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Kim JJ, Wyche IS, Olson W, Lu J, Bakir MS, Sober SJ, O'Connor DH. Myo-optogenetics: optogenetic stimulation and electrical recording in skeletal muscles. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.21.600113. [PMID: 38979246 PMCID: PMC11230246 DOI: 10.1101/2024.06.21.600113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Complex movements involve highly coordinated control of local muscle elements. Highly controlled perturbations of motor outputs can reveal insights into the neural control of movements. Here we introduce an optogenetic method, compatible with electromyography (EMG) recordings, to perturb muscles in transgenic mice. By expressing channelrhodopsin in muscle fibers, we achieved noninvasive, focal activation of orofacial muscles, enabling detailed examination of the mechanical properties of optogenetically evoked jaw muscle contractions. We demonstrated simultaneous EMG recording and optical stimulation, revealing the electrophysiological characteristics of optogenetically triggered muscle activity. Additionally, we applied optogenetic activation of muscles in physiologically and behaviorally relevant settings, mapping precise muscle actions and perturbing active behaviors. Our findings highlight the potential of muscle optogenetics to precisely manipulate muscle activity, offering a powerful tool for probing neuromuscular control systems and advancing our understanding of motor control.
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2
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Shigematsu N, Miyamoto Y, Esumi S, Fukuda T. The Anterolateral Barrel Subfield Differs from the Posteromedial Barrel Subfield in the Morphology and Cell Density of Parvalbumin-Positive GABAergic Interneurons. eNeuro 2024; 11:ENEURO.0518-22.2024. [PMID: 38438262 DOI: 10.1523/eneuro.0518-22.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 12/20/2023] [Accepted: 02/23/2024] [Indexed: 03/06/2024] Open
Abstract
Layer 4 of the rodent somatosensory cortex has unitary structures called barrels that receive tactile information from individual vibrissae. Barrels in the anterolateral barrel subfield (ALBSF) are much smaller and have gained less attention than larger barrels in the posteromedial barrel subfield (PMBSF), though the former outnumber the latter. We compared the morphological features of barrels between the ALBSF and PMBSF in male mice using deformation-free tangential sections and confocal optical slice-based, precise reconstructions of barrels. The average volume of a single barrel in the ALBSF was 34.7% of that in the PMBSF, but the numerical density of parvalbumin (PV)-positive interneurons in the former was 1.49 times higher than that in the latter. Moreover, PV neuron density in septa was 2.08 times higher in the ALBSF than that in the PMBSF. The proportions of PV neuron number to both all neuron number and all GABAergic neuron number in the ALBSF were also higher than those in the PMBSF. Somata of PV neurons in barrels and septa in the ALBSF received 1.64 and 1.50 times more vesicular glutamate transporter Type 2-labeled boutons than those in the PMBSF, suggesting more potent feedforward inhibitory circuits in the ALBSF. The mode of connectivity through dendritic gap junctions among PV neurons also differed between the ALBSF and PMBSF. Clusters of smaller unitary structures containing a higher density of representative GABAergic interneurons with differential morphological features in the ALBSF suggest a division of functional roles in the two vibrissa-barrel systems, as has been demonstrated by behavioral studies.
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Affiliation(s)
- Naoki Shigematsu
- Department of Anatomy and Neurobiology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto 860-8556, Japan
| | - Yuta Miyamoto
- Department of Anatomy and Neurobiology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto 860-8556, Japan
| | - Shigeyuki Esumi
- Department of Anatomy and Neurobiology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto 860-8556, Japan
| | - Takaichi Fukuda
- Department of Anatomy and Neurobiology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto 860-8556, Japan
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3
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Lande AS, Garvert AC, Ebbesen NC, Jordbræk SV, Vervaeke K. Representations of tactile object location in the retrosplenial cortex. Curr Biol 2023; 33:4599-4610.e7. [PMID: 37774708 DOI: 10.1016/j.cub.2023.09.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 07/23/2023] [Accepted: 09/06/2023] [Indexed: 10/01/2023]
Abstract
How animals use tactile sensation to detect important objects and remember their location in a world-based coordinate system is unclear. Here, we hypothesized that the retrosplenial cortex (RSC), a key network for contextual memory and spatial navigation, represents the location of objects based on tactile sensation. We studied mice palpating objects with their whiskers while navigating in a tactile virtual reality in darkness. Using two-photon Ca2+ imaging, we discovered that a population of neurons in the agranular RSC signal the location of objects. Responses to objects do not simply reflect the sensory stimulus. Instead, they are highly position, task, and context dependent and often predict the upcoming object before it is within reach. In addition, a large fraction of neurons encoding object location maintain a memory trace of the object's location. These data show that the RSC encodes the location and arrangement of tactile objects in a spatial reference frame.
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Affiliation(s)
- Andreas Sigstad Lande
- Institute of Basic Medical Sciences, Section of Physiology, University of Oslo, Sognsvannsveien 9, 0372 Oslo, Norway
| | - Anna Christina Garvert
- Institute of Basic Medical Sciences, Section of Physiology, University of Oslo, Sognsvannsveien 9, 0372 Oslo, Norway
| | - Nora Cecilie Ebbesen
- Institute of Basic Medical Sciences, Section of Physiology, University of Oslo, Sognsvannsveien 9, 0372 Oslo, Norway
| | - Sondre Valentin Jordbræk
- Institute of Basic Medical Sciences, Section of Physiology, University of Oslo, Sognsvannsveien 9, 0372 Oslo, Norway
| | - Koen Vervaeke
- Institute of Basic Medical Sciences, Section of Physiology, University of Oslo, Sognsvannsveien 9, 0372 Oslo, Norway.
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4
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Bresee CS, Belli HM, Luo Y, Hartmann MJZ. Comparative morphology of the whiskers and faces of mice (Mus musculus) and rats (Rattus norvegicus). J Exp Biol 2023; 226:jeb245597. [PMID: 37577985 PMCID: PMC10617617 DOI: 10.1242/jeb.245597] [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: 01/30/2023] [Accepted: 07/17/2023] [Indexed: 08/15/2023]
Abstract
Understanding neural function requires quantification of the sensory signals that an animal's brain evolved to interpret. These signals in turn depend on the morphology and mechanics of the animal's sensory structures. Although the house mouse (Mus musculus) is one of the most common model species used in neuroscience, the spatial arrangement of its facial sensors has not yet been quantified. To address this gap, the present study quantifies the facial morphology of the mouse, with a particular focus on the geometry of its vibrissae (whiskers). The study develops equations that establish relationships between the three-dimensional (3D) locations of whisker basepoints, whisker geometry (arclength, curvature) and the 3D angles at which the whiskers emerge from the face. Additionally, the positions of facial sensory organs are quantified relative to bregma-lambda. Comparisons with the Norway rat (Rattus norvegicus) indicate that when normalized for head size, the whiskers of these two species have similar spacing density. The rostral-caudal distances between facial landmarks of the rat are a factor of ∼2.0 greater than the mouse, while the scale of bilateral distances is larger and more variable. We interpret these data to suggest that the larger size of rats compared with mice is a derived (apomorphic) trait. As rodents are increasingly important models in behavioral neuroscience, the morphological model developed here will help researchers generate naturalistic, multimodal patterns of stimulation for neurophysiological experiments and allow the generation of synthetic datasets and simulations to close the loop between brain, body and environment.
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Affiliation(s)
- Chris S. Bresee
- Northwestern University Institute for Neuroscience, Northwestern University, Evanston, IL 60208,USA
| | - Hayley M. Belli
- Department of Biomedical Engineering,Northwestern University, Evanston, IL 60208, USA
| | - Yifu Luo
- Department of Mechanical Engineering,Northwestern University, Evanston, IL 60208,USA
| | - Mitra J. Z. Hartmann
- Department of Biomedical Engineering,Northwestern University, Evanston, IL 60208, USA
- Department of Mechanical Engineering,Northwestern University, Evanston, IL 60208,USA
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5
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Vaissiere T, Michaelson S, Creson T, Goins J, Fürth D, Balazsfi D, Rojas C, Golovin R, Meletis K, Miller CA, O’Connor D, Rumbaugh G. Sensorimotor Integration Supporting Perception Requires Syngap1 Expression in Cortex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.27.559787. [PMID: 37808765 PMCID: PMC10557642 DOI: 10.1101/2023.09.27.559787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Perception, a cognitive construct, emerges through sensorimotor integration (SMI). The molecular and cellular mechanisms that shape SMI within circuits that promote cognition are poorly understood. Here, we demonstrate that expression of the autism/intellectual disability gene, Syngap1, in mouse cortical excitatory neurons promotes touch sensitivity required to elicit perceptual behaviors. Cortical Syngap1 expression enabled touch-induced feedback signals within sensorimotor loops by assembling circuits that support tactile sensitivity. These circuits also encoded correlates of attention that promoted self-generated whisker movements underlying purposeful and sustained object exploration. As Syngap1 deficient animals explored objects with whiskers, relatively weak touch signals were integrated with relatively strong motor signals. This produced a signal-to-noise deficit consistent with impaired tactile sensitivity, reduced tactile exploration, and weak tactile learning. Thus, Syngap1 expression in cortex promotes tactile perception by assembling circuits that integrate touch and whisker motor signals. Deficient Syngap1 expression likely contributes to cognitive impairment through abnormal top-down SMI.
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Affiliation(s)
- Thomas Vaissiere
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Jupiter, FL, USA
| | - Sheldon Michaelson
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Jupiter, FL, USA
| | - Thomas Creson
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Jupiter, FL, USA
| | - Jessie Goins
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Jupiter, FL, USA
| | - Daniel Fürth
- SciLifeLab, Department of Immunology, Genetics & Pathology, Uppsala University, Uppsala, Sweden
| | - Diana Balazsfi
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Jupiter, FL, USA
| | - Camilo Rojas
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Jupiter, FL, USA
| | - Randall Golovin
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Jupiter, FL, USA
| | | | - Courtney A. Miller
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Jupiter, FL, USA
- Department of Molecular Medicine, UF Scripps Biomedical Research, Jupiter, FL, USA
| | - Daniel O’Connor
- Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Gavin Rumbaugh
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Jupiter, FL, USA
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6
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Ding Y, Vlasov Y. Pre-neuronal processing of haptic sensory cues via dispersive high-frequency vibrational modes. Sci Rep 2023; 13:14370. [PMID: 37658126 PMCID: PMC10474056 DOI: 10.1038/s41598-023-40675-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Accepted: 08/16/2023] [Indexed: 09/03/2023] Open
Abstract
Sense of touch is one of the major perception channels. Neural coding of object textures conveyed by rodents' whiskers has been a model to study early stages of haptic information uptake. While high-precision spike timing has been observed during whisker sweeping across textured surfaces, the exact nature of whisker micromotions that spikes encode remains elusive. Here, we discovered that a single micro-collision of a whisker with surface features generates vibrational eigenmodes spanning frequencies up to 10 kHz. While propagating along the whisker, these high-frequency modes can carry up to 80% of shockwave energy, exhibit 100× smaller damping ratio, and arrive at the follicle 10× faster than low frequency components. The mechano-transduction of these energy bursts into time-sequenced population spike trains may generate temporally unique "bar code" with ultra-high information capacity. This hypothesis of pre-neuronal processing of haptic signals based on dispersive temporal separation of the vibrational modal frequencies can shed light on neural coding of haptic signals in many whisker-like sensory organs across the animal world as well as in texture perception in primate's glabrous skin.
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Affiliation(s)
- Yu Ding
- Department of Physics, University of Illinois Urbana Champaign, 208 North Wright Street, Urbana, IL, 61801, USA
| | - Yurii Vlasov
- Department of Physics, University of Illinois Urbana Champaign, 208 North Wright Street, Urbana, IL, 61801, USA.
- Department of BioEngineering, University of Illinois Urbana Champaign, 208 North Wright Street, Urbana, IL, 61801, USA.
- Carle Illinois College of Medicine, University of Illinois Urbana Champaign, 208 North Wright Street, Urbana, IL, 61801, USA.
- Department of Electrical and Computer Engineering, University of Illinois Urbana Champaign, 208 North Wright Street, Urbana, IL, 61801, USA.
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7
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Dougill G, Brassey CA, Starostin EL, Andrews H, Kitchener A, van der Heijden GHM, Goss VGA, Grant RA. Describing whisker morphology of the Carnivora. J Morphol 2023; 284:e21628. [PMID: 37585221 DOI: 10.1002/jmor.21628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 07/18/2023] [Accepted: 07/24/2023] [Indexed: 08/17/2023]
Abstract
One of the largest ecological transitions in carnivoran evolution was the shift from terrestrial to aquatic lifestyles, which has driven morphological diversity in skulls and other skeletal structures. In this paper, we investigate the association between those lifestyles and whisker morphology. However, comparing whisker morphology over a range of species is challenging since the number of whiskers and their positions on the mystacial pads vary between species. Also, each whisker will be at a different stage of growth and may have incurred damage due to wear and tear. Identifying a way to easily capture whisker morphology in a small number of whisker samples would be beneficial. Here, we describe individual and species variation in whisker morphology from two-dimensional scans in red fox, European otter and grey seal. A comparison of long, caudal whiskers shows inter-species differences most clearly. We go on to describe global whisker shape in 24 species of carnivorans, using linear approximations of curvature and taper, as well as traditional morphometric methods. We also qualitatively examine surface texture, or the presence of scales, using scanning electron micrographs. We show that gross whisker shape is highly conserved, with whisker curvature and taper obeying simple linear relationships with length. However, measures of whisker base radius, length, and maybe even curvature, can vary between species and substrate preferences. Specifically, the aquatic species in our sample have thicker, shorter whiskers that are smoother, with less scales present than those of terrestrial species. We suggest that these thicker whiskers may be stiffer and able to maintain their shape and position during underwater sensing, but being stiffer may also increase wear.
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Affiliation(s)
- Gary Dougill
- Faculty of Science and Engineering, Manchester Metropolitan University, Manchester, UK
| | - Charlotte A Brassey
- Faculty of Science and Engineering, Manchester Metropolitan University, Manchester, UK
| | - Eugene L Starostin
- School of Engineering, London South Bank University, London, UK
- Department of Civil, Environmental and Geomatic Engineering, University College London, London, UK
| | - Hayley Andrews
- Faculty of Science and Engineering, Manchester Metropolitan University, Manchester, UK
| | - Andrew Kitchener
- Department of Natural Sciences, National Museums Scotland, Edinburgh, UK
| | - Gert H M van der Heijden
- Department of Civil, Environmental and Geomatic Engineering, University College London, London, UK
| | - Victor G A Goss
- School of Engineering, London South Bank University, London, UK
| | - Robyn A Grant
- Faculty of Science and Engineering, Manchester Metropolitan University, Manchester, UK
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8
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On the intrinsic curvature of animal whiskers. PLoS One 2023; 18:e0269210. [PMID: 36607960 PMCID: PMC9821693 DOI: 10.1371/journal.pone.0269210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Accepted: 12/05/2022] [Indexed: 01/07/2023] Open
Abstract
Facial vibrissae (whiskers) are thin, tapered, flexible, hair-like structures that are an important source of tactile sensory information for many species of mammals. In contrast to insect antennae, whiskers have no sensors along their lengths. Instead, when a whisker touches an object, the resulting deformation is transmitted to mechanoreceptors in a follicle at the whisker base. Previous work has shown that the mechanical signals transmitted along the whisker will depend strongly on the whisker's geometric parameters, specifically on its taper (how diameter varies with arc length) and on the way in which the whisker curves, often called "intrinsic curvature." Although previous studies have largely agreed on how to define taper, multiple methods have been used to quantify intrinsic curvature. The present work compares and contrasts different mathematical approaches towards quantifying this important parameter. We begin by reviewing and clarifying the definition of "intrinsic curvature," and then show results of fitting whisker shapes with several different functions, including polynomial, fractional exponent, elliptical, and Cesàro. Comparisons are performed across ten species of whiskered animals, ranging from rodents to pinnipeds. We conclude with a discussion of the advantages and disadvantages of using the various models for different modeling situations. The fractional exponent model offers an approach towards developing a species-specific parameter to characterize whisker shapes within a species. Constructing models of how the whisker curves is important for the creation of mechanical models of tactile sensory acquisition behaviors, for studies of comparative evolution, morphology, and anatomy, and for designing artificial systems that can begin to emulate the whisker-based tactile sensing of animals.
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9
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Columnar Lesions in Barrel Cortex Persistently Degrade Object Location Discrimination Performance. eNeuro 2022; 9:ENEURO.0393-22.2022. [PMID: 36316120 PMCID: PMC9665881 DOI: 10.1523/eneuro.0393-22.2022] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 10/03/2022] [Accepted: 10/21/2022] [Indexed: 12/24/2022] Open
Abstract
Primary sensory cortices display functional topography, suggesting that even small cortical volumes may underpin perception of specific stimuli. Traditional loss-of-function approaches have a relatively large radius of effect (>1 mm), and few studies track recovery following loss-of-function perturbations. Consequently, the behavioral necessity of smaller cortical volumes remains unclear. In the mouse primary vibrissal somatosensory cortex (vS1), "barrels" with a radius of ∼150 μm receive input predominantly from a single whisker, partitioning vS1 into a topographic map of well defined columns. Here, we train animals implanted with a cranial window over vS1 to perform single-whisker perceptual tasks. We then use high-power laser exposure centered on the barrel representing the spared whisker to produce lesions with a typical volume of one to two barrels. These columnar-scale lesions impair performance in an object location discrimination task for multiple days without disrupting vibrissal kinematics. Animals with degraded location discrimination performance can immediately perform a whisker touch detection task with high accuracy. Animals trained de novo on both simple and complex whisker touch detection tasks showed no permanent behavioral deficits following columnar-scale lesions. Thus, columnar-scale lesions permanently degrade performance in object location discrimination tasks.
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10
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Demonstration of three-dimensional contact point determination and contour reconstruction during active whisking behavior of an awake rat. PLoS Comput Biol 2022; 18:e1007763. [PMID: 36108064 PMCID: PMC9477318 DOI: 10.1371/journal.pcbi.1007763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 05/06/2022] [Indexed: 11/19/2022] Open
Abstract
The rodent vibrissal (whisker) system has been studied for decades as a model of active touch sensing. There are no sensors along the length of a whisker; all sensing occurs at the whisker base. Therefore, a large open question in many neuroscience studies is how an animal could estimate the three-dimensional (3D) location at which a whisker makes contact with an object. In the present work we simulated the shape of a real rat whisker to demonstrate the existence of several unique mappings from triplets of mechanical signals at the whisker base to the three-dimensional whisker-object contact point. We then used high speed video to record whisker deflections as an awake rat whisked against a peg, and used the mechanics resulting from those deflections to extract the contact points along the peg surface. These results demonstrate that measurement of specific mechanical triplets at the base of a biological whisker can enable 3D contact point determination during natural whisking behavior. The approach is viable even though the biological whisker has non-ideal, non-planar curvature, and even given the rat’s real-world choices of whisking parameters. Visual intuition for the quality of the approach is provided in a video that shows the contour of the peg gradually emerging during active whisking behavior.
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11
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Lemercier CE, Krieger P. Reducing Merkel cell activity in the whisker follicle disrupts cortical encoding of whisker movement amplitude and velocity. IBRO Neurosci Rep 2022; 13:356-363. [PMID: 36281438 PMCID: PMC9586890 DOI: 10.1016/j.ibneur.2022.09.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 09/26/2022] [Indexed: 11/26/2022] Open
Abstract
Merkel cells (MCs) and associated primary sensory afferents of the whisker follicle-sinus complex, accurately code whisker self-movement, angle, and whisk phase during whisking. However, little is known about their roles played in cortical encoding of whisker movement. To this end, the spiking activity of primary somatosensory barrel cortex (wS1) neurons was measured in response to varying the whisker deflection amplitude and velocity in transgenic mice with previously established reduced mechanoelectrical coupling at MC-associated afferents. Under reduced MC activity, wS1 neurons exhibited increased sensitivity to whisker deflection. This appeared to arise from a lack of variation in response magnitude to varying the whisker deflection amplitude and velocity. This latter effect was further indicated by weaker variation in the temporal profile of the evoked spiking activity when either whisker deflection amplitude or velocity was varied. Nevertheless, under reduced MC activity, wS1 neurons retained the ability to differentiate stimulus features based on the timing of their first post-stimulus spike. Collectively, results from this study suggest that MCs contribute to cortical encoding of both whisker amplitude and velocity, predominantly by tuning wS1 response magnitude, and by patterning the evoked spiking activity, rather than by tuning wS1 response latency. The role of Merkel cells (MCs) in cortical encoding of whisker deflection amplitude and velocity was investigated. Reducing MC synaptic activity increased barrel cortex neurons response sensitivity to whisker deflection. This effect occurred from a lack of variation in response magnitude to varying whisker deflection amplitude and velocity. However, stimuli differentiation through changes in cortical response latency was preserved. MCs are thus suggested to play a predominant role in tuning the cortical response magnitude over the response latency.
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12
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Starostin EL, Goss VGA, van der Heijden GHM. Whisker Sensing by Force and Moment Measurements at the Whisker Base. Soft Robot 2022; 10:326-335. [PMID: 35994004 DOI: 10.1089/soro.2021.0085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We address the theoretical question which forces and moments measured at the base of a whisker (tactile sensor) allow for the prediction of the location in space of the point at which a whisker makes contact with an object. We deal with the general case of three-dimensional deformations as well as with the special case of planar configurations. All deformations are treated as quasi-static, and contact is assumed to be frictionless. We show that the minimum number of independent forces or moments required is three but that conserved quantities of the governing elastic equilibrium equations prevent certain triples from giving a unique solution in the case of contact at any point along the whisker except the tip. The existence of these conserved quantities depends on the material and geometrical properties of the whisker. For whiskers that are tapered and intrinsically curved, there is no obstruction to the prediction of the contact point. We show that the choice of coordinate system (Cartesian or cylindrical) affects the number of suitable triples. Tip and multiple point contact are also briefly discussed. Our results explain recent numerical observations in the literature and offer guidance for the design of robotic tactile sensory devices.
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Affiliation(s)
- E L Starostin
- School of Engineering, London South Bank University, London, United Kingdom.,Department of Civil, Environmental and Geomatic Engineering, University College London, London, United Kingdom
| | - V G A Goss
- School of Engineering, London South Bank University, London, United Kingdom
| | - G H M van der Heijden
- Department of Civil, Environmental and Geomatic Engineering, University College London, London, United Kingdom
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13
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Rodgers CC, Nogueira R, Pil BC, Greeman EA, Park JM, Hong YK, Fusi S, Bruno RM. Sensorimotor strategies and neuronal representations for shape discrimination. Neuron 2021; 109:2308-2325.e10. [PMID: 34133944 PMCID: PMC8298290 DOI: 10.1016/j.neuron.2021.05.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 01/28/2021] [Accepted: 05/14/2021] [Indexed: 10/21/2022]
Abstract
Humans and other animals can identify objects by active touch, requiring the coordination of exploratory motion and tactile sensation. Both the motor strategies and neural representations employed could depend on the subject's goals. We developed a shape discrimination task that challenged head-fixed mice to discriminate concave from convex shapes. Behavioral decoding revealed that mice did this by comparing contacts across whiskers. In contrast, a separate group of mice performing a shape detection task simply summed up contacts over whiskers. We recorded populations of neurons in the barrel cortex, which processes whisker input, and found that individual neurons across the cortical layers encoded touch, whisker motion, and task-related signals. Sensory representations were task-specific: during shape discrimination, but not detection, neurons responded most to behaviorally relevant whiskers, overriding somatotopy. Thus, sensory cortex employs task-specific representations compatible with behaviorally relevant computations.
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Affiliation(s)
- Chris C Rodgers
- Department of Neuroscience, Columbia University, New York, NY 10027, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Kavli Institute for Brain Science, Columbia University, New York, NY 10027, USA.
| | - Ramon Nogueira
- Department of Neuroscience, Columbia University, New York, NY 10027, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Center for Theoretical Neuroscience, Columbia University, New York, NY 10027, USA
| | - B Christina Pil
- Department of Neuroscience, Columbia University, New York, NY 10027, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Kavli Institute for Brain Science, Columbia University, New York, NY 10027, USA
| | - Esther A Greeman
- Department of Neuroscience, Columbia University, New York, NY 10027, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Kavli Institute for Brain Science, Columbia University, New York, NY 10027, USA
| | - Jung M Park
- Department of Neuroscience, Columbia University, New York, NY 10027, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Kavli Institute for Brain Science, Columbia University, New York, NY 10027, USA
| | - Y Kate Hong
- Department of Neuroscience, Columbia University, New York, NY 10027, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Kavli Institute for Brain Science, Columbia University, New York, NY 10027, USA
| | - Stefano Fusi
- Department of Neuroscience, Columbia University, New York, NY 10027, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Kavli Institute for Brain Science, Columbia University, New York, NY 10027, USA; Center for Theoretical Neuroscience, Columbia University, New York, NY 10027, USA
| | - Randy M Bruno
- Department of Neuroscience, Columbia University, New York, NY 10027, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Kavli Institute for Brain Science, Columbia University, New York, NY 10027, USA.
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14
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de Kock CPJ, Pie J, Pieneman AW, Mease RA, Bast A, Guest JM, Oberlaender M, Mansvelder HD, Sakmann B. High-frequency burst spiking in layer 5 thick-tufted pyramids of rat primary somatosensory cortex encodes exploratory touch. Commun Biol 2021; 4:709. [PMID: 34112934 PMCID: PMC8192911 DOI: 10.1038/s42003-021-02241-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 05/18/2021] [Indexed: 01/14/2023] Open
Abstract
Diversity of cell-types that collectively shape the cortical microcircuit ensures the necessary computational richness to orchestrate a wide variety of behaviors. The information content embedded in spiking activity of identified cell-types remain unclear to a large extent. Here, we recorded spike responses upon whisker touch of anatomically identified excitatory cell-types in primary somatosensory cortex in naive, untrained rats. We find major differences across layers and cell-types. The temporal structure of spontaneous spiking contains high-frequency bursts (≥100 Hz) in all morphological cell-types but a significant increase upon whisker touch is restricted to layer L5 thick-tufted pyramids (L5tts) and thus provides a distinct neurophysiological signature. We find that whisker touch can also be decoded from L5tt bursting, but not from other cell-types. We observed high-frequency bursts in L5tts projecting to different subcortical regions, including thalamus, midbrain and brainstem. We conclude that bursts in L5tts allow accurate coding and decoding of exploratory whisker touch. In order to investigate the information encoded by spiking activity in different neuronal cell types in the primary somatosensory cortex, de Kock et al performed electrophysiological recordings in untrained rats. They demonstrated that an increase in high-frequency burst spiking in thick tufted pyramids in layer 5 of the cortex allow accurate encoding of exploratory whisker touch.
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Affiliation(s)
- Christiaan P J de Kock
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU, Amsterdam, the Netherlands.
| | - Jean Pie
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU, Amsterdam, the Netherlands.,University of Amsterdam, Swammerdam Institute for Life Sciences, Amsterdam, Netherlands
| | - Anton W Pieneman
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU, Amsterdam, the Netherlands
| | - Rebecca A Mease
- Institute of Physiology and Pathophysiology, Heidelberg University, Heidelberg, Germany
| | - Arco Bast
- Max Planck Group: In Silico Brain Sciences, Center of Advanced European Studies and Research, Bonn, Germany
| | - Jason M Guest
- Max Planck Group: In Silico Brain Sciences, Center of Advanced European Studies and Research, Bonn, Germany
| | - Marcel Oberlaender
- Max Planck Group: In Silico Brain Sciences, Center of Advanced European Studies and Research, Bonn, Germany
| | - Huibert D Mansvelder
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU, Amsterdam, the Netherlands
| | - Bert Sakmann
- Max Planck Institute for Neurobiology, Martinsried, Germany
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15
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O'Connor DH, Krubitzer L, Bensmaia S. Of mice and monkeys: Somatosensory processing in two prominent animal models. Prog Neurobiol 2021; 201:102008. [PMID: 33587956 PMCID: PMC8096687 DOI: 10.1016/j.pneurobio.2021.102008] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 12/26/2020] [Accepted: 02/07/2021] [Indexed: 11/20/2022]
Abstract
Our understanding of the neural basis of somatosensation is based largely on studies of the whisker system of mice and rats and the hands of macaque monkeys. Results across these animal models are often interpreted as providing direct insight into human somatosensation. Work on these systems has proceeded in parallel, capitalizing on the strengths of each model, but has rarely been considered as a whole. This lack of integration promotes a piecemeal understanding of somatosensation. Here, we examine the functions and morphologies of whiskers of mice and rats, the hands of macaque monkeys, and the somatosensory neuraxes of these three species. We then discuss how somatosensory information is encoded in their respective nervous systems, highlighting similarities and differences. We reflect on the limitations of these models of human somatosensation and consider key gaps in our understanding of the neural basis of somatosensation.
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Affiliation(s)
- Daniel H O'Connor
- Solomon H. Snyder Department of Neuroscience, Kavli Neuroscience Discovery Institute, Johns Hopkins University School of Medicine, United States; Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, United States
| | - Leah Krubitzer
- Department of Psychology and Center for Neuroscience, University of California at Davis, United States
| | - Sliman Bensmaia
- Department of Organismal Biology and Anatomy, University of Chicago, United States; Committee on Computational Neuroscience, University of Chicago, United States; Grossman Institute for Neuroscience, Quantitative Biology, and Human Behavior, University of Chicago, United States.
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16
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Abstract
Recent studies have been inspired by natural whiskers for a proposal of tactile sensing system to augment the sensory ability of autonomous robots. In this study, we propose a novel artificial soft whisker sensor that is not only flexible but also adapts and compensates for being trimmed or broken during operation. In this morphological compensation designed from an analytical model of the whisker, our sensing device actively adjusts its morphology to regain sensitivity close to that of its original form (before being broken). To serve this purpose, the body of the whisker comprises a silicon-rubber truncated cone with an air chamber inside as the medulla layer, which is inflated to achieve rigidity. A small strain gauge is attached to the outer wall of the chamber for recording strain variation upon contact of the whisker. The chamber wall is reinforced by two inextensible nylon fibers wound around it to ensure that morphology change occurs only in the measuring direction of the strain gauge by compressing or releasing pressurized air contained in the chamber. We investigated an analytical model for the regulation of whisker sensitivity by changing the chamber morphology. Experimental results showed good agreement with the numerical results of performance by an intact whisker in normal mode, as well as in compensation mode. Finally, adaptive functionality was tested in two separate scenarios for thorough evaluation: (1) A short whisker (65 mm) compensating for a longer one (70 mm), combined with a special case (self-compensation), and (2) vice versa. Preliminary results showed good feasibility of the idea and efficiency of the analytical model in the compensation process, in which the compensator in the typical scenario performed with 20.385% average compensation error. Implementation of the concept in the present study fulfills the concept of morphological computation in soft robotics and paves the way toward accomplishment of an active sensing system that overcomes a critical event (broken whisker) based on optimized morphological compensation.
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Affiliation(s)
- Nhan Huu Nguyen
- School of Materials Science, Japan Advanced Institute of Science and Technology (JAIST), Nomi, Japan
| | - Van Anh Ho
- School of Materials Science, Japan Advanced Institute of Science and Technology (JAIST), Nomi, Japan
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17
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Voigts J, Deister CA, Moore CI. Layer 6 ensembles can selectively regulate the behavioral impact and layer-specific representation of sensory deviants. eLife 2020; 9:48957. [PMID: 33263283 PMCID: PMC7817180 DOI: 10.7554/elife.48957] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Accepted: 12/01/2020] [Indexed: 11/21/2022] Open
Abstract
Predictive models can enhance the salience of unanticipated input. Here, we tested a key potential node in neocortical model formation in this process, layer (L) 6, using behavioral, electrophysiological and imaging methods in mouse primary somatosensory neocortex. We found that deviant stimuli enhanced tactile detection and were encoded in L2/3 neural tuning. To test the contribution of L6, we applied weak optogenetic drive that changed which L6 neurons were sensory responsive, without affecting overall firing rates in L6 or L2/3. This stimulation selectively suppressed behavioral sensitivity to deviant stimuli, without impacting baseline performance. This stimulation also eliminated deviance encoding in L2/3 but did not impair basic stimulus responses across layers. In contrast, stronger L6 drive inhibited firing and suppressed overall sensory function. These findings indicate that, despite their sparse activity, specific ensembles of stimulus-driven L6 neurons are required to form neocortical predictions, and to realize their behavioral benefit.
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Affiliation(s)
- Jakob Voigts
- Department of Neuroscience and Carney Institute for Brain Science, Brown University, Providence, United States.,Department of Brain and Cognitive Sciences, MIT, Cambridge, United States
| | - Christopher A Deister
- Department of Neuroscience and Carney Institute for Brain Science, Brown University, Providence, United States
| | - Christopher I Moore
- Department of Neuroscience and Carney Institute for Brain Science, Brown University, Providence, United States
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18
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Cheung JA, Maire P, Kim J, Lee K, Flynn G, Hires SA. Independent representations of self-motion and object location in barrel cortex output. PLoS Biol 2020; 18:e3000882. [PMID: 33141817 PMCID: PMC7665803 DOI: 10.1371/journal.pbio.3000882] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 11/13/2020] [Accepted: 09/18/2020] [Indexed: 11/19/2022] Open
Abstract
During active tactile exploration, the dynamic patterns of touch are transduced to electrical signals and transformed by the brain into a mental representation of the object under investigation. This transformation from sensation to perception is thought to be a major function of the mammalian cortex. In primary somatosensory cortex (S1) of mice, layer 5 (L5) pyramidal neurons are major outputs to downstream areas that influence perception, decision-making, and motor control. We investigated self-motion and touch representations in L5 of S1 with juxtacellular loose-seal patch recordings of optogenetically identified excitatory neurons. We found that during rhythmic whisker movement, 54 of 115 active neurons (47%) represented self-motion. This population was significantly more modulated by whisker angle than by phase. Upon active touch, a distinct pattern of activity was evoked across L5, which represented the whisker angle at the time of touch. Object location was decodable with submillimeter precision from the touch-evoked spike counts of a randomly sampled handful of these neurons. These representations of whisker angle during self-motion and touch were independent, both in the selection of which neurons were active and in the angle-tuning preference of coactive neurons. Thus, the output of S1 transiently shifts from a representation of self-motion to an independent representation of explored object location during active touch.
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Affiliation(s)
- Jonathan Andrew Cheung
- Department of Biological Sciences, Section of Neurobiology, University of Southern California, Los Angeles, California, United States of America
- Neuroscience Graduate Program, University of Southern California, Los Angeles, California, United States of America
| | - Phillip Maire
- Department of Biological Sciences, Section of Neurobiology, University of Southern California, Los Angeles, California, United States of America
- Neuroscience Graduate Program, University of Southern California, Los Angeles, California, United States of America
| | - Jinho Kim
- Department of Biological Sciences, Section of Neurobiology, University of Southern California, Los Angeles, California, United States of America
| | - Kiana Lee
- Department of Biological Sciences, Section of Neurobiology, University of Southern California, Los Angeles, California, United States of America
| | - Garrett Flynn
- Department of Biological Sciences, Section of Neurobiology, University of Southern California, Los Angeles, California, United States of America
| | - Samuel Andrew Hires
- Department of Biological Sciences, Section of Neurobiology, University of Southern California, Los Angeles, California, United States of America
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19
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Kim J, Erskine A, Cheung JA, Hires SA. Behavioral and Neural Bases of Tactile Shape Discrimination Learning in Head-Fixed Mice. Neuron 2020; 108:953-967.e8. [PMID: 33002411 DOI: 10.1016/j.neuron.2020.09.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 07/31/2020] [Accepted: 09/08/2020] [Indexed: 11/29/2022]
Abstract
Tactile shape recognition requires the perception of object surface angles. We investigate how neural representations of object angles are constructed from sensory input and how they reorganize across learning. Head-fixed mice learned to discriminate object angles by active exploration with one whisker. Calcium imaging of layers 2-4 of the barrel cortex revealed maps of object-angle tuning before and after learning. Three-dimensional whisker tracking demonstrated that the sensory input components that best discriminate angles (vertical bending and slide distance) also have the greatest influence on object-angle tuning. Despite the high turnover in active ensemble membership across learning, the population distribution of object-angle tuning preferences remained stable. Angle tuning sharpened, but only in neurons that preferred trained angles. This was correlated with a selective increase in the influence of the most task-relevant sensory component on object-angle tuning. These results show how discrimination training enhances stimulus selectivity in the primary somatosensory cortex while maintaining perceptual stability.
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Affiliation(s)
- Jinho Kim
- Department of Biological Sciences, Section of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
| | - Andrew Erskine
- Department of Biological Sciences, Section of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
| | - Jonathan Andrew Cheung
- Department of Biological Sciences, Section of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
| | - Samuel Andrew Hires
- Department of Biological Sciences, Section of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA.
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20
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Staiger JF, Petersen CCH. Neuronal Circuits in Barrel Cortex for Whisker Sensory Perception. Physiol Rev 2020; 101:353-415. [PMID: 32816652 DOI: 10.1152/physrev.00019.2019] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The array of whiskers on the snout provides rodents with tactile sensory information relating to the size, shape and texture of objects in their immediate environment. Rodents can use their whiskers to detect stimuli, distinguish textures, locate objects and navigate. Important aspects of whisker sensation are thought to result from neuronal computations in the whisker somatosensory cortex (wS1). Each whisker is individually represented in the somatotopic map of wS1 by an anatomical unit named a 'barrel' (hence also called barrel cortex). This allows precise investigation of sensory processing in the context of a well-defined map. Here, we first review the signaling pathways from the whiskers to wS1, and then discuss current understanding of the various types of excitatory and inhibitory neurons present within wS1. Different classes of cells can be defined according to anatomical, electrophysiological and molecular features. The synaptic connectivity of neurons within local wS1 microcircuits, as well as their long-range interactions and the impact of neuromodulators, are beginning to be understood. Recent technological progress has allowed cell-type-specific connectivity to be related to cell-type-specific activity during whisker-related behaviors. An important goal for future research is to obtain a causal and mechanistic understanding of how selected aspects of tactile sensory information are processed by specific types of neurons in the synaptically connected neuronal networks of wS1 and signaled to downstream brain areas, thus contributing to sensory-guided decision-making.
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Affiliation(s)
- Jochen F Staiger
- University Medical Center Göttingen, Institute for Neuroanatomy, Göttingen, Germany; and Laboratory of Sensory Processing, Faculty of Life Sciences, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Carl C H Petersen
- University Medical Center Göttingen, Institute for Neuroanatomy, Göttingen, Germany; and Laboratory of Sensory Processing, Faculty of Life Sciences, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
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21
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Watson LS, Stone TD, Williams D, Williams AS, Sims-Robinson C. High-Fat Diet Impairs Tactile Discrimination Memory in the Mouse. Behav Brain Res 2020; 382:112454. [PMID: 31926214 PMCID: PMC7129774 DOI: 10.1016/j.bbr.2019.112454] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 12/09/2019] [Accepted: 12/25/2019] [Indexed: 12/13/2022]
Abstract
Research on the impact of diet and memory has garnered considerable attention while exploring the link between obesity and cognitive impairment. High-fat diet (HFD) rodent models recapitulate the obesity phenotype and subsequent cognitive impairments. While it is known that HFD is associated with sensory impairment, little attention has been given to the potential role these sensory deficits may play in recognition memory testing, one of the most commonly used cognitive tests. Because mice utilize their facial whiskers as their primary sensory apparatus, we modified a common recognition test, the novel object recognition task, by replacing objects with sandpaper grits at ground level, herein referred to as the novel tactile recognition task (NTR). First, we tested whisker-manipulated mice in this task to determine its reliance on intact whiskers. Then, we tested the HFD mouse in the NTR. Finally, to ensure that deficits in the NTR are due to cognitive impairment and not HFD-induced sensory deficiencies, we tested the whisker sensitivity of HFD mice via the corner test. Our results indicate that the NTR is a whisker dependent task, and that HFD mice exhibit tactile recognition memory impairment, not accompanied by whisker sensory deficits.
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Affiliation(s)
- Luke S Watson
- Department of Neurology, Medical University of South Carolina, Charleston, South Carolina, 29425 USA; Molecular and Cellular Biology and Pathobiology Program, Medical University of South Carolina, Charleston, South Carolina, 29425 USA
| | - Tyler D Stone
- Department of Neurology, Medical University of South Carolina, Charleston, South Carolina, 29425 USA; Honors College, College of Charleston, Charleston, South Carolina, 29424 USA
| | - Dominique Williams
- Department of Neurology, Medical University of South Carolina, Charleston, South Carolina, 29425 USA
| | - Alexus S Williams
- Department of Neurology, Medical University of South Carolina, Charleston, South Carolina, 29425 USA
| | - Catrina Sims-Robinson
- Department of Neurology, Medical University of South Carolina, Charleston, South Carolina, 29425 USA; Molecular and Cellular Biology and Pathobiology Program, Medical University of South Carolina, Charleston, South Carolina, 29425 USA.
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22
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Petersen RS, Colins Rodriguez A, Evans MH, Campagner D, Loft MSE. A system for tracking whisker kinematics and whisker shape in three dimensions. PLoS Comput Biol 2020; 16:e1007402. [PMID: 31978043 PMCID: PMC7028309 DOI: 10.1371/journal.pcbi.1007402] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 02/18/2020] [Accepted: 12/05/2019] [Indexed: 11/18/2022] Open
Abstract
Quantification of behaviour is essential for biology. Since the whisker system is a popular model, it is important to have methods for measuring whisker movements from behaving animals. Here, we developed a high-speed imaging system that measures whisker movements simultaneously from two vantage points. We developed a whisker tracker algorithm that automatically reconstructs 3D whisker information directly from the ‘stereo’ video data. The tracker is controlled via a Graphical User Interface that also allows user-friendly curation. The algorithm tracks whiskers, by fitting a 3D Bezier curve to the basal section of each target whisker. By using prior knowledge of natural whisker motion and natural whisker shape to constrain the fits and by minimising the number of fitted parameters, the algorithm is able to track multiple whiskers in parallel with low error rate. We used the output of the tracker to produce a 3D description of each tracked whisker, including its 3D orientation and 3D shape, as well as bending-related mechanical force. In conclusion, we present a non-invasive, automatic system to track whiskers in 3D from high-speed video, creating the opportunity for comprehensive 3D analysis of sensorimotor behaviour and its neural basis. The great ethologist Niko Tinbergen described a crucial challenge in biology to measure the “total movements made by the intact animal”[1]. Advances in high-speed video and machine analysis of such data have made it possible to make profound advances. Here, we target the whisker system. The whisker system is a major experimental model in neurobiology and, since the whiskers are readily imageable, the system is ideally suited to machine vision. Rats and mice explore their environment by sweeping their whiskers to and fro. It is important to measure whisker movements in 3D, since whiskers move in 3D and since the mechanical forces that act on them are 3D. However, the computational problem of automatically tracking whiskers in 3D from video has generally been regarded as prohibitively difficult. Our innovation here is to extract 3D information about whiskers using a two-camera, high-speed imaging system and to develop computational methods to reconstruct 3D whisker state from the imaging data. Our hope is that this study will facilitate comprehensive, 3D analysis of whisker behaviour and, more generally, contribute new insight into brain mechanisms of perception and behaviour.
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Affiliation(s)
- Rasmus S. Petersen
- Division of Neuroscience and Experimental Psychology, University of Manchester, Manchester, United Kingdom
- * E-mail:
| | - Andrea Colins Rodriguez
- Division of Neuroscience and Experimental Psychology, University of Manchester, Manchester, United Kingdom
| | - Mathew H. Evans
- Division of Neuroscience and Experimental Psychology, University of Manchester, Manchester, United Kingdom
| | - Dario Campagner
- Division of Neuroscience and Experimental Psychology, University of Manchester, Manchester, United Kingdom
| | - Michaela S. E. Loft
- Division of Neuroscience and Experimental Psychology, University of Manchester, Manchester, United Kingdom
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23
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Deutsch D, Schneidman E, Ahissar E. Generalization of Object Localization From Whiskers to Other Body Parts in Freely Moving Rats. Front Integr Neurosci 2019; 13:64. [PMID: 31736724 PMCID: PMC6839537 DOI: 10.3389/fnint.2019.00064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 10/16/2019] [Indexed: 11/13/2022] Open
Abstract
Rats can be trained to associate relative spatial locations of objects with the spatial location of rewards. Here we ask whether rats can localize static silent objects with other body parts in the dark, and if so with what resolution. We addressed these questions in trained rats, whose interactions with the objects were tracked at high-resolution before and after whisker trimming. We found that rats can use other body parts, such as trunk and ears, to localize objects. Localization resolution with non-whisking body parts (henceforth, ‘body’) was poorer than that obtained with whiskers, even when left with a single whisker at each side. Part of the superiority of whiskers was obtained via the use of multiple contacts. Transfer from whisker to body localization occurred within one session, provided that body contacts with the objects occurred before whisker trimming, or in the next session otherwise. This transfer occurred whether temporal cues were used for discrimination or when discrimination was based on spatial cues alone. Rats’ decision in each trial was based on the sensory cues acquired in that trial and on decisions and reward locations in previous trials. When sensory cues were acquired by body contacts, rat decisions relied more on the reward location in previous trials. Overall, the results suggest that rats can generalize the idea of relative object location across different body parts, while preferring to rely on whiskers-based localization, which occurs earlier and conveys higher resolution.
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Affiliation(s)
- David Deutsch
- Department of Neurobiology, The Weizmann Institute of Science, Rehovot, Israel
| | - Elad Schneidman
- Department of Neurobiology, The Weizmann Institute of Science, Rehovot, Israel
| | - Ehud Ahissar
- Department of Neurobiology, The Weizmann Institute of Science, Rehovot, Israel
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24
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Gillespie D, Yap MH, Hewitt BM, Driscoll H, Simanaviciute U, Hodson-Tole EF, Grant RA. Description and validation of the LocoWhisk system: Quantifying rodent exploratory, sensory and motor behaviours. J Neurosci Methods 2019; 328:108440. [PMID: 31560929 DOI: 10.1016/j.jneumeth.2019.108440] [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: 05/01/2019] [Revised: 09/20/2019] [Accepted: 09/22/2019] [Indexed: 12/22/2022]
Abstract
BACKGROUND Previous studies have demonstrated that analysing whisker movements and locomotion allows us to quantify the behavioural consequences of sensory, motor and cognitive deficits in rodents. Independent whisker and feet trackers exist but there is no fully-automated, open-source software and hardware solution, that measures both whisker movements and gait. NEW METHOD We present the LocoWhisk arena and new accompanying software (ARTv2) that allows the automatic detection and measurement of both whisker and gait information from high-speed video footage. RESULTS We demonstrate the new whisker and foot detector algorithms on high-speed video footage of freely moving small mammals, and show that whisker movement and gait measurements collected in the LocoWhisk arena are similar to previously reported values in the literature. COMPARISON WITH EXISTING METHOD(S) We demonstrate that the whisker and foot detector algorithms, are comparable in accuracy, and in some cases significantly better, than readily available software and manual trackers. CONCLUSION The LocoWhisk system enables the collection of quantitative data from whisker movements and locomotion in freely behaving rodents. The software automatically records both whisker and gait information and provides added statistical tools to analyse the data. We hope the LocoWhisk system and software will serve as a solid foundation from which to support future research in whisker and gait analysis.
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Affiliation(s)
- David Gillespie
- School of Engineering, Manchester Metropolitan University, Manchester, UK
| | - Moi Hoon Yap
- School of Computing, Mathematics and Digital Technology, Manchester Metropolitan University, Manchester, UK
| | - Brett M Hewitt
- School of Computing, Mathematics and Digital Technology, Manchester Metropolitan University, Manchester, UK; School of Science and Environment, Manchester Metropolitan University, Manchester, UK; CSols Ltd, Runcorn, Cheshire, WA7 4QX, UK
| | - Heather Driscoll
- School of Engineering, Manchester Metropolitan University, Manchester, UK; Advanced Manufacturing Research Center, University of Sheffield, Sheffield, UK
| | - Ugne Simanaviciute
- School of Science and Environment, Manchester Metropolitan University, Manchester, UK; School of Biological Sciences, University of Manchester, Manchester, UK
| | - Emma F Hodson-Tole
- Musculoskeletal Science and Sports Medicine Research Centre, Dpt. Lifesciences, Manchester Metropolitan University, Manchester, UK
| | - Robyn A Grant
- School of Science and Environment, Manchester Metropolitan University, Manchester, UK.
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25
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The Sensorimotor Basis of Whisker-Guided Anteroposterior Object Localization in Head-Fixed Mice. Curr Biol 2019; 29:3029-3040.e4. [PMID: 31474537 PMCID: PMC6771421 DOI: 10.1016/j.cub.2019.07.068] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 06/26/2019] [Accepted: 07/23/2019] [Indexed: 11/22/2022]
Abstract
Active tactile perception combines directed motion with sensory signals to generate mental representations of objects in space. Competing models exist for how mice use these signals to determine the precise location of objects along their face. We tested six of these models using behavioral manipulations and statistical learning in head-fixed mice. Trained mice used a whisker to locate a pole in a continuous range of locations along the anteroposterior axis. Mice discriminated locations to ≤0.5 mm (<2°) resolution. Their motor program was noisy, adaptive to touch, and directed to the rewarded range. This exploration produced several sets of sensorimotor features that could discriminate location. Integration of two features, touch count and whisking midpoint at touch, was the simplest model that explained behavior best. These results show how mice locate objects at hyperacute resolution using a learned motor strategy and minimal set of mentally accessible sensorimotor features.
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26
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Yu J, Hu H, Agmon A, Svoboda K. Recruitment of GABAergic Interneurons in the Barrel Cortex during Active Tactile Behavior. Neuron 2019; 104:412-427.e4. [PMID: 31466734 DOI: 10.1016/j.neuron.2019.07.027] [Citation(s) in RCA: 97] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 06/07/2019] [Accepted: 07/22/2019] [Indexed: 10/26/2022]
Abstract
Neural computation involves diverse types of GABAergic inhibitory interneurons that are integrated with excitatory (E) neurons into precisely structured circuits. To understand how each neuron type shapes sensory representations, we measured firing patterns of defined types of neurons in the barrel cortex while mice performed an active, whisker-dependent object localization task. Touch excited fast-spiking (FS) interneurons at short latency, followed by activation of E neurons and somatostatin-expressing (SST) interneurons. Touch only weakly modulated vasoactive intestinal polypeptide-expressing (VIP) interneurons. Voluntary whisker movement activated FS neurons in the ventral posteromedial nucleus (VPM) target layers, a subset of SST neurons and a majority of VIP neurons. Together, FS neurons track thalamic input, mediating feedforward inhibition. SST neurons monitor local excitation, providing feedback inhibition. VIP neurons are activated by non-sensory inputs, disinhibiting E and FS neurons. Our data reveal rules of recruitment for interneuron types during behavior, providing foundations for understanding computation in cortical microcircuits.
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Affiliation(s)
- Jianing Yu
- Janelia Research Campus, Howard Hughes Medical Institute (HHMI), Ashburn, VA 20147, USA.
| | - Hang Hu
- Department of Neuroscience, West Virginia University School of Medicine and Rockefeller Neuroscience Institute, Morgantown, WV 26506, USA
| | - Ariel Agmon
- Janelia Research Campus, Howard Hughes Medical Institute (HHMI), Ashburn, VA 20147, USA; Department of Neuroscience, West Virginia University School of Medicine and Rockefeller Neuroscience Institute, Morgantown, WV 26506, USA
| | - Karel Svoboda
- Janelia Research Campus, Howard Hughes Medical Institute (HHMI), Ashburn, VA 20147, USA.
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27
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van der Bourg A, Yang JW, Stüttgen MC, Reyes-Puerta V, Helmchen F, Luhmann HJ. Temporal refinement of sensory-evoked activity across layers in developing mouse barrel cortex. Eur J Neurosci 2019; 50:2955-2969. [PMID: 30941846 DOI: 10.1111/ejn.14413] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 03/05/2019] [Accepted: 03/17/2019] [Indexed: 12/22/2022]
Abstract
Rhythmic whisking behavior in rodents fully develops during a critical period about 2 weeks after birth, in parallel with the maturation of other sensory modalities and the onset of exploratory locomotion. How whisker-related sensory processing develops during this period in the primary somatosensory cortex (S1) remains poorly understood. Here, we characterized neuronal activity evoked by single- or dual-whisker stimulation patterns in developing S1, before, during and after the occurrence of active whisking. Employing multi-electrode recordings in all layers of barrel cortex in urethane-anesthetized mice, we find layer-specific changes in multi-unit activity for principal and neighboring barrel columns. While whisker stimulation evoked similar early responses (0-50 ms post-stimulus) across development, the late response (50-150 ms post-stimulus) decreased in all layers with age. Furthermore, peak onset times and the duration of the late response decreased in all layers across age groups. Responses to paired-pulse stimulation showed increases in spiking precision and in paired-pulse ratios in all cortical layers during development. Sequential activation of two neighboring whiskers with varying stimulus intervals evoked distinct response profiles in the activated barrel columns, depending on the direction and temporal separation of the stimuli. In conclusion, our findings indicate that the temporal sharpening of sensory-evoked activity coincides with the onset of active whisking.
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Affiliation(s)
- Alexander van der Bourg
- Laboratory of Neural Circuit Dynamics, Brain Research Institute, University of Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, Zurich, Switzerland
| | - Jenq-Wei Yang
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Maik C Stüttgen
- Institute of Pathophysiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Vicente Reyes-Puerta
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Fritjof Helmchen
- Laboratory of Neural Circuit Dynamics, Brain Research Institute, University of Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, Zurich, Switzerland
| | - Heiko J Luhmann
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
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28
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Ranjbar-Slamloo Y, Arabzadeh E. Diverse tuning underlies sparse activity in layer 2/3 vibrissal cortex of awake mice. J Physiol 2019; 597:2803-2817. [PMID: 30932197 DOI: 10.1113/jp277506] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 03/22/2019] [Indexed: 12/23/2022] Open
Abstract
KEY POINTS Sparse population activity is a common feature observed across cortical areas, yet the implications for sensory coding are not clear. We recorded single neuron activity in the vibrissal somatosensory cortex of awake head-fixed mice using the cell-attached technique. Unlike the anaesthetised condition, in awake mice a high-velocity, piezo-controlled whisker deflection excited only a small fraction of neurons. Manual probing of whiskers revealed that the majority of these silent neurons could be activated by specific forms of whisker-object contact. Our results suggest that sparse coding in vibrissal cortex may be due to high dimensionality of the stimulus space and narrow tuning of individual neurons. ABSTRACT It is widely reported that superficial layers of the somatosensory cortex exhibit sparse firing. This sparseness could reflect weak feedforward sensory inputs that are not sufficient to generate action potentials in these layers. Alternatively, sparseness might reflect tuning to unknown or higher-level complex features that are not fully explored in the stimulus space. Here, we examined these hypotheses by applying a range of vibrotactile and manual vibrissal stimuli in awake, head-fixed mice while performing loose-seal cell-attached recordings from the vibrissal primary somatosensory (vS1) cortex. A high-velocity stimulus delivered by a piezo-electric actuator evoked activity in a small fraction of regular spiking supragranular neurons (23%) in the awake condition. However, a majority of the supragranular regular spiking neurons (84%) were driven by manual stimulation of whiskers. Our results suggest that most neurons in the superficial layers of vS1 cortex contribute to coding in the awake condition when neurons may encounter their preferred feature(s) during whisker-object interactions.
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Affiliation(s)
- Yadollah Ranjbar-Slamloo
- Eccles Institute of Neuroscience, The John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory, Australia.,Australian Research Council Centre of Excellence for Integrative Brain Function, The Australian National University Node, Canberra, Australian Capital Territory, Australia
| | - Ehsan Arabzadeh
- Eccles Institute of Neuroscience, The John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory, Australia.,Australian Research Council Centre of Excellence for Integrative Brain Function, The Australian National University Node, Canberra, Australian Capital Territory, Australia
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29
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Wang X, Chou X, Peng B, Shen L, Huang JJ, Zhang LI, Tao HW. A cross-modality enhancement of defensive flight via parvalbumin neurons in zona incerta. eLife 2019; 8:42728. [PMID: 30985276 PMCID: PMC6486150 DOI: 10.7554/elife.42728] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 04/14/2019] [Indexed: 12/13/2022] Open
Abstract
The ability to adjust defensive behavior is critical for animal survival in dynamic environments. However, neural circuits underlying the modulation of innate defensive behavior remain not well-understood. In particular, environmental threats are commonly associated with cues of multiple sensory modalities. It remains to be investigated how these modalities interact to shape defensive behavior. In this study, we report that auditory-induced defensive flight behavior can be facilitated by somatosensory input in mice. This cross-modality modulation of defensive behavior is mediated by the projection from the primary somatosensory cortex (SSp) to the ventral sector of zona incerta (ZIv). Parvalbumin (PV)-positive neurons in ZIv, receiving direct input from SSp, mediate the enhancement of the flight behavior via their projections to the medial posterior complex of thalamus (POm). Thus, defensive flight can be enhanced in a somatosensory context-dependent manner via recruiting PV neurons in ZIv, which may be important for increasing survival of prey animals.
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Affiliation(s)
- Xiyue Wang
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, United States.,Graduate Program in Neuroscience, University of Southern California, Los Angeles, United States
| | - Xiaolin Chou
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, United States.,Graduate Program in Neuroscience, University of Southern California, Los Angeles, United States
| | - Bo Peng
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, United States.,Graduate Program in Neuroscience, University of Southern California, Los Angeles, United States
| | - Li Shen
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, United States
| | - Junxiang J Huang
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, United States.,Graduate Program in Biomedical and Biological Sciences, University of Southern California, Los Angeles, United States
| | - Li I Zhang
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, United States.,Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, United States
| | - Huizhong W Tao
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, United States.,Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, United States
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30
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Prediction of Choice from Competing Mechanosensory and Choice-Memory Cues during Active Tactile Decision Making. J Neurosci 2019; 39:3921-3933. [PMID: 30850514 PMCID: PMC6520515 DOI: 10.1523/jneurosci.2217-18.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 01/11/2019] [Accepted: 01/16/2019] [Indexed: 01/15/2023] Open
Abstract
Perceptual decision making is an active process where animals move their sense organs to extract task-relevant information. To investigate how the brain translates sensory input into decisions during active sensation, we developed a mouse active touch task where the mechanosensory input can be precisely measured and that challenges animals to use multiple mechanosensory cues. Male mice were trained to localize a pole using a single whisker and to report their decision by selecting one of three choices. Using high-speed imaging and machine vision, we estimated whisker-object mechanical forces at millisecond resolution. Mice solved the task by a sensory-motor strategy where both the strength and direction of whisker bending were informative cues to pole location. We found competing influences of immediate sensory input and choice memory on mouse choice. On correct trials, choice could be predicted from the direction and strength of whisker bending, but not from previous choice. In contrast, on error trials, choice could be predicted from previous choice but not from whisker bending. This study shows that animal choices during active tactile decision making can be predicted from mechanosensory and choice-memory signals, and provides a new task well suited for the future study of the neural basis of active perceptual decisions.SIGNIFICANCE STATEMENT Due to the difficulty of measuring the sensory input to moving sense organs, active perceptual decision making remains poorly understood. The whisker system provides a way forward since it is now possible to measure the mechanical forces due to whisker-object contact during behavior. Here we train mice in a novel behavioral task that challenges them to use rich mechanosensory cues but can be performed using one whisker and enables task-relevant mechanical forces to be precisely estimated. This approach enables rigorous study of how sensory cues translate into action during active, perceptual decision making. Our findings provide new insight into active touch and how sensory/internal signals interact to determine behavioral choices.
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31
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Lee CCY, Clifford CWG, Arabzadeh E. Temporal cueing enhances neuronal and behavioral discrimination performance in rat whisker system. J Neurophysiol 2019; 121:1048-1058. [DOI: 10.1152/jn.00604.2018] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Since sensory systems operate with a finite quantity of processing resources, an animal would benefit from prioritizing processing of sensory stimuli within a time window that is expected to provide key information. This behavioral manifestation of such prioritization is known as attention. Here, we investigate attention with temporal cueing and its neuronal correlates in the rat primary vibrissal somatosensory (vS1) cortex. Rats were trained in a simple whisker vibration detection task. A vibration was presented at one of two spatial locations (left or right), sometimes after an unknown time interval and sometimes after receiving an auditory cue. The auditory cue provided temporal but not spatial information about the vibration. We found that for all rats ( n = 6), the auditory cue consistently enhanced detection of the vibration stimulus. Neuronal activity in vS1 cortex reflected the observed behavioral enhancement from temporal cueing with single units responded differentially to the whisker vibration stimulus when it was temporally predicted by the auditory cue, exhibiting an enhanced signal-to-noise ratio. Our findings indicate that rats are capable of prioritizing processing within a specified time window and provide evidence that the primary sensory cortex may participate in the temporal allocation of resources. NEW & NOTEWORTHY We demonstrate a novel paradigm of temporal cueing in rats. In a two-alternative whisker detection task, an auditory cue provided information about the timing of the stimulus but not the correct choice. In the presence of cue, detection was faster and more accurate, and neuronal activity from the primary somatosensory cortex revealed enhanced representation of vibrations. These results thus establish the rat as an alternative model organism to primates for studying temporal attention.
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Affiliation(s)
- Conrad C. Y. Lee
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory, Australia
- Australian Research Council Centre of Excellence for Integrative Brain Function, The Australian National University Node, Canberra, Australian Capital Territory, Australia
| | - Colin W. G. Clifford
- School of Psychology, University of New South Wales Sydney, Sydney, New South Wales, Australia
| | - Ehsan Arabzadeh
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, Australian Capital Territory, Australia
- Australian Research Council Centre of Excellence for Integrative Brain Function, The Australian National University Node, Canberra, Australian Capital Territory, Australia
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32
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Severson KS, Xu D, Yang H, O'Connor DH. Coding of whisker motion across the mouse face. eLife 2019; 8:41535. [PMID: 30816844 PMCID: PMC6395061 DOI: 10.7554/elife.41535] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 02/11/2019] [Indexed: 12/15/2022] Open
Abstract
Haptic perception synthesizes touch with proprioception, the sense of body position. Humans and mice alike experience rich active touch of the face. Because most facial muscles lack proprioceptor endings, the sensory basis of facial proprioception remains unsolved. Facial proprioception may instead rely on mechanoreceptors that encode both touch and self-motion. In rodents, whisker mechanoreceptors provide a signal that informs the brain about whisker position. Whisking involves coordinated orofacial movements, so mechanoreceptors innervating facial regions other than whiskers could also provide information about whisking. To define all sources of sensory information about whisking available to the brain, we recorded spikes from mechanoreceptors innervating diverse parts of the face. Whisker motion was encoded best by whisker mechanoreceptors, but also by those innervating whisker pad hairy skin and supraorbital vibrissae. Redundant self-motion responses may provide the brain with a stable proprioceptive signal despite mechanical perturbations during active touch.
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Affiliation(s)
- Kyle S Severson
- The Solomon H. Snyder Department of Neuroscience, Kavli Neuroscience Discovery Institute, Brain Science Institute, The Johns Hopkins University School of Medicine, Baltimore, United States
| | - Duo Xu
- The Solomon H. Snyder Department of Neuroscience, Kavli Neuroscience Discovery Institute, Brain Science Institute, The Johns Hopkins University School of Medicine, Baltimore, United States
| | - Hongdian Yang
- The Solomon H. Snyder Department of Neuroscience, Kavli Neuroscience Discovery Institute, Brain Science Institute, The Johns Hopkins University School of Medicine, Baltimore, United States
| | - Daniel H O'Connor
- The Solomon H. Snyder Department of Neuroscience, Kavli Neuroscience Discovery Institute, Brain Science Institute, The Johns Hopkins University School of Medicine, Baltimore, United States
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33
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Chaudhary R, Rema V. Deficits in Behavioral Functions of Intact Barrel Cortex Following Lesions of Homotopic Contralateral Cortex. Front Syst Neurosci 2018; 12:57. [PMID: 30524251 PMCID: PMC6262316 DOI: 10.3389/fnsys.2018.00057] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 10/17/2018] [Indexed: 12/02/2022] Open
Abstract
Focal unilateral injuries to the somatosensory whisker barrel cortex have been shown cause long-lasting deficits in the activity and experience-dependent plasticity of neurons in the intact contralateral barrel cortex. However, the long-term effect of these deficits on behavioral functions of the intact contralesional cortex is not clear. In this study, we used the “Gap-crossing task” a barrel cortex-dependent, whisker-sensitive, tactile behavior to test the hypothesis that unilateral lesions of the somatosensory cortex would affect behavioral functions of the intact somatosensory cortex and degrade the execution of a bilaterally learnt behavior. Adult rats were trained to perform the Gap-crossing task using whiskers on both sides of the face. The barrel cortex was then lesioned unilaterally by subpial aspiration. As observed in other studies, when rats used whiskers that directly projected to the lesioned hemisphere the performance of Gap-crossing was drastically compromised, perhaps due to direct effect of lesion. Significant and persistent deficits were present when the lesioned rats performed Gap-crossing task using whiskers that projected to the intact cortex. The deficits were specific to performance of the task at the highest levels of sensitivity. Comparable deficits were seen when normal, bilaterally trained, rats performed the Gap-crossing task with only the whiskers on one side of the face or when they used only two rows of whiskers (D row and E row) intact on both side of the face. These findings indicate that the prolonged impairment in execution of the learnt task by rats with unilateral lesions of somatosensory cortex could be because sensory inputs from one set of whiskers to the intact cortex is insufficient to provide adequate sensory information at higher thresholds of detection. Our data suggest that optimal performance of somatosensory behavior requires dynamic activity-driven interhemispheric interactions from the entire somatosensory inputs between homotopic areas of the cerebral cortex. These results imply that focal unilateral cortical injuries, including those in humans, are likely to have widespread bilateral effects on information processing including in intact areas of the cortex.
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Affiliation(s)
| | - V Rema
- National Brain Research Centre, Manesar, India
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34
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Astreinidi Blandin A, Bernardeschi I, Beccai L. Biomechanics in Soft Mechanical Sensing: From Natural Case Studies to the Artificial World. Biomimetics (Basel) 2018; 3:E32. [PMID: 31105254 PMCID: PMC6352697 DOI: 10.3390/biomimetics3040032] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 09/14/2018] [Accepted: 10/12/2018] [Indexed: 12/25/2022] Open
Abstract
Living beings use mechanical interaction with the environment to gather essential cues for implementing necessary movements and actions. This process is mediated by biomechanics, primarily of the sensory structures, meaning that, at first, mechanical stimuli are morphologically computed. In the present paper, we select and review cases of specialized sensory organs for mechanical sensing-from both the animal and plant kingdoms-that distribute their intelligence in both structure and materials. A focus is set on biomechanical aspects, such as morphology and material characteristics of the selected sensory organs, and on how their sensing function is affected by them in natural environments. In this route, examples of artificial sensors that implement these principles are provided, and/or ways in which they can be translated artificially are suggested. Following a biomimetic approach, our aim is to make a step towards creating a toolbox with general tailoring principles, based on mechanical aspects tuned repeatedly in nature, such as orientation, shape, distribution, materials, and micromechanics. These should be used for a future methodical design of novel soft sensing systems for soft robotics.
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Affiliation(s)
- Afroditi Astreinidi Blandin
- Center for Micro-BioRobotics, Istituto Italiano di Tecnologia, Pontedera, 56025 Pisa, Italy.
- The BioRobotics Institute, Scuola Superiore Sant'Anna, Pontedera, 56025 Pisa, Italy.
| | - Irene Bernardeschi
- Center for Micro-BioRobotics, Istituto Italiano di Tecnologia, Pontedera, 56025 Pisa, Italy.
| | - Lucia Beccai
- Center for Micro-BioRobotics, Istituto Italiano di Tecnologia, Pontedera, 56025 Pisa, Italy.
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35
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Ranganathan GN, Apostolides PF, Harnett MT, Xu NL, Druckmann S, Magee JC. Active dendritic integration and mixed neocortical network representations during an adaptive sensing behavior. Nat Neurosci 2018; 21:1583-1590. [PMID: 30349100 PMCID: PMC6203624 DOI: 10.1038/s41593-018-0254-6] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 09/13/2018] [Indexed: 02/08/2023]
Abstract
Animals strategically scan the environment to form an accurate perception of their surroundings. Here we investigated the neuronal representations that mediate this behavior. Ca2+ imaging and selective optogenetic manipulation during an active sensing task reveals that layer 5 pyramidal neurons in the vibrissae cortex produce a diverse and distributed representation that is required for mice to adapt their whisking motor strategy to changing sensory cues. The optogenetic perturbation degraded single-neuron selectivity and network population encoding through a selective inhibition of active dendritic integration. Together the data indicate that active dendritic integration in pyramidal neurons produces a nonlinearly mixed network representation of joint sensorimotor parameters that is used to transform sensory information into motor commands during adaptive behavior. The prevalence of the layer 5 cortical circuit motif suggests that this is a general circuit computation.
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Affiliation(s)
| | - Pierre F Apostolides
- Howard Hughes Medical Institute, Janelia Research Campus, Ashburn, VA, USA.,Kresge Hearing Research Institute Department of Otolaryngology, University of Michigan , Ann Arbor, MI, USA
| | - Mark T Harnett
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Ning-Long Xu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Shaul Druckmann
- Howard Hughes Medical Institute, Janelia Research Campus, Ashburn, VA, USA
| | - Jeffrey C Magee
- Howard Hughes Medical Institute, Janelia Research Campus, Ashburn, VA, USA. .,Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX, USA.
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36
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Goldin MA, Harrell ER, Estebanez L, Shulz DE. Rich spatio-temporal stimulus dynamics unveil sensory specialization in cortical area S2. Nat Commun 2018; 9:4053. [PMID: 30282992 PMCID: PMC6170455 DOI: 10.1038/s41467-018-06585-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 09/12/2018] [Indexed: 11/21/2022] Open
Abstract
Tactile perception in rodents depends on simultaneous, multi-whisker contacts with objects. Although it is known that neurons in secondary somatosensory cortex (wS2) respond to individual deflections of many whiskers, wS2′s precise function remains unknown. The convergence of information from multiple whiskers into wS2 neurons suggests that they are good candidates for integrating multi-whisker information. Here, we apply stimulation patterns with rich dynamics simultaneously to 24 macro-vibrissae of rats while recording large populations of single neurons. Varying inter-whisker correlations without changing single whisker statistics, we observe pronounced supra-linear multi-whisker integration. Using novel analysis methods, we show that continuous multi-whisker movements contribute to the firing of wS2 neurons over long temporal windows, facilitating spatio-temporal integration. In contrast, primary cortex (wS1) neurons encode fine features of whisker movements on precise temporal scales. These results provide the first description of wS2′s representation during multi-whisker stimulation and outline its specialized role in parallel to wS1 tactile processing. Sensory tuning properties of neurons in the secondary whisker somatosensory cortex (wS2) are not well understood. Here, the authors report that wS2 neurons supralinearly integrate concurrent multi-whisker input with larger temporal windows than primary somatosensory cortex.
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Affiliation(s)
- Matías A Goldin
- Unité de Neurosciences, Information et Complexité, UNIC-FRE3693, Centre National de la Recherche Scientifique, Gif sur Yvette, 91198, France
| | - Evan R Harrell
- Unité de Neurosciences, Information et Complexité, UNIC-FRE3693, Centre National de la Recherche Scientifique, Gif sur Yvette, 91198, France
| | - Luc Estebanez
- Unité de Neurosciences, Information et Complexité, UNIC-FRE3693, Centre National de la Recherche Scientifique, Gif sur Yvette, 91198, France
| | - Daniel E Shulz
- Unité de Neurosciences, Information et Complexité, UNIC-FRE3693, Centre National de la Recherche Scientifique, Gif sur Yvette, 91198, France.
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37
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de Haan R, Lim J, van der Burg SA, Pieneman AW, Nigade V, Mansvelder HD, de Kock CPJ. Neural Representation of Motor Output, Context and Behavioral Adaptation in Rat Medial Prefrontal Cortex During Learned Behavior. Front Neural Circuits 2018; 12:75. [PMID: 30327591 PMCID: PMC6174330 DOI: 10.3389/fncir.2018.00075] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 09/04/2018] [Indexed: 11/13/2022] Open
Abstract
Selecting behavioral outputs in a dynamic environment is the outcome of integrating multiple information streams and weighing possible action outcomes with their value. Integration depends on the medial prefrontal cortex (mPFC), but how mPFC neurons encode information necessary for appropriate behavioral adaptation is poorly understood. To identify spiking patterns of mPFC during learned behavior, we extracellularly recorded neuronal action potential firing in the mPFC of rats performing a whisker-based "Go"/"No-go" object localization task. First, we identify three functional groups of neurons, which show different degrees of spiking modulation during task performance. One group increased spiking activity during correct "Go" behavior (positively modulated), the second group decreased spiking (negatively modulated) and one group did not change spiking. Second, the relative change in spiking was context-dependent and largest when motor output had contextual value. Third, the negatively modulated population spiked more when rats updated behavior following an error compared to trials without integration of error information. Finally, insufficient spiking in the positively modulated population predicted erroneous behavior under dynamic "No-go" conditions. Thus, mPFC neuronal populations with opposite spike modulation characteristics differentially encode context and behavioral updating and enable flexible integration of error corrections in future actions.
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Affiliation(s)
- Roel de Haan
- Center for Neurogenomics and Cognitive Research, Department of Integrative Neurophysiology, VU Amsterdam, Amsterdam, Netherlands
| | - Judith Lim
- Center for Neurogenomics and Cognitive Research, Department of Integrative Neurophysiology, VU Amsterdam, Amsterdam, Netherlands
| | - Sven A van der Burg
- Center for Neurogenomics and Cognitive Research, Department of Integrative Neurophysiology, VU Amsterdam, Amsterdam, Netherlands
| | - Anton W Pieneman
- Center for Neurogenomics and Cognitive Research, Department of Integrative Neurophysiology, VU Amsterdam, Amsterdam, Netherlands
| | - Vinod Nigade
- Center for Neurogenomics and Cognitive Research, Department of Integrative Neurophysiology, VU Amsterdam, Amsterdam, Netherlands
| | - Huibert D Mansvelder
- Center for Neurogenomics and Cognitive Research, Department of Integrative Neurophysiology, VU Amsterdam, Amsterdam, Netherlands
| | - Christiaan P J de Kock
- Center for Neurogenomics and Cognitive Research, Department of Integrative Neurophysiology, VU Amsterdam, Amsterdam, Netherlands
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38
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Sensation, movement and learning in the absence of barrel cortex. Nature 2018; 561:542-546. [PMID: 30224746 PMCID: PMC6173956 DOI: 10.1038/s41586-018-0527-y] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 07/27/2018] [Indexed: 11/29/2022]
Abstract
For many of our senses, the role of the cerebral cortex in detecting stimuli is controversial1–17. Here, we examine the effects of both acute and chronic inactivation of primary somatosensory cortex (S1) in mice trained to move their large facial whiskers to detect an object via touch and respond with a lever to obtain a water reward. Using transgenic animals, we expressed inhibitory opsins in excitatory cortical neurons. Transient optogenetic inactivation of S1, as well as permanent lesions, initially produced both movement and sensory deficits that impaired detection behavior, demonstrating the inextricable link between sensory and motor systems during active sensing. Surprisingly, lesioned mice rapidly recovered full behavioral capabilities by the subsequent session. Recovery was experience-dependent, and early re-exposure to the task after lesion facilitated recovery. Furthermore, primary sensory cortex ablation prior to learning did not affect task acquisition. This combined optogenetic and lesion approach suggests that manipulations of sensory cortex may be only temporarily disruptive to other brain structures, which are themselves capable of coordinating multiple, arbitrary movements with sensation. Thus, the somatosensory cortex may be dispensable for active detection of objects in the environment.
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39
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Maier E, Brecht M. Layer 4 barrel cortex neurons retain their response properties during whisker replacement. J Neurophysiol 2018; 120:2218-2231. [PMID: 30044148 DOI: 10.1152/jn.00333.2018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Bodies change continuously, but we do not know if and how these changes affect somatosensory cortex. We address this issue in the whisker-barrel-cortex-pathway. We ask how outgrowing whiskers are mapped onto layer 4 barrel neuron responses. Half of whisker follicles contained dual whiskers, a shorter presumably outgrowing whisker (referred to as young whisker) and a longer one (referred to as old whisker). Young whiskers were much thinner than old ones but were inserted more deeply into the whisker follicle. Both whiskers were embedded in one outer root sheath surrounded by a common set of afferent nerve fibers. We juxtacellularly identified layer 4 barrel neurons representing dual whiskers with variable whisker length differences in anesthetized rats. Strength and latency of neuronal responses were strongly correlated for deflections of young and old whiskers but were not correlated with whisker length. The direction preferences of young and old whiskers were more similar than expected by chance. Old whiskers evoked marginally stronger and slightly shorter latency spike and local field potential responses than young whiskers. Our data suggest a conservative rewiring mechanism, which connects young whiskers to existing peripheral sensors. The fact that layer 4 barrel neurons retain their response properties is remarkable given the different length, thickness, and insertion depth of young and old whiskers. Retention of cortical response properties might be related to the placement of young and old whisker in one common outer root sheath and may contribute to perceptual stability across whisker replacement. NEW & NOTEWORTHY A particularly dramatic bodily change is whisker regrowth, which involves the formation of dual whisker follicles. Our results suggest that both whiskers are part of the same mechanoreceptive unit. Despite their distinct whisker length and thickness, responses of single cortical neurons to young and old whisker deflection were similar in strength, latency, and directional tuning. We suggest the congruence of young and old whisker cortical responses contributes to perceptual stability over whisker regrowth.
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Affiliation(s)
- Eduard Maier
- Bernstein Center for Computational Neuroscience Berlin, Humboldt-Universität zu Berlin, Berlin , Germany
| | - Michael Brecht
- Bernstein Center for Computational Neuroscience Berlin, Humboldt-Universität zu Berlin, Berlin , Germany.,NeuroCure Cluster of Excellence, Humboldt-Universität zu Berlin, Berlin , Germany
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40
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van der Bourg A, Yang JW, Reyes-Puerta V, Laurenczy B, Wieckhorst M, Stüttgen MC, Luhmann HJ, Helmchen F. Layer-Specific Refinement of Sensory Coding in Developing Mouse Barrel Cortex. Cereb Cortex 2018; 27:4835-4850. [PMID: 27620976 DOI: 10.1093/cercor/bhw280] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 08/17/2016] [Indexed: 12/20/2022] Open
Abstract
Rodent rhythmic whisking behavior matures during a critical period around 2 weeks after birth. The functional adaptations of neocortical circuitry during this developmental period remain poorly understood. Here, we characterized stimulus-evoked neuronal activity across all layers of mouse barrel cortex before, during, and after the onset of whisking behavior. Employing multi-electrode recordings and 2-photon calcium imaging in anesthetized mice, we tested responses to rostro-caudal whisker deflections, axial "tapping" stimuli, and their combination from postnatal day 10 (P10) to P28. Within this period, whisker-evoked activity of neurons displayed a general decrease in layer 2/3 (L2/3) and L4, but increased in L5 and L6. Distinct alterations in neuronal response adaptation during the 2-s period of stimulation at ~5 Hz accompanied these changes. Moreover, single-unit analysis revealed that response selectivity in favor of either lateral deflection or axial tapping emerges in deeper layers within the critical period around P14. For superficial layers we confirmed this finding using calcium imaging of L2/3 neurons, which also exhibited emergence of response selectivity as well as progressive sparsification and decorrelation of evoked responses around P14. Our results demonstrate layer-specific development of sensory responsiveness and response selectivity in mouse somatosensory cortex coinciding with the onset of exploratory behavior.
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Affiliation(s)
- Alexander van der Bourg
- Laboratory of Neural Circuit Dynamics, Brain Research Institute, University of Zurich, CH-8057 Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich and ETH Zurich, CH-8057 Zurich, Switzerland
| | - Jenq-Wei Yang
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University, D-55128 Mainz, Germany
| | - Vicente Reyes-Puerta
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University, D-55128 Mainz, Germany
| | - Balazs Laurenczy
- Laboratory of Neural Circuit Dynamics, Brain Research Institute, University of Zurich, CH-8057 Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich and ETH Zurich, CH-8057 Zurich, Switzerland
| | - Martin Wieckhorst
- Laboratory of Neural Circuit Dynamics, Brain Research Institute, University of Zurich, CH-8057 Zurich, Switzerland
| | - Maik C Stüttgen
- Institute of Pathophysiology, University Medical Center of the Johannes Gutenberg University, D-55128 Mainz, Germany
| | - Heiko J Luhmann
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University, D-55128 Mainz, Germany
| | - Fritjof Helmchen
- Laboratory of Neural Circuit Dynamics, Brain Research Institute, University of Zurich, CH-8057 Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich and ETH Zurich, CH-8057 Zurich, Switzerland
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41
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Gul JZ, Su KY, Choi KH. Fully 3D Printed Multi-Material Soft Bio-Inspired Whisker Sensor for Underwater-Induced Vortex Detection. Soft Robot 2018; 5:122-132. [DOI: 10.1089/soro.2016.0069] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Jahan Zeb Gul
- Department of Mechatronics Engineering, Jeju National University, Jeju, South Korea
| | - Kim Young Su
- Department of Mechatronics Engineering, Jeju National University, Jeju, South Korea
| | - Kyung Hyun Choi
- Department of Mechatronics Engineering, Jeju National University, Jeju, South Korea
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42
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Vaxenburg R, Wyche I, Svoboda K, Efros AL, Hires SA. Dynamic cues for whisker-based object localization: An analytical solution to vibration during active whisker touch. PLoS Comput Biol 2018; 14:e1006032. [PMID: 29584719 PMCID: PMC5889188 DOI: 10.1371/journal.pcbi.1006032] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 04/06/2018] [Accepted: 02/08/2018] [Indexed: 11/24/2022] Open
Abstract
Vibrations are important cues for tactile perception across species. Whisker-based sensation in mice is a powerful model system for investigating mechanisms of tactile perception. However, the role vibration plays in whisker-based sensation remains unsettled, in part due to difficulties in modeling the vibration of whiskers. Here, we develop an analytical approach to calculate the vibrations of whiskers striking objects. We use this approach to quantify vibration forces during active whisker touch at a range of locations along the whisker. The frequency and amplitude of vibrations evoked by contact are strongly dependent on the position of contact along the whisker. The magnitude of vibrational shear force and bending moment is comparable to quasi-static forces. The fundamental vibration frequencies are in a detectable range for mechanoreceptor properties and below the maximum spike rates of primary sensory afferents. These results suggest two dynamic cues exist that rodents can use for object localization: vibration frequency and comparison of vibrational to quasi-static force magnitude. These complement the use of quasi-static force angle as a distance cue, particularly for touches close to the follicle, where whiskers are stiff and force angles hardly change during touch. Our approach also provides a general solution to calculation of whisker vibrations in other sensing tasks. Vibrations play an important role in the sense of touch in many species, but exactly how they influence touch perception remains mysterious. An important reason for this mystery is the difficulty in measuring vibrations during touch. Mice are a powerful model system for investigating touch perception because they actively sweep their whiskers into objects and the resulting bending from touch can be video recorded. However, vibrations of the whiskers during touch are usually too small and fast to be seen. To overcome this limitation, we develop a new mathematical approach to calculating whisker vibrations from the speed at impact, maximum whisker bending during touch, and location of contact along a whisker, which is more easily observed. We find that vibration frequency and amplitude is strongly dependent on the location of contact along the whisker, which mice may use to deduce the distance between their face and touched objects. We confirm our calculations with high-speed imaging of whisker vibration during touch.
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Affiliation(s)
- Roman Vaxenburg
- Computational Materials Science Center, George Mason University, Fairfax, Virginia, United States of America
| | - Isis Wyche
- Section of Neurobiology, Department of Biological Sciences, University of South California, Los Angeles, California, United States of America
| | - Karel Svoboda
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, United States of America
| | - Alexander L. Efros
- Center for Computational Material Science, Code 6390, Naval Research Laboratory, Washington, DC, United States of America
| | - Samuel Andrew Hires
- Section of Neurobiology, Department of Biological Sciences, University of South California, Los Angeles, California, United States of America
- * E-mail:
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43
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Information Processing Across Behavioral States: Modes of Operation and Population Dynamics in Rodent Sensory Cortex. Neuroscience 2018; 368:214-228. [DOI: 10.1016/j.neuroscience.2017.09.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 09/08/2017] [Accepted: 09/10/2017] [Indexed: 11/24/2022]
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44
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Abstract
Understanding how perception emerges depends on the understanding of sensory acquisition by sensory organs. In this issue of Neuron, Severson et al. (2017) present a brilliant leap towards understanding active sensory coding by mechanoreceptors.
