scholarly journals Stroke Induces Long-Lasting Deficits in the Temporal Fidelity of Sensory Processing in the Somatosensory Cortex

2012 ◽  
Vol 33 (1) ◽  
pp. 91-96 ◽  
Author(s):  
Danielle A Sweetnam ◽  
Craig E Brown
Keyword(s):  
Sensory Processing ◽  
Sensory Function ◽  
Cortical Circuits ◽  
Cortical Networks ◽  
Sensory Stimuli ◽  
Experimental Animals ◽  
Temporal Precision ◽  
Temporal Aspects ◽  
Voltage Sensitive Dyes ◽  
Sensory Functions

Recovery from stroke is rarely complete as humans and experimental animals typically show lingering deficits in sensory function. One explanation for limited recovery could be that rewired cortical networks do not process sensory stimuli with the same temporal precision as they normally would. To examine how well peri-infarct and more distant cortical networks process successive vibrotactile stimulations of the affected forepaw (a measure of temporal fidelity), we imaged cortical depolarizations with millisecond temporal resolution using voltage-sensitive dyes. In control mice, paired forepaw stimulations (ranging from 50 to 200 milliseconds apart) induced temporally distinct depolarizations in primary forelimb somatosensory (FLS1) cortex, and to a lesser extent in secondary FLS (FLS2) cortex. For mice imaged 3 months after stroke, the first forepaw stimulus reliably evoked a strong depolarization in the surviving region of FLS1 and FLS2 cortex. However, depolarizations to subsequent forepaw stimuli were significantly reduced or completely absent (for stimuli ≤100 milliseconds apart) in the FLS1 cortex, whereas FLS2 responses were relatively unaffected. Our data reveal that stroke induces long-lasting impairments in how well the rewired FLS1 cortex processes temporal aspects of sensory stimuli. Future therapies directed at enhancing the temporal fidelity of cortical circuits may be necessary for achieving full recovery of sensory functions.

scholarly journals Minimum Standards for Clinical Evoked Potential Studies

1994 ◽  
Vol 21 (1) ◽  
pp. 75-77 ◽  
Author(s):  
Keyword(s):  
Evoked Potentials ◽  
Sensory Processing ◽  
Sensory Function ◽  
Sensory Response ◽  
Sensory Stimuli ◽  
Sensory Pathways ◽  
Neurological Patients ◽  
Electrical Activities ◽  
The Brain ◽  
Averaging Techniques

Evoked potentials are the electrical changes that occur in the brain in response to sensory stimuli. They can be recorded from scalp electrodes using sensitive amplifiers. Averaging techniques are necessary to separate the evoked potentials from other electrical activities. Evoked potentials can provide helpful information for the clinical evaluation of neurological patients. They can assess sensory function by demonstrating the brain's response to sensory stimuli. They can localize dysfunction in sensory pathways by showing where and when a sensory response becomes abnormal. They can identify abnormalities of sensory processing that are not apparent during the usual clinical examination. They can assess the extent of normal or abnormal function and thereby assist prognosis in patients with brain-damage.

scholarly journals Shared Song Detector Neurons in Drosophila Male and Female Brains Drive Sex-Specific Behaviors

2018 ◽  
Author(s):  
David Deutsch ◽  
Jan Clemens ◽  
Stephan Y. Thiberge ◽  
Georgia Guan ◽  
Mala Murthy
Keyword(s):  
Sensory Processing ◽  
Acoustic Communication ◽  
Auditory Perception ◽  
Time Varying ◽  
Sensory Stimuli ◽  
Male And Female ◽  
Communication Signal ◽  
Temporal Aspects ◽  
Sensory Modalities ◽  
Males And Females

AbstractMales and females often produce distinct responses to the same sensory stimuli. How such differences arise – at the level of sensory processing or in the circuits that generate behavior – remains largely unresolved across sensory modalities. We address this issue in the acoustic communication system of Drosophila. During courtship, males generate time-varying songs, and each sex responds with specific behaviors. We characterize male and female behavioral tuning for all aspects of song, and show that feature tuning is similar between sexes, suggesting sex-shared song detectors drive divergent behaviors. We then identify higher-order neurons in the Drosophila brain, called pC2, that are tuned for multiple temporal aspects of one mode of the male’s song, and drive sex-specific behaviors. We thus uncover neurons that are specifically tuned to an acoustic communication signal and that reside at the sensory-motor interface, flexibly linking auditory perception with sex-specific behavioral responses.

scholarly journals Implication of the Sensory Environment in Children with Autism Spectrum Disorder: Perspectives from School

2021 ◽  
Vol 18 (14) ◽  
pp. 7670
Author(s):  
Ana Gentil-Gutiérrez ◽  
José Luis Cuesta-Gómez ◽  
Paula Rodríguez-Fernández ◽  
Jerónimo Javier González-Bernal
Keyword(s):  
Autism Spectrum Disorder ◽  
Sensory Processing ◽  
Children With Autism ◽  
Autism Spectrum ◽  
Spectrum Disorder ◽  
Sensory Profile ◽  
School Factors ◽  
Cross Sectional ◽  
Sensory Stimuli ◽  
Children With Asd

(1) Background: Children with Autism Spectrum Disorder (ASD) frequently have difficulties in processing sensory information, which is a limitation when participating in different contexts, such as school. The objective of the present study was to compare the sensory processing characteristics of children with ASD in the natural context of school through the perception of professionals in the field of education, in comparison with neurodevelopmental children (2) Methods: A cross-sectional descriptive study as conducted with study population consisting of children between three and ten years old, 36 of whom were diagnosed with ASD and attended the Autismo Burgos association; the remaining 24 had neurotypical development. The degree of response of the children to sensory stimuli at school was evaluated using the Sensory Profile-2 (SP-2) questionnaire in its school version, answered by the teachers. (3) Results: Statistically significant differences were found in sensory processing patterns (p = 0.001), in sensory systems (p = 0.001) and in school factors (p = 0.001). Children with ASD who obtained worse results. (4) Conclusions: Children with ASD are prone to present sensory alterations in different contexts, giving nonadapted behavioral and learning responses.

