The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
David Kleinfeld - One of the best experts on this subject based on the ideXlab platform.
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Parallel Inhibitory and Excitatory Trigemino-Facial Feedback Circuitry for Reflexive Vibrissa Movement.
Neuron, 2017Co-Authors: Marie-andrée Bellavance, David Kleinfeld, Jun Takatoh, Fan Wang, Maxime Demers, Martin DeschênesAbstract:Animals employ active touch to optimize the acuity of their tactile sensors. Prior experimental results and models lead to the hypothesis that sensory inputs are used in a recurrent manner to tune the position of the sensors. A combination of electrophysiology, intersectional genetic viral labeling and manipulation, and classical tracing allowed us to identify second-order sensorimotor loops that control Vibrissa movements by rodents. Facial motoneurons that drive intrinsic muscles to protract the Vibrissae receive a short latency inhibitory input, followed by synaptic excitation, from neurons located in the oralis division of the trigeminal sensory complex. In contrast, motoneurons that retract the mystacial pad and indirectly retract the Vibrissae receive only excitatory input from interpolaris cells that further project to the thalamus. Silencing this feedback alters retraction. The observed pull-push circuit at the lowest-level sensorimotor loop provides a mechanism for the rapid modulation of Vibrissa touch during exploration of peri-personal space.
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Precision mapping of the Vibrissa representation within murine primary somatosensory cortex.
Philosophical transactions of the Royal Society of London. Series B Biological sciences, 2016Co-Authors: Per Magne Knutsen, Celine Mateo, David KleinfeldAbstract:The ability to form an accurate map of sensory input to the brain is an essential aspect of interpreting functional brain signals. Here, we consider the somatotopic map of Vibrissa-based touch in the primary somatosensory (vS1) cortex of mice. The Vibrissae are represented by a Manhattan-like grid of columnar structures that are separated by inter-digitating septa. The development, dynamics and plasticity of this organization is widely used as a model system. Yet, the exact anatomical position of this organization within the vS1 cortex varies between individual mice. Targeting of a particular column in vivo therefore requires prior mapping of the activated cortical region, for instance by imaging the evoked intrinsic optical signal (eIOS) during Vibrissa stimulation. Here, we describe a procedure for constructing a complete somatotopic map of the Vibrissa representation in the vS1 cortex using eIOS. This enables precise targeting of individual cortical columns. We found, using C57BL/6 mice, that although the precise location of the columnar field varies between animals, the relative spatial arrangement of the columns is highly preserved. This finding enables us to construct a canonical somatotopic map of the Vibrissae in the vS1 cortex. In particular, the position of any column, in absolute anatomical coordinates, can be established with near certainty when the functional representations in the vS1 cortex for as few as two Vibrissae have been mapped with eIOS.This article is part of the themed issue 'Interpreting BOLD: a dialogue between cognitive and cellular neuroscience'.
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Behavioral/Systems/Cognitive Biomechanics of the Vibrissa Motor Plant in Rat: Rhythmic Whisking Consists of Triphasic Neuromuscular Activity
2016Co-Authors: Dan N. Hill, R. Bermejo, Philip H. Zeigler, David KleinfeldAbstract:The biomechanics of a motor plant constrain the behavioral strategies that an animal has available to extract information from its environment. We used the rat Vibrissa system as a model for active sensing and determined the pattern of muscle activity that drives rhythmic exploratory whisking. Our approach made use of electromyography to measure the activation of all relevant muscles in both head-fixed and unrestrained rats and two-dimensional imaging tomonitor the position of the Vibrissae in head-fixed rats. Our essential finding is that the periodicmotion of the Vibrissae andmystacial pad during whisking results from three phases ofmuscle activity. First, the Vibrissae are thrust forward as the rostral extrinsic muscle, musculus (m.) nasalis, contracts to pull the pad and initiate protraction. Second, late in protraction, the intrinsicmuscles pivot the Vibrissae farther forward. Third, retraction involves the cessation ofm. nasalis and intrinsicmuscle activity and the contraction of the caudal extrinsicmusclesm. nasolabialis andm.maxillolabialis to pull the pad and the Vibrissae backward. We developed a biomechanical model of the whisking motor plant that incorporates the measured muscular mechanics along withmovement vectors observed from direct muscle stimulation in anesthetized rats. The results of simulations of the model quantify how the combination of extrinsic and intrinsicmuscle activity leads to an enhanced range of Vibrissamotion than would be available from the intrinsic muscles alone. Key words: biomechanics; central pattern generator; EMG (electromyogram); motor control; movement (motion; motor activity); rat; Vibrissa (whisker
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RESEARCH ARTICLE Vibrissa Self-Motion and Touch Are Reliably Encoded along the Same Somatosensory Pathway from Brainstem through Thalamus
2016Co-Authors: Jeffrey D Moore, Martin Deschênes, Nicole Mercer Lindsay, David KleinfeldAbstract:Active sensing involves the fusion of internally generated motor events with external sensa-tion. 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 tha-lamic nuclei, are substantially modulated by touch. In contrast, spike rates along the para-lemniscal 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 functio
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Vibrissa self motion and touch are reliably encoded along the same somatosensory pathway from brainstem through thalamus
PLOS Biology, 2015Co-Authors: Jeffrey D Moore, Martin Deschênes, Nicole Mercer Lindsay, David KleinfeldAbstract: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.
Daniel S. Barth - One of the best experts on this subject based on the ideXlab platform.
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two dimensional coincidence detection in the Vibrissa barrel field
Journal of Neurophysiology, 2006Co-Authors: Krista M Rodgers, Alexander M Benison, Daniel S. BarthAbstract:Coincidence detection in visual and auditory cortex may also be critical for feature analysis in somatosensory cortex. We examined its role in the rat posteromedial barrel subfield (PMBSF) using high-resolution arrays of epipial electrodes. Five Vibrissae, forming an arc, row, or diagonal, were simultaneously or asynchronously stimulated to simulate contact with a straight edge of different angles at natural whisking velocities. Results indicated supralinear responses for both slow-wave and fast oscillations (FOs, about 350 Hz) at interVibrissa delays <2 ms. FO represented the earliest and most precisely tuned response to coincident Vibrissa displacement. There was little difference in the spatiotemporal pattern of slow-wave or FO responses in the row, arc, or diagonal. This equivalence of function suggests that the PMBSF may be capable of working as a two-dimensional integrative array, processing spatial features based on coincidence detection despite the direction that the Vibrissae pass across an object.
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temporal patterns of field potentials in Vibrissa barrel cortex reveal stimulus orientation and shape
Journal of Neurophysiology, 2006Co-Authors: Alexander M Benison, Tyler Ard, Allison M Crosby, Daniel S. BarthAbstract:During environmental exploration, rats rhythmically whisk their Vibrissae along the rostrocaudal axis. Each forward extension of the Vibrissa array establishes rapid spatiotemporal contact with an ...
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Temporal Patterns of Field Potentials in Vibrissa/Barrel Cortex Reveal Stimulus Orientation and Shape
Journal of neurophysiology, 2006Co-Authors: Alexander M Benison, Tyler Ard, Allison M Crosby, Daniel S. BarthAbstract:During environmental exploration, rats rhythmically whisk their Vibrissae along the rostrocaudal axis. Each forward extension of the Vibrissa array establishes rapid spatiotemporal contact with an object under investigation. This contact presumably produces equally rapid spatiotemporal patterns of population responses in the Vibrissa representation of somatosensory cortex [the posterior medial barrel subfield (PMBSF)] reflecting features of a stimulus. We used extracellular mapping to identify object features based on spatiotemporal patterns of evoked potentials. Spatiotemporal modeling of evoked potential patterns accurately reconstructed linear versus curved stimuli and detected orientation changes as small as 5 degrees. Whiskers forming arcs in the PMBSF, essential for this reconstruction, may represent a fundamental processing module. We propose that the PMBSF may function as a spatial frequency analyzer, with intrarow processing integrating a complementary set of spatial frequencies from the arcs in a single whisk.
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Spatiotemporal Organization of Fast (>200 Hz) Electrical Oscillations in Rat Vibrissa/Barrel Cortex
Journal of neurophysiology, 1999Co-Authors: Michael S. Jones, Daniel S. BarthAbstract:A 64-channel electrode array was used to study the spatial and temporal characteristics of fast (>200 Hz) electrical oscillations recorded from the surface of rat cortex in both awake and anesthetized animals. Transient Vibrissal displacements were effective in evoking oscillatory responses in the Vibrissa/barrel field and were tightly time-locked to stimulus onset, coinciding with the earliest temporal components of the coincident slow-wave response. Vibrissa-evoked fast oscillations exhibited modality specificity and were earliest and of largest amplitude over the cortical barrel, which corresponded to the Vibrissa stimulated, spreading to sequentially engage neighboring barrels over subsequent oscillatory cycles. The response was enhanced after paired-Vibrissal stimulation and was sensitive to time delays between movement of separate Vibrissae. These data suggest that spatiotemporal interactions between fast oscillatory bursts in the barrel field may play a role in rapidly integrating information from the Vibrissal array during the earliest cortical response to somatosensory stimulation.
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spatiotemporal organization of fast 200 hz electrical oscillations in rat Vibrissa barrel cortex
Journal of Neurophysiology, 1999Co-Authors: Michael S. Jones, Daniel S. BarthAbstract:A 64-channel electrode array was used to study the spatial and temporal characteristics of fast (>200 Hz) electrical oscillations recorded from the surface of rat cortex in both awake and anesthetized animals. Transient Vibrissal displacements were effective in evoking oscillatory responses in the Vibrissa/barrel field and were tightly time-locked to stimulus onset, coinciding with the earliest temporal components of the coincident slow-wave response. Vibrissa-evoked fast oscillations exhibited modality specificity and were earliest and of largest amplitude over the cortical barrel, which corresponded to the Vibrissa stimulated, spreading to sequentially engage neighboring barrels over subsequent oscillatory cycles. The response was enhanced after paired-Vibrissal stimulation and was sensitive to time delays between movement of separate Vibrissae. These data suggest that spatiotemporal interactions between fast oscillatory bursts in the barrel field may play a role in rapidly integrating information from the Vibrissal array during the earliest cortical response to somatosensory stimulation.
Christopher I. Moore - One of the best experts on this subject based on the ideXlab platform.
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Mechanical resonance enhances the sensitivity of the Vibrissa sensory system to near-threshold stimuli.
Brain research, 2008Co-Authors: Mark L. Andermann, Christopher I. MooreAbstract:Abstract The representation of high-frequency sensory information is a crucial problem faced by the nervous system. Rodent facial Vibrissae constitute a high-resolution sensory system, capable of discriminating and detecting subtle changes in tactual input. During active sensing, the mechanical properties of Vibrissae may play a key role in filtering sensory information and translating it into neural activity. Previous studies have shown that rat Vibrissae resonate, conferring frequency specificity to trigeminal ganglion (NV) and primary somatosensory cortex (SI) neurons during suprathreshold sensory stimulation. In addition to frequency specificity , a further potential impact of Vibrissa resonance is enhancement of sensitivity to near-threshold stimuli through signal amplification. To examine the effect of resonance on peri-threshold inputs (≤ 80 μm at the Vibrissa tip), we recorded NV and SI neurons during stimulation at multiple amplitudes and frequencies, and generated minimal amplitude tuning curves. Several novel findings emerged from this study. First, Vibrissa resonance significantly lowered the threshold for evoked neural activity, in many cases by an order of magnitude compared to stimuli presented at off-resonance frequencies. When stimulated at the fundamental resonance frequency, motions as small as 8 μm at the Vibrissa tip, corresponding to angular deflections of less than 0.2°, drove neural firing in the periphery and cortex. Second, a closer match between Vibrissal and neural frequency tuning was found for lower amplitude motions. Third, simultaneous paired recordings demonstrated that the minimal amplitude of resonant Vibrissa stimulation required to evoke responses in SI increased significantly for recordings outside the primary Vibrissa barrel column, providing additional evidence for somatotopically localized frequency columns. These data demonstrate that resonant amplification can increase the sensitivity of the Vibrissa sensory system to an ecologically relevant range of low-amplitude, high-frequency stimuli.
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Embodied Information Processing: Vibrissa Mechanics and Texture Features Shape Micromotions in Actively Sensing Rats
Neuron, 2008Co-Authors: Jason T. Ritt, Mark L. Andermann, Christopher I. MooreAbstract:Peripheral sensory organs provide the first transformation of sensory information, and understanding how their physical embodiment shapes transduction is central to understanding perception. We report the characterization of surface transduction during active sensing in the rodent Vibrissa sensory system, a widely used model. Employing high-speed videography, we tracked Vibrissae while rats sampled rough and smooth textures. Variation in Vibrissa length predicted motion mean frequencies, including for the highest velocity events, indicating that biomechanics, such as Vibrissa resonance, shape signals most likely to drive neural activity. Rough surface contact generated large amplitude, high-velocity "stick-slip-ring" events, while smooth surfaces generated smaller and more regular stick-slip oscillations. Both surfaces produced velocities exceeding those applied in reduced preparations, indicating active sensation of surfaces generates more robust drive than previously predicted. These findings demonstrate a key role for embodiment in Vibrissal sensing and the importance of input transformations in sensory representation.
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Neural correlates of Vibrissa resonance; band-pass and somatotopic representation of high-frequency stimuli.
Neuron, 2004Co-Authors: Mark L. Andermann, Jason T. Ritt, Maria A. Neimark, Christopher I. MooreAbstract:The array of Vibrissae on a rat's face is the first stage of a high-resolution tactile sensing system. Recently, it was discovered that Vibrissae (whiskers) resonate when stimulated at specific frequencies, generating several-fold increases in motion amplitude. We investigated the neural correlates of Vibrissa resonance in trigeminal ganglion and primary somatosensory cortex (SI) neurons (regular and fast spiking units) by presenting low-amplitude, high-frequency Vibrissa stimulation. We found that somatosensory neurons showed band-pass tuning and enhanced sensitivity to small amplitude stimuli, reflecting the resonance amplification of Vibrissa motion. Further, a putative somatotopic map of frequency selectivity was observed in SI, with isofrequency columns extending along the representations of arcs of Vibrissae, in agreement with the gradient in Vibrissa resonance across the Vibrissa pad. These findings suggest several parallels between frequency processing in the Vibrissa system and the auditory system and have important implications for detection and discrimination of tactile information.
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Vibrissa Resonance as a Transduction Mechanism for Tactile Encoding
The Journal of neuroscience : the official journal of the Society for Neuroscience, 2003Co-Authors: Maria A. Neimark, Mark L. Andermann, John J. Hopfield, Christopher I. MooreAbstract:We present evidence that resonance properties of rat Vibrissae differentially amplify high-frequency and complex tactile signals. Consistent with a model of Vibrissa mechanics, optical measurements of Vibrissae revealed that their first mechanical resonance frequencies systematically varied from low (60-100 Hz) in longer, posterior Vibrissae to high ( approximately 750 Hz) in shorter, anterior Vibrissae. Resonance amplification of tactile input was observed in vivo and ex vivo, and in a variety of boundary conditions that are likely to occur during perception, including stimulation of the Vibrissa with moving complex natural stimuli such as sandpaper. Vibrissae were underdamped, allowing for sharp tuning to resonance frequencies. Vibrissa resonance constitutes a potentially useful mechanism for perception of high-frequency and complex tactile signals. Amplification of small amplitude signals by resonance could facilitate detection of stimuli that would otherwise fail to drive neural activity. The systematic map of frequency sensitivity across the face could facilitate texture discrimination through somatotopic encoding of frequency content. These findings suggest strong parallels between Vibrissa tactile processing and auditory encoding, in which the cochlea also uses resonance to amplify low-amplitude signals and to generate a spatial map of frequency sensitivity.
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Vibrissa resonance as a transduction mechanism for tactile encoding
The Journal of Neuroscience, 2003Co-Authors: Maria A. Neimark, Mark L. Andermann, John J. Hopfield, Christopher I. MooreAbstract:We present evidence that resonance properties of rat Vibrissae differentially amplify high-frequency and complex tactile signals. Consistent with a model of Vibrissa mechanics, optical measurements of Vibrissae revealed that their first mechanical resonance frequencies systematically varied from low (60 ‐100 Hz) in longer, posterior Vibrissae to high (750 Hz) in shorter, anterior Vibrissae. Resonance amplification of tactile input was observed in vivo and ex vivo, and in a variety of boundary conditions that are likely to occur during perception, including stimulation of the Vibrissa with moving complex natural stimuli such as sandpaper. Vibrissae were underdamped, allowing for sharp tuning to resonance frequencies. Vibrissa resonance constitutes a potentially useful mechanism for perception of high-frequency and complex tactile signals. Amplification of small amplitude signals by resonance could facilitate detection of stimuli that would otherwise fail to drive neural activity. The systematic map of frequency sensitivity across the face could facilitate texture discrimination through somatotopic encoding of frequency content. These findings suggest strong parallels between Vibrissa tactile processing and auditory encoding, in which the cochlea also uses resonance to amplify low-amplitude signals and to generate a spatial map of frequency sensitivity.
Mark L. Andermann - One of the best experts on this subject based on the ideXlab platform.
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Mechanical resonance enhances the sensitivity of the Vibrissa sensory system to near-threshold stimuli.
Brain research, 2008Co-Authors: Mark L. Andermann, Christopher I. MooreAbstract:Abstract The representation of high-frequency sensory information is a crucial problem faced by the nervous system. Rodent facial Vibrissae constitute a high-resolution sensory system, capable of discriminating and detecting subtle changes in tactual input. During active sensing, the mechanical properties of Vibrissae may play a key role in filtering sensory information and translating it into neural activity. Previous studies have shown that rat Vibrissae resonate, conferring frequency specificity to trigeminal ganglion (NV) and primary somatosensory cortex (SI) neurons during suprathreshold sensory stimulation. In addition to frequency specificity , a further potential impact of Vibrissa resonance is enhancement of sensitivity to near-threshold stimuli through signal amplification. To examine the effect of resonance on peri-threshold inputs (≤ 80 μm at the Vibrissa tip), we recorded NV and SI neurons during stimulation at multiple amplitudes and frequencies, and generated minimal amplitude tuning curves. Several novel findings emerged from this study. First, Vibrissa resonance significantly lowered the threshold for evoked neural activity, in many cases by an order of magnitude compared to stimuli presented at off-resonance frequencies. When stimulated at the fundamental resonance frequency, motions as small as 8 μm at the Vibrissa tip, corresponding to angular deflections of less than 0.2°, drove neural firing in the periphery and cortex. Second, a closer match between Vibrissal and neural frequency tuning was found for lower amplitude motions. Third, simultaneous paired recordings demonstrated that the minimal amplitude of resonant Vibrissa stimulation required to evoke responses in SI increased significantly for recordings outside the primary Vibrissa barrel column, providing additional evidence for somatotopically localized frequency columns. These data demonstrate that resonant amplification can increase the sensitivity of the Vibrissa sensory system to an ecologically relevant range of low-amplitude, high-frequency stimuli.
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Embodied Information Processing: Vibrissa Mechanics and Texture Features Shape Micromotions in Actively Sensing Rats
Neuron, 2008Co-Authors: Jason T. Ritt, Mark L. Andermann, Christopher I. MooreAbstract:Peripheral sensory organs provide the first transformation of sensory information, and understanding how their physical embodiment shapes transduction is central to understanding perception. We report the characterization of surface transduction during active sensing in the rodent Vibrissa sensory system, a widely used model. Employing high-speed videography, we tracked Vibrissae while rats sampled rough and smooth textures. Variation in Vibrissa length predicted motion mean frequencies, including for the highest velocity events, indicating that biomechanics, such as Vibrissa resonance, shape signals most likely to drive neural activity. Rough surface contact generated large amplitude, high-velocity "stick-slip-ring" events, while smooth surfaces generated smaller and more regular stick-slip oscillations. Both surfaces produced velocities exceeding those applied in reduced preparations, indicating active sensation of surfaces generates more robust drive than previously predicted. These findings demonstrate a key role for embodiment in Vibrissal sensing and the importance of input transformations in sensory representation.
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Neural correlates of Vibrissa resonance; band-pass and somatotopic representation of high-frequency stimuli.
Neuron, 2004Co-Authors: Mark L. Andermann, Jason T. Ritt, Maria A. Neimark, Christopher I. MooreAbstract:The array of Vibrissae on a rat's face is the first stage of a high-resolution tactile sensing system. Recently, it was discovered that Vibrissae (whiskers) resonate when stimulated at specific frequencies, generating several-fold increases in motion amplitude. We investigated the neural correlates of Vibrissa resonance in trigeminal ganglion and primary somatosensory cortex (SI) neurons (regular and fast spiking units) by presenting low-amplitude, high-frequency Vibrissa stimulation. We found that somatosensory neurons showed band-pass tuning and enhanced sensitivity to small amplitude stimuli, reflecting the resonance amplification of Vibrissa motion. Further, a putative somatotopic map of frequency selectivity was observed in SI, with isofrequency columns extending along the representations of arcs of Vibrissae, in agreement with the gradient in Vibrissa resonance across the Vibrissa pad. These findings suggest several parallels between frequency processing in the Vibrissa system and the auditory system and have important implications for detection and discrimination of tactile information.
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Vibrissa Resonance as a Transduction Mechanism for Tactile Encoding
The Journal of neuroscience : the official journal of the Society for Neuroscience, 2003Co-Authors: Maria A. Neimark, Mark L. Andermann, John J. Hopfield, Christopher I. MooreAbstract:We present evidence that resonance properties of rat Vibrissae differentially amplify high-frequency and complex tactile signals. Consistent with a model of Vibrissa mechanics, optical measurements of Vibrissae revealed that their first mechanical resonance frequencies systematically varied from low (60-100 Hz) in longer, posterior Vibrissae to high ( approximately 750 Hz) in shorter, anterior Vibrissae. Resonance amplification of tactile input was observed in vivo and ex vivo, and in a variety of boundary conditions that are likely to occur during perception, including stimulation of the Vibrissa with moving complex natural stimuli such as sandpaper. Vibrissae were underdamped, allowing for sharp tuning to resonance frequencies. Vibrissa resonance constitutes a potentially useful mechanism for perception of high-frequency and complex tactile signals. Amplification of small amplitude signals by resonance could facilitate detection of stimuli that would otherwise fail to drive neural activity. The systematic map of frequency sensitivity across the face could facilitate texture discrimination through somatotopic encoding of frequency content. These findings suggest strong parallels between Vibrissa tactile processing and auditory encoding, in which the cochlea also uses resonance to amplify low-amplitude signals and to generate a spatial map of frequency sensitivity.
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Vibrissa resonance as a transduction mechanism for tactile encoding
The Journal of Neuroscience, 2003Co-Authors: Maria A. Neimark, Mark L. Andermann, John J. Hopfield, Christopher I. MooreAbstract:We present evidence that resonance properties of rat Vibrissae differentially amplify high-frequency and complex tactile signals. Consistent with a model of Vibrissa mechanics, optical measurements of Vibrissae revealed that their first mechanical resonance frequencies systematically varied from low (60 ‐100 Hz) in longer, posterior Vibrissae to high (750 Hz) in shorter, anterior Vibrissae. Resonance amplification of tactile input was observed in vivo and ex vivo, and in a variety of boundary conditions that are likely to occur during perception, including stimulation of the Vibrissa with moving complex natural stimuli such as sandpaper. Vibrissae were underdamped, allowing for sharp tuning to resonance frequencies. Vibrissa resonance constitutes a potentially useful mechanism for perception of high-frequency and complex tactile signals. Amplification of small amplitude signals by resonance could facilitate detection of stimuli that would otherwise fail to drive neural activity. The systematic map of frequency sensitivity across the face could facilitate texture discrimination through somatotopic encoding of frequency content. These findings suggest strong parallels between Vibrissa tactile processing and auditory encoding, in which the cochlea also uses resonance to amplify low-amplitude signals and to generate a spatial map of frequency sensitivity.
Michael Brecht - One of the best experts on this subject based on the ideXlab platform.
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Vibrissa motor cortex activity suppresses contralateral whisking behavior
Nature Neuroscience, 2016Co-Authors: Christian Laut Ebbesen, Guy Doron, Constanze Lenschow, Michael BrechtAbstract:Previous work on mammalian motor cortex has focused on the role of this region in movement generation. Here the authors demonstrate that activity of Vibrissa motor cortex neurons decreases during various forms of Vibrissal touch, suggesting that a primary function of Vibrissa motor cortex is to suppress whisking behavior.
