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Regele-Blasco E, Palmer LM. The plasticity of pyramidal neurons in the behaving brain. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230231. [PMID: 38853566 DOI: 10.1098/rstb.2023.0231] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Accepted: 04/23/2024] [Indexed: 06/11/2024] Open
Abstract
Neurons are plastic. That is, they change their activity according to different behavioural conditions. This endows pyramidal neurons with an incredible computational power for the integration and processing of synaptic inputs. Plasticity can be investigated at different levels of investigation within a single neuron, from spines to dendrites, to synaptic input. Although most of our knowledge stems from the in vitro brain slice preparation, plasticity plays a vital role during behaviour by providing a flexible substrate for the execution of appropriate actions in our ever-changing environment. Owing to advances in recording techniques, the plasticity of neurons and the neural networks in which they are embedded is now beginning to be realized in the in vivo intact brain. This review focuses on the structural and functional synaptic plasticity of pyramidal neurons, with a specific focus on the latest developments from in vivo studies. This article is part of a discussion meeting issue 'Long-term potentiation: 50 years on'.
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Affiliation(s)
- Elena Regele-Blasco
- The Florey Institute of Neuroscience and Mental Health, The Florey Department of Neuroscience and Mental Health, University of Melbourne , Victoria 3052, Australia
| | - Lucy M Palmer
- The Florey Institute of Neuroscience and Mental Health, The Florey Department of Neuroscience and Mental Health, University of Melbourne , Victoria 3052, Australia
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2
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Rvachev MM. An operating principle of the cerebral cortex, and a cellular mechanism for attentional trial-and-error pattern learning and useful classification extraction. Front Neural Circuits 2024; 18:1280604. [PMID: 38505865 PMCID: PMC10950307 DOI: 10.3389/fncir.2024.1280604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Accepted: 02/13/2024] [Indexed: 03/21/2024] Open
Abstract
A feature of the brains of intelligent animals is the ability to learn to respond to an ensemble of active neuronal inputs with a behaviorally appropriate ensemble of active neuronal outputs. Previously, a hypothesis was proposed on how this mechanism is implemented at the cellular level within the neocortical pyramidal neuron: the apical tuft or perisomatic inputs initiate "guess" neuron firings, while the basal dendrites identify input patterns based on excited synaptic clusters, with the cluster excitation strength adjusted based on reward feedback. This simple mechanism allows neurons to learn to classify their inputs in a surprisingly intelligent manner. Here, we revise and extend this hypothesis. We modify synaptic plasticity rules to align with behavioral time scale synaptic plasticity (BTSP) observed in hippocampal area CA1, making the framework more biophysically and behaviorally plausible. The neurons for the guess firings are selected in a voluntary manner via feedback connections to apical tufts in the neocortical layer 1, leading to dendritic Ca2+ spikes with burst firing, which are postulated to be neural correlates of attentional, aware processing. Once learned, the neuronal input classification is executed without voluntary or conscious control, enabling hierarchical incremental learning of classifications that is effective in our inherently classifiable world. In addition to voluntary, we propose that pyramidal neuron burst firing can be involuntary, also initiated via apical tuft inputs, drawing attention toward important cues such as novelty and noxious stimuli. We classify the excitations of neocortical pyramidal neurons into four categories based on their excitation pathway: attentional versus automatic and voluntary/acquired versus involuntary. Additionally, we hypothesize that dendrites within pyramidal neuron minicolumn bundles are coupled via depolarization cross-induction, enabling minicolumn functions such as the creation of powerful hierarchical "hyperneurons" and the internal representation of the external world. We suggest building blocks to extend the microcircuit theory to network-level processing, which, interestingly, yields variants resembling the artificial neural networks currently in use. On a more speculative note, we conjecture that principles of intelligence in universes governed by certain types of physical laws might resemble ours.
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3
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Barber KR, Vizcarra VS, Zilch A, Majuta L, Diezel CC, Culver OP, Hughes BW, Taniguchi M, Streicher JM, Vanderah TW, Riegel AC. The Role of Ryanodine Receptor 2 in Drug-Associated Learning. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.03.560743. [PMID: 37873212 PMCID: PMC10592901 DOI: 10.1101/2023.10.03.560743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Type-2 ryanodine receptor (RyR2) ion channels facilitate the release of Ca 2+ from stores and serve an important function in neuroplasticity. The role for RyR2 in hippocampal-dependent learning and memory is well established and chronic hyperphosphorylation of RyR2 (RyR2P) is associated with pathological calcium leakage and cognitive disorders, including Alzheimer's disease. By comparison, little is known about the role of RyR2 in the ventral medial prefrontal cortex (vmPFC) circuitry important for working memory, decision making, and reward seeking. Here, we evaluated the basal expression and localization of RyR2 and RyR2P in the vmPFC. Next, we employed an operant model of sucrose, cocaine, or morphine self-administration (SA) followed by a (reward-free) recall test, to reengage vmPFC neurons and reactivate reward-seeking and re-evaluated the expression and localization of RyR2 and RyR2P in vmPFC. Under basal conditions, RyR2 was expressed in pyramidal cells but not regularly detected in PV/SST interneurons. On the contrary, RyR2P was rarely observed in PFC somata and was restricted to a different subcompartment of the same neuron - the apical dendrites of layer-5 pyramidal cells. Chronic SA of drug (cocaine or morphine) and nondrug (sucrose) rewards produced comparable increases in RyR2 protein expression. However, recalling either drug reward impaired the usual localization of RyR2P in dendrites and markedly increased its expression in somata immunoreactive for Fos, a marker of highly activated neurons. These effects could not be explained by chronic stress or drug withdrawal and instead appeared to require a recall experience associated with prior drug SA. In addition to showing the differential distribution of RyR2/RyR2P and affirming the general role of vmPFC in reward learning, this study provides information on the propensity of addictive drugs to redistribute RyR2P ion channels in a neuronal population engaged in drug-seeking. Hence, focusing on the early impact of addictive drugs on RyR2 function may serve as a promising approach to finding a treatment for substance use disorders.
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Zhu JJ. Architectural organization of ∼1,500-neuron modular minicolumnar disinhibitory circuits in healthy and Alzheimer's cortices. Cell Rep 2023; 42:112904. [PMID: 37531251 DOI: 10.1016/j.celrep.2023.112904] [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: 02/15/2023] [Revised: 06/21/2023] [Accepted: 07/13/2023] [Indexed: 08/04/2023] Open
Abstract
Acquisition of neuronal circuit architectures, central to understanding brain function and dysfunction, remains prohibitively challenging. Here I report the development of a simultaneous and sequential octuple-sexdecuple whole-cell patch-clamp recording system that enables architectural reconstruction of complex cortical circuits. The method unveils the canonical layer 1 single bouquet cell (SBC)-led disinhibitory neuronal circuits across the mouse somatosensory, motor, prefrontal, and medial entorhinal cortices. The ∼1,500-neuron modular circuits feature the translaminar, unidirectional, minicolumnar, and independent disinhibition and optimize cortical complexity, subtlety, plasticity, variation, and redundancy. Moreover, architectural reconstruction uncovers age-dependent deficits at SBC-disinhibited synapses in the senescence-accelerated mouse prone 8, an animal model of Alzheimer's disease. The deficits exhibit the characteristic Alzheimer's-like cortical spread and correlation with cognitive impairments. These findings decrypt operations of the elementary processing units in healthy and Alzheimer's mouse cortices and validate the efficacy of octuple-sexdecuple patch-clamp recordings for architectural reconstruction of complex neuronal circuits.
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Affiliation(s)
- J Julius Zhu
- Kavli Institute for Systems Neuroscience, Norwegian University of Science and Technology, 7491 Trondheim, Norway; Department of Neurophysiology, Donders Institute for Brain, Cognition and Behavior, Radboud University, 6500 GL Nijmegen, the Netherlands; Departments of Pharmacology and Neuroscience, University of Virginia School of Medicine, Charlottesville, VA 22908, USA.
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5
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Batista-Brito R, Majumdar A, Nuño A, Ward C, Barnes C, Nikouei K, Vinck M, Cardin JA. Developmental loss of ErbB4 in PV interneurons disrupts state-dependent cortical circuit dynamics. Mol Psychiatry 2023; 28:3133-3143. [PMID: 37069344 PMCID: PMC10618960 DOI: 10.1038/s41380-023-02066-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 03/28/2023] [Accepted: 04/03/2023] [Indexed: 04/19/2023]
Abstract
GABAergic inhibition plays an important role in the establishment and maintenance of cortical circuits during development. Neuregulin 1 (Nrg1) and its interneuron-specific receptor ErbB4 are key elements of a signaling pathway critical for the maturation and proper synaptic connectivity of interneurons. Using conditional deletions of the ERBB4 gene in mice, we tested the role of this signaling pathway at two developmental timepoints in parvalbumin-expressing (PV) interneurons, the largest subpopulation of cortical GABAergic cells. Loss of ErbB4 in PV interneurons during embryonic, but not late postnatal development leads to alterations in the activity of excitatory and inhibitory cortical neurons, along with severe disruption of cortical temporal organization. These impairments emerge by the end of the second postnatal week, prior to the complete maturation of the PV interneurons themselves. Early loss of ErbB4 in PV interneurons also results in profound dysregulation of excitatory pyramidal neuron dendritic architecture and a redistribution of spine density at the apical dendritic tuft. In association with these deficits, excitatory cortical neurons exhibit normal tuning for sensory inputs, but a loss of state-dependent modulation of the gain of sensory responses. Together these data support a key role for early developmental Nrg1/ErbB4 signaling in PV interneurons as a powerful mechanism underlying the maturation of both the inhibitory and excitatory components of cortical circuits.
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Affiliation(s)
- Renata Batista-Brito
- Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Ave, The Bronx, NY, 10461, USA.
- Department of Neuroscience, Yale University School of Medicine, 333 Cedar St., New Haven, CT, 06520, USA.
- Department of Psychiatry and Behavioral Sciences, Einstein College of Medicine, 1300 Morris Park Ave, The Bronx, NY, 10461, USA.
- Department of Genetics, Einstein College of Medicine, 1300 Morris Park Ave, The Bronx, NY, 10461, USA.
| | - Antara Majumdar
- Department of Neuroscience, Yale University School of Medicine, 333 Cedar St., New Haven, CT, 06520, USA
- Department of Physiology, Anatomy and Genetics, University of Oxford, Sherrington Building, Sherrington Road, Oxford, OX1 3PT, England
| | - Alejandro Nuño
- Department of Neuroscience, Yale University School of Medicine, 333 Cedar St., New Haven, CT, 06520, USA
| | - Claire Ward
- Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Ave, The Bronx, NY, 10461, USA
| | - Clayton Barnes
- Department of Neuroscience, Yale University School of Medicine, 333 Cedar St., New Haven, CT, 06520, USA
| | - Kasra Nikouei
- Department of Neuroscience, Yale University School of Medicine, 333 Cedar St., New Haven, CT, 06520, USA
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Martin Vinck
- Department of Neuroscience, Yale University School of Medicine, 333 Cedar St., New Haven, CT, 06520, USA
- Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, Deutschordenstraße 46, 60528, Frankfurt, Germany
| | - Jessica A Cardin
- Department of Neuroscience, Yale University School of Medicine, 333 Cedar St., New Haven, CT, 06520, USA.
- Kavli Institute of Neuroscience, Yale University, 333 Cedar St., New Haven, CT, 06520, USA.
- Wu Tsai Institute, Yale University, 100 College St., New Haven, CT, 06520, USA.
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6
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Oda S, Funato H. D1- and D2-type dopamine receptors are immunolocalized in pial and layer I astrocytes in the rat cerebral cortex. Front Neuroanat 2023; 17:1111008. [PMID: 36865631 PMCID: PMC9971002 DOI: 10.3389/fnana.2023.1111008] [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: 11/29/2022] [Accepted: 01/25/2023] [Indexed: 02/16/2023] Open
Abstract
Pial astrocytes, a cellular component of the cerebral cortex surface structure, are observed in a wide range of mammalian species. Despite being recognized as such, the functional potential of pial astrocytes has long been overlooked. Our previous research demonstrated that pial astrocytes exhibit stronger immunoreactivity for muscarinic acetylcholine receptor M1 than protoplasmic astrocytes, indicating sensitivity to neuromodulators. Here, we examined whether pial astrocytes express receptors for dopamine, another crucial neuromodulator of cortical activity. We investigated the immunolocalization of each dopamine receptor subtype (D1R, D2R, D4R, D5R) in the rat cerebral cortex, and compared the intensity of immunoreactivity between pial astrocytes, protoplasmic astrocytes, and pyramidal cells. Our findings revealed that pial astrocytes and layer I astrocytes exhibit stronger D1R- and D4R-immunoreactivity than D2R and D5R. These immunoreactivities were primarily localized in the somata and thick processes of pial and layer I astrocytes. In contrast, protoplasmic astrocytes located in cortical layers II-VI displayed low or negligible immunoreactivities for dopamine receptors. D4R- and D5R-immunopositivity was distributed throughout pyramidal cells including somata and apical dendrites. These findings suggest that the dopaminergic system may regulate the activity of pial and layer I astrocytes via D1R and D4R.
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Affiliation(s)
- Satoko Oda
- Department of Anatomy, Graduate School of Medicine, Toho University, Tokyo, Japan,*Correspondence: Satoko Oda Hiromasa Funato
| | - Hiromasa Funato
- Department of Anatomy, Graduate School of Medicine, Toho University, Tokyo, Japan,International Institute for Integrative Sleep Medicine (IIIS), University of Tsukuba, Tsukuba, Japan,*Correspondence: Satoko Oda Hiromasa Funato
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7
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Aru J, Drüke M, Pikamäe J, Larkum ME. Mental navigation and the neural mechanisms of insight. Trends Neurosci 2023; 46:100-109. [PMID: 36462993 DOI: 10.1016/j.tins.2022.11.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 11/01/2022] [Accepted: 11/07/2022] [Indexed: 12/03/2022]
Abstract
How do new ideas come about? The central hypothesis presented here states that insights might happen during mental navigation and correspond to rapid plasticity at the cellular level. We highlight the differences between neocortical and hippocampal mechanisms of insight. We argue that the suddenness of insight can be related to the sudden emergence of place fields in the hippocampus. According to our hypothesis, insights are supported by a state of mind-wandering that can be tied to the process of combining knowledge pieces during sharp-wave ripples (SWRs). Our framework connects the dots between research on creativity, mental navigation, and specific synaptic plasticity mechanisms in the hippocampus.
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Affiliation(s)
- Jaan Aru
- Institute of Computer Science, University of Tartu, Tartu, Estonia.
| | - Moritz Drüke
- Institute of Biology, Humboldt University Berlin, Berlin, Germany
| | - Juhan Pikamäe
- Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Matthew E Larkum
- Institute of Biology, Humboldt University Berlin, Berlin, Germany; Neurocure Center for Excellence, Charité Universitätsmedizin Berlin, Berlin, Germany
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8
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Rindner DJ, Proddutur A, Lur G. Cell-type-specific integration of feedforward and feedback synaptic inputs in the posterior parietal cortex. Neuron 2022; 110:3760-3773.e5. [PMID: 36087582 PMCID: PMC9671855 DOI: 10.1016/j.neuron.2022.08.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 07/19/2022] [Accepted: 08/16/2022] [Indexed: 12/15/2022]
Abstract
The integration of feedforward (sensory) and feedback (top-down) neuronal signals is a principal function of the neocortex. Yet, we have limited insight into how these information streams are combined by individual neurons. Using a two-color optogenetic strategy, we found that layer 5 pyramidal neurons in the posterior parietal cortex receive monosynaptic dual innervation, combining sensory inputs with top-down signals. Subclasses of layer 5 pyramidal neurons integrated these synapses with distinct temporal dynamics. Specifically, regular spiking cells exhibited supralinear enhancement of delayed-but not coincident-inputs, while intrinsic burst-firing neurons selectively boosted coincident synaptic events. These subthreshold integration characteristics translated to a nonlinear summation of action potential firing. Complementing electrophysiology with computational modeling, we found that distinct integration profiles arose from a cell-type-specific interaction of ionic mechanisms and feedforward inhibition. These data provide insight into the cellular properties that guide the nonlinear interaction of distinct long-range afferents in the neocortex.
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Affiliation(s)
- Daniel J Rindner
- Department of Neurobiology and Behavior, University of California, Irvine, 1215 McGaugh Hall, Irvine, CA 92697, USA
| | - Archana Proddutur
- Department of Neurobiology and Behavior, University of California, Irvine, 1215 McGaugh Hall, Irvine, CA 92697, USA
| | - Gyorgy Lur
- Department of Neurobiology and Behavior, University of California, Irvine, 1215 McGaugh Hall, Irvine, CA 92697, USA.
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9
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Dendritic Morphology Affects the Velocity and Amplitude of Back-propagating Action Potentials. Neurosci Bull 2022; 38:1330-1346. [PMID: 35984622 PMCID: PMC9672184 DOI: 10.1007/s12264-022-00931-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 05/20/2022] [Indexed: 11/30/2022] Open
Abstract
The back-propagating action potential (bpAP) is crucial for neuronal signal integration and synaptic plasticity in dendritic trees. Its properties (velocity and amplitude) can be affected by dendritic morphology. Due to limited spatial resolution, it has been difficult to explore the specific propagation process of bpAPs along dendrites and examine the influence of dendritic morphology, such as the dendrite diameter and branching pattern, using patch-clamp recording. By taking advantage of Optopatch, an all-optical electrophysiological method, we made detailed recordings of the real-time propagation of bpAPs in dendritic trees. We found that the velocity of bpAPs was not uniform in a single dendrite, and the bpAP velocity differed among distinct dendrites of the same neuron. The velocity of a bpAP was positively correlated with the diameter of the dendrite on which it propagated. In addition, when bpAPs passed through a dendritic branch point, their velocity decreased significantly. Similar to velocity, the amplitude of bpAPs was also positively correlated with dendritic diameter, and the attenuation patterns of bpAPs differed among different dendrites. Simulation results from neuron models with different dendritic morphology corresponded well with the experimental results. These findings indicate that the dendritic diameter and branching pattern significantly influence the properties of bpAPs. The diversity among the bpAPs recorded in different neurons was mainly due to differences in dendritic morphology. These results may inspire the construction of neuronal models to predict the propagation of bpAPs in dendrites with enormous variation in morphology, to further illuminate the role of bpAPs in neuronal communication.
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10
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Moore JJ, Robert V, Rashid SK, Basu J. Assessing Local and Branch-specific Activity in Dendrites. Neuroscience 2022; 489:143-164. [PMID: 34756987 PMCID: PMC9125998 DOI: 10.1016/j.neuroscience.2021.10.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 10/09/2021] [Accepted: 10/21/2021] [Indexed: 01/12/2023]
Abstract
Dendrites are elaborate neural processes which integrate inputs from various sources in space and time. While decades of work have suggested an independent role for dendrites in driving nonlinear computations for the cell, only recently have technological advances enabled us to capture the variety of activity in dendrites and their coupling dynamics with the soma. Under certain circumstances, activity generated in a given dendritic branch remains isolated, such that the soma or even sister dendrites are not privy to these localized signals. Such branch-specific activity could radically increase the capacity and flexibility of coding for the cell as a whole. Here, we discuss these forms of localized and branch-specific activity, their functional relevance in plasticity and behavior, and their supporting biophysical and circuit-level mechanisms. We conclude by showcasing electrical and optical approaches in hippocampal area CA3, using original experimental data to discuss experimental and analytical methodology and key considerations to take when investigating the functional relevance of independent dendritic activity.
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Affiliation(s)
- Jason J Moore
- Neuroscience Institute, New York University Langone Health, New York, NY 10016, USA
| | - Vincent Robert
- Neuroscience Institute, New York University Langone Health, New York, NY 10016, USA
| | - Shannon K Rashid
- Neuroscience Institute, New York University Langone Health, New York, NY 10016, USA
| | - Jayeeta Basu
- Neuroscience Institute, New York University Langone Health, New York, NY 10016, USA; Department of Neuroscience and Physiology, New York University Grossman School of Medicine, New York, NY 10016, USA; Department of Psychiatry, New York University Grossman School of Medicine, New York, NY 10016, USA.
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11
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Im S, Ueta Y, Otsuka T, Morishima M, Youssef M, Hirai Y, Kobayashi K, Kaneko R, Morita K, Kawaguchi Y. Corticocortical innervation subtypes of layer 5 intratelencephalic cells in the murine secondary motor cortex. Cereb Cortex 2022; 33:50-67. [PMID: 35396593 PMCID: PMC9758586 DOI: 10.1093/cercor/bhac052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 01/25/2022] [Accepted: 01/26/2022] [Indexed: 11/15/2022] Open
Abstract
Feedback projections from the secondary motor cortex (M2) to the primary motor and sensory cortices are essential for behavior selection and sensory perception. Intratelencephalic (IT) cells in layer 5 (L5) contribute feedback projections to diverse cortical areas. Here we show that L5 IT cells participating in feedback connections to layer 1 (L1) exhibit distinct projection patterns, genetic profiles, and electrophysiological properties relative to other L5 IT cells. An analysis of the MouseLight database found that L5 IT cells preferentially targeting L1 project broadly to more cortical regions, including the perirhinal and auditory cortices, and innervate a larger volume of striatum than the other L5 IT cells. We found experimentally that in upper L5 (L5a), ER81 (ETV1) was found more often in L1-preferring IT cells, and in IT cells projecting to perirhinal/auditory regions than those projecting to primary motor or somatosensory regions. The perirhinal region-projecting L5a IT cells were synaptically connected to each other and displayed lower input resistance than contra-M2 projecting IT cells including L1-preferring and nonpreferring cells. Our findings suggest that M2-L5a IT L1-preferring cells exhibit stronger ER81 expression and broader cortical/striatal projection fields than do cells that do not preferentially target L1.
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Affiliation(s)
- Sanghun Im
- National Institute for Physiological Sciences (NIPS), Okazaki 444-8787, Japan,Department of Physiological Sciences, The Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8787, Japan,Brain Science Institute, Tamagawa University, Machida, Tokyo 194-8610, Japan
| | - Yoshifumi Ueta
- Department of Physiology, Division of Neurophysiology, School of Medicine, Tokyo Women's Medical University, Tokyo 162-8666, Japan
| | - Takeshi Otsuka
- National Institute for Physiological Sciences (NIPS), Okazaki 444-8787, Japan,Department of Physiological Sciences, The Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8787, Japan
| | - Mieko Morishima
- National Institute for Physiological Sciences (NIPS), Okazaki 444-8787, Japan,Institute of Clinical Medicine and Research, Jikei University School of Medicine, Chiba 277-8567, Japan
| | - Mohammed Youssef
- National Institute for Physiological Sciences (NIPS), Okazaki 444-8787, Japan,Department of Animal Physiology, Faculty of Veterinary Medicine, South Valley University, Qena 83523, Egypt
| | - Yasuharu Hirai
- Laboratory of Histology and Cytology, Faculty of Medicine, Hokkaido University, Sapporo 060-8638, Japan
| | - Kenta Kobayashi
- Section of Viral Vector Development, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
| | - Ryosuke Kaneko
- Bioresource Center, Gunma University Graduate School of Medicine, Gunma 371-8511, Japan,KOKORO-Biology Group, Laboratories for Integrated Biology, Graduate School of Frontier Biosciences, Osaka University, Osaka 565-0871, Japan
| | - Kenji Morita
- Physical and Health Education, Graduate School of Education, The University of Tokyo, Tokyo 113-0033, Japan,International Research Center for Neurointelligence (WPI-IRCN), The University of Tokyo, Tokyo 113-0033, Japan
| | - Yasuo Kawaguchi
- Corresponding author: Brain Science Institute, Tamagawa University Machida, Tokyo 1948610, Japan.
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12
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Larkum ME, Wu J, Duverdin SA, Gidon A. The guide to dendritic spikes of the mammalian cortex in vitro and in vivo. Neuroscience 2022; 489:15-33. [PMID: 35182699 DOI: 10.1016/j.neuroscience.2022.02.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 02/01/2022] [Accepted: 02/10/2022] [Indexed: 12/23/2022]
Abstract
Half a century since their discovery by Llinás and colleagues, dendritic spikes have been observed in various neurons in different brain regions, from the neocortex and cerebellum to the basal ganglia. Dendrites exhibit a terrifically diverse but stereotypical repertoire of spikes, sometimes specific to subregions of the dendrite. Despite their prevalence, we only have a glimpse into their role in the behaving animal. This article aims to survey the full range of dendritic spikes found in excitatory and inhibitory neurons, compare them in vivo versus in vitro, and discuss new studies describing dendritic spikes in the human cortex. We focus on dendritic spikes in neocortical and hippocampal neurons and present a roadmap to identify and understand the broader role of dendritic spikes in single-cell computation.
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Affiliation(s)
- Matthew E Larkum
- Institute for Biology, Humboldt-Universität zu Berlin, Berlin, Germany; NeuroCure Cluster, Charité - Universitätsmedizin Berlin, Germany
| | - Jiameng Wu
- Institute for Biology, Humboldt-Universität zu Berlin, Berlin, Germany; Einstein Center for Neurosciences Berlin, Berlin, Germany
| | - Sarah A Duverdin
- Institute for Biology, Humboldt-Universität zu Berlin, Berlin, Germany; Department of Integrative Neurophysiology, Amsterdam Neuroscience, Center for Neurogenomics and Cognitive Research (CNCR), Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Albert Gidon
- Institute for Biology, Humboldt-Universität zu Berlin, Berlin, Germany
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13
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Sinha M, Narayanan R. Active Dendrites and Local Field Potentials: Biophysical Mechanisms and Computational Explorations. Neuroscience 2021; 489:111-142. [PMID: 34506834 PMCID: PMC7612676 DOI: 10.1016/j.neuroscience.2021.08.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 08/30/2021] [Accepted: 08/31/2021] [Indexed: 10/27/2022]
Abstract
Neurons and glial cells are endowed with membranes that express a rich repertoire of ion channels, transporters, and receptors. The constant flux of ions across the neuronal and glial membranes results in voltage fluctuations that can be recorded from the extracellular matrix. The high frequency components of this voltage signal contain information about the spiking activity, reflecting the output from the neurons surrounding the recording location. The low frequency components of the signal, referred to as the local field potential (LFP), have been traditionally thought to provide information about the synaptic inputs that impinge on the large dendritic trees of various neurons. In this review, we discuss recent computational and experimental studies pointing to a critical role of several active dendritic mechanisms that can influence the genesis and the location-dependent spectro-temporal dynamics of LFPs, spanning different brain regions. We strongly emphasize the need to account for the several fast and slow dendritic events and associated active mechanisms - including gradients in their expression profiles, inter- and intra-cellular spatio-temporal interactions spanning neurons and glia, heterogeneities and degeneracy across scales, neuromodulatory influences, and activitydependent plasticity - towards gaining important insights about the origins of LFP under different behavioral states in health and disease. We provide simple but essential guidelines on how to model LFPs taking into account these dendritic mechanisms, with detailed methodology on how to account for various heterogeneities and electrophysiological properties of neurons and synapses while studying LFPs.
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Affiliation(s)
- Manisha Sinha
- Cellular Neurophysiology Laboratory, Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | - Rishikesh Narayanan
- Cellular Neurophysiology Laboratory, Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka 560012, India.
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14
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Harkin EF, Shen PR, Goel A, Richards BA, Naud R. Parallel and Recurrent Cascade Models as a Unifying Force for Understanding Sub-cellular Computation. Neuroscience 2021; 489:200-215. [PMID: 34358629 DOI: 10.1016/j.neuroscience.2021.07.026] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 07/06/2021] [Accepted: 07/25/2021] [Indexed: 11/15/2022]
Abstract
Neurons are very complicated computational devices, incorporating numerous non-linear processes, particularly in their dendrites. Biophysical models capture these processes directly by explicitly modelling physiological variables, such as ion channels, current flow, membrane capacitance, etc. However, another option for capturing the complexities of real neural computation is to use cascade models, which treat individual neurons as a cascade of linear and non-linear operations, akin to a multi-layer artificial neural network. Recent research has shown that cascade models can capture single-cell computation well, but there are still a number of sub-cellular, regenerative dendritic phenomena that they cannot capture, such as the interaction between sodium, calcium, and NMDA spikes in different compartments. Here, we propose that it is possible to capture these additional phenomena using parallel, recurrent cascade models, wherein an individual neuron is modelled as a cascade of parallel linear and non-linear operations that can be connected recurrently, akin to a multi-layer, recurrent, artificial neural network. Given their tractable mathematical structure, we show that neuron models expressed in terms of parallel recurrent cascades can themselves be integrated into multi-layered artificial neural networks and trained to perform complex tasks. We go on to discuss potential implications and uses of these models for artificial intelligence. Overall, we argue that parallel, recurrent cascade models provide an important, unifying tool for capturing single-cell computation and exploring the algorithmic implications of physiological phenomena.
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Affiliation(s)
- Emerson F Harkin
- uOttawa Brain and Mind Institute, Centre for Neural Dynamics, Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Peter R Shen
- Department of Systems Design Engineering, University of Waterloo, Waterloo, ON, Canada
| | - Anish Goel
- Lisgar Collegiate Institute, Ottawa, ON, Canada
| | - Blake A Richards
- Mila, Montréal, QC, Canada; Montreal Neurological Institute, Montréal, QC, Canada; Department of Neurology and Neurosurgery, McGill University, Montréal, QC, Canada; School of Computer Science, McGill University, Montréal, QC, Canada.
| | - Richard Naud
- uOttawa Brain and Mind Institute, Centre for Neural Dynamics, Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada; Department of Physics, University of Ottawa, Ottawa, ON, Canada.
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15
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Circuit mechanisms for cortical plasticity and learning. Semin Cell Dev Biol 2021; 125:68-75. [PMID: 34332885 DOI: 10.1016/j.semcdb.2021.07.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 07/15/2021] [Accepted: 07/16/2021] [Indexed: 11/22/2022]
Abstract
The cerebral cortex integrates sensory information with emotional states and internal representations to produce coherent percepts, form associations, and execute voluntary actions. For the cortex to optimize perception, its neuronal network needs to dynamically retrieve and encode new information. Over the last few decades, research has started to provide insight into how the cortex serves these functions. Building on classical Hebbian plasticity models, the latest hypotheses hold that throughout experience and learning, streams of feedforward, feedback, and modulatory information operate in selective and coordinated manners to alter the strength of synapses and ultimately change the response properties of cortical neurons. Here, we describe cortical plasticity mechanisms that involve the concerted action of feedforward and long-range feedback input onto pyramidal neurons as well as the implication of local disinhibitory circuit motifs in this process.
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16
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Combe CL, Gasparini S. I h from synapses to networks: HCN channel functions and modulation in neurons. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2021; 166:119-132. [PMID: 34181891 DOI: 10.1016/j.pbiomolbio.2021.06.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 05/25/2021] [Accepted: 06/03/2021] [Indexed: 01/16/2023]
Abstract
Hyperpolarization-activated cyclic nucleotide gated (HCN) channels and the current they carry, Ih, are widely and diversely distributed in the central nervous system (CNS). The distribution of the four subunits of HCN channels is variable within the CNS, within brain regions, and often within subcellular compartments. The precise function of Ih can depend heavily on what other channels are co-expressed. In this review, we give an overview of HCN channel structure, distribution, and modulation by cyclic adenosine monophosphate (cAMP). We then discuss HCN channel and Ih functions, where we have parsed the roles into two main effects: a steady effect on maintaining the resting membrane potential at relatively depolarized values, and slow channel dynamics. Within this framework, we discuss Ih involvement in resonance, synaptic integration, transmitter release, plasticity, and point out a special case, where the effects of Ih on the membrane potential and its slow channel dynamics have dual roles in thalamic neurons.
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Affiliation(s)
- Crescent L Combe
- Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, LA, 70112, USA
| | - Sonia Gasparini
- Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, LA, 70112, USA.
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17
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Neurophysiological basis of the N400 deflection, from Mismatch Negativity to Semantic Prediction Potentials and late positive components. Int J Psychophysiol 2021; 166:134-150. [PMID: 34097935 DOI: 10.1016/j.ijpsycho.2021.06.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 05/20/2021] [Accepted: 06/02/2021] [Indexed: 11/21/2022]
Abstract
The first theoretical model on the neurophysiological basis of the N400: the deflection reflects layer I dendritic plateaus on a preparatory state of synaptic integration that precedes layer V somatic burst firing for conscious identification of the higher-order features of the stimulus (a late positive shift). Plateaus ensue from apical disinhibition by vasoactive intestinal polypeptide-positive interneurons (VIPs) through suppression of Martinotti cells, opening the gates for glutamatergic feedback to trigger dendritic regenerative potentials. Cholinergic transients contribute to these dynamics directly, holding a central role in the N400 deflection. The stereotypical timing of the (frontal) glutamatergic feedback and the accompanying cholinergic transients account for the enigmatic "invariability" of the peak latency in the face of a gamut of different stimuli and paradigms. The theoretical postulations presented here may bring about unprecedented level of detail for the N400 deflection to be used in the study of schizophrenia, Alzheimer's disease and other higher-order pathologies. The substrates of a late positive component, the Mismatch Negativity and the Semantic Prediction Potentials are also surveyed.
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18
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Doron G, Shin JN, Takahashi N, Drüke M, Bocklisch C, Skenderi S, de Mont L, Toumazou M, Ledderose J, Brecht M, Naud R, Larkum ME. Perirhinal input to neocortical layer 1 controls learning. Science 2021; 370:370/6523/eaaz3136. [PMID: 33335033 DOI: 10.1126/science.aaz3136] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 08/27/2020] [Accepted: 10/23/2020] [Indexed: 12/28/2022]
Abstract
Hippocampal output influences memory formation in the neocortex, but this process is poorly understood because the precise anatomical location and the underlying cellular mechanisms remain elusive. Here, we show that perirhinal input, predominantly to sensory cortical layer 1 (L1), controls hippocampal-dependent associative learning in rodents. This process was marked by the emergence of distinct firing responses in defined subpopulations of layer 5 (L5) pyramidal neurons whose tuft dendrites receive perirhinal inputs in L1. Learning correlated with burst firing and the enhancement of dendritic excitability, and it was suppressed by disruption of dendritic activity. Furthermore, bursts, but not regular spike trains, were sufficient to retrieve learned behavior. We conclude that hippocampal information arriving at L5 tuft dendrites in neocortical L1 mediates memory formation in the neocortex.
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Affiliation(s)
- Guy Doron
- Institute for Biology, Humboldt-Universität zu Berlin, D-10117 Berlin, Germany.
| | - Jiyun N Shin
- Institute for Biology, Humboldt-Universität zu Berlin, D-10117 Berlin, Germany
| | - Naoya Takahashi
- Institute for Biology, Humboldt-Universität zu Berlin, D-10117 Berlin, Germany
| | - Moritz Drüke
- Institute for Biology, Humboldt-Universität zu Berlin, D-10117 Berlin, Germany
| | - Christina Bocklisch
- Institute for Biology, Humboldt-Universität zu Berlin, D-10117 Berlin, Germany
| | - Salina Skenderi
- Institute for Biology, Humboldt-Universität zu Berlin, D-10117 Berlin, Germany
| | - Lisa de Mont
- Institute for Biology, Humboldt-Universität zu Berlin, D-10117 Berlin, Germany
| | - Maria Toumazou
- Institute for Biology, Humboldt-Universität zu Berlin, D-10117 Berlin, Germany
| | - Julia Ledderose
- Institute for Biology, Humboldt-Universität zu Berlin, D-10117 Berlin, Germany
| | - Michael Brecht
- Bernstein Center for Computational Neuroscience, Humboldt-Universität zu Berlin, D-10115 Berlin, Germany.,NeuroCure Cluster, Charité - Universitätsmedizin Berlin, D-10117 Berlin, Germany
| | - Richard Naud
- University of Ottawa Brain and Mind Institute, Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada.,Department of Physics, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Matthew E Larkum
- Institute for Biology, Humboldt-Universität zu Berlin, D-10117 Berlin, Germany. .,NeuroCure Cluster, Charité - Universitätsmedizin Berlin, D-10117 Berlin, Germany
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19
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Anastasiades PG, Collins DP, Carter AG. Mediodorsal and Ventromedial Thalamus Engage Distinct L1 Circuits in the Prefrontal Cortex. Neuron 2021; 109:314-330.e4. [PMID: 33188733 PMCID: PMC7855187 DOI: 10.1016/j.neuron.2020.10.031] [Citation(s) in RCA: 70] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 09/03/2020] [Accepted: 10/26/2020] [Indexed: 11/25/2022]
Abstract
Interactions between the thalamus and prefrontal cortex (PFC) play a critical role in cognitive function and arousal. Here, we use anatomical tracing, electrophysiology, optogenetics, and 2-photon Ca2+ imaging to determine how ventromedial (VM) and mediodorsal (MD) thalamus target specific cell types and subcellular compartments in layer 1 (L1) of mouse PFC. We find thalamic inputs make distinct connections in L1, where VM engages neuron-derived neurotrophic factor (NDNF+) cells in L1a and MD drives vasoactive intestinal peptide (VIP+) cells in L1b. These separate populations of L1 interneurons participate in different inhibitory networks in superficial layers by targeting either parvalbumin (PV+) or somatostatin (SOM+) interneurons. NDNF+ cells also inhibit the apical dendrites of L5 pyramidal tract (PT) cells to suppress action potential (AP)-evoked Ca2+ signals. Lastly, NDNF+ cells mediate a unique form of thalamus-evoked inhibition at PT cells, selectively blocking VM-evoked dendritic Ca2+ spikes. Together, our findings reveal how two thalamic nuclei differentially communicate with the PFC through distinct L1 micro-circuits.
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Affiliation(s)
- Paul G Anastasiades
- Center for Neural Science, New York University, 4 Washington Place, New York, NY 10003, USA
| | - David P Collins
- Center for Neural Science, New York University, 4 Washington Place, New York, NY 10003, USA
| | - Adam G Carter
- Center for Neural Science, New York University, 4 Washington Place, New York, NY 10003, USA.
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20
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Rich S, Moradi Chameh H, Sekulic V, Valiante TA, Skinner FK. Modeling Reveals Human-Rodent Differences in H-Current Kinetics Influencing Resonance in Cortical Layer 5 Neurons. Cereb Cortex 2021; 31:845-872. [PMID: 33068000 PMCID: PMC7906797 DOI: 10.1093/cercor/bhaa261] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 08/18/2020] [Accepted: 08/18/2020] [Indexed: 01/01/2023] Open
Abstract
While our understanding of human neurons is often inferred from rodent data, inter-species differences between neurons can be captured by building cellular models specifically from human data. This includes understanding differences at the level of ion channels and their implications for human brain function. Thus, we here present a full spiking, biophysically detailed multi-compartment model of a human layer 5 (L5) cortical pyramidal cell. Model development was primarily based on morphological and electrophysiological data from the same human L5 neuron, avoiding confounds of experimental variability. Focus was placed on describing the behavior of the hyperpolarization-activated cation (h-) channel, given increasing interest in this channel due to its role in pacemaking and differentiating cell types. We ensured that the model exhibited post-inhibitory rebound spiking considering its relationship with the h-current, along with other general spiking characteristics. The model was validated against data not used in its development, which highlighted distinctly slower kinetics of the human h-current relative to the rodent setting. We linked the lack of subthreshold resonance observed in human L5 neurons to these human-specific h-current kinetics. This work shows that it is possible and necessary to build human-specific biophysical neuron models in order to understand human brain dynamics.
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Affiliation(s)
- Scott Rich
- Division of Clinical and Computational Neuroscience, Krembil Research Institute, University Health Network, Toronto, ON M5T 0S8, Canada
| | - Homeira Moradi Chameh
- Division of Clinical and Computational Neuroscience, Krembil Research Institute, University Health Network, Toronto, ON M5T 0S8, Canada
| | - Vladislav Sekulic
- Division of Clinical and Computational Neuroscience, Krembil Research Institute, University Health Network, Toronto, ON M5T 0S8, Canada
| | - Taufik A Valiante
- Division of Clinical and Computational Neuroscience, Krembil Research Institute, University Health Network, Toronto, ON M5T 0S8, Canada
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON M5S 1A1, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON M5S 1A1, Canada
- Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, ON M5S 1A1, Canada
- Electrical and Computer Engineering, University of Toronto, Toronto, ON M5S 1A1, Canada
| | - Frances K Skinner
- Division of Clinical and Computational Neuroscience, Krembil Research Institute, University Health Network, Toronto, ON M5T 0S8, Canada
- Departments of Medicine (Neurology) and Physiology, University of Toronto, Toronto, ON M5S 1A1, Canada
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21
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Borda Bossana S, Verbist C, Giugliano M. Homogeneous and Narrow Bandwidth of Spike Initiation in Rat L1 Cortical Interneurons. Front Cell Neurosci 2020; 14:118. [PMID: 32625063 PMCID: PMC7313227 DOI: 10.3389/fncel.2020.00118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 04/14/2020] [Indexed: 12/02/2022] Open
Abstract
The cortical layer 1 (L1) contains a population of GABAergic interneurons, considered a key component of information integration, processing, and relaying in neocortical networks. In fact, L1 interneurons combine top–down information with feed-forward sensory inputs in layer 2/3 and 5 pyramidal cells (PCs), while filtering their incoming signals. Despite the importance of L1 for network emerging phenomena, little is known on the dynamics of the spike initiation and the encoding properties of its neurons. Using acute brain tissue slices from the rat neocortex, combined with the analysis of an existing database of model neurons, we investigated the dynamical transfer properties of these cells by sampling an entire population of known “electrical classes” and comparing experiments and model predictions. We found the bandwidth of spike initiation to be significantly narrower than in L2/3 and 5 PCs, with values below 100 cycle/s, but without significant heterogeneity in the cell response properties across distinct electrical types. The upper limit of the neuronal bandwidth was significantly correlated to the mean firing rate, as anticipated from theoretical studies but not reported for PCs. At high spectral frequencies, the magnitude of the neuronal response attenuated as a power-law, with an exponent significantly smaller than what was reported for pyramidal neurons and reminiscent of the dynamics of a “leaky” integrate-and-fire model of spike initiation. Finally, most of our in vitro results matched quantitatively the numerical simulations of the models as a further contribution to independently validate the models against novel experimental data.
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Affiliation(s)
- Stefano Borda Bossana
- Molecular, Cellular, and Network Excitability Laboratory, Department of Biomedical Sciences, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, Institute Born-Bunge, Universiteit Antwerpen, Wilrijk, Belgium
| | - Christophe Verbist
- Molecular, Cellular, and Network Excitability Laboratory, Department of Biomedical Sciences, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, Institute Born-Bunge, Universiteit Antwerpen, Wilrijk, Belgium
| | - Michele Giugliano
- Molecular, Cellular, and Network Excitability Laboratory, Department of Biomedical Sciences, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, Institute Born-Bunge, Universiteit Antwerpen, Wilrijk, Belgium.,Neuroscience Area, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste, Italy
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22
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Wild AR, Sinnen BL, Dittmer PJ, Kennedy MJ, Sather WA, Dell'Acqua ML. Synapse-to-Nucleus Communication through NFAT Is Mediated by L-type Ca 2+ Channel Ca 2+ Spike Propagation to the Soma. Cell Rep 2020; 26:3537-3550.e4. [PMID: 30917310 PMCID: PMC6521872 DOI: 10.1016/j.celrep.2019.03.005] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 12/11/2018] [Accepted: 02/28/2019] [Indexed: 12/21/2022] Open
Abstract
Long-term information storage in the brain requires continual modification of the neuronal transcriptome. Synaptic inputs located hundreds of micrometers from the nucleus can regulate gene transcription, requiring high-fidelity, long-range signaling from synapses in dendrites to the nucleus in the cell soma. Here, we describe a synapse-to-nucleus signaling mechanism for the activity-dependent transcription factor NFAT. NMDA receptors activated on distal dendrites were found to initiate L-type Ca2+ channel (LTCC) spikes that quickly propagated the length of the dendrite to the soma. Surprisingly, LTCC propagation did not require voltage-gated Na+ channels or back-propagating action potentials. NFAT nuclear recruitment and transcriptional activation only occurred when LTCC spikes invaded the somatic compartment, and the degree of NFAT activation correlated with the number of somatic LTCC Ca2+ spikes. Together, these data support a model for synapse to nucleus communication where NFAT integrates somatic LTCC Ca2+ spikes to alter transcription during periods of heightened neuronal activity. Signaling from synapse to nucleus can alter transcription and consolidate long-term changes in neuronal function. Wild et al. uncover a mechanism for rapid long-distance signaling from distal dendrites to the nucleus that utilizes L-type voltage-gated Ca2+ channel Ca2+ spikes to activate the transcription factor NFAT.
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Affiliation(s)
- Angela R Wild
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Brooke L Sinnen
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Philip J Dittmer
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Matthew J Kennedy
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - William A Sather
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Mark L Dell'Acqua
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA.
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23
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Karimi A, Odenthal J, Drawitsch F, Boergens KM, Helmstaedter M. Cell-type specific innervation of cortical pyramidal cells at their apical dendrites. eLife 2020; 9:e46876. [PMID: 32108571 PMCID: PMC7297530 DOI: 10.7554/elife.46876] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 02/26/2020] [Indexed: 01/21/2023] Open
Abstract
We investigated the synaptic innervation of apical dendrites of cortical pyramidal cells in a region between layers (L) 1 and 2 using 3-D electron microscopy applied to four cortical regions in mouse. We found the relative inhibitory input at the apical dendrite's main bifurcation to be more than 2-fold larger for L2 than L3 and L5 thick-tufted pyramidal cells. Towards the distal tuft dendrites in upper L1, the relative inhibitory input was at least about 2-fold larger for L5 pyramidal cells than for all others. Only L3 pyramidal cells showed homogeneous inhibitory input fraction. The inhibitory-to-excitatory synaptic ratio is thus specific for the types of pyramidal cells. Inhibitory axons preferentially innervated either L2 or L3/5 apical dendrites, but not both. These findings describe connectomic principles for the control of pyramidal cells at their apical dendrites and support differential computational properties of L2, L3 and subtypes of L5 pyramidal cells in cortex.
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Affiliation(s)
- Ali Karimi
- Department of Connectomics, Max Planck Institute for Brain ResearchFrankfurtGermany
| | - Jan Odenthal
- Department of Connectomics, Max Planck Institute for Brain ResearchFrankfurtGermany
| | - Florian Drawitsch
- Department of Connectomics, Max Planck Institute for Brain ResearchFrankfurtGermany
| | - Kevin M Boergens
- Department of Connectomics, Max Planck Institute for Brain ResearchFrankfurtGermany
| | - Moritz Helmstaedter
- Department of Connectomics, Max Planck Institute for Brain ResearchFrankfurtGermany
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24
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Lee K, Park TIH, Heppner P, Schweder P, Mee EW, Dragunow M, Montgomery JM. Human in vitro systems for examining synaptic function and plasticity in the brain. J Neurophysiol 2020; 123:945-965. [PMID: 31995449 DOI: 10.1152/jn.00411.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The human brain shows remarkable complexity in its cellular makeup and function, which are distinct from nonhuman species, signifying the need for human-based research platforms for the study of human cellular neurophysiology and neuropathology. However, the use of adult human brain tissue for research purposes is hampered by technical, methodological, and accessibility challenges. One of the major problems is the limited number of in vitro systems that, in contrast, are readily available from rodent brain tissue. With recent advances in the optimization of protocols for adult human brain preparations, there is a significant opportunity for neuroscientists to validate their findings in human-based systems. This review addresses the methodological aspects, advantages, and disadvantages of human neuron in vitro systems, focusing on the unique properties of human neurons and synapses in neocortical microcircuits. These in vitro models provide the incomparable advantage of being a direct representation of the neurons that have formed part of the human brain until the point of recording, which cannot be replicated by animal models nor human stem-cell systems. Important distinct cellular mechanisms are observed in human neurons that may underlie the higher order cognitive abilities of the human brain. The use of human brain tissue in neuroscience research also raises important ethical, diversity, and control tissue limitations that need to be considered. Undoubtedly however, these human neuron systems provide critical information to increase the potential of translation of treatments from the laboratory to the clinic in a way animal models are failing to provide.
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Affiliation(s)
- Kevin Lee
- Department of Physiology, University of Auckland, Auckland, New Zealand.,Centre for Brain Research, University of Auckland, New Zealand
| | - Thomas I-H Park
- Centre for Brain Research, University of Auckland, New Zealand.,Department of Pharmacology, University of Auckland, Auckland, New Zealand
| | - Peter Heppner
- Centre for Brain Research, University of Auckland, New Zealand.,Department of Neurosurgery, Auckland City Hospital, Auckland, New Zealand
| | - Patrick Schweder
- Centre for Brain Research, University of Auckland, New Zealand.,Department of Neurosurgery, Auckland City Hospital, Auckland, New Zealand
| | - Edward W Mee
- Centre for Brain Research, University of Auckland, New Zealand.,Department of Neurosurgery, Auckland City Hospital, Auckland, New Zealand
| | - Michael Dragunow
- Centre for Brain Research, University of Auckland, New Zealand.,Department of Pharmacology, University of Auckland, Auckland, New Zealand
| | - Johanna M Montgomery
- Department of Physiology, University of Auckland, Auckland, New Zealand.,Centre for Brain Research, University of Auckland, New Zealand
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25
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Morrissette AE, Chen PH, Bhamani C, Borden PY, Waiblinger C, Stanley GB, Jaeger D. Unilateral Optogenetic Inhibition and Excitation of Basal Ganglia Output Affect Directional Lick Choices and Movement Initiation in Mice. Neuroscience 2019; 423:55-65. [PMID: 31705892 DOI: 10.1016/j.neuroscience.2019.10.031] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 10/17/2019] [Accepted: 10/17/2019] [Indexed: 11/30/2022]
Abstract
Models of basal ganglia (BG) function predict that tonic inhibitory output to motor thalamus (MT) suppresses unwanted movements, and that a decrease in such activity leads to action selection. Further, for unilateral activity changes in the BG, a lateralized effect on contralateral movements can be expected due to ipsilateral thalamocortical connectivity. However, a direct test of these outcomes of thalamic inhibition has not been performed. To conduct such a direct test, we utilized rapid optogenetic activation and inactivation of the GABAergic output of the substantia nigra pars reticulata (SNr) to MT in male and female mice that were trained in a sensory cued left/right licking task. Directional licking tasks have previously been shown to depend on a thalamocortical feedback loop between ventromedial MT and antero-lateral premotor cortex. In confirmation of model predictions, we found that unilateral optogenetic inhibition of GABAergic output from the SNr, during ipsilaterally cued trials, biased decision making towards a contralateral lick without affecting motor performance. In contrast, optogenetic excitation of SNr terminals in MT resulted in an opposite bias towards the ipsilateral direction confirming a bidirectional effect of tonic nigral output on directional decision making. However, direct optogenetic excitation of neurons in the SNr resulted in bilateral movement suppression, which is in agreement with previous results that show such suppression for nigral terminals in the superior colliculus (SC), which receives a bilateral projection from SNr.
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Affiliation(s)
| | - Po-Han Chen
- Department of Biology, Emory University, Atlanta, GA, United States
| | | | - Peter Y Borden
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, United States
| | - Christian Waiblinger
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, United States
| | - Garrett B Stanley
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, United States
| | - Dieter Jaeger
- Department of Biology, Emory University, Atlanta, GA, United States.
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26
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Beaulieu-Laroche L, Toloza EHS, van der Goes MS, Lafourcade M, Barnagian D, Williams ZM, Eskandar EN, Frosch MP, Cash SS, Harnett MT. Enhanced Dendritic Compartmentalization in Human Cortical Neurons. Cell 2019; 175:643-651.e14. [PMID: 30340039 DOI: 10.1016/j.cell.2018.08.045] [Citation(s) in RCA: 146] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 06/11/2018] [Accepted: 08/17/2018] [Indexed: 12/20/2022]
Abstract
The biophysical features of neurons shape information processing in the brain. Cortical neurons are larger in humans than in other species, but it is unclear how their size affects synaptic integration. Here, we perform direct electrical recordings from human dendrites and report enhanced electrical compartmentalization in layer 5 pyramidal neurons. Compared to rat dendrites, distal human dendrites provide limited excitation to the soma, even in the presence of dendritic spikes. Human somas also exhibit less bursting due to reduced recruitment of dendritic electrogenesis. Finally, we find that decreased ion channel densities result in higher input resistance and underlie the lower coupling of human dendrites. We conclude that the increased length of human neurons alters their input-output properties, which will impact cortical computation. VIDEO ABSTRACT.
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Affiliation(s)
- Lou Beaulieu-Laroche
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Enrique H S Toloza
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Marie-Sophie van der Goes
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Mathieu Lafourcade
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Derrick Barnagian
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Ziv M Williams
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA, USA
| | - Emad N Eskandar
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA, USA
| | - Matthew P Frosch
- C.S. Kubik Laboratory for Neuropathology, Massachusetts General Hospital, Boston, MA, USA
| | - Sydney S Cash
- Department of Neurology, Harvard Medical School and Massachusetts General Hospital, Boston, MA, USA.
| | - Mark T Harnett
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA.
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27
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Emmenegger V, Qi G, Wang H, Feldmeyer D. Morphological and Functional Characterization of Non-fast-Spiking GABAergic Interneurons in Layer 4 Microcircuitry of Rat Barrel Cortex. Cereb Cortex 2019; 28:1439-1457. [PMID: 29329401 PMCID: PMC6093438 DOI: 10.1093/cercor/bhx352] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Indexed: 12/23/2022] Open
Abstract
GABAergic interneurons are notorious for their heterogeneity, despite constituting a small fraction of the neuronal population in the neocortex. Classification of interneurons is crucial for understanding their widespread cortical functions as they provide a complex and dynamic network, balancing excitation and inhibition. Here, we investigated different types of non-fast-spiking (nFS) interneurons in Layer 4 (L4) of rat barrel cortex using whole-cell patch-clamp recordings with biocytin-filling. Based on a quantitative analysis on a combination of morphological and electrophysiological parameters, we identified 5 distinct types of L4 nFS interneurons: 1) trans-columnar projecting interneurons, 2) locally projecting non-Martinotti-like interneurons, 3) supra-granular projecting Martinotti-like interneurons, 4) intra-columnar projecting VIP-like interneurons, and 5) locally projecting neurogliaform-like interneurons. Trans-columnar projecting interneurons are one of the most striking interneuron types, which have not been described so far in Layer 4. They feature extensive axonal collateralization not only in their home barrel but also in adjacent barrels. Furthermore, we identified that most of the L4 nFS interneurons express somatostatin, while few are positive for the transcription factor Prox1. The morphological and electrophysiological characterization of different L4 nFS interneuron types presented here provides insights into their synaptic connectivity and functional role in cortical information processing.
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Affiliation(s)
- Vishalini Emmenegger
- Institute of Neuroscience and Medicine, INM-2 and INM-10, Research Centre Jülich, Jülich, Germany
- Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Aachen, Germany
- Department of Biosystems Sciences and Engineering, Bio Engineering Lab, ETH Zürich, Basel, Switzerland
| | - Guanxiao Qi
- Institute of Neuroscience and Medicine, INM-2 and INM-10, Research Centre Jülich, Jülich, Germany
| | - Haijun Wang
- Institute of Neuroscience and Medicine, INM-2 and INM-10, Research Centre Jülich, Jülich, Germany
- Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Aachen, Germany
- School of Electronic Engineering, Nanjing Xiaozhuang University, Nanjing, P.R. China
| | - Dirk Feldmeyer
- Institute of Neuroscience and Medicine, INM-2 and INM-10, Research Centre Jülich, Jülich, Germany
- Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Aachen, Germany
- Jülich Aachen Research Alliance, Translational Brain Medicine (JARA Brain), Aachen, Germany
- Address correspondence to Dirk Feldmeyer, Institute of Neuroscience and Medicine (INM-2), Research Centre Jülich, D-52425 Jülich, Germany.
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28
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Hertäg L, Sprekeler H. Amplifying the redistribution of somato-dendritic inhibition by the interplay of three interneuron types. PLoS Comput Biol 2019; 15:e1006999. [PMID: 31095556 PMCID: PMC6541306 DOI: 10.1371/journal.pcbi.1006999] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 05/29/2019] [Accepted: 04/01/2019] [Indexed: 01/24/2023] Open
Abstract
GABAergic interneurons play an important role in shaping the activity of excitatory pyramidal cells (PCs). How the various inhibitory cell types contribute to neuronal information processing, however, is not resolved. Here, we propose a functional role for a widespread network motif consisting of parvalbumin- (PV), somatostatin- (SOM) and vasoactive intestinal peptide (VIP)-expressing interneurons. Following the idea that PV and SOM interneurons control the distribution of somatic and dendritic inhibition onto PCs, we suggest that mutual inhibition between VIP and SOM cells translates weak inputs to VIP interneurons into large changes of somato-dendritic inhibition of PCs. Using a computational model, we show that the neuronal and synaptic properties of the circuit support this hypothesis. Moreover, we demonstrate that the SOM-VIP motif allows transient inputs to persistently switch the circuit between two processing modes, in which top-down inputs onto apical dendrites of PCs are either integrated or cancelled. Neurons in the brain can be classified as excitatory or inhibitory based on whether they activate or deactivate the cells to whom they send signals. Compared to their excitatory counterpart, inhibitory neurons present themselves as a wild diversity of cell classes. It is broadly believed that these classes serve different purposes, but as of now, those are poorly understood. In this article, we suggest how an intricate interplay of three inhibitory cell classes can control whether internal signals—such as predictions, memory signals or motor commands—are taken into account when sensory signals are interpreted. Using a mathematical model and computer simulations, we show that such internal signals can be shut down by regulating which inhibitory cell types are active, and that the interaction of different cell classes allows weak control signals to do so.
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Affiliation(s)
- Loreen Hertäg
- Modelling of Cognitive Processes, Berlin Institute of Technology, Berlin, Germany.,Bernstein Center for Computational Neuroscience, Berlin, Germany
| | - Henning Sprekeler
- Modelling of Cognitive Processes, Berlin Institute of Technology, Berlin, Germany.,Bernstein Center for Computational Neuroscience, Berlin, Germany
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29
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Sieveritz B, García-Muñoz M, Arbuthnott GW. Thalamic afferents to prefrontal cortices from ventral motor nuclei in decision-making. Eur J Neurosci 2018; 49:646-657. [PMID: 30346073 PMCID: PMC6587977 DOI: 10.1111/ejn.14215] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 07/19/2018] [Accepted: 07/24/2018] [Indexed: 01/23/2023]
Abstract
The focus of this literature review is on the three interacting brain areas that participate in decision‐making: basal ganglia, ventral motor thalamic nuclei, and medial prefrontal cortex, with an emphasis on the participation of the ventromedial and ventral anterior motor thalamic nuclei in prefrontal cortical function. Apart from a defining input from the mediodorsal thalamus, the prefrontal cortex receives inputs from ventral motor thalamic nuclei that combine to mediate typical prefrontal functions such as associative learning, action selection, and decision‐making. Motor, somatosensory and medial prefrontal cortices are mainly contacted in layer 1 by the ventral motor thalamic nuclei and in layer 3 by thalamocortical input from mediodorsal thalamus. We will review anatomical, electrophysiological, and behavioral evidence for the proposed participation of ventral motor thalamic nuclei and medial prefrontal cortex in rat and mouse motor decision‐making.
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Affiliation(s)
- Bianca Sieveritz
- Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| | - Marianela García-Muñoz
- Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
| | - Gordon W Arbuthnott
- Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa, Japan
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30
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Richards BA, Lillicrap TP. Dendritic solutions to the credit assignment problem. Curr Opin Neurobiol 2018; 54:28-36. [PMID: 30205266 DOI: 10.1016/j.conb.2018.08.003] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 07/19/2018] [Accepted: 08/07/2018] [Indexed: 11/27/2022]
Abstract
Guaranteeing that synaptic plasticity leads to effective learning requires a means for assigning credit to each neuron for its contribution to behavior. The 'credit assignment problem' refers to the fact that credit assignment is non-trivial in hierarchical networks with multiple stages of processing. One difficulty is that if credit signals are integrated with other inputs, then it is hard for synaptic plasticity rules to distinguish credit-related activity from non-credit-related activity. A potential solution is to use the spatial layout and non-linear properties of dendrites to distinguish credit signals from other inputs. In cortical pyramidal neurons, evidence hints that top-down feedback signals are integrated in the distal apical dendrites and have a distinct impact on spike-firing and synaptic plasticity. This suggests that the distal apical dendrites of pyramidal neurons help the brain to solve the credit assignment problem.
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Affiliation(s)
- Blake A Richards
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, Canada; Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada; Learning in Machines and Brains Program, Canadian Institute for Advanced Research, Toronto, ON, Canada
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31
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Phillips WA, Bachmann T, Storm JF. Apical Function in Neocortical Pyramidal Cells: A Common Pathway by Which General Anesthetics Can Affect Mental State. Front Neural Circuits 2018; 12:50. [PMID: 30013465 PMCID: PMC6036169 DOI: 10.3389/fncir.2018.00050] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 06/05/2018] [Indexed: 11/27/2022] Open
Abstract
It has been argued that general anesthetics suppress the level of consciousness, or the contents of consciousness, or both. The distinction between level and content is important because, in addition to clarifying the mechanisms of anesthesia, it may help clarify the neural bases of consciousness. We assess these arguments in the light of evidence that both the level and the content of consciousness depend upon the contribution of apical input to the information processing capabilities of neocortical pyramidal cells which selectively amplify relevant signals. We summarize research suggesting that what neocortical pyramidal cells transmit information about can be distinguished from levels of arousal controlled by sub-cortical nuclei and from levels of prioritization specified by interactions within the thalamocortical system. Put simply, on the basis of the observations reviewed, we hypothesize that when conscious we have particular, directly experienced, percepts, thoughts, feelings and intentions, and that general anesthetics affect consciousness by interfering with the subcellular processes by which particular activities are selectively amplified when relevant to the current context.
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Affiliation(s)
- William A. Phillips
- Faculty of Natural Sciences, Psychology, University of Stirling, Stirling, United Kingdom
| | - Talis Bachmann
- Department of Penal Law, University of Tartu, Tartu, Estonia
| | - Johan F. Storm
- IBMS Department of Physiology, University of Oslo, Oslo, Norway
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32
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Lee AK, Brecht M. Elucidating Neuronal Mechanisms Using Intracellular Recordings during Behavior. Trends Neurosci 2018; 41:385-403. [DOI: 10.1016/j.tins.2018.03.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 03/19/2018] [Accepted: 03/23/2018] [Indexed: 12/17/2022]
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33
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Aspart F, Remme MWH, Obermayer K. Differential polarization of cortical pyramidal neuron dendrites through weak extracellular fields. PLoS Comput Biol 2018; 14:e1006124. [PMID: 29727454 PMCID: PMC5955601 DOI: 10.1371/journal.pcbi.1006124] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 05/16/2018] [Accepted: 04/06/2018] [Indexed: 01/13/2023] Open
Abstract
The rise of transcranial current stimulation (tCS) techniques have sparked an increasing interest in the effects of weak extracellular electric fields on neural activity. These fields modulate ongoing neural activity through polarization of the neuronal membrane. While the somatic polarization has been investigated experimentally, the frequency-dependent polarization of the dendritic trees in the presence of alternating (AC) fields has received little attention yet. Using a biophysically detailed model with experimentally constrained active conductances, we analyze the subthreshold response of cortical pyramidal cells to weak AC fields, as induced during tCS. We observe a strong frequency resonance around 10-20 Hz in the apical dendrites sensitivity to polarize in response to electric fields but not in the basal dendrites nor the soma. To disentangle the relative roles of the cell morphology and active and passive membrane properties in this resonance, we perform a thorough analysis using simplified models, e.g. a passive pyramidal neuron model, simple passive cables and reconstructed cell model with simplified ion channels. We attribute the origin of the resonance in the apical dendrites to (i) a locally increased sensitivity due to the morphology and to (ii) the high density of h-type channels. Our systematic study provides an improved understanding of the subthreshold response of cortical cells to weak electric fields and, importantly, allows for an improved design of tCS stimuli.
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Affiliation(s)
- Florian Aspart
- Department of Software Engineering and Theoretical Computer Science, Technische Universität Berlin, Berlin, Germany
- * E-mail: (FA); (MWHR); (KO)
| | - Michiel W. H. Remme
- Institute for Theoretical Biology, Humboldt-Universität zu Berlin, Berlin, Germany
- * E-mail: (FA); (MWHR); (KO)
| | - Klaus Obermayer
- Department of Software Engineering and Theoretical Computer Science, Technische Universität Berlin, Berlin, Germany
- Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
- * E-mail: (FA); (MWHR); (KO)
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34
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Bohannon AS, Hablitz JJ. Developmental Changes in HCN Channel Modulation of Neocortical Layer 1 Interneurons. Front Cell Neurosci 2018; 12:20. [PMID: 29440994 PMCID: PMC5797556 DOI: 10.3389/fncel.2018.00020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 01/15/2018] [Indexed: 01/31/2023] Open
Abstract
Layer 1 (L1) interneurons (INs) play a key role in modulating the integration of inputs to pyramidal neurons (PNs) and controlling cortical network activity. Hyperpolarization-activated, cyclic nucleotide-gated, non-specific cation (HCN) channels are known to alter the intrinsic and synaptic excitability of principal components (PCs) as well as select populations of GABAergic INs. However, the developmental profile and functional role of HCN channels in diverse L1 IN populations is not completely understood. In the present study, we used electrophysiological characterization, in conjunction with unbiased hierarchical cluster analysis, to examine developmental modulation of L1 INs by HCN channels in the rat medial agranular cortex (AGm). We identified three physiologically discrete IN populations which were classified as regular spiking (RS), burst accommodating (BA) and non-accommodating (NA). A distinct developmental pattern of excitability modulation by HCN channels was observed for each group. RS and NA cells displayed distinct morphologies with modulation of EPSPs increasing in RS cells and decreasing in NA cells across development. The results indicate a possible role of HCN channels in the formation and maintenance of cortical circuits through alteration of the excitability of distinct AGm L1 INs.
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Affiliation(s)
- Andrew S Bohannon
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - John J Hablitz
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, United States
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35
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Johnson KW, Herold KF, Milner TA, Hemmings HC, Platholi J. Sodium channel subtypes are differentially localized to pre- and post-synaptic sites in rat hippocampus. J Comp Neurol 2017; 525:3563-3578. [PMID: 28758202 PMCID: PMC5927368 DOI: 10.1002/cne.24291] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 07/24/2017] [Accepted: 07/25/2017] [Indexed: 12/16/2022]
Abstract
Voltage-gated Na+ channels (Nav ) modulate neuronal excitability, but the roles of the various Nav subtypes in specific neuronal functions such as synaptic transmission are unclear. We investigated expression of the three major brain Nav subtypes (Nav 1.1, Nav 1.2, Nav 1.6) in area CA1 and dentate gyrus of rat hippocampus. Using light and electron microscopy, we found labeling for all three Nav subtypes on dendrites, dendritic spines, and axon terminals, but the proportion of pre- and post-synaptic labeling for each subtype varied within and between subregions of CA1 and dentate gyrus. In the central hilus (CH) of the dentate gyrus, Nav 1.1 immunoreactivity was selectively expressed in presynaptic profiles, while Nav 1.2 and Nav 1.6 were expressed both pre- and post-synaptically. In contrast, in the stratum radiatum (SR) of CA1, Nav 1.1, Nav 1.2, and Nav 1.6 were selectively expressed in postsynaptic profiles. We next compared differences in Nav subtype expression between CH and SR axon terminals and between CH and SR dendrites and spines. Nav 1.1 and Nav 1.2 immunoreactivity was preferentially localized to CH axon terminals compared to SR, and in SR dendrites and spines compared to CH. No differences in Nav 1.6 immunoreactivity were found between axon terminals of CH and SR or between dendrites and spines of CH and SR. All Nav subtypes in both CH and SR were preferentially associated with asymmetric synapses rather than symmetric synapses. These findings indicate selective presynaptic and postsynaptic Nav expression in glutamatergic synapses of CH and SR supporting neurotransmitter release and synaptic plasticity.
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Affiliation(s)
| | - Karl F. Herold
- Department of Anesthesiology, Weill Cornell Medicine, New York, NY
| | - Teresa A. Milner
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY
- Harold and Milliken Hatch Laboratory of Neuroendocrinology, The Rockefeller University, NY NY
| | - Hugh C. Hemmings
- Department of Anesthesiology, Weill Cornell Medicine, New York, NY
- Department of Pharmacology, Weill Cornell Medicine, New York, NY
| | - Jimcy Platholi
- Department of Anesthesiology, Weill Cornell Medicine, New York, NY
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY
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36
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Petersen CCH. Whole-Cell Recording of Neuronal Membrane Potential during Behavior. Neuron 2017; 95:1266-1281. [PMID: 28910617 DOI: 10.1016/j.neuron.2017.06.049] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 06/29/2017] [Accepted: 06/30/2017] [Indexed: 11/16/2022]
Abstract
Neuronal membrane potential is of fundamental importance for the mechanistic understanding of brain function. This review discusses progress in whole-cell patch-clamp recordings for low-noise measurement of neuronal membrane potential in awake behaving animals. Whole-cell recordings can be combined with two-photon microscopy to target fluorescently labeled neurons, revealing cell-type-specific membrane potential dynamics of retrogradely or genetically labeled neurons. Dual whole-cell recordings reveal behavioral modulation of membrane potential synchrony and properties of synaptic transmission in vivo. Optogenetic manipulations are also readily integrated with whole-cell recordings, providing detailed information about the effect of specific perturbations on the membrane potential of diverse types of neurons. Exciting developments for future behavioral experiments include dendritic whole-cell recordings and imaging, and use of the whole-cell recording pipette for single-cell delivery of drugs and DNA, as well as RNA expression profiling. Whole-cell recordings therefore offer unique opportunities for investigating the neuronal circuits and synaptic mechanisms driving membrane potential dynamics during behavior.
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Affiliation(s)
- Carl C H Petersen
- Laboratory of Sensory Processing, Faculty of Life Sciences, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland.