scholarly journals Contribution of the basal forebrain to corticocortical network interactions

2021 ◽  
Author(s):  
Peter Gombkoto ◽  
Matthew Gielow ◽  
Peter Varsanyi ◽  
Candice Chavez ◽  
Laszlo Zaborszky
Keyword(s):  
Sensory Processing ◽  
Basal Forebrain ◽  
Field Potential ◽  
Cholinergic Neurons ◽  
Attention And Memory ◽  
Cortical Circuits ◽  
Cholinergic Signaling ◽  
Spatial Changes ◽  
Gamma Power ◽  
Gamma Coherence

AbstractBasal forebrain (BF) cholinergic neurons provide the cerebral cortex with acetylcholine. Despite the long-established involvement of these cells in sensory processing, attention, and memory, the mechanisms by which cholinergic signaling regulates cognitive processes remain elusive. In this study, we recorded spiking and local field potential data simultaneously from several locations in the BF, and sites in the orbitofrontal and visual cortex in transgenic ChAT-Cre rats performing a visual discrimination task. We observed distinct differences in the fine spatial distributions of gamma coherence values between specific basalo-cortical and cortico-cortical sites that shifted across task phases. Additionally, cholinergic firing induced spatial changes in cortical gamma power, and optogenetic activation of BF increased coherence between specific cortico-cortical sites, suggesting that the cholinergic system contributes to selective modulation of cortico-cortical circuits. Furthermore, the results suggest that cells in specific BF locations are dynamically recruited across behavioral epochs to coordinate interregional cortical processes underlying cognition.

Dynamical Constraints on Using Precise Spike Timing to Compute in Recurrent Cortical Networks

2008 ◽  
Vol 20 (4) ◽  
pp. 974-993 ◽  
Author(s):  
Arunava Banerjee ◽  
Peggy Seriès ◽  
Alexandre Pouget
Keyword(s):  
Dynamical System ◽  
Initial Conditions ◽  
Internal State ◽  
Spike Timing ◽  
Spiking Neurons ◽  
Spatiotemporal Patterns ◽  
Cortical Networks ◽  
Temporal Precision ◽  
Cortical Areas ◽  
Dynamical Constraints

Several recent models have proposed the use of precise timing of spikes for cortical computation. Such models rely on growing experimental evidence that neurons in the thalamus as well as many primary sensory cortical areas respond to stimuli with remarkable temporal precision. Models of computation based on spike timing, where the output of the network is a function not only of the input but also of an independently initializable internal state of the network, must, however, satisfy a critical constraint: the dynamics of the network should not be sensitive to initial conditions. We have previously developed an abstract dynamical system for networks of spiking neurons that has allowed us to identify the criterion for the stationary dynamics of a network to be sensitive to initial conditions. Guided by this criterion, we analyzed the dynamics of several recurrent cortical architectures, including one from the orientation selectivity literature. Based on the results, we conclude that under conditions of sustained, Poisson-like, weakly correlated, low to moderate levels of internal activity as found in the cortex, it is unlikely that recurrent cortical networks can robustly generate precise spike trajectories, that is, spatiotemporal patterns of spikes precise to the millisecond timescale.

scholarly journals Functional selectivity and specific connectivity of inhibitory neurons in primary visual cortex

2018 ◽  
Author(s):  
Petr Znamenskiy ◽  
Mean-Hwan Kim ◽  
Dylan R. Muir ◽  
Maria Florencia Iacaruso ◽  
Sonja B. Hofer ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Pyramidal Cells ◽  
Fine Tuning ◽  
Inhibitory Neurons ◽  
Local Network ◽  
Cortical Circuits ◽  
Sensory Stimuli ◽  
Excitatory Neurons ◽  
Strong Excitation

In the cerebral cortex, the interaction of excitatory and inhibitory synaptic inputs shapes the responses of neurons to sensory stimuli, stabilizes network dynamics1 and improves the efficiency and robustness of the neural code2–4. Excitatory neurons receive inhibitory inputs that track excitation5–8. However, how this co-tuning of excitation and inhibition is achieved by cortical circuits is unclear, since inhibitory interneurons are thought to pool the inputs of nearby excitatory cells and provide them with non-specific inhibition proportional to the activity of the local network9–13. Here we show that although parvalbumin-expressing (PV) inhibitory cells in mouse primary visual cortex make connections with the majority of nearby pyramidal cells, the strength of their synaptic connections is structured according to the similarity of the cells’ responses. Individual PV cells strongly inhibit those pyramidal cells that provide them with strong excitation and share their visual selectivity. This fine-tuning of synaptic weights supports co-tuning of inhibitory and excitatory inputs onto individual pyramidal cells despite dense connectivity between inhibitory and excitatory neurons. Our results indicate that individual PV cells are preferentially integrated into subnetworks of inter-connected, co-tuned pyramidal cells, stabilising their recurrent dynamics. Conversely, weak but dense inhibitory connectivity between subnetworks is sufficient to support competition between them, de-correlating their output. We suggest that the history and structure of correlated firing adjusts the weights of both inhibitory and excitatory connections, supporting stable amplification and selective recruitment of cortical subnetworks.

scholarly journals Fast Synaptic Inhibition in Spