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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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2
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Butovas S, Schwarz C. Local Neuronal Responses to Intracortical Microstimulation in Rats' Barrel Cortex Are Dependent on Behavioral Context. Front Behav Neurosci 2022; 16:805178. [PMID: 35391784 PMCID: PMC8981908 DOI: 10.3389/fnbeh.2022.805178] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 02/09/2022] [Indexed: 12/05/2022] Open
Abstract
The goal of cortical neuroprosthetics is to imprint sensory information as precisely as possible directly into cortical networks. Sensory processing, however, is dependent on the behavioral context. Therefore, a specific behavioral context may alter stimulation effects and, thus, perception. In this study, we reported how passive vs. active touch, i.e., the presence or absence of whisker movements, affects local field potential (LFP) responses to microstimulation in the barrel cortex in head-fixed behaving rats trained to move their whiskers voluntarily. The LFP responses to single-current pulses consisted of a short negative deflection corresponding to a volley of spike activity followed by a positive deflection lasting ~100 ms, corresponding to long-lasting suppression of spikes. Active touch had a characteristic effect on this response pattern. While the first phase including the negative peak remained stable, the later parts consisting of the positive peak were considerably suppressed. The stable phase varied systematically with the distance of the electrode from the stimulation site, pointing to saturation of neuronal responses to electrical stimulation in an intensity-dependent way. Our results suggest that modulatory effects known from normal sensory processing affect the response to cortical microstimulation as well. The network response to microstimulation is highly amenable to the behavioral state and must be considered for future approaches to imprint sensory signals into cortical circuits with neuroprostheses.
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3
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Bush NE, Solla SA, Hartmann MJZ. Continuous, multidimensional coding of 3D complex tactile stimuli by primary sensory neurons of the vibrissal system. Proc Natl Acad Sci U S A 2021; 118:e2020194118. [PMID: 34353902 PMCID: PMC8364131 DOI: 10.1073/pnas.2020194118] [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] [Indexed: 11/18/2022] Open
Abstract
Across all sensory modalities, first-stage sensory neurons are an information bottleneck: they must convey all information available for an animal to perceive and act in its environment. Our understanding of coding properties of primary sensory neurons in the auditory and visual systems has been aided by the use of increasingly complex, naturalistic stimulus sets. By comparison, encoding properties of primary somatosensory afferents are poorly understood. Here, we use the rodent whisker system to examine how tactile information is represented in primary sensory neurons of the trigeminal ganglion (Vg). Vg neurons have long been thought to segregate into functional classes associated with separate streams of information processing. However, this view is based on Vg responses to restricted stimulus sets which potentially underreport the coding capabilities of these neurons. In contrast, the current study records Vg responses to complex three-dimensional (3D) stimulation while quantifying the complete 3D whisker shape and mechanics, thereby beginning to reveal their full representational capabilities. The results show that individual Vg neurons simultaneously represent multiple mechanical features of a stimulus, do not preferentially encode principal components of the stimuli, and represent continuous and tiled variations of all available mechanical information. These results directly contrast with proposed codes in which subpopulations of Vg neurons encode select stimulus features. Instead, individual Vg neurons likely overcome the information bottleneck by encoding large regions of a complex sensory space. This proposed tiled and multidimensional representation at the Vg directly constrains the computations performed by more central neurons of the vibrissotrigeminal pathway.
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Affiliation(s)
- Nicholas E Bush
- Interdepartmental Neuroscience Program, Northwestern University, Evanston, IL 60208
| | - Sara A Solla
- Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208
- Department of Physiology, Northwestern University, Chicago, IL 60611
| | - Mitra J Z Hartmann
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208;
- Department of Mechanical Engineering, Northwestern University, Evanston, IL 60208
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4
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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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5
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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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Toward the Bionic Face: A Novel Neuroprosthetic Device Paradigm for Facial Reanimation Consisting of Neural Blockade and Functional Electrical Stimulation. Plast Reconstr Surg 2019; 143:62e-76e. [PMID: 30589784 DOI: 10.1097/prs.0000000000005164] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Facial palsy is a devastating condition potentially amenable to rehabilitation by functional electrical stimulation. Herein, a novel paradigm for unilateral facial reanimation using an implantable neuroprosthetic device is proposed and its feasibility demonstrated in a live rodent model. The paradigm comprises use of healthy-side electromyographic activity as control inputs to a system whose outputs are neural stimuli to effect symmetric facial displacements. The vexing issue of suppressing undesirable activity resulting from aberrant neural regeneration (synkinesis) or nerve transfer procedures is addressed using proximal neural blockade. METHODS Epimysial and nerve cuff electrode arrays were implanted in the faces of Wistar rats. Stimuli were delivered to evoke blinks and whisks of various durations and amplitudes. The dynamic relation between electromyographic signals and facial displacements was modeled, and model predictions were compared against measured displacements. Optimal parameters to achieve facial nerve blockade by means of high-frequency alternating current were determined, and the safety of continuous delivery was assessed. RESULTS Electrode implantation was well tolerated. Blinks and whisks of tunable amplitudes and durations were evoked by controlled variation of neural stimuli parameters. Facial displacements predicted from electromyographic input modelling matched those observed with a variance-accounted-for exceeding 96 percent. Effective and reversible facial nerve blockade in awake behaving animals was achieved, without detrimental effect noted from long-term continual use. CONCLUSIONS Proof-of-principle of rehabilitation of hemifacial palsy by means of a neuroprosthetic device has been demonstrated. The use of proximal neural blockade coupled with distal functional electrical stimulation may have relevance to rehabilitation of other peripheral motor nerve deficits.
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7
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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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8
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Martini FJ, Molano-Mazón M, Maravall M. Interspersed Distribution of Selectivity to Kinematic Stimulus Features in Supragranular Layers of Mouse Barrel Cortex. Cereb Cortex 2018; 27:3782-3789. [PMID: 28334121 DOI: 10.1093/cercor/bhx019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 12/14/2016] [Indexed: 01/17/2023] Open
Abstract
Neurons in the primary sensory regions of neocortex have heterogeneous response properties. The spatial arrangement of neurons with particular response properties is a key aspect of population representations and can shed light on how local circuits are wired. Here, we investigated how neurons with sensitivity to different kinematic features of whisker stimuli are distributed across local circuits in supragranular layers of the barrel cortex. Using 2-photon calcium population imaging in anesthetized mice, we found that nearby neurons represent diverse kinematic features, providing a rich population representation at the local scale. Neurons interspersed in space therefore responded differently to a common stimulus kinematic feature. Conversely, neurons with similar feature selectivity were located no closer to each other than predicted by a random distribution null hypothesis. This finding relied on defining a null hypothesis that was specific for testing the spatial distribution of tuning across neurons. We also measured how neurons sensitive to specific features were distributed relative to barrel boundaries, and found no systematic organization. Our results are compatible with randomly distributed selectivity to kinematic features, with no systematic ordering superimposed upon the whisker map.
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Affiliation(s)
- Francisco J Martini
- Instituto de Neurociencias de Alicante UMH-CSIC, Avda. Ramón y Cajal s/n, Campus de San Juan, 03550 Sant Joan d'Alacant, Spain
| | - Manuel Molano-Mazón
- Instituto de Neurociencias de Alicante UMH-CSIC, Avda. Ramón y Cajal s/n, Campus de San Juan, 03550 Sant Joan d'Alacant, Spain.,Laboratory of Neural Computation, Center for Neuroscience and Cognitive Systems @UniTn, Istituto Italiano di Tecnologia, 38068 Rovereto, Italy
| | - Miguel Maravall
- Instituto de Neurociencias de Alicante UMH-CSIC, Avda. Ramón y Cajal s/n, Campus de San Juan, 03550 Sant Joan d'Alacant, Spain.,Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, UK
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9
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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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10
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Pitas A, Albarracín AL, Molano-Mazón M, Maravall M. Variable Temporal Integration of Stimulus Patterns in the Mouse Barrel Cortex. Cereb Cortex 2017; 27:1758-1764. [PMID: 26838770 DOI: 10.1093/cercor/bhw006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Making sense of the world requires distinguishing temporal patterns and sequences lasting hundreds of milliseconds or more. How cortical circuits integrate over time to represent specific sensory sequences remains elusive. Here we assessed whether neurons in the barrel cortex (BC) integrate information about temporal patterns of whisker movements. We performed cell-attached recordings in anesthetized mice while delivering whisker deflections at variable intervals and compared the information carried by neurons about the latest interstimulus interval (reflecting sensitivity to instantaneous frequency) and earlier intervals (reflecting integration over timescales up to several hundred milliseconds). Neurons carried more information about the latest interval than earlier ones. The amount of temporal integration varied with neuronal responsiveness and with the cortical depth of the recording site, that is, with laminar location. A subset of neurons in the upper layers displayed the strongest integration. Highly responsive neurons in the deeper layers encoded the latest interval but integrated particularly weakly. Under these conditions, BC neurons act primarily as encoders of current stimulation parameters; however, our results suggest that temporal integration over hundreds of milliseconds can emerge in some neurons within BC.
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Affiliation(s)
- Anna Pitas
- Instituto de Neurociencias de Alicante, CSIC and Universidad Miguel Hernández, 03550 Sant Joan d'Alacant, Spain.,Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, UK
| | - Ana Lía Albarracín
- Instituto de Neurociencias de Alicante, CSIC and Universidad Miguel Hernández, 03550 Sant Joan d'Alacant, Spain.,Laboratorio de Medios e Interfases, Departamento de Bioingeniería, Universidad Nacional de Tucumán-Consejo Superior de Investigaciones Científicas y Técnicas, Tucumán, Argentina
| | - Manuel Molano-Mazón
- Instituto de Neurociencias de Alicante, CSIC and Universidad Miguel Hernández, 03550 Sant Joan d'Alacant, Spain.,Laboratory of Neural Computation, Istituto Italiano di Tecnologia Rovereto, 38068 Rovereto, Italy
| | - Miguel Maravall
- Instituto de Neurociencias de Alicante, CSIC and Universidad Miguel Hernández, 03550 Sant Joan d'Alacant, Spain.,Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, UK
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11
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Severson KS, Xu D, Van de Loo M, Bai L, Ginty DD, O'Connor DH. Active Touch and Self-Motion Encoding by Merkel Cell-Associated Afferents. Neuron 2017; 94:666-676.e9. [PMID: 28434802 DOI: 10.1016/j.neuron.2017.03.045] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 02/15/2017] [Accepted: 03/29/2017] [Indexed: 01/12/2023]
Abstract
Touch perception depends on integrating signals from multiple types of peripheral mechanoreceptors. Merkel-cell associated afferents are thought to play a major role in form perception by encoding surface features of touched objects. However, activity of Merkel afferents during active touch has not been directly measured. Here, we show that Merkel and unidentified slowly adapting afferents in the whisker system of behaving mice respond to both self-motion and active touch. Touch responses were dominated by sensitivity to bending moment (torque) at the base of the whisker and its rate of change and largely explained by a simple mechanical model. Self-motion responses encoded whisker position within a whisk cycle (phase), not absolute whisker angle, and arose from stresses reflecting whisker inertia and activity of specific muscles. Thus, Merkel afferents send to the brain multiplexed information about whisker position and surface features, suggesting that proprioception and touch converge at the earliest neural level.
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Affiliation(s)
- Kyle S Severson
- Kavli Neuroscience Discovery Institute, Brain Science Institute, The Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Neuroscience Training Program, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Duo Xu
- Kavli Neuroscience Discovery Institute, Brain Science Institute, The Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Neuroscience Training Program, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Margaret Van de Loo
- Kavli Neuroscience Discovery Institute, Brain Science Institute, The Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Ling Bai
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Neuroscience Training Program, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - David D Ginty
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Daniel H O'Connor
- Kavli Neuroscience Discovery Institute, Brain Science Institute, The Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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12
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Whisking mechanics and active sensing. Curr Opin Neurobiol 2016; 40:178-188. [PMID: 27632212 DOI: 10.1016/j.conb.2016.08.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 08/03/2016] [Accepted: 08/04/2016] [Indexed: 11/20/2022]
Abstract
We describe recent advances in quantifying the three-dimensional (3D) geometry and mechanics of whisking. Careful delineation of relevant 3D reference frames reveals important geometric and mechanical distinctions between the localization problem ('where' is an object) and the feature extraction problem ('what' is an object). Head-centered and resting-whisker reference frames lend themselves to quantifying temporal and kinematic cues used for object localization. The whisking-centered reference frame lends itself to quantifying the contact mechanics likely associated with feature extraction. We offer the 'windowed sampling' hypothesis for active sensing: that rats can estimate an object's spatial features by integrating mechanical information across whiskers during brief (25-60ms) windows of 'haptic enclosure' with the whiskers, a motion that resembles a hand grasp.
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13
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Yu YSW, Graff MM, Bresee CS, Man YB, Hartmann MJZ. Whiskers aid anemotaxis in rats. SCIENCE ADVANCES 2016; 2:e1600716. [PMID: 27574705 PMCID: PMC4996642 DOI: 10.1126/sciadv.1600716] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 07/12/2016] [Indexed: 05/27/2023]
Abstract
Observation of terrestrial mammals suggests that they can follow the wind (anemotaxis), but the sensory cues underlying this ability have not been studied. We identify a significant contribution to anemotaxis mediated by whiskers (vibrissae), a modality previously studied only in the context of direct tactile contact. Five rats trained on a five-alternative forced-choice airflow localization task exhibited significant performance decrements after vibrissal removal. In contrast, vibrissal removal did not disrupt the performance of control animals trained to localize a light source. The performance decrement of individual rats was related to their airspeed threshold for successful localization: animals that found the task more challenging relied more on the vibrissae for localization cues. Following vibrissal removal, the rats deviated more from the straight-line path to the air source, choosing sources farther from the correct location. Our results indicate that rats can perform anemotaxis and that whiskers greatly facilitate this ability. Because air currents carry information about both odor content and location, these findings are discussed in terms of the adaptive significance of the interaction between sniffing and whisking in rodents.
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Affiliation(s)
- Yan S. W. Yu
- Department of Mechanical Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Matthew M. Graff
- Department of Mechanical Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Chris S. Bresee
- Interdepartmental Neuroscience Program, Northwestern University, Evanston, IL 60208, USA
| | - Yan B. Man
- Department of Mechanical Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Mitra J. Z. Hartmann
- Department of Mechanical Engineering, Northwestern University, Evanston, IL 60208, USA
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
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14
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Kaloti AS, Johnson EC, Bresee CS, Naufel SN, Perich MG, Jones DL, Hartmann MJZ. Representation of Stimulus Speed and Direction in Vibrissal-Sensitive Regions of the Trigeminal Nuclei: A Comparison of Single Unit and Population Responses. PLoS One 2016; 11:e0158399. [PMID: 27463524 PMCID: PMC4963183 DOI: 10.1371/journal.pone.0158399] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 06/15/2016] [Indexed: 11/24/2022] Open
Abstract
The rat vibrissal (whisker) system is one of the oldest and most important models for the study of active tactile sensing and sensorimotor integration. It is well established that primary sensory neurons in the trigeminal ganglion respond to deflections of one and only one whisker, and that these neurons are strongly tuned for both the speed and direction of individual whisker deflections. During active whisking behavior, however, multiple whiskers will be deflected simultaneously. Very little is known about how neurons at central levels of the trigeminal pathway integrate direction and speed information across multiple whiskers. In the present work, we investigated speed and direction coding in the trigeminal brainstem nuclei, the first stage of neural processing that exhibits multi-whisker receptive fields. Specifically, we recorded both single-unit spikes and local field potentials from fifteen sites in spinal trigeminal nucleus interpolaris and oralis while systematically varying the speed and direction of coherent whisker deflections delivered across the whisker array. For 12/15 neurons, spike rate was higher when the whisker array was stimulated from caudal to rostral rather than rostral to caudal. In addition, 10/15 neurons exhibited higher firing rates for slower stimulus speeds. Interestingly, using a simple decoding strategy for the local field potentials and spike trains, classification of speed and direction was higher for field potentials than for single unit spike trains, suggesting that the field potential is a robust reflection of population activity. Taken together, these results point to the idea that population responses in these brainstem regions in the awake animal will be strongest during behaviors that stimulate a population of whiskers with a directionally coherent motion.
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Affiliation(s)
- Aniket S. Kaloti
- Interdepartmental Neuroscience Program, Northwestern University, Evanston, IL, United States of America
| | - Erik C. Johnson
- Department of Electrical and Computer Engineering, University of Illinois, Urbana, IL, United States of America
- Coordinated Science Laboratory, University of Illinois, Urbana, IL, United States of America
- Beckman Institute for Advanced Science and Technology, University of Illinois, Urbana, IL, United States of America
| | - Chris S. Bresee
- Interdepartmental Neuroscience Program, Northwestern University, Evanston, IL, United States of America
| | - Stephanie N. Naufel
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, United States of America
| | - Matthew G. Perich
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, United States of America
| | - Douglas L. Jones
- Department of Electrical and Computer Engineering, University of Illinois, Urbana, IL, United States of America
- Coordinated Science Laboratory, University of Illinois, Urbana, IL, United States of America
- Beckman Institute for Advanced Science and Technology, University of Illinois, Urbana, IL, United States of America
- Advanced Digital Sciences Center, Illinois at Singapore Pte., Singapore, Singapore
| | - Mitra J. Z. Hartmann
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, United States of America
- Department of Mechanical Engineering, Northwestern University, Evanston, IL, United States of America
- * E-mail:
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15
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Yang AET, Hartmann MJZ. Whisking Kinematics Enables Object Localization in Head-Centered Coordinates Based on Tactile Information from a Single Vibrissa. Front Behav Neurosci 2016; 10:145. [PMID: 27486390 PMCID: PMC4949211 DOI: 10.3389/fnbeh.2016.00145] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2016] [Accepted: 06/23/2016] [Indexed: 11/13/2022] Open
Abstract
During active tactile exploration with their whiskers (vibrissae), rodents can rapidly orient to an object even though there are very few proprioceptors in the whisker muscles. Thus a long-standing question in the study of the vibrissal system is how the rat can localize an object in head-centered coordinates without muscle-based proprioception. We used a three-dimensional model of whisker bending to simulate whisking motions against a peg to investigate the possibility that the 3D mechanics of contact from a single whisker are sufficient for localization in head-centered coordinates. Results show that for nearly all whiskers in the array, purely tactile signals at the whisker base - as would be measured by mechanoreceptors, in whisker-centered coordinates - could be used to determine the location of a vertical peg in head-centered coordinates. Both the "roll" and the "elevation" components of whisking kinematics contribute to the uniqueness and resolution of the localization. These results offer an explanation for a behavioral study showing that rats can more accurately determine the horizontal angle of an object if one column, rather than one row, of whiskers is spared.
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Affiliation(s)
- Anne E T Yang
- Department of Mechanical Engineering, Northwestern University, Evanston IL, USA
| | - Mitra J Z Hartmann
- Department of Mechanical Engineering, Northwestern University, EvanstonIL, USA; Department of Biomedical Engineering, Northwestern University, EvanstonIL, USA
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16
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Kleinfeld D, Deschênes M, Ulanovsky N. Whisking, Sniffing, and the Hippocampal θ-Rhythm: A Tale of Two Oscillators. PLoS Biol 2016; 14:e1002385. [PMID: 26890361 PMCID: PMC4758648 DOI: 10.1371/journal.pbio.1002385] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The hippocampus has unique access to neuronal activity across all of the neocortex. Yet an unanswered question is how the transfer of information between these structures is gated. One hypothesis involves temporal-locking of activity in the neocortex with that in the hippocampus. New data from the Matthew E. Diamond laboratory shows that the rhythmic neuronal activity that accompanies vibrissa-based sensation, in rats, transiently locks to ongoing hippocampal θ-rhythmic activity during the sensory-gathering epoch of a discrimination task. This result complements past studies on the locking of sniffing and the θ-rhythm as well as the relation of sniffing and whisking. An overarching possibility is that the preBötzinger inspiration oscillator, which paces whisking, can selectively lock with the θ-rhythm to traffic sensorimotor information between the rat's neocortex and hippocampus.
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Affiliation(s)
- David Kleinfeld
- Department of Physics, University of California, San Diego, La Jolla, California, United States of America
- Section of Neurobiology, University of California, San Diego, La Jolla, California, United States of America
- * E-mail:
| | - Martin Deschênes
- Department of Psychiatry and Neuroscience, Laval University, Québec City, Canada
| | - Nachum Ulanovsky
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
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17
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Campagner D, Evans MH, Bale MR, Erskine A, Petersen RS. Prediction of primary somatosensory neuron activity during active tactile exploration. eLife 2016; 5. [PMID: 26880559 PMCID: PMC4764568 DOI: 10.7554/elife.10696] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 01/06/2016] [Indexed: 11/13/2022] Open
Abstract
Primary sensory neurons form the interface between world and brain. Their function is well-understood during passive stimulation but, under natural behaving conditions, sense organs are under active, motor control. In an attempt to predict primary neuron firing under natural conditions of sensorimotor integration, we recorded from primary mechanosensory neurons of awake, head-fixed mice as they explored a pole with their whiskers, and simultaneously measured both whisker motion and forces with high-speed videography. Using Generalised Linear Models, we found that primary neuron responses were poorly predicted by whisker angle, but well-predicted by rotational forces acting on the whisker: both during touch and free-air whisker motion. These results are in apparent contrast to previous studies of passive stimulation, but could be reconciled by differences in the kinematics-force relationship between active and passive conditions. Thus, simple statistical models can predict rich neural activity elicited by natural, exploratory behaviour involving active movement of sense organs.
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Affiliation(s)
- Dario Campagner
- Faculty of Life Sciences, The University of Manchester, Manchester, United Kingdom
| | - Mathew Hywel Evans
- Faculty of Life Sciences, The University of Manchester, Manchester, United Kingdom
| | - Michael Ross Bale
- Faculty of Life Sciences, The University of Manchester, Manchester, United Kingdom.,School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - Andrew Erskine
- Faculty of Life Sciences, The University of Manchester, Manchester, United Kingdom.,Mill Hill Laboratory, The Francis Crick Institute, London, United Kingdom
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18
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Hobbs JA, Towal RB, Hartmann MJZ. Spatiotemporal Patterns of Contact Across the Rat Vibrissal Array During Exploratory Behavior. Front Behav Neurosci 2016; 9:356. [PMID: 26778990 PMCID: PMC4700281 DOI: 10.3389/fnbeh.2015.00356] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 12/08/2015] [Indexed: 11/13/2022] Open
Abstract
The rat vibrissal system is an important model for the study of somatosensation, but the small size and rapid speed of the vibrissae have precluded measuring precise vibrissal-object contact sequences during behavior. We used a laser light sheet to quantify, with 1 ms resolution, the spatiotemporal structure of whisker-surface contact as five naïve rats freely explored a flat, vertical glass wall. Consistent with previous work, we show that the whisk cycle cannot be uniquely defined because different whiskers often move asynchronously, but that quasi-periodic (~8 Hz) variations in head velocity represent a distinct temporal feature on which to lock analysis. Around times of minimum head velocity, whiskers protract to make contact with the surface, and then sustain contact with the surface for extended durations (~25-60 ms) before detaching. This behavior results in discrete temporal windows in which large numbers of whiskers are in contact with the surface. These "sustained collective contact intervals" (SCCIs) were observed on 100% of whisks for all five rats. The overall spatiotemporal structure of the SCCIs can be qualitatively predicted based on information about head pose and the average whisk cycle. In contrast, precise sequences of whisker-surface contact depend on detailed head and whisker kinematics. Sequences of vibrissal contact were highly variable, equally likely to propagate in all directions across the array. Somewhat more structure was found when sequences of contacts were examined on a row-wise basis. In striking contrast to the high variability associated with contact sequences, a consistent feature of each SCCI was that the contact locations of the whiskers on the glass converged and moved more slowly on the sheet. Together, these findings lead us to propose that the rat uses a strategy of "windowed sampling" to extract an object's spatial features: specifically, the rat spatially integrates quasi-static mechanical signals across whiskers during the period of sustained contact, resembling an "enclosing" haptic procedure.
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Affiliation(s)
- Jennifer A Hobbs
- Department of Physics and Astronomy, Northwestern University Evanston, IL, USA
| | - R Blythe Towal
- Department of Biomedical Engineering, Northwestern University Evanston, IL, USA
| | - Mitra J Z Hartmann
- Department of Biomedical Engineering, Northwestern UniversityEvanston, IL, USA; Department of Mechanical Engineering, Northwestern UniversityEvanston, IL, USA
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19
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Moore JD, Mercer Lindsay N, Deschênes M, Kleinfeld D. Vibrissa Self-Motion and Touch Are Reliably Encoded along the Same Somatosensory Pathway from Brainstem through Thalamus. PLoS Biol 2015; 13:e1002253. [PMID: 26393890 PMCID: PMC4579082 DOI: 10.1371/journal.pbio.1002253] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 08/13/2015] [Indexed: 11/29/2022] Open
Abstract
Active sensing involves the fusion of internally generated motor events with external sensation. For rodents, active somatosensation includes scanning the immediate environment with the mystacial vibrissae. In doing so, the vibrissae may touch an object at any angle in the whisk cycle. The representation of touch and vibrissa self-motion may in principle be encoded along separate pathways, or share a single pathway, from the periphery to cortex. Past studies established that the spike rates in neurons along the lemniscal pathway from receptors to cortex, which includes the principal trigeminal and ventral-posterior-medial thalamic nuclei, are substantially modulated by touch. In contrast, spike rates along the paralemniscal pathway, which includes the rostral spinal trigeminal interpolaris, posteromedial thalamic, and ventral zona incerta nuclei, are only weakly modulated by touch. Here we find that neurons along the lemniscal pathway robustly encode rhythmic whisking on a cycle-by-cycle basis, while encoding along the paralemniscal pathway is relatively poor. Thus, the representations of both touch and self-motion share one pathway. In fact, some individual neurons carry both signals, so that upstream neurons with a supralinear gain function could, in principle, demodulate these signals to recover the known decoding of touch as a function of vibrissa position in the whisk cycle.
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Affiliation(s)
- Jeffrey D. Moore
- Department of Physics, University of California, San Diego, La Jolla, California, United States of America
| | - Nicole Mercer Lindsay
- Section of Neurobiology, University of California, San Diego, La Jolla, California, United States of America
| | - Martin Deschênes
- Centre de Recherche Université Laval Robert-Giffard, Québec City, Québec, Canada
| | - David Kleinfeld
- Department of Physics, University of California, San Diego, La Jolla, California, United States of America
- Section of Neurobiology, University of California, San Diego, La Jolla, California, United States of America
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20
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A novel videographic method for quantitatively tracking vibrissal motor recovery following facial nerve injuries in rats. J Neurosci Methods 2015; 249:16-21. [DOI: 10.1016/j.jneumeth.2015.03.035] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Revised: 03/29/2015] [Accepted: 03/30/2015] [Indexed: 01/07/2023]
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Abstract
Communication in the nervous system occurs by spikes: the timing precision with which spikes are fired is a fundamental limit on neural information processing. In sensory systems, spike-timing precision is constrained by first-order neurons. We found that spike-timing precision of trigeminal primary afferents in rats and mice is limited both by stimulus speed and by electrophysiological sampling rate. High-speed video of behaving mice revealed whisker velocities of at least 17,000°/s, so we delivered an ultrafast "ping" (>50,000°/s) to single whiskers and sampled primary afferent activity at 500 kHz. Median spike jitter was 17.4 μs; 29% of neurons had spike jitter < 10 μs. These results indicate that the input stage of the trigeminal pathway has extraordinary spike-timing precision and very high potential information capacity. This timing precision ranks among the highest in biology.
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22
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Castro-Alamancos MA, Bezdudnaya T. Modulation of artificial whisking related signals in barrel cortex. J Neurophysiol 2014; 113:1287-301. [PMID: 25505118 DOI: 10.1152/jn.00809.2014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Rats use rhythmic whisker movements, called active whisking, to sense the environment, which include whisker protractions followed by retractions at various frequencies. Using a proxy of active whisking in anesthetized rats, called artificial whisking, which is induced by electrically stimulating the facial motor nerve, we characterized the neural responses evoked in the barrel cortex by whisking in air (without contact) and on a surface (with contact). Neural responses were compared between distinct network states consisting of cortical deactivation (synchronized slow oscillations) and activation (desynchronized state) produced by neuromodulation (cholinergic or noradrenergic stimulation in neocortex or thalamus). Here we show that population responses in the barrel cortex consist of a robust signal driven by the onset of the whisker protraction followed by a whisking retraction signal that emerges during low frequency whisking on a surface. The whisking movement onset signal is suppressed by increasing whisking frequency, is controlled by cortical synaptic inhibition, is suppressed during cortical activation states, is little affected by whisking on a surface, and is ubiquitous in ventroposterior medial (VPM) thalamus, barrel cortex, and superior colliculus. The whisking retraction signal codes the duration of the preceding whisker protraction, is present in thalamocortical networks but not in superior colliculus, and is robust during cortical activation; a state associated with natural exploratory whisking. The expression of different whisking signals in forebrain and midbrain may define the sensory processing abilities of those sensorimotor circuits. Whisking related signals in the barrel cortex are controlled by network states that are set by neuromodulators.
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Affiliation(s)
- Manuel A Castro-Alamancos
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania
| | - Tatiana Bezdudnaya
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania
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23
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Modeling forces and moments at the base of a rat vibrissa during noncontact whisking and whisking against an object. J Neurosci 2014; 34:9828-44. [PMID: 25057187 DOI: 10.1523/jneurosci.1707-12.2014] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
During exploratory behavior, rats brush and tap their whiskers against objects, and the mechanical signals so generated constitute the primary sensory variables upon which these animals base their vibrissotactile perception of the world. To date, however, we lack a general dynamic model of the vibrissa that includes the effects of inertia, damping, and collisions. We simulated vibrissal dynamics to compute the time-varying forces and bending moment at the vibrissa base during both noncontact (free-air) whisking and whisking against an object (collision). Results show the following: (1) during noncontact whisking, mechanical signals contain components at both the whisking frequency and also twice the whisking frequency (the latter could code whisking speed); (2) when rats whisk rhythmically against an object, the intrinsic dynamics of the vibrissa can be as large as many of the mechanical effects of the collision, however, the axial force could still generate responses that reliably indicate collision based on thresholding; and (3) whisking velocity will have only a small effect on the transient response generated during a whisker-object collision. Instead, the transient response will depend in large part on how the rat chooses to decelerate its vibrissae after the collision. The model allows experimentalists to estimate error bounds on quasi-static descriptions of vibrissal shape, and its predictions can be used to bound realistic expectations from neurons that code vibrissal sensing. We discuss the implications of these results under the assumption that primary sensory neurons of the trigeminal ganglion are sensitive to various combinations of mechanical signals.
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24
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Abstract
The superior colliculus is part of a broader neural network that can decode whisker movements in air and on objects, which is a strategy used by behaving rats to sense the environment. The intermediate layers of the superior colliculus receive whisker-related excitatory afferents from the trigeminal complex and barrel cortex, inhibitory afferents from extrinsic and intrinsic sources, and neuromodulatory afferents from cholinergic and monoaminergic nuclei. However, it is not well known how these inputs regulate whisker-related activity in the superior colliculus. We found that barrel cortex afferents drive the superior colliculus during the middle portion of the rising phase of the whisker movement protraction elicited by artificial (fictive) whisking in anesthetized rats. In addition, both spontaneous and whisker-related neural activities in the superior colliculus are under strong inhibitory and neuromodulator control. Cholinergic stimulation activates the superior colliculus by increasing spontaneous firing and, in some cells, whisker-evoked responses. Monoaminergic stimulation has the opposite effects. The actions of neuromodulator and inhibitory afferents may be the basis of the different firing rates and sensory responsiveness observed in the superior colliculus of behaving animals during distinct behavioral states.
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25
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Moore JD, Deschênes M, Kurnikova A, Kleinfeld D. Activation and measurement of free whisking in the lightly anesthetized rodent. Nat Protoc 2014; 9:1792-802. [PMID: 24992095 PMCID: PMC4934662 DOI: 10.1038/nprot.2014.119] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The rodent vibrissa system is a widely used experimental model of active sensation and motor control. Vibrissa-based touch in rodents involves stereotypic, rhythmic sweeping of the vibrissae as the animal explores its environment. Although pharmacologically induced rhythmic movements have long been used to understand the neural circuitry that underlies a variety of rhythmic behaviors, including locomotion, digestion and ingestion, these techniques have not been available for active sensory movements such as whisking. However, recent work that delineated the location of the central pattern generator for whisking has enabled pharmacological control over this behavior. Here we specify a protocol for the pharmacological induction of rhythmic vibrissa movements that mimic exploratory whisking. The rhythmic vibrissa movements are induced by local injection of a glutamatergic agonist, kainic acid. This protocol produces coordinated rhythmic vibrissa movements that are sustained for several hours in the anesthetized mouse or rat and thus provides unprecedented experimental control in studies related to vibrissa-based neuronal circuitry.
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Affiliation(s)
- Jeffrey D. Moore
- Department of Physics, University of California San Diego, La Jolla, CA 92093
| | - Martin Deschênes
- Department of Psychiatry and Neuroscience, Laval University, Québec City G1J 2G3, Canada
| | - Anastasia Kurnikova
- Department of Physics, University of California San Diego, La Jolla, CA 92093
- Graduate Program in Neurosciences, University of California San Diego, La Jolla, CA 92093
| | - David Kleinfeld
- Department of Physics, University of California San Diego, La Jolla, CA 92093
- Graduate Program in Neurosciences, University of California San Diego, La Jolla, CA 92093
- Section on Neurobiology, University of California San Diego, La Jolla, CA 92093
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26
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Maravall M, Diamond ME. Algorithms of whisker-mediated touch perception. Curr Opin Neurobiol 2014; 25:176-86. [PMID: 24549178 DOI: 10.1016/j.conb.2014.01.014] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 01/23/2014] [Indexed: 11/18/2022]
Abstract
Comparison of the functional organization of sensory modalities can reveal the specialized mechanisms unique to each modality as well as processing algorithms that are common across modalities. Here we examine the rodent whisker system. The whisker's mechanical properties shape the forces transmitted to specialized receptors. The sensory and motor systems are intimately interconnected, giving rise to two forms of sensation: generative and receptive. The sensory pathway is a test bed for fundamental concepts in computation and coding: hierarchical feature detection, sparseness, adaptive representations, and population coding. The central processing of signals can be considered a sequence of filters. At the level of cortex, neurons represent object features by a coordinated population code which encompasses cells with heterogeneous properties.
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Affiliation(s)
- Miguel Maravall
- Instituto de Neurociencias de Alicante UMH-CSIC, Campus de San Juan, Apartado 18, 03550 Sant Joan d'Alacant, Spain
| | - Mathew E Diamond
- Tactile Perception and Learning Lab, International School for Advanced Studies-SISSA, Via Bonomea 265, 34136 Trieste, Italy.
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Mameli O, Stanzani S, Russo A, Pellitteri R, Manca P, De Riu PL, Caria MA. Involvement of trigeminal mesencephalic nucleus in kinetic encoding of whisker movements. Brain Res Bull 2014; 102:37-45. [PMID: 24518654 DOI: 10.1016/j.brainresbull.2014.01.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 01/22/2014] [Accepted: 01/31/2014] [Indexed: 01/02/2023]
Abstract
In previous experiments performed on anaesthetised rats, we demonstrated that whisking neurons responsive to spontaneous movement of the macrovibrissae are located within the trigeminal mesencephalic nucleus (Me5) and that retrograde tracers injected into the mystacial pad of the rat muzzle extensively labelled a number of Me5 neurons. In order to evaluate the electrophysiological characteristics of the Me5-whisker pad neural connection, the present study analysed the Me5 neurons responses to artificial whisking induced by electrical stimulation of the peripheral stump of the facial nerve. Furthermore, an anterograde tracer was injected into the Me5 to identify and localise the peripheral terminals of these neurons in the mystacial structures. The electrophysiological data demonstrated that artificial whisking induced Me5 evoked potentials as well as single and multiunit Me5 neurons responses consistent with a direct connection. Furthermore, the neuroanatomical findings showed that the peripheral terminals of the Me5 stained neurons established direct connections with the upper part of the macrovibrissae, at the conical body level, with fibres spiralling around the circumference of the vibrissae shaft. As for the functional role of this sensory innervation, we speculated that the Me5 neurons are possibly involved in encoding and relaying proprioceptive information related to vibrissae movements to other CNS structures.
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Affiliation(s)
- Ombretta Mameli
- Department of Clinical and Experimental Medicine, Human Physiology, School of Medicine, Sassari University, viale San Pietro 8, 07100 Sassari, Italy.
| | - Stefania Stanzani
- Department of Biomedical Sciences, Physiology Division, Catania University, 95125 Catania, Italy
| | - Antonella Russo
- Department of Biomedical Sciences, Physiology Division, Catania University, 95125 Catania, Italy
| | - Rosalia Pellitteri
- Institute of Neurological Sciences, National Research Council, Section of Catania, 95125 Catania, Italy
| | - Paolo Manca
- Department of Clinical and Experimental Medicine, Human Physiology, School of Medicine, Sassari University, viale San Pietro 8, 07100 Sassari, Italy
| | - Pier Luigi De Riu
- Department of Clinical and Experimental Medicine, Human Physiology, School of Medicine, Sassari University, viale San Pietro 8, 07100 Sassari, Italy
| | - Marcello Alessandro Caria
- Department of Clinical and Experimental Medicine, Human Physiology, School of Medicine, Sassari University, viale San Pietro 8, 07100 Sassari, Italy
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Rhythmic whisking area (RW) in rat primary motor cortex: an internal monitor of movement-related signals? J Neurosci 2013; 33:14193-204. [PMID: 23986253 DOI: 10.1523/jneurosci.0337-13.2013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Vibrissae-related sensorimotor cortex controls whisking movements indirectly via modulation of lower-level sensorimotor loops and a brainstem central pattern generator (CPG). Two different whisker representations in primary motor cortex (vM1) affect whisker movements in different ways. Prolonged microstimulation in RF, a larger anterior subregion of vM1, gives rise to complex face movements and whisker retraction while the same stimulation evokes large-amplitude rhythmic whisker movement in a small caudo-medial area (RW). To characterize the motor cortex representation of explorative whisking movements, here we recorded RW units in head-fixed rats trained to contact a moving object with one whisker. RW single units were found to encode two aspects of whisker movement independently, albeit on slow time scales (hundreds of milliseconds). The first is whisker position. The second consists of speed (absolute velocity), intensity (instantaneous power), and frequency (spectral centroid). The coding for the latter three parameters was tightly correlated and realized by a continuum of RW responses-ranging from a preference of movement to a preference of rest. Information theory analysis indicated that RW spikes carry most information about position and frequency, while intensity and speed are less well represented. Further, investigating multiple and single RW units, we found a lack of phase locking, movement anticipation, and contact-related tactile responses. These findings suggest that RW neither programs detailed whisker trajectories nor initiates them. Nor does it play a role in processing object touch. Its relationship to whisking is thus indirect and may be related to movement monitoring, perhaps using feedback from the CPG.
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29
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Abstract
In any sensory system, the primary afferents constitute the first level of sensory representation and fundamentally constrain all subsequent information processing. Here, we show that the spike timing, reliability, and stimulus selectivity of primary afferents in the whisker system can be accurately described by a simple model consisting of linear stimulus filtering combined with spike feedback. We fitted the parameters of the model by recording the responses of primary afferents to filtered, white noise whisker motion in anesthetized rats. The model accurately predicted not only the response of primary afferents to white noise whisker motion (median correlation coefficient 0.92) but also to naturalistic, texture-induced whisker motion. The model accounted both for submillisecond spike-timing precision and for non-Poisson spike train structure. We found substantial diversity in the responses of the afferent population, but this diversity was accurately captured by the model: a 2D filter subspace, corresponding to different mixtures of position and velocity sensitivity, captured 94% of the variance in the stimulus selectivity. Our results suggest that the first stage of the whisker system can be well approximated as a bank of linear filters, forming an overcomplete representation of a low-dimensional feature space.
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30
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Abstract
Sense organs are often actively controlled by motor processes and such active sensing profoundly shapes the timing of sensory information flow. The temporal coordination between different active sensing processes is less well understood but is essential for multisensory integration, coordination between brain regions, and energetically optimal sampling strategies. Here we studied the coordination between sniffing and whisking, the motor processes in rodents that control the acquisition of smell and touch information, respectively. Sniffing, high-frequency respiratory bouts, and whisking, rapid back and forth movements of mystacial whiskers, occur in the same theta frequency range (4-12 Hz) leading to a hypothesis that these sensorimotor rhythms are phase locked. To test this, we monitored sniffing using a thermocouple in the nasal cavity and whisking with an electromyogram of the mystacial pad in rats engaged in an open field reward foraging behavior. During bouts of exploration, sniffing and whisking showed strong one-to-one phase locking within the theta frequency range (4-12 Hz). Interestingly, we also observed multimode phase locking with multiple whisks within a sniff cycle or multiple sniffs within a whisk cycle-always at the same preferred phase. This specific phase relationship coupled the acquisition phases of the two sensorimotor rhythms, inhalation and whisker protraction. Our results suggest that sniffing and whisking may be under the control of interdependent rhythm generators that dynamically coordinate active acquisition of olfactory and somatosensory information.
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31
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An internal model architecture for novelty detection: implications for cerebellar and collicular roles in sensory processing. PLoS One 2012; 7:e44560. [PMID: 22957083 PMCID: PMC3434152 DOI: 10.1371/journal.pone.0044560] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 08/06/2012] [Indexed: 11/20/2022] Open
Abstract
The cerebellum is thought to implement internal models for sensory prediction, but details of the underlying circuitry are currently obscure. We therefore investigated a specific example of internal-model based sensory prediction, namely detection of whisker contacts during whisking. Inputs from the vibrissae in rats can be affected by signals generated by whisker movement, a phenomenon also observable in whisking robots. Robot novelty-detection can be improved by adaptive noise-cancellation, in which an adaptive filter learns a forward model of the whisker plant that allows the sensory effects of whisking to be predicted and thus subtracted from the noisy sensory input. However, the forward model only uses information from an efference copy of the whisking commands. Here we show that the addition of sensory information from the whiskers allows the adaptive filter to learn a more complex internal model that performs more robustly than the forward model, particularly when the whisking-induced interference has a periodic structure. We then propose a neural equivalent of the circuitry required for adaptive novelty-detection in the robot, in which the role of the adaptive filter is carried out by the cerebellum, with the comparison of its output (an estimate of the self-induced interference) and the original vibrissal signal occurring in the superior colliculus, a structure noted for its central role in novelty detection. This proposal makes a specific prediction concerning the whisker-related functions of a region in cerebellar cortical zone A2 that in rats receives climbing fibre input from the superior colliculus (via the inferior olive). This region has not been observed in non-whisking animals such as cats and primates, and its functional role in vibrissal processing has hitherto remained mysterious. Further investigation of this system may throw light on how cerebellar-based internal models could be used in broader sensory, motor and cognitive contexts.
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32
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Ollerenshaw DR, Bari BA, Millard DC, Orr LE, Wang Q, Stanley GB. Detection of tactile inputs in the rat vibrissa pathway. J Neurophysiol 2012; 108:479-90. [PMID: 22514290 DOI: 10.1152/jn.00004.2012] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The rapid detection of sensory inputs is crucial for survival. Sensory detection explicitly requires the integration of incoming sensory information and the ability to distinguish between relevant information and ongoing neural activity. In this study, head-fixed rats were trained to detect the presence of a brief deflection of their whiskers resulting from a focused puff of air. The animals showed a monotonic increase in response probability and a decrease in reaction time with increased stimulus strength. High-speed video analysis of whisker motion revealed that animals were more likely to detect the stimulus during periods of reduced self-induced motion of the whiskers, thereby allowing the stimulus-induced whisker motion to exceed the ongoing noise. In parallel, we used voltage-sensitive dye (VSD) imaging of barrel cortex in anesthetized rats receiving the same stimulus set as those in the behavioral portion of this study to assess candidate codes that make use of the full spatiotemporal representation and to compare variability in the trial-by-trial nature of the cortical response and the corresponding variability in the behavioral response. By application of an accumulating evidence framework to the population cortical activity measured in separate animals, a strong correspondence was made between the behavioral output and the neural signaling, in terms of both the response probabilities and the reaction times. Taken together, the results here provide evidence for detection performance that is strongly reliant on the relative strength of signal versus noise, with strong correspondence between behavior and parallel electrophysiological findings.
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Affiliation(s)
- Douglas R Ollerenshaw
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30332, USA
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33
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Deschênes M, Moore J, Kleinfeld D. Sniffing and whisking in rodents. Curr Opin Neurobiol 2012; 22:243-50. [PMID: 22177596 PMCID: PMC4934665 DOI: 10.1016/j.conb.2011.11.013] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Revised: 11/27/2011] [Accepted: 11/28/2011] [Indexed: 10/14/2022]
Abstract
Sniffing and whisking are two rhythmic orofacial motor activities that enable rodents to localize and track objects in their environment. They have related temporal dynamics, possibly as a result of both shared musculature and shared sensory tasks. Sniffing and whisking also constitute the overt expression of an animal's anticipation of a reward. Yet, the neuronal mechanisms that underlie the control of these behaviors have not been established. Here, we review the similarities between sniffing and whisking and suggest that such similarities indicate a mechanistic link between these two rhythmic exploratory behaviors.
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Affiliation(s)
- Martin Deschênes
- Department of Psychiatry and Neuroscience, Laval University, Québec City G1J 2G3, Canada.
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Kleinfeld D, Deschênes M. Neuronal basis for object location in the vibrissa scanning sensorimotor system. Neuron 2011; 72:455-68. [PMID: 22078505 DOI: 10.1016/j.neuron.2011.10.009] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/13/2011] [Indexed: 01/10/2023]
Abstract
An essential issue in perception is how the location of an object is estimated from tactile signals in the context of self-generated changes in sensor configuration. Here, we review the pathways and dynamics of neuronal signals that encode touch in the rodent vibrissa sensorimotor system. Rodents rhythmically scan an array of long, facial hairs across a region of interest. Behavioral evidence shows that these animals maintain knowledge of the azimuthal position of their vibrissae. Electrophysiological measurements have identified a reafferent signal of the azimuth that is coded in normalized coordinates, broadcast throughout primary sensory cortex and provides strong modulation of signals of vibrissa contact. Efferent signals in motor cortex report the range of the scan. Collectively, these signals allow the rodent to form a percept of object location.
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Affiliation(s)
- David Kleinfeld
- Department of Physics and Section of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA.
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Bosman LWJ, Houweling AR, Owens CB, Tanke N, Shevchouk OT, Rahmati N, Teunissen WHT, Ju C, Gong W, Koekkoek SKE, De Zeeuw CI. Anatomical pathways involved in generating and sensing rhythmic whisker movements. Front Integr Neurosci 2011; 5:53. [PMID: 22065951 PMCID: PMC3207327 DOI: 10.3389/fnint.2011.00053] [Citation(s) in RCA: 158] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 08/26/2011] [Indexed: 11/29/2022] Open
Abstract
The rodent whisker system is widely used as a model system for investigating sensorimotor integration, neural mechanisms of complex cognitive tasks, neural development, and robotics. The whisker pathways to the barrel cortex have received considerable attention. However, many subcortical structures are paramount to the whisker system. They contribute to important processes, like filtering out salient features, integration with other senses, and adaptation of the whisker system to the general behavioral state of the animal. We present here an overview of the brain regions and their connections involved in the whisker system. We do not only describe the anatomy and functional roles of the cerebral cortex, but also those of subcortical structures like the striatum, superior colliculus, cerebellum, pontomedullary reticular formation, zona incerta, and anterior pretectal nucleus as well as those of level setting systems like the cholinergic, histaminergic, serotonergic, and noradrenergic pathways. We conclude by discussing how these brain regions may affect each other and how they together may control the precise timing of whisker movements and coordinate whisker perception.
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Affiliation(s)
- Laurens W. J. Bosman
- Department of Neuroscience, Erasmus MCRotterdam, Netherlands
- Netherlands Institute for Neuroscience, Royal Academy of Arts and SciencesAmsterdam, Netherlands
| | | | - Cullen B. Owens
- Department of Neuroscience, Erasmus MCRotterdam, Netherlands
| | - Nouk Tanke
- Department of Neuroscience, Erasmus MCRotterdam, Netherlands
| | | | - Negah Rahmati
- Department of Neuroscience, Erasmus MCRotterdam, Netherlands
| | | | - Chiheng Ju
- Department of Neuroscience, Erasmus MCRotterdam, Netherlands
| | - Wei Gong
- Department of Neuroscience, Erasmus MCRotterdam, Netherlands
| | | | - Chris I. De Zeeuw
- Department of Neuroscience, Erasmus MCRotterdam, Netherlands
- Netherlands Institute for Neuroscience, Royal Academy of Arts and SciencesAmsterdam, Netherlands
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Tseng WT, Yen CT, Tsai ML. A bundled microwire array for long-term chronic single-unit recording in deep brain regions of behaving rats. J Neurosci Methods 2011; 201:368-76. [PMID: 21889539 DOI: 10.1016/j.jneumeth.2011.08.028] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Revised: 08/17/2011] [Accepted: 08/18/2011] [Indexed: 11/29/2022]
Affiliation(s)
- Wan-Ting Tseng
- Institute of Zoology and Department of Life Science, National Taiwan University, Taipei, Taiwan
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Tahon K, Wijnants M, De Schutter E. The RAT-ROTADRUM: a reaction time task depending on a continuous stream of tactile sensory information to the rat. J Neurosci Methods 2011; 200:153-63. [PMID: 21767567 DOI: 10.1016/j.jneumeth.2011.06.031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Revised: 05/25/2011] [Accepted: 06/29/2011] [Indexed: 11/24/2022]
Abstract
Rats running in their natural habitat monitor the immediate environment with their micro- and macrovibrissae as if reading Braille. These sensory inputs can serve as a cue to change their ongoing motor patterns, for instance to avoid obstacles. To mimic this behavior in a laboratory setting we present a novel behavioral test design. It includes a self-controlled stimulus presentation with sensory discrimination acting as a cue to redirect motor behavior. To acquire the final paradigm, rats undergo a sequenced training protocol. Extracellular neuronal activity was recorded during task performance in the final paradigm. Together with this behavioral test box we present a flexible, easy to build and affordable modular stimulus control system.
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Affiliation(s)
- Koen Tahon
- Laboratory for Theoretical Neurobiology, University of Antwerp, Belgium.
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Abstract
The rat vibrissal (whisker) system is an increasingly important model for the study of the sense of touch. This paper describes recent results obtained from high-speed videography of rat exploratory behavior and from modeling studies of vibrissal biomechanics. We review several features of vibrissal touch, including the mechanics of contact versus noncontact whisking, the coordination between head and whisker movements, and the use of information obtained from the whiskers to detect, localize, and extract the spatial properties of objects. This work highlights the idea that mechanics are critical to an understanding of sensory systems and describes some new tools to monitor the spatiotemporal patterns of whisker-object contact during natural tactile exploratory behavior.
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Affiliation(s)
- Mitra J Z Hartmann
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, USA.
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Bezdudnaya T, Castro-Alamancos MA. Superior colliculus cells sensitive to active touch and texture during whisking. J Neurophysiol 2011; 106:332-46. [PMID: 21525369 DOI: 10.1152/jn.00072.2011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Rats sense the environment through rhythmic vibrissa protractions, called active whisking, which can be simulated in anesthetized rats by electrically stimulating the facial motor nerve. Using this method, we investigated barrel cortex field potential and superior colliculus single-unit responses during passive touch, whisking movement, active touch, and texture discrimination. Similar to passive touch, whisking movement is signaled during the onset of the whisker protraction by short-latency responses in barrel cortex that drive corticotectal responses in superior colliculus, and all these responses show robust adaptation with increases in whisking frequency. Active touch and texture are signaled by longer latency responses, first in superior colliculus during the rising phase of the protraction, likely driven by trigeminotectal inputs, and later in barrel cortex by the falling phase of the protraction. Thus, superior colliculus is part of a broader vibrissa neural network that can decode whisking movement, active touch, and texture.
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Affiliation(s)
- Tatiana Bezdudnaya
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129, USA
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Zeigler HP. Wally Welker and neurobehavioral evolution: an appreciation and bibliography. Ann N Y Acad Sci 2011; 1225:1-13. [DOI: 10.1111/j.1749-6632.2011.06012.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Khatri V, Bermejo R, Brumberg JC, Zeigler HP. Whisking in air: encoding of kinematics by VPM neurons in awake rats. Somatosens Mot Res 2011; 27:111-20. [PMID: 20722492 DOI: 10.3109/08990220.2010.502381] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Rodent whisking behavior generates two types of neural signals: one produced by whisker contact with objects; the other by movements in air. While kinematic signals generated by contact reliably activate neurons at all levels of the trigeminal neuraxis, the extent to which the kinematics of whisking in air are reliably encoded at each level remains unclear. Previously, we showed that the responses of trigeminal ganglion (TG) neurons in awake, head-fixed rats are correlated with whisking kinematic parameters, but that individual neurons may differ substantially in the reliability of their kinematic encoding. Here, we extend that analysis to neurons in the ventral posterior medial (VPM) nucleus. Three possible coding strategies were examined: (1) firing rate across an entire movement; (2) the probability of individual spikes as a function of the instantaneous movement trajectory; and (3) the coherence between spikes and whisking. While VPM neurons were clearly responsive to variations in whisker kinematics during whisking in air, the encoding of whisker kinematics by VPM neurons was less consistent than that of TG neurons. Furthermore, we found that, in VPM as in TG, movement direction is an important determinant of unit responsiveness during whisking in air.
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Affiliation(s)
- V Khatri
- Department of Biology, City College of New York, New York, NY, USA.
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Mameli O, Stanzani S, Mulliri G, Pellitteri R, Caria MA, Russo A, De Riu P. Role of the trigeminal mesencephalic nucleus in rat whisker pad proprioception. Behav Brain Funct 2010; 6:69. [PMID: 21078134 PMCID: PMC2993642 DOI: 10.1186/1744-9081-6-69] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2010] [Accepted: 11/15/2010] [Indexed: 11/23/2022] Open
Abstract
Background Trigeminal proprioception related to rodent macrovibrissae movements is believed to involve skin receptors on the whisker pad because pad muscles operate without muscle spindles. This study was aimed to investigate in rats whether the trigeminal mesencephalic nucleus (TMnu), which provides proprioceptive feedback for chewing muscles, may be also involved in whisker pad proprioception. Methods Two retrograde tracers, Dil and True Blue Chloride, were injected into the mystacial pad and the masseter muscle on the same side of deeply anesthetized rats to label the respective projecting sensory neurons. This double-labeling technique was used to assess the co-innervation of both structures by the trigeminal mesencephalic nucleus (TMnu). In a separate group of anesthetized animals, the spontaneous electrical activities of TMnu neurons were analyzed by extracellular recordings during spontaneous movements of the macrovibrissae. Mesencephalic neurons (TMne) were previously identified by their responses to masseter muscle stretching. Changes in TMne spontaneous electrical activities, analyzed under baseline conditions and during whisking movements, were statistically evaluated using Student's t-test for paired observations. Results Neuroanatomical experiments revealed different subpopulations of trigeminal mesencephalic neurons: i) those innervating the neuromuscular spindles of the masseter muscle, ii) those innervating the mystacial pad, and iii) those innervating both structures. Extracellular recordings made during spontaneous movements of the macrovibrisae showed that whisking neurons similar to those observed in the trigeminal ganglion were located in the TMnu. These neurons had different patterns of activation, which were dependent on the type of spontaneous macrovibrissae movement. In particular, their spiking activity tonically increased during fan-like movements of the vibrissae and showed phasic bursting during rhythmic whisking. Furthermore, the same neurons may also respond to masseter muscle stretch. Conclusions results strongly support the hypothesis that the TMnu also contains first-order neurons specialized for relaying spatial information related to whisker movement and location to trigeminal-cortical pathways. In fact, the TMnu projects to second-order trigeminal neurons, thus allowing the rat brain to deduce higher-order information regarding executed movements of the vibrissae by combining touch information carried by trigeminal ganglion neurons with proprioceptive information carried by mesencephalic neurons.
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Affiliation(s)
- Ombretta Mameli
- Department of Neuroscience, Human Physiology Division, University of Sassari, viale San Pietro 43/B, 07100 Sassari, Italy.
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Schwarz C, Hentschke H, Butovas S, Haiss F, Stüttgen MC, Gerdjikov TV, Bergner CG, Waiblinger C. The head-fixed behaving rat--procedures and pitfalls. Somatosens Mot Res 2010; 27:131-48. [PMID: 20954892 PMCID: PMC3018133 DOI: 10.3109/08990220.2010.513111] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
This paper describes experimental techniques with head-fixed, operantly conditioned rodents that allow the control of stimulus presentation and tracking of motor output at hitherto unprecedented levels of spatio-temporal precision. Experimental procedures for the surgery and behavioral training are presented. We place particular emphasis on potential pitfalls using these procedures in order to assist investigators who intend to engage in this type of experiment. We argue that head-fixed rodent models, by allowing the combination of methodologies from molecular manipulations, intracellular electrophysiology, and imaging to behavioral measurements, will be instrumental in combining insights into the functional neuronal organization at different levels of observation. Provided viable behavioral methods are implemented, model systems based on rodents will be complementary to current primate models—the latter providing highest comparability with the human brain, while the former offer hugely advanced methodologies on the lower levels of organization, for example, genetic alterations, intracellular electrophysiology, and imaging.
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Affiliation(s)
- Cornelius Schwarz
- Systems Neurophysiology Group, Werner Reichardt Centre for Integrative Neuroscience, University of Tübingen, Germany.
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