1
|
Montero T, Gatica RI, Farassat N, Meza R, González-Cabrera C, Roeper J, Henny P. Dendritic Architecture Predicts in vivo Firing Pattern in Mouse Ventral Tegmental Area and Substantia Nigra Dopaminergic Neurons. Front Neural Circuits 2021; 15:769342. [PMID: 34867214 PMCID: PMC8640462 DOI: 10.3389/fncir.2021.769342] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 10/12/2021] [Indexed: 11/13/2022] Open
Abstract
The firing activity of ventral tegmental area (VTA) and substantia nigra pars compacta (SNc) dopaminergic (DA) neurons is an important factor in shaping DA release and its role in motivated behavior. Dendrites in DA neurons are the main postsynaptic compartment and, along with cell body and axon initial segment, contribute to action potential generation and firing pattern. In this study, the organization of the dendritic domain in individual VTA and SNc DA neurons of adult male mice, and their relationship to in vivo spontaneous firing, are described. In comparison with dorsal VTA DA neurons, ventrally located VTA neurons (as measured by cell body location) possess a shorter total dendritic length and simpler dendritic architecture, and exhibit the most irregular in vivo firing patterns among DA neurons. In contrast, for DA neurons in the SNc, the higher irregularity of firing was related to a smaller dendritic domain, as measured by convex hull volumes. However, firing properties were also related to the specific regional distribution of the dendritic tree. Thus, VTA DA neurons with a larger extension of their dendritic tree within the parabrachial pigmented (PBP) nucleus fired more regularly compared with those with relatively more dendrites extending outside the PBP. For DA neurons in the SNc, enhanced firing irregularity was associated with a smaller proportion of dendrites penetrating the substantia nigra pars reticulata. These results suggest that differences in dendritic morphology contribute to the in vivo firing properties of individual DA neurons, and that the existence of region-specific synaptic connectivity rules that shape firing diversity.
Collapse
Affiliation(s)
- Trinidad Montero
- Laboratorio de Neuroanatomía, Departamento de Anatomía, and Centro Interdisciplinario de Neurociencia, NeuroUC, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Rafael Ignacio Gatica
- Laboratorio de Neuroanatomía, Departamento de Anatomía, and Centro Interdisciplinario de Neurociencia, NeuroUC, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Navid Farassat
- Institute of Neurophysiology, Goethe University, Frankfurt, Germany
| | - Rodrigo Meza
- Laboratorio de Neuroanatomía, Departamento de Anatomía, and Centro Interdisciplinario de Neurociencia, NeuroUC, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Cristian González-Cabrera
- Laboratorio de Neuroanatomía, Departamento de Anatomía, and Centro Interdisciplinario de Neurociencia, NeuroUC, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Jochen Roeper
- Institute of Neurophysiology, Goethe University, Frankfurt, Germany
| | - Pablo Henny
- Laboratorio de Neuroanatomía, Departamento de Anatomía, and Centro Interdisciplinario de Neurociencia, NeuroUC, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| |
Collapse
|
2
|
Zhang X, Gaudry Q. Examining Monosynaptic Connections in Drosophila Using Tetrodotoxin Resistant Sodium Channels. J Vis Exp 2018. [PMID: 29553525 DOI: 10.3791/57052] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Here, a new technique termed Tetrotoxin (TTX) Engineered Resistance for Probing Synapses (TERPS) is applied to test for monosynaptic connections between target neurons. The method relies on co-expression of a transgenic activator with the tetrodotoxin-resistant sodium channel, NaChBac, in a specific presynaptic neuron. Connections with putative post-synaptic partners are determined by whole-cell recordings in the presence of TTX, which blocks electrical activity in neurons that do not express NaChBac. This approach can be modified to work with any activator or calcium imaging as a reporter of connections. TERPS adds to the growing set of tools available for determining connectivity within networks. However, TERPS is unique in that it also reliably reports bulk or volume transmission and spillover transmission.
Collapse
|
3
|
Lee HU, Nag S, Blasiak A, Jin Y, Thakor N, Yang IH. Subcellular Optogenetic Stimulation for Activity-Dependent Myelination of Axons in a Novel Microfluidic Compartmentalized Platform. ACS Chem Neurosci 2016; 7:1317-1324. [PMID: 27570883 DOI: 10.1021/acschemneuro.6b00157] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Myelination is governed by neuron-glia communication, which in turn is modulated by neural activity. The exact mechanisms remain elusive. We developed a novel in vitro optogenetic stimulation platform that facilitates subcellular activity induction in hundreds of neurons simultaneously. The light isolation was achieved by creating a biocompatible, light-absorbent, black microfluidic device integrated with a programmable, high-power LED array. The system was applied to a compartmentalized culture of primary neurons whose distal axons were interacting with oligodendrocyte precursor cells. Neural activity was induced along whole neurons or was constrained to cell bodies with proximal axons or distal axons only. All three modes of stimulation promoted oligodendrocyte differentiation and the myelination of axons as evidenced by a decrease in the number of oligodendrocyte precursor cells followed by increases in the number of mature oligodendrocytes and myelin sheath fragments. These results demonstrated the potential of our novel optogenetic stimulation system for the global and focal induction of neural activity in vitro for studying axon myelination.
Collapse
Affiliation(s)
- Hae Ung Lee
- Singapore
Institute for Neurotechnology, National University of Singapore, Singapore 119077
| | - Sudip Nag
- Singapore
Institute for Neurotechnology, National University of Singapore, Singapore 119077
| | - Agata Blasiak
- Singapore
Institute for Neurotechnology, National University of Singapore, Singapore 119077
| | - Yan Jin
- Singapore
Institute for Neurotechnology, National University of Singapore, Singapore 119077
| | - Nitish Thakor
- Singapore
Institute for Neurotechnology, National University of Singapore, Singapore 119077
- Department
of Biomedical Engineering, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - In Hong Yang
- Singapore
Institute for Neurotechnology, National University of Singapore, Singapore 119077
- Department
of Biomedical Engineering, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21218, United States
| |
Collapse
|
4
|
Lerner TN, Ye L, Deisseroth K. Communication in Neural Circuits: Tools, Opportunities, and Challenges. Cell 2016; 164:1136-1150. [PMID: 26967281 PMCID: PMC5725393 DOI: 10.1016/j.cell.2016.02.027] [Citation(s) in RCA: 109] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 01/27/2016] [Accepted: 02/03/2016] [Indexed: 11/27/2022]
Abstract
Communication, the effective delivery of information, is fundamental to life across all scales and species. Nervous systems (by necessity) may be most specifically adapted among biological tissues for high rate and complexity of information transmitted, and thus, the properties of neural tissue and principles of its organization into circuits may illuminate capabilities and limitations of biological communication. Here, we consider recent developments in tools for studying neural circuits with particular attention to defining neuronal cell types by input and output information streams--i.e., by how they communicate. Complementing approaches that define cell types by virtue of genetic promoter/enhancer properties, this communication-based approach to defining cell types operationally by input/output (I/O) relationships links structure and function, resolves difficulties associated with single-genetic-feature definitions, leverages technology for observing and testing significance of precisely these I/O relationships in intact brains, and maps onto processes through which behavior may be adapted during development, experience, and evolution.
Collapse
Affiliation(s)
- Talia N Lerner
- Bioengineering Department, 318 Campus Drive, Stanford University, Stanford, CA 94305, USA
| | - Li Ye
- Bioengineering Department, 318 Campus Drive, Stanford University, Stanford, CA 94305, USA
| | - Karl Deisseroth
- Bioengineering Department, 318 Campus Drive, Stanford University, Stanford, CA 94305, USA; Psychiatry Department, 318 Campus Drive, Stanford University, Stanford, CA 94305, USA; Howard Hughes Medical Institute, 318 Campus Drive, Stanford University, Stanford, CA 94305, USA.