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37
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Yi G, Wang J, Wei X, Deng B. Dendritic Properties Control Energy Efficiency of Action Potentials in Cortical Pyramidal Cells. Front Cell Neurosci 2017; 11:265. [PMID: 28919852 PMCID: PMC5585200 DOI: 10.3389/fncel.2017.00265] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 08/18/2017] [Indexed: 12/31/2022] Open
Abstract
Neural computation is performed by transforming input signals into sequences of action potentials (APs), which is metabolically expensive and limited by the energy available to the brain. The metabolic efficiency of single AP has important consequences for the computational power of the cell, which is determined by its biophysical properties and morphologies. Here we adopt biophysically-based two-compartment models to investigate how dendrites affect energy efficiency of APs in cortical pyramidal neurons. We measure the Na+ entry during the spike and examine how it is efficiently used for generating AP depolarization. We show that increasing the proportion of dendritic area or coupling conductance between two chambers decreases Na+ entry efficiency of somatic AP. Activating inward Ca2+ current in dendrites results in dendritic spike, which increases AP efficiency. Activating Ca2+-activated outward K+ current in dendrites, however, decreases Na+ entry efficiency. We demonstrate that the active and passive dendrites take effects by altering the overlap between Na+ influx and internal current flowing from soma to dendrite. We explain a fundamental link between dendritic properties and AP efficiency, which is essential to interpret how neural computation consumes metabolic energy and how biophysics and morphologies contribute to such consumption.
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Affiliation(s)
- Guosheng Yi
- School of Electrical and Information Engineering, Tianjin UniversityTianjin, China
| | - Jiang Wang
- School of Electrical and Information Engineering, Tianjin UniversityTianjin, China
| | - Xile Wei
- School of Electrical and Information Engineering, Tianjin UniversityTianjin, China
| | - Bin Deng
- School of Electrical and Information Engineering, Tianjin UniversityTianjin, China
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38
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D'Souza RD, Burkhalter A. A Laminar Organization for Selective Cortico-Cortical Communication. Front Neuroanat 2017; 11:71. [PMID: 28878631 PMCID: PMC5572236 DOI: 10.3389/fnana.2017.00071] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 08/07/2017] [Indexed: 11/13/2022] Open
Abstract
The neocortex is central to mammalian cognitive ability, playing critical roles in sensory perception, motor skills and executive function. This thin, layered structure comprises distinct, functionally specialized areas that communicate with each other through the axons of pyramidal neurons. For the hundreds of such cortico-cortical pathways to underlie diverse functions, their cellular and synaptic architectures must differ so that they result in distinct computations at the target projection neurons. In what ways do these pathways differ? By originating and terminating in different laminae, and by selectively targeting specific populations of excitatory and inhibitory neurons, these “interareal” pathways can differentially control the timing and strength of synaptic inputs onto individual neurons, resulting in layer-specific computations. Due to the rapid development in transgenic techniques, the mouse has emerged as a powerful mammalian model for understanding the rules by which cortical circuits organize and function. Here we review our understanding of how cortical lamination constrains long-range communication in the mammalian brain, with an emphasis on the mouse visual cortical network. We discuss the laminar architecture underlying interareal communication, the role of neocortical layers in organizing the balance of excitatory and inhibitory actions, and highlight the structure and function of layer 1 in mouse visual cortex.
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Affiliation(s)
- Rinaldo D D'Souza
- Department of Neuroscience, Washington University School of MedicineSt. Louis, MO, United States
| | - Andreas Burkhalter
- Department of Neuroscience, Washington University School of MedicineSt. Louis, MO, United States
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39
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Dendritic calcium spikes are clearly detectable at the cortical surface. Nat Commun 2017; 8:276. [PMID: 28819259 PMCID: PMC5561206 DOI: 10.1038/s41467-017-00282-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 06/19/2017] [Indexed: 12/02/2022] Open
Abstract
Cortical surface recording techniques such as EEG and ECoG are widely used for measuring brain activity. The prevailing assumption is that surface potentials primarily reflect synaptic activity, although non-synaptic events may also contribute. Here we show that dendritic calcium spikes occurring in pyramidal neurons (that we showed previously are cognitively relevant) are clearly detectable in cortical surface potentials. To show this we developed an optogenetic, non-synaptic approach to evoke dendritic calcium spikes in vivo. We found that optogenetically evoked calcium spikes were easily detectable and had an unexpected waveform near the cortical surface. Sensory-evoked dendritic calcium spikes were also clearly detectable with amplitudes that matched the contribution of synaptic input. These results reveal how dendritic calcium spikes appear at the cortical surface and their significant impact on surface potentials, suggesting that long-standing surface recording data may contain information about dendritic activity that is relevant to behavior and cognitive function. Surface EEG recordings are thought to primarily detect synaptic activity. Here the authors devise an optogenetic method to evoke dendritic calcium spikes in layer 5 pyramidal cells of the rat somatosensory cortex, and report that optogenetically evoked, as well as sensory-evoked dendritic calcium spikes make a significant contribution to surface EEG recordings.
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40
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Krieger P, de Kock CPJ, Frick A. Calcium Dynamics in Basal Dendrites of Layer 5A and 5B Pyramidal Neurons Is Tuned to the Cell-Type Specific Physiological Action Potential Discharge. Front Cell Neurosci 2017; 11:194. [PMID: 28744201 PMCID: PMC5504123 DOI: 10.3389/fncel.2017.00194] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 06/21/2017] [Indexed: 11/13/2022] Open
Abstract
Layer 5 (L5) is a major neocortical output layer containing L5A slender-tufted (L5A-st) and L5B thick-tufted (L5B-tt) pyramidal neurons. These neuron types differ in their in vivo firing patterns, connectivity and dendritic morphology amongst other features, reflecting their specific functional role within the neocortical circuits. Here, we asked whether the active properties of the basal dendrites that receive the great majority of synaptic inputs within L5 differ between these two pyramidal neuron classes. To quantify their active properties, we measured the efficacy with which action potential (AP) firing patterns backpropagate along the basal dendrites by measuring the accompanying calcium transients using two-photon laser scanning microscopy in rat somatosensory cortex slices. For these measurements we used both "artificial" three-AP patterns and more complex physiological AP patterns that were previously recorded in anesthetized rats in L5A-st and L5B-tt neurons in response to whisker stimulation. We show that AP patterns with relatively few APs (3APs) evoke a calcium response in L5B-tt, but not L5A-st, that is dependent on the temporal pattern of the three APs. With more complex in vivo recorded AP patterns, the average calcium response was similar in the proximal dendrites but with a decay along dendrites (measured up to 100 μm) of L5B-tt but not L5A-st neurons. Interestingly however, the whisker evoked AP patterns-although very different for the two cell types-evoke similar calcium responses. In conclusion, although the effectiveness with which different AP patterns evoke calcium transients vary between L5A-st and L5B-tt cell, the calcium influx appears to be tuned such that whisker-evoked calcium transients are within the same dynamic range for both cell types.
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Affiliation(s)
- Patrik Krieger
- Department of Cell Physiology, Max Planck Institute for Medical ResearchHeidelberg, Germany.,Department of Systems Neuroscience, Medical Faculty, Ruhr University BochumBochum, Germany
| | - Christiaan P J de Kock
- Department of Cell Physiology, Max Planck Institute for Medical ResearchHeidelberg, Germany.,Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research (CNCR), VU University AmsterdamAmsterdam, Netherlands
| | - Andreas Frick
- Department of Cell Physiology, Max Planck Institute for Medical ResearchHeidelberg, Germany.,INSERM, Neurocentre Magendie, U1215Bordeaux, France.,University of Bordeaux, Neurocentre Magendie, U1215Bordeaux, France
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41
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Schmidt-Hieber C, Toleikyte G, Aitchison L, Roth A, Clark BA, Branco T, Häusser M. Active dendritic integration as a mechanism for robust and precise grid cell firing. Nat Neurosci 2017. [PMID: 28628104 DOI: 10.1038/nn.4582] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Understanding how active dendrites are exploited for behaviorally relevant computations is a fundamental challenge in neuroscience. Grid cells in medial entorhinal cortex are an attractive model system for addressing this question, as the computation they perform is clear: they convert synaptic inputs into spatially modulated, periodic firing. Whether active dendrites contribute to the generation of the dual temporal and rate codes characteristic of grid cell output is unknown. We show that dendrites of medial entorhinal cortex neurons are highly excitable and exhibit a supralinear input-output function in vitro, while in vivo recordings reveal membrane potential signatures consistent with recruitment of active dendritic conductances. By incorporating these nonlinear dynamics into grid cell models, we show that they can sharpen the precision of the temporal code and enhance the robustness of the rate code, thereby supporting a stable, accurate representation of space under varying environmental conditions. Our results suggest that active dendrites may therefore constitute a key cellular mechanism for ensuring reliable spatial navigation.
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Affiliation(s)
- Christoph Schmidt-Hieber
- Wolfson Institute for Biomedical Research and Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK.,Institut Pasteur, Paris, France
| | - Gabija Toleikyte
- Wolfson Institute for Biomedical Research and Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Laurence Aitchison
- Gatsby Computational Neuroscience Unit, University College London, London, UK
| | - Arnd Roth
- Wolfson Institute for Biomedical Research and Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Beverley A Clark
- Wolfson Institute for Biomedical Research and Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Tiago Branco
- Wolfson Institute for Biomedical Research and Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK.,Sainsbury Wellcome Centre, University College London, London, UK
| | - Michael Häusser
- Wolfson Institute for Biomedical Research and Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
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42
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Action potential initiation in a two-compartment model of pyramidal neuron mediated by dendritic Ca 2+ spike. Sci Rep 2017; 7:45684. [PMID: 28367964 PMCID: PMC5377381 DOI: 10.1038/srep45684] [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: 12/19/2016] [Accepted: 03/02/2017] [Indexed: 11/12/2022] Open
Abstract
Dendritic Ca2+ spike endows cortical pyramidal cell with powerful ability of synaptic integration, which is critical for neuronal computation. Here we propose a two-compartment conductance-based model to investigate how the Ca2+ activity of apical dendrite participates in the action potential (AP) initiation to affect the firing properties of pyramidal neurons. We have shown that the apical input with sufficient intensity triggers a dendritic Ca2+ spike, which significantly boosts dendritic inputs as it propagates to soma. Such event instantaneously shifts the limit cycle attractor of the neuron and results in a burst of APs, which makes its firing rate reach a plateau steady-state level. Delivering current to two chambers simultaneously increases the level of neuronal excitability and decreases the threshold of input-output relation. Here the back-propagating APs facilitate the initiation of dendritic Ca2+ spike and evoke BAC firing. These findings indicate that the proposed model is capable of reproducing in vitro experimental observations. By determining spike initiating dynamics, we have provided a fundamental link between dendritic Ca2+ spike and output APs, which could contribute to mechanically interpreting how dendritic Ca2+ activity participates in the simple computations of pyramidal neuron.
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43
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Moore JJ, Ravassard PM, Ho D, Acharya L, Kees AL, Vuong C, Mehta MR. Dynamics of cortical dendritic membrane potential and spikes in freely behaving rats. Science 2017; 355:science.aaj1497. [DOI: 10.1126/science.aaj1497] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Accepted: 01/31/2017] [Indexed: 11/02/2022]
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44
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Kalmbach BE, Gray R, Johnston D, Cook EP. Systems-based analysis of dendritic nonlinearities reveals temporal feature extraction in mouse L5 cortical neurons. J Neurophysiol 2017; 117:2188-2208. [PMID: 28250154 DOI: 10.1152/jn.00951.2016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Revised: 02/14/2017] [Accepted: 02/27/2017] [Indexed: 01/29/2023] Open
Abstract
What do dendritic nonlinearities tell a neuron about signals injected into the dendrite? Linear and nonlinear dendritic components affect how time-varying inputs are transformed into action potentials (APs), but the relative contribution of each component is unclear. We developed a novel systems-identification approach to isolate the nonlinear response of layer 5 pyramidal neuron dendrites in mouse prefrontal cortex in response to dendritic current injections. We then quantified the nonlinear component and its effect on the soma, using functional models composed of linear filters and static nonlinearities. Both noise and waveform current injections revealed linear and nonlinear components in the dendritic response. The nonlinear component consisted of fast Na+ spikes that varied in amplitude 10-fold in a single neuron. A functional model reproduced the timing and amplitude of the dendritic spikes and revealed that they were selective to a preferred input dynamic (~4.5 ms rise time). The selectivity of the dendritic spikes became wider in the presence of additive noise, which was also predicted by the functional model. A second functional model revealed that the dendritic spikes were weakly boosted before being linearly integrated at the soma. For both our noise and waveform dendritic input, somatic APs were dependent on the somatic integration of the stimulus, followed a subset of large dendritic spikes, and were selective to the same input dynamics preferred by the dendrites. Our results suggest that the amplitude of fast dendritic spikes conveys information about high-frequency features in the dendritic input, which is then combined with low-frequency somatic integration.NEW & NOTEWORTHY The nonlinear response of layer 5 mouse pyramidal dendrites was isolated with a novel systems-based approach. In response to dendritic current injections, the nonlinear component contained mostly fast, variable-amplitude, Na+ spikes. A functional model accounted for the timing and amplitude of the dendritic spikes and revealed that dendritic spikes are selective to a preferred input dynamic, which was verified experimentally. Thus, fast dendritic nonlinearities behave as high-frequency feature detectors that influence somatic action potentials.
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Affiliation(s)
- Brian E Kalmbach
- Center for Learning and Memory, Department of Neuroscience, The University of Texas at Austin, Austin, Texas; and
| | - Richard Gray
- Center for Learning and Memory, Department of Neuroscience, The University of Texas at Austin, Austin, Texas; and
| | - Daniel Johnston
- Center for Learning and Memory, Department of Neuroscience, The University of Texas at Austin, Austin, Texas; and
| | - Erik P Cook
- Centre for Mathematics in Bioscience and Medicine, Department of Physiology, McGill University, Montreal, Quebec, Canada
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45
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Manita S, Miyakawa H, Kitamura K, Murayama M. Dendritic Spikes in Sensory Perception. Front Cell Neurosci 2017; 11:29. [PMID: 28261060 PMCID: PMC5309249 DOI: 10.3389/fncel.2017.00029] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 01/31/2017] [Indexed: 11/13/2022] Open
Abstract
What is the function of dendritic spikes? One might argue that they provide conditions for neuronal plasticity or that they are essential for neural computation. However, despite a long history of dendritic research, the physiological relevance of dendritic spikes in brain function remains unknown. This could stem from the fact that most studies on dendrites have been performed in vitro. Fortunately, the emergence of novel techniques such as improved two-photon microscopy, genetically encoded calcium indicators (GECIs), and optogenetic tools has provided the means for vital breakthroughs in in vivo dendritic research. These technologies enable the investigation of the functions of dendritic spikes in behaving animals, and thus, help uncover the causal relationship between dendritic spikes, and sensory information processing and synaptic plasticity. Understanding the roles of dendritic spikes in brain function would provide mechanistic insight into the relationship between the brain and the mind. In this review article, we summarize the results of studies on dendritic spikes from a historical perspective and discuss the recent advances in our understanding of the role of dendritic spikes in sensory perception.
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Affiliation(s)
- Satoshi Manita
- Laboratory for Behavioral Neurophysiology, Brain Science Institute, RIKENWako City, Saitama, Japan; Department of Neurophysiology, Division of Medicine, University of YamanashiChuo-shi, Japan
| | - Hiroyoshi Miyakawa
- Laboratory of Cellular Neurobiology, Tokyo University of Pharmacy and Life Sciences Hachioji, Japan
| | - Kazuo Kitamura
- Department of Neurophysiology, Division of Medicine, University of Yamanashi Chuo-shi, Japan
| | - Masanori Murayama
- Laboratory for Behavioral Neurophysiology, Brain Science Institute, RIKEN Wako City, Saitama, Japan
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46
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Petro LS, Paton AT, Muckli L. Contextual modulation of primary visual cortex by auditory signals. Philos Trans R Soc Lond B Biol Sci 2017; 372:rstb.2016.0104. [PMID: 28044015 PMCID: PMC5206272 DOI: 10.1098/rstb.2016.0104] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/22/2016] [Indexed: 12/04/2022] Open
Abstract
Early visual cortex receives non-feedforward input from lateral and top-down connections (Muckli & Petro 2013 Curr. Opin. Neurobiol.23, 195–201. (doi:10.1016/j.conb.2013.01.020)), including long-range projections from auditory areas. Early visual cortex can code for high-level auditory information, with neural patterns representing natural sound stimulation (Vetter et al. 2014 Curr. Biol.24, 1256–1262. (doi:10.1016/j.cub.2014.04.020)). We discuss a number of questions arising from these findings. What is the adaptive function of bimodal representations in visual cortex? What type of information projects from auditory to visual cortex? What are the anatomical constraints of auditory information in V1, for example, periphery versus fovea, superficial versus deep cortical layers? Is there a putative neural mechanism we can infer from human neuroimaging data and recent theoretical accounts of cortex? We also present data showing we can read out high-level auditory information from the activation patterns of early visual cortex even when visual cortex receives simple visual stimulation, suggesting independent channels for visual and auditory signals in V1. We speculate which cellular mechanisms allow V1 to be contextually modulated by auditory input to facilitate perception, cognition and behaviour. Beyond cortical feedback that facilitates perception, we argue that there is also feedback serving counterfactual processing during imagery, dreaming and mind wandering, which is not relevant for immediate perception but for behaviour and cognition over a longer time frame. This article is part of the themed issue ‘Auditory and visual scene analysis’.
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Affiliation(s)
- L S Petro
- Centre for Cognitive Neuroimaging, Institute of Neuroscience and Psychology, University of Glasgow, 58 Hillhead Street, Glasgow G12 8QB, UK
| | - A T Paton
- Centre for Cognitive Neuroimaging, Institute of Neuroscience and Psychology, University of Glasgow, 58 Hillhead Street, Glasgow G12 8QB, UK
| | - L Muckli
- Centre for Cognitive Neuroimaging, Institute of Neuroscience and Psychology, University of Glasgow, 58 Hillhead Street, Glasgow G12 8QB, UK
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47
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Almog M, Korngreen A. Is realistic neuronal modeling realistic? J Neurophysiol 2016; 116:2180-2209. [PMID: 27535372 DOI: 10.1152/jn.00360.2016] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 08/17/2016] [Indexed: 11/22/2022] Open
Abstract
Scientific models are abstractions that aim to explain natural phenomena. A successful model shows how a complex phenomenon arises from relatively simple principles while preserving major physical or biological rules and predicting novel experiments. A model should not be a facsimile of reality; it is an aid for understanding it. Contrary to this basic premise, with the 21st century has come a surge in computational efforts to model biological processes in great detail. Here we discuss the oxymoronic, realistic modeling of single neurons. This rapidly advancing field is driven by the discovery that some neurons don't merely sum their inputs and fire if the sum exceeds some threshold. Thus researchers have asked what are the computational abilities of single neurons and attempted to give answers using realistic models. We briefly review the state of the art of compartmental modeling highlighting recent progress and intrinsic flaws. We then attempt to address two fundamental questions. Practically, can we realistically model single neurons? Philosophically, should we realistically model single neurons? We use layer 5 neocortical pyramidal neurons as a test case to examine these issues. We subject three publically available models of layer 5 pyramidal neurons to three simple computational challenges. Based on their performance and a partial survey of published models, we conclude that current compartmental models are ad hoc, unrealistic models functioning poorly once they are stretched beyond the specific problems for which they were designed. We then attempt to plot possible paths for generating realistic single neuron models.
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Affiliation(s)
- Mara Almog
- The Leslie and Susan Gonda Interdisciplinary Brain Research Centre, Bar-Ilan University, Ramat Gan, Israel; and.,The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Alon Korngreen
- The Leslie and Susan Gonda Interdisciplinary Brain Research Centre, Bar-Ilan University, Ramat Gan, Israel; and .,The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
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48
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Naka A, Adesnik H. Inhibitory Circuits in Cortical Layer 5. Front Neural Circuits 2016; 10:35. [PMID: 27199675 PMCID: PMC4859073 DOI: 10.3389/fncir.2016.00035] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 04/18/2016] [Indexed: 01/19/2023] Open
Abstract
Inhibitory neurons play a fundamental role in cortical computation and behavior. Recent technological advances, such as two photon imaging, targeted in vivo recording, and molecular profiling, have improved our understanding of the function and diversity of cortical interneurons, but for technical reasons most work has been directed towards inhibitory neurons in the superficial cortical layers. Here we review current knowledge specifically on layer 5 (L5) inhibitory microcircuits, which play a critical role in controlling cortical output. We focus on recent work from the well-studied rodent barrel cortex, but also draw on evidence from studies in primary visual cortex and other cortical areas. The diversity of both deep inhibitory neurons and their pyramidal cell targets make this a challenging but essential area of study in cortical computation and sensory processing.
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Affiliation(s)
- Alexander Naka
- The Helen Wills Neuroscience Institute, University of California Berkeley Berkeley, CA, USA
| | - Hillel Adesnik
- The Helen Wills Neuroscience Institute, University of California BerkeleyBerkeley, CA, USA; Department of Molecular and Cell Biology, University of California BerkeleyBerkeley, CA, USA
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49
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Dendritic integration: 60 years of progress. Nat Neurosci 2015; 18:1713-21. [PMID: 26605882 DOI: 10.1038/nn.4157] [Citation(s) in RCA: 244] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 09/24/2015] [Indexed: 12/12/2022]
Abstract
Understanding how individual neurons integrate the thousands of synaptic inputs they receive is critical to understanding how the brain works. Modeling studies in silico and experimental work in vitro, dating back more than half a century, have revealed that neurons can perform a variety of different passive and active forms of synaptic integration on their inputs. But how are synaptic inputs integrated in the intact brain? With the development of new techniques, this question has recently received substantial attention, with new findings suggesting that many of the forms of synaptic integration observed in vitro also occur in vivo, including in awake animals. Here we review six decades of progress, which collectively highlights the complex ways that single neurons integrate their inputs, emphasizing the critical role of dendrites in information processing in the brain.
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50
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Garcia-Munoz M, Arbuthnott GW. Basal ganglia-thalamus and the "crowning enigma". Front Neural Circuits 2015; 9:71. [PMID: 26582979 PMCID: PMC4631818 DOI: 10.3389/fncir.2015.00071] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 10/22/2015] [Indexed: 11/13/2022] Open
Abstract
When Hubel (1982) referred to layer 1 of primary visual cortex as "… a 'crowning mystery' to keep area-17 physiologists busy for years to come …" he could have been talking about any cortical area. In the 80's and 90's there were no methods to examine this neuropile on the surface of the cortex: a tangled web of axons and dendrites from a variety of different places with unknown specificities and doubtful connections to the cortical output neurons some hundreds of microns below. Recently, three changes have made the crowning enigma less of an impossible mission: the clear presence of neurons in layer 1 (L1), the active conduction of voltage along apical dendrites and optogenetic methods that might allow us to look at one source of input at a time. For all of those reasons alone, it seems it is time to take seriously the function of L1. The functional properties of this layer will need to wait for more experiments but already L1 cells are GAD67 positive, i.e., inhibitory! They could reverse the sign of the thalamic glutamate (GLU) input for the entire cortex. It is at least possible that in the near future normal activity of individual sources of L1 could be detected using genetic tools. We are at the outset of important times in the exploration of thalamic functions and perhaps the solution to the crowning enigma is within sight. Our review looks forward to that solution from the solid basis of the anatomy of the basal ganglia output to motor thalamus. We will focus on L1, its afferents, intrinsic neurons and its influence on responses of pyramidal neurons in layers 2/3 and 5. Since L1 is present in the whole cortex we will provide a general overview considering evidence mainly from the somatosensory (S1) cortex before focusing on motor cortex.
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Affiliation(s)
| | - Gordon W Arbuthnott
- Okinawa Institute of Science and Technology Graduate University Okinawa, Japan
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