understood. In this study, we designed an electrophysiology-based experimental procedure to identify gene expression profiles using RNA sequencing of single hippocampal pyramidal neurons whose spike patterns were recorded in living mice. This technique involves a sequence of experiments consisting of in vivo juxtacellular recording and labeling, brain slicing, cell collection, and transcriptome analysis. We demonstrated that the expression levels of a subset of genes in individual hippocampal pyramidal neurons were significantly correlated with their spike burstiness, submillisecond-level spike rise times or spike rates, directly measured by in vivo electrophysiological recordings. Because this methodological approach can be applied across a wide range of brain regions, it is expected to contribute to studies on various neuronal heterogeneities to understand how physiological spike patterns are associated with gene expression profiles.
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Affiliation(s)
- Haruya Yagishita
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Yasuhiro Go
- Graduate School of Information Science, University of Hyogo, Hyogo, Japan
- Department of System Neuroscience, Division of Behavioral Development, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi, Japan
- Cognitive Genomics Research Group, Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Okazaki, Aichi, Japan
| | - Kazuki Okamoto
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
- Department of Neuroanatomy, Graduate School of Medicine, Juntendo University, Tokyo, Japan
- Department of Cell Biology and Neuroscience, Graduate School of Medicine, Juntendo University, Bunkyo, Tokyo, Japan
| | - Nariko Arimura
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan
| | - Yuji Ikegaya
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
- Center for Information and Neural Networks, National Institute of Information and Communications Technology, Osaka, Japan
- Institute for AI and Beyond, The University of Tokyo, Tokyo, Japan
| | - Takuya Sasaki
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
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4
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Bhandare A, van de Wiel J, Roberts R, Braren I, Huckstepp R, Dale N. Analyzing the brainstem circuits for respiratory chemosensitivity in freely moving mice. eLife 2022; 11:e70671. [PMID: 36300918 PMCID: PMC9643001 DOI: 10.7554/elife.70671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 10/12/2022] [Indexed: 11/13/2022] Open
Abstract
Regulation of systemic PCO2 is a life-preserving homeostatic mechanism. In the medulla oblongata, the retrotrapezoid nucleus (RTN) and rostral medullary Raphe are proposed as CO2 chemosensory nuclei mediating adaptive respiratory changes. Hypercapnia also induces active expiration, an adaptive change thought to be controlled by the lateral parafacial region (pFL). Here, we use GCaMP6 expression and head-mounted mini-microscopes to image Ca2+ activity in these nuclei in awake adult mice during hypercapnia. Activity in the pFL supports its role as a homogenous neuronal population that drives active expiration. Our data show that chemosensory responses in the RTN and Raphe differ in their temporal characteristics and sensitivity to CO2, raising the possibility these nuclei act in a coordinated way to generate adaptive ventilatory responses to hypercapnia. Our analysis revises the understanding of chemosensory control in awake adult mouse and paves the way to understanding how breathing is coordinated with complex non-ventilatory behaviours.
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Affiliation(s)
- Amol Bhandare
- School of Life Sciences, University of WarwickCoventryUnited Kingdom
| | | | - Reno Roberts
- School of Life Sciences, University of WarwickCoventryUnited Kingdom
| | - Ingke Braren
- University Medical Center Eppendorf, Vector Facility, Institute of Experimental Pharmacology and ToxicologyHamburgGermany
| | - Robert Huckstepp
- School of Life Sciences, University of WarwickCoventryUnited Kingdom
| | - Nicholas Dale
- School of Life Sciences, University of WarwickCoventryUnited Kingdom
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Iqbal S, Walsh TR, Rodger A, Packer NH. Interaction between Polysialic Acid and the MARCKS-ED Peptide at the Molecular Level. ACS Chem Neurosci 2020; 11:1944-1954. [PMID: 32412743 DOI: 10.1021/acschemneuro.0c00139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Polysialic acid (polySia) is a highly negatively charged linear homopolymer comprising α-2,8-linked sialic acids. It is abundant in the embryonic brain and modulates various functions such as differentiation and synaptic plasticity in the adult central nervous system by direct binding to its protein partners. One such example is the binding of polySia to myristoylated-alanine rich C-kinase substrate (MARCKS) to modulate neuritogenesis. To understand their interaction mechanism at the molecular level, we performed a binding assay which showed a direct binding of the MARCKS-ED peptide (KKKKKRFSFKKSFKLSGFSFKKNKK) with polySia in a concentration-dependent manner. Molecular dynamics simulations revealed that this binding is not exclusively dominated by electrostatics but can in part be attributed to the presence of near-regularly spaced Phe residues, that confer a compact 3D conformation based on pseudoglycine loop structures supported by Phe-Phe interactions. Our simulations, which are confirmed by circular dichroism measurements, also indicate that the peptide-polySia binding induces large-scale conformational rearrangement of polySia into coils at the binding site, whereas the peptide conformation is relatively unperturbed. As a consequence, we predict that each peptide can bind to a domain extending ∼14 polySia repeat units. Using the fluorescently tagged MARCKS-ED peptide on rat brainstem tissue sections, we demonstrate the ability of the peptide to detect polySia, similarly to polySia-specific antibody mAb735, especially in the spinal trigeminal nucleus and the dorsal vagal complex. This study provides information about the interaction between polySia and its CNS protein binding partner, MARCKS, and provides a fundamental platform for further studies to explore the prospect of the MARCKS-ED as an effective polySia-binding peptide for bioimaging and drug delivery applications.
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Affiliation(s)
- Sameera Iqbal
- Department of Molecular Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
- ARC Centre of Excellence for Nanoscale Biophotonics, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Tiffany R. Walsh
- Institute for Frontier Materials, Deakin University, Geelong, Victoria 3216, Australia
| | - Alison Rodger
- Department of Molecular Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Nicolle H. Packer
- Department of Molecular Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
- ARC Centre of Excellence for Nanoscale Biophotonics, Macquarie University, Sydney, New South Wales 2109, Australia
- Institute for Glycomics, Griffith University, Gold Coast, Queensland 4222, Australia
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6
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Saleeba C, Dempsey B, Le S, Goodchild A, McMullan S. Corrigendum: A Student's Guide to Neural Circuit Tracing. Front Neurosci 2020; 14:177. [PMID: 32210751 PMCID: PMC7076267 DOI: 10.3389/fnins.2020.00177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 02/17/2020] [Indexed: 11/13/2022] Open
Affiliation(s)
- Christine Saleeba
- Neurobiology of Vital Systems Node, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
- The School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Bowen Dempsey
- CNRS, Hindbrain Integrative Neurobiology Laboratory, Neuroscience Paris-Saclay Institute (Neuro-PSI), Université Paris-Saclay, Gif-sur-Yvette, France
| | - Sheng Le
- Neurobiology of Vital Systems Node, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Ann Goodchild
- Neurobiology of Vital Systems Node, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Simon McMullan
- Neurobiology of Vital Systems Node, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
- *Correspondence: Simon McMullan
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7
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Stevens L, Vonck K, Larsen LE, Van Lysebettens W, Germonpré C, Baekelandt V, Van den Haute C, Carrette E, Wadman WJ, Boon P, Raedt R. A Feasibility Study to Investigate Chemogenetic Modulation of the Locus Coeruleus by Means of Single Unit Activity. Front Neurosci 2020; 14:162. [PMID: 32210746 PMCID: PMC7067893 DOI: 10.3389/fnins.2020.00162] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 02/12/2020] [Indexed: 11/13/2022] Open
Abstract
Aim Selective chemogenetic modulation of locus coeruleus (LC) neurons would allow dedicated investigation of the role of the LC-NA pathway in brain excitability and disorders such as epilepsy. This study investigated the feasibility of an experimental set-up where chemogenetic modification of the brainstem locus coeruleus NA neurons is aimed at and followed by LC unit activity recording in response to clozapine. Methods The LC of male Sprague-Dawley rats was injected with 10 nl of adeno-associated viral vector AAV2/7-PRSx8-hM3Dq-mCherry (n = 19, DREADD group) or AAV2/7-PRSx8-eGFP (n = 13, Controls). Three weeks later, LC unit recordings were performed in anesthetized rats. We investigated whether clozapine, a drug known to bind to modified neurons expressing hM3Dq receptors, was able to increase the LC firing rate. Baseline unit activity was recorded followed by subsequent administration of 0.01 and 0.1 mg/kg of clozapine in all rats. hM3Dq-mcherry expression levels were investigated using immunofluorescence staining of brainstem slices at the end of the experiment. Results Unit recordings could be performed in 12 rats and in a total of 12 neurons (DREADDs: n = 7, controls: n = 5). Clozapine 0.01 mg/kg did not affect the mean firing rate of recorded LC-neurons; 0.1 mg/kg induced an increased firing rate, irrespective whether neurons were recorded from DREADD or control rats (p = 0.006). Co-labeling of LC neurons and mCherry-tag showed that 20.6 ± 2.3% LC neurons expressed the hM3Dq receptor. Aspecific expression of hM3Dq-mCherry was also observed in non-LC neurons (26.0 ± 4.1%). Conclusion LC unit recording is feasible in an experimental set-up following manipulations for DREADD induction. A relatively low transduction efficiency of the used AAV was found. In view of this finding, the effect of injected clozapine on LC-NA could not be investigated as a reliable outcome parameter for activation of chemogenetically modified LC neurons. The use of AAV2/7, a vector previously applied successfully to target dopaminergic neurons in the substantia nigra, leads to insufficient chemogenetic modification of the LC compared to transduction with AAV2/9.
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Affiliation(s)
- Latoya Stevens
- 4BRAIN, Institute for Neuroscience, Department of Neurology, Ghent University, Ghent, Belgium
| | - Kristl Vonck
- 4BRAIN, Institute for Neuroscience, Department of Neurology, Ghent University, Ghent, Belgium
| | - Lars Emil Larsen
- 4BRAIN, Institute for Neuroscience, Department of Neurology, Ghent University, Ghent, Belgium
| | - Wouter Van Lysebettens
- 4BRAIN, Institute for Neuroscience, Department of Neurology, Ghent University, Ghent, Belgium
| | - Charlotte Germonpré
- 4BRAIN, Institute for Neuroscience, Department of Neurology, Ghent University, Ghent, Belgium
| | - Veerle Baekelandt
- Laboratory for Neurobiology and Gene Therapy, Center for Molecular Medicine, Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Chris Van den Haute
- Laboratory for Neurobiology and Gene Therapy, Center for Molecular Medicine, Leuven Brain Institute, KU Leuven, Leuven, Belgium.,Leuven Viral Vector Core, Centre for Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Evelien Carrette
- 4BRAIN, Institute for Neuroscience, Department of Neurology, Ghent University, Ghent, Belgium
| | - Wytse Jan Wadman
- 4BRAIN, Institute for Neuroscience, Department of Neurology, Ghent University, Ghent, Belgium
| | - Paul Boon
- 4BRAIN, Institute for Neuroscience, Department of Neurology, Ghent University, Ghent, Belgium
| | - Robrecht Raedt
- 4BRAIN, Institute for Neuroscience, Department of Neurology, Ghent University, Ghent, Belgium
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Keener DG, Cheung A, Futai K. A highly efficient method for single-cell electroporation in mouse organotypic hippocampal slice culture. J Neurosci Methods 2020; 337:108632. [PMID: 32126275 DOI: 10.1016/j.jneumeth.2020.108632] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 01/19/2020] [Accepted: 02/10/2020] [Indexed: 01/06/2023]
Abstract
BACKGROUND Exogenous gene introduction by transfection is one of the most important approaches for understanding the function of specific genes at the cellular level. Electroporation has a long-standing history as a versatile gene delivery technique in vitro and in vivo. However, it has been underutilized in vitro because of technical difficulty and insufficient transfection efficiency. NEW METHOD We have developed an electroporation technique that combines the use of large glass electrodes, tetrodotoxin-containing artificial cerebrospinal fluid and mild electrical pulses. Here, we describe the technique and compare it with existing methods. RESULTS Our method achieves a high transfection efficiency (∼80 %) in both excitatory and inhibitory neurons with no detectable side effects on their function. We demonstrate this method is capable of transferring at least three different genes into a single neuron. In addition, we demonstrate the ability to transfect different genes into neighboring cells. COMPARISON WITH EXISTING METHODS The majority of existing methods use fine-tipped glass electrodes (i.e. > 10 MΩ) and apply high voltage (10 V) pulses with high frequency (100 Hz) for 1 s. These parameters contribute to practical difficulties thus lowering the transfection efficiency. Our unique method minimizes electrode clogging and therefore procedure duration, increasing transfection efficiency and cellular viability. CONCLUSIONS Our modifications, relative to current methods, optimize electroporation efficiency and cell survival. Our approach offers distinct research strategies not only in elucidating cell-autonomous functions of genes but also for assessing genes contributing to intercellular functions, such as trans-synaptic interactions.