| |
Collapse
|
5
|
Wang G, Wyskiel DR, Yang W, Wang Y, Milbern LC, Lalanne T, Jiang X, Shen Y, Sun QQ, Zhu JJ. An optogenetics- and imaging-assisted simultaneous multiple patch-clamp recording system for decoding complex neural circuits. Nat Protoc 2015; 10:397-412. [PMID: 25654757 PMCID: PMC4505930 DOI: 10.1038/nprot.2015.019] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Deciphering neuronal circuitry is central to understanding brain function and dysfunction, yet it remains a daunting task. To facilitate the dissection of neuronal circuits, a process requiring functional analysis of synaptic connections and morphological identification of interconnected neurons, we present here a method for stable simultaneous octuple patch-clamp recordings. This method allows physiological analysis of synaptic interconnections among 4-8 simultaneously recorded neurons and/or 10-30 sequentially recorded neurons, and it allows anatomical identification of >85% of recorded interneurons and >99% of recorded principal neurons. We describe how to apply the method to rodent tissue slices; however, it can be used on other model organisms. We also describe the latest refinements and optimizations of mechanics, electronics, optics and software programs that are central to the realization of a combined single- and two-photon microscopy-based, optogenetics- and imaging-assisted, stable, simultaneous quadruple-viguple patch-clamp recording system. Setting up the system, from the beginning of instrument assembly and software installation to full operation, can be completed in 3-4 d.
Collapse
Affiliation(s)
- Guangfu Wang
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA
| | - Daniel R Wyskiel
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA
| | - Weiguo Yang
- Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming, USA
| | - Yiqing Wang
- 1] Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA. [2] Department of Chemistry, University of Virginia, Charlottesville, Virginia, USA
| | - Lana C Milbern
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA
| | - Txomin Lalanne
- 1] Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA. [2] Neuroscience Graduate Program, Department of Health and Life Sciences, Bordeaux University, Bordeaux, France
| | - Xiaolong Jiang
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA
| | - Ying Shen
- Department of Neurobiology and Key Laboratory of Medical Neurobiology of Chinese Ministry of Health, Zhejiang University School of Medicine, Hangzhou, China
| | - Qian-Quan Sun
- Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming, USA
| | - J Julius Zhu
- 1] Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA. [2] Department of Neuroscience, University of Virginia, Charlottesville, Virginia, USA
| |
Collapse
|
6
|
Wang X, Hooks BM, Sun QQ. Thorough GABAergic innervation of the entire axon initial segment revealed by an optogenetic 'laserspritzer'. J Physiol 2014; 592:4257-76. [PMID: 25085892 DOI: 10.1113/jphysiol.2014.275719] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
GABAergic terminals of chandelier cells exclusively innervate the axon initial segment (AIS) of excitatory neurons. Although the anatomy of these synapses has been well-studied in several brain areas, relatively little is known about their physiological properties. Using vesicular γ-aminobutyric acid transporter-channelrhodopsin 2-enhanced yellow fluorescence protein (VGAT-ChR2-YFP)-expressing mice and a novel fibreoptic 'laserspritzer' approach that we developed, we investigated the physiological properties of axo-axonic synapses (AASs) in brain slices from the piriform cortex (PC) of mice. AASs were in close proximity to voltage-gated Na(+) (NaV) channels located at the AIS. AASs were selectively activated by a 5 μm laserspritzer placed in close proximity to the AIS. Under a minimal laser stimulation condition and using whole-cell somatic voltage-clamp recordings, the amplitudes and kinetics of IPSCs mediated by AASs were similar to those mediated by perisomatic inhibitions. Results were further validated with channelrhodopsin 2-assisted circuit mapping (CRACM) of the entire inhibitory inputs map. For the first time, we revealed that the laserspritzer-induced AAS-IPSCs persisted in the presence of TTX and TEA but not 4-AP. Next, using gramicidin-based perforated patch recordings, we found that the GABA reversal potential (EGABA) was -73.6 ± 1.2 mV when induced at the AIS and -72.8 ± 1.1 mV when induced at the perisomatic site. Our anatomical and physiological results lead to the novel conclusions that: (1) AASs innervate the entire length of the AIS, as opposed to forming a highly concentrated cartridge, (2) AAS inhibition suppresses action potentials and epileptiform activity more robustly than perisomatic inhibitions, and (3) AAS activation alone can be sufficient to inhibit action potential generation and epileptiform activities in vitro.
Collapse
Affiliation(s)
- Xinjun Wang
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY, 82071, USA Graduate Neuroscience Program, University of Wyoming, Laramie, WY, 82071, USA
| | - Bryan M Hooks
- Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, VA, 20147, USA
| | - Qian-Quan Sun
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY, 82071, USA
| |
Collapse
|