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45
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Helmchen F, Gilad A, Chen JL. Neocortical dynamics during whisker-based sensory discrimination in head-restrained mice. Neuroscience 2017; 368:57-69. [PMID: 28919043 DOI: 10.1016/j.neuroscience.2017.09.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 08/30/2017] [Accepted: 09/01/2017] [Indexed: 10/18/2022]
Abstract
A fundamental task frequently encountered by brains is to rapidly and reliably discriminate between sensory stimuli of the same modality, be it distinct auditory sounds, odors, visual patterns, or tactile textures. A key mammalian brain structure involved in discrimination behavior is the neocortex. Sensory processing not only involves the respective primary sensory area, which is crucial for perceptual detection, but additionally relies on cortico-cortical communication among several regions including higher-order sensory areas as well as frontal cortical areas. It remains elusive how these regions exchange information to process neural representations of distinct stimuli to bring about a decision and initiate appropriate behavioral responses. Likewise, it is poorly understood how these neural computations are conjured during task learning. In this review, we discuss recent studies investigating cortical dynamics during discrimination behaviors that utilize head-fixed behavioral tasks in combination with in vivo electrophysiology, two-photon calcium imaging, and cell-type-specific targeting. We particularly focus on information flow in distinct cortico-cortical pathways when mice use their whiskers to discriminate between different objects or different locations. Within the primary and secondary somatosensory cortices (S1 and S2, respectively) as well as vibrissae motor cortex (M1), intermingled functional representations of touch, whisking, and licking were found, which partially re-organized during discrimination learning. These findings provide first glimpses of cortico-cortical communication but emphasize that for understanding the complete process of discrimination it will be crucial to elucidate the details of how neural processing is coordinated across brain-wide neuronal networks including the S1-S2-M1 triangle and cortical areas beyond.
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Affiliation(s)
- Fritjof Helmchen
- Laboratory of Neural Circuit Dynamics, Brain Research Institute, University of Zurich, Switzerland.
| | - Ariel Gilad
- Laboratory of Neural Circuit Dynamics, Brain Research Institute, University of Zurich, Switzerland
| | - Jerry L Chen
- Laboratory of Neural Circuit Dynamics, Brain Research Institute, University of Zurich, Switzerland
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46
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Bale MR, Maravall M. Organization of sensory feature selectivity in the whisker system. Neuroscience 2017; 368:70-80. [PMID: 28918260 PMCID: PMC5798594 DOI: 10.1016/j.neuroscience.2017.09.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 08/25/2017] [Accepted: 09/05/2017] [Indexed: 12/14/2022]
Abstract
Neurons in the whisker system are selective to spatial and dynamical properties – features – of sensory stimuli. At each stage of the pathway, different neurons encode distinct features, generating a rich population representation. Whisker touch is robustly represented; neurons respond to touch-driven fast fluctuations in forces at the whisker base. Cortical neurons have more complex and context-dependent selectivity than subcortical, e.g., to collective whisker motion. Understanding how these signals are integrated to construct whisker-mediated percepts requires further research.
Our sensory receptors are faced with an onslaught of different environmental inputs. Each sensory event or encounter with an object involves a distinct combination of physical energy sources impinging upon receptors. In the rodent whisker system, each primary afferent neuron located in the trigeminal ganglion innervates and responds to a single whisker and encodes a distinct set of physical stimulus properties – features – corresponding to changes in whisker angle and shape and the consequent forces acting on the whisker follicle. Here we review the nature of the features encoded by successive stages of processing along the whisker pathway. At each stage different neurons respond to distinct features, such that the population as a whole represents diverse properties. Different neuronal types also have distinct feature selectivity. Thus, neurons at the same stage of processing and responding to the same whisker nevertheless play different roles in representing objects contacted by the whisker. This diversity, combined with the precise timing and high reliability of responses, enables populations at each stage to represent a wide range of stimuli. Cortical neurons respond to more complex stimulus properties – such as correlated motion across whiskers – than those at early subcortical stages. Temporal integration along the pathway is comparatively weak: neurons up to barrel cortex (BC) are sensitive mainly to fast (tens of milliseconds) fluctuations in whisker motion. The topographic organization of whisker sensitivity is paralleled by systematic organization of neuronal selectivity to certain other physical features, but selectivity to touch and to dynamic stimulus properties is distributed in “salt-and-pepper” fashion.
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Affiliation(s)
- Michael R Bale
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton BN1 9QG, United Kingdom
| | - Miguel Maravall
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton BN1 9QG, United Kingdom.
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47
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Abstract
A fundamental question in the investigation of any sensory system is what physical signals drive its sensory neurons during natural behavior. Surprisingly, in the whisker system, it is only recently that answers to this question have emerged. Here, we review the key developments, focussing mainly on the first stage of the ascending pathway - the primary whisker afferents (PWAs). We first consider a biomechanical framework, which describes the fundamental mechanical forces acting on the whiskers during active sensation. We then discuss technical progress that has allowed such mechanical variables to be estimated in awake, behaving animals. We discuss past electrophysiological evidence concerning how PWAs function and reinterpret it within the biomechanical framework. Finally, we consider recent studies of PWAs in awake, behaving animals and compare the results to related studies of the cortex. We argue that understanding 'what the whiskers tell the brain' sheds valuable light on the computational functions of downstream neural circuits, in particular, the barrel cortex.
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48
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Carvell GE, Simons DJ. Effect of whisker geometry on contact force produced by vibrissae moving at different velocities. J Neurophysiol 2017; 118:1637-1649. [PMID: 28659457 DOI: 10.1152/jn.00046.2017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 06/27/2017] [Accepted: 06/27/2017] [Indexed: 11/22/2022] Open
Abstract
Rats and mice are able to perform a variety of subtle tactile discriminations with their mystacial vibrissae. Increasingly, the design and interpretation of neurophysiological and behavioral studies are inspired by and linked to a more precise understanding of the detailed physical properties of the whiskers and their associated hair follicles. Here we used a piezoelectric sensor (bimorph) to examine how contact forces are influenced by the geometry of individual whisker hairs. For a given point along a whisker, bimorph signals are linearly related to whisker movement velocity. The slope of this linear function, called velocity sensitivity (VS), diminishes nonlinearly as whisker diameter decreases. Whiskers differ in overall length, thickness, and proximal-distal taper. Thus VS varies along an individual whisker and among different whiskers on the mystacial pad. Thinner, shorter whiskers, such as those located rostrally in rats and those in mice, have lower overall VSs, rendering them potentially less effective for mediating discriminations that rely on subtle velocity cues. The nonlinear effect of diameter combined with the linear effect of arc length produces radial distance tuning curves wherein small differences in the proximal-distal location of impacts yields larger differences in signal magnitude. Such position-dependent cues could contribute to the localization of objects near the face. Proximal-to-distal changes in contact location during whisking sweeps could also provide signals that aid texture discrimination.NEW & NOTEWORTHY This study describes the geometry of facial whiskers distributed across the mystacial pad with emphasis on velocity encoding of object strikes. Findings indicate how the shapes, lengths, and thicknesses of individual hairs can contribute to sophisticated vibrissa-based tactile discrimination.
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Affiliation(s)
- George E Carvell
- Department of Physical Therapy, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania; and.,Department of Neurobiology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Daniel J Simons
- Department of Neurobiology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
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49
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Mechanisms underlying a thalamocortical transformation during active tactile sensation. PLoS Comput Biol 2017; 13:e1005576. [PMID: 28591219 PMCID: PMC5479597 DOI: 10.1371/journal.pcbi.1005576] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 06/21/2017] [Accepted: 05/05/2017] [Indexed: 12/03/2022] Open
Abstract
During active somatosensation, neural signals expected from movement of the sensors are suppressed in the cortex, whereas information related to touch is enhanced. This tactile suppression underlies low-noise encoding of relevant tactile features and the brain’s ability to make fine tactile discriminations. Layer (L) 4 excitatory neurons in the barrel cortex, the major target of the somatosensory thalamus (VPM), respond to touch, but have low spike rates and low sensitivity to the movement of whiskers. Most neurons in VPM respond to touch and also show an increase in spike rate with whisker movement. Therefore, signals related to self-movement are suppressed in L4. Fast-spiking (FS) interneurons in L4 show similar dynamics to VPM neurons. Stimulation of halorhodopsin in FS interneurons causes a reduction in FS neuron activity and an increase in L4 excitatory neuron activity. This decrease of activity of L4 FS neurons contradicts the "paradoxical effect" predicted in networks stabilized by inhibition and in strongly-coupled networks. To explain these observations, we constructed a model of the L4 circuit, with connectivity constrained by in vitro measurements. The model explores the various synaptic conductance strengths for which L4 FS neurons actively suppress baseline and movement-related activity in layer 4 excitatory neurons. Feedforward inhibition, in concert with recurrent intracortical circuitry, produces tactile suppression. Synaptic delays in feedforward inhibition allow transmission of temporally brief volleys of activity associated with touch. Our model provides a mechanistic explanation of a behavior-related computation implemented by the thalamocortical circuit. We study how information is transformed between connected brain areas: the thalamus, the gateway to the cortex, and layer 4 (L4) in cortex, which is the first station to process sensory input from the thalamus. When mice perform an active object localization task with their whiskers, thalamic neurons and inhibitory fast-spiking (FS) interneurons in L4 encode whisker movement and touch, whereas L4 excitatory neurons respond almost exclusively to touch. To explain these observations, we constructed a computational model based on measured circuit parameters. The model reveals that without touch, when thalamic activity varies slowly, strong inhibition from FS neurons prevents activity in L4 excitatory neurons. Brief and strong touch-induced thalamic activity excites both excitatory and FS neurons in L4. FS neurons inhibit excitatory neurons with a delay of approximately 1 ms relative to ascending excitation, allowing L4 excitatory neurons to spike. Our results demonstrate that cortical circuits exploit synaptic delays for fast computations. Similar mechanisms likely also operate for rapid stimuli in the visual and auditory systems.
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50
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Huet LA, Rudnicki JW, Hartmann MJZ. Tactile Sensing with Whiskers of Various Shapes: Determining the Three-Dimensional Location of Object Contact Based on Mechanical Signals at the Whisker Base. Soft Robot 2017; 4:88-102. [PMID: 28616371 DOI: 10.1089/soro.2016.0028] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Almost all mammals use their mystacial vibrissae (whiskers) as important tactile sensors. There are no sensors along the length of a whisker: all sensing is performed by mechanoreceptors at the whisker base. To use artificial whiskers as a sensing tool in robotics, it is essential to be able to determine the three-dimensional (3D) location at which a whisker has made contact with an object. With the assumption of quasistatic, frictionless, single-point contact, previous work demonstrated that the 3D contact point can be uniquely determined if all six components of force and moment are measured at the whisker base, but these measurements require a six-axis load cell. Here, we perform simulations to investigate the extent to which each of the 20 possible "triplet" combinations of the six mechanical signals at the whisker base uniquely determine 3D contact point location. We perform this analysis for four different whisker profiles (shapes): tapered with and without intrinsic curvature, and cylindrical with and without intrinsic curvature. We show that whisker profile has a strong influence on the particular triplet(s) of signals that uniquely map to the 3D contact point. The triplet of bending moment, bending moment direction, and axial force produces unique mappings for tapered whiskers. Four different mappings are unique for a cylindrical whisker without intrinsic curvature, but only when large deflections are excluded. These results inform the neuroscience of vibrissotactile sensing and represent an important step toward the development of artificial whiskers for robotic applications.
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Affiliation(s)
- Lucie A Huet
- Department of Mechanical Engineering, Northwestern University, Evanston, Illinois
| | - John W Rudnicki
- Department of Mechanical Engineering, Northwestern University, Evanston, Illinois.,Department of Civil and Environmental Engineering, Northwestern University, Evanston, Illinois
| | - Mitra J Z Hartmann
- Department of Mechanical Engineering, Northwestern University, Evanston, Illinois.,Department of Biomedical Engineering, Northwestern University, Evanston, Illinois
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