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Affiliation(s)
- David G Keener
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical School, 364 Plantation Street, LRB-706, Worcester, MA, 01605-2324, USA; Graduate Program in Neuroscience, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Amy Cheung
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical School, 364 Plantation Street, LRB-706, Worcester, MA, 01605-2324, USA; UMMS MD/PhD Program, University of Massachusetts Medical School, Worcester, Massachusetts, 01604, USA
| | - Kensuke Futai
- Brudnick Neuropsychiatric Research Institute, Department of Neurobiology, University of Massachusetts Medical School, 364 Plantation Street, LRB-706, Worcester, MA, 01605-2324, USA.
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Cid E, de la Prida LM. Methods for single-cell recording and labeling in vivo. J Neurosci Methods 2019; 325:108354. [PMID: 31302156 DOI: 10.1016/j.jneumeth.2019.108354] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 07/07/2019] [Accepted: 07/07/2019] [Indexed: 01/29/2023]
Abstract
Targeting individual neurons in vivo is a key method to study the role of single cell types within local and brain-wide microcircuits. While novel technological developments now permit assessing activity from large number of cells simultaneously, there is currently no better solution than glass micropipettes to relate the physiology and morphology of single-cells. Sharp intracellular, juxtacellular, loose-patch and whole-cell approaches are some of the configurations used to record and label individual neurons. Here, we review procedures to establish successful electrophysiological recordings in vivo followed by appropriate labeling for post hoc morphological analysis. We provide operational recommendations for optimizing each configuration and a generic framework for functional, neurochemical and morphological identification of the different cell-types in a given region. Finally, we highlight emerging approaches that are challenging our current paradigms for single-cell recording and labeling in the living brain.
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Affiliation(s)
- Elena Cid
- Instituto Cajal, CSIC, Ave Doctor Arce 37, Madrid, 28002, Spain
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10
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Saleeba C, Dempsey B, Le S, Goodchild A, McMullan S. A Student's Guide to Neural Circuit Tracing. Front Neurosci 2019; 13:897. [PMID: 31507369 PMCID: PMC6718611 DOI: 10.3389/fnins.2019.00897] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 08/12/2019] [Indexed: 12/17/2022] Open
Abstract
The mammalian nervous system is comprised of a seemingly infinitely complex network of specialized synaptic connections that coordinate the flow of information through it. The field of connectomics seeks to map the structure that underlies brain function at resolutions that range from the ultrastructural, which examines the organization of individual synapses that impinge upon a neuron, to the macroscopic, which examines gross connectivity between large brain regions. At the mesoscopic level, distant and local connections between neuronal populations are identified, providing insights into circuit-level architecture. Although neural tract tracing techniques have been available to experimental neuroscientists for many decades, considerable methodological advances have been made in the last 20 years due to synergies between the fields of molecular biology, virology, microscopy, computer science and genetics. As a consequence, investigators now enjoy an unprecedented toolbox of reagents that can be directed against selected subpopulations of neurons to identify their efferent and afferent connectomes. Unfortunately, the intersectional nature of this progress presents newcomers to the field with a daunting array of technologies that have emerged from disciplines they may not be familiar with. This review outlines the current state of mesoscale connectomic approaches, from data collection to analysis, written for the novice to this field. A brief history of neuroanatomy is followed by an assessment of the techniques used by contemporary neuroscientists to resolve mesoscale organization, such as conventional and viral tracers, and methods of selecting for sub-populations of neurons. We consider some weaknesses and bottlenecks of the most widely used approaches for the analysis and dissemination of tracing data and explore the trajectories that rapidly developing neuroanatomy technologies are likely to take.
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Affiliation(s)
- Christine Saleeba
- Neurobiology of Vital Systems Node, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
- The School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Bowen Dempsey
- CNRS, Hindbrain Integrative Neurobiology Laboratory, Neuroscience Paris-Saclay Institute (Neuro-PSI), Université Paris-Saclay, Gif-sur-Yvette, France
| | - Sheng Le
- Neurobiology of Vital Systems Node, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Ann Goodchild
- Neurobiology of Vital Systems Node, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Simon McMullan
- Neurobiology of Vital Systems Node, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
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11
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Affiliation(s)
- Ede A Rancz
- Cortical Circuits Laboratory, Francis Crick Institute, London, UK
| | - Andreas T Schaefer
- Neurophysiology of Behaviour Laboratory, Francis Crick Institute, London, UK, and the Department of Neuroscience, Physiology & Pharmacology, University College London, London, UK
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12
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A robot for high yield electrophysiology and morphology of single neurons in vivo. Nat Commun 2017; 8:15604. [PMID: 28569837 PMCID: PMC5461495 DOI: 10.1038/ncomms15604] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 04/06/2017] [Indexed: 01/13/2023] Open
Abstract
Single-cell characterization and perturbation of neurons provides knowledge critical to addressing fundamental neuroscience questions including the structure–function relationship and neuronal cell-type classification. Here we report a robot for efficiently performing in vivo single-cell experiments in deep brain tissues optically difficult to access. This robot automates blind (non-visually guided) single-cell electroporation (SCE) and extracellular electrophysiology, and can be used to characterize neuronal morphological and physiological properties of, and/or manipulate genetic/chemical contents via delivering extraneous materials (for example, genes) into single neurons in vivo. Tested in the mouse brain, our robot successfully reveals the full morphology of single-infragranular neurons recorded in multiple neocortical regions, as well as deep brain structures such as hippocampal CA3, with high efficiency. Our robot thus can greatly facilitate the study of in vivo full morphology and electrophysiology of single neurons in the brain. Single-cell characterization and perturbation of neurons is critical for revealing the structure-function relationship of brain cells. Here the authors develop a robot that performs single-cell electroporation and extracellular electrophysiology and can be used for performing in vivo single-cell experiments in deep brain tissues optically difficult to access.
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Le S, Turner AJ, Parker LM, Burke PG, Kumar NN, Goodchild AK, McMullan S. Somatostatin 2a receptors are not expressed on functionally identified respiratory neurons in the ventral respiratory column of the rat. J Comp Neurol 2015; 524:1384-98. [PMID: 26470751 DOI: 10.1002/cne.23912] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 10/09/2015] [Accepted: 10/12/2015] [Indexed: 01/09/2023]
Abstract
Microinjection of somatostatin (SST) causes site-specific effects on respiratory phase transition, frequency, and amplitude when microinjected into the ventrolateral medulla (VLM) of the anesthetized rat, suggesting selective expression of SST receptors on different functional classes of respiratory neurons. Of the six subtypes of SST receptor, somatostatin 2a (sst2a ) is the most prevalent in the VLM, and other investigators have suggested that glutamatergic neurons in the preBötzinger Complex (preBötC) that coexpress neurokinin-1 receptor (NK1R), SST, and sst2a are critical for the generation of respiratory rhythm. However, quantitative data describing the distribution of sst2a in respiratory compartments other than preBötC, or on functionally identified respiratory neurons, is absent. Here we examine the medullary expression of sst2a with particular reference to glycinergic/expiratory neurons in the Bötzinger Complex (BötC) and NK1R-immunoreactive/inspiratory neurons in the preBötC. We found robust sst2a expression at all rostrocaudal levels of the VLM, including a large proportion of catecholaminergic neurons, but no colocalization of sst2a and glycine transporter 2 mRNA in the BötC. In the preBötC 54% of sst2a -immunoreactive neurons were also positive for NK1R. sst2a was not observed in any of 52 dye-labeled respiratory interneurons, including seven BötC expiratory-decrementing and 11 preBötC preinspiratory neurons. We conclude that sst2a is not expressed on BötC respiratory neurons and that phasic respiratory activity is a poor predictor of sst2a expression in the preBötC. Therefore, sst2a is unlikely to underlie responses to BötC SST injection, and is sparse or absent on respiratory neurons identified by classical functional criteria. J. Comp. Neurol. 524:1384-1398, 2016. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
- Sheng Le
- Faculty of Medicine & Health Sciences, Macquarie University, NSW, Australia
| | - Anita J Turner
- Faculty of Medicine & Health Sciences, Macquarie University, NSW, Australia
| | - Lindsay M Parker
- ARC Center of Excellence for Nanoscale BioPhotonics, Macquarie University, NSW, Australia
| | - Peter G Burke
- Neuroscience Research Australia, Randwick, NSW, Australia
| | - Natasha N Kumar
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA
| | - Ann K Goodchild
- Faculty of Medicine & Health Sciences, Macquarie University, NSW, Australia
| | - Simon McMullan
- Faculty of Medicine & Health Sciences, Macquarie University, NSW, Australia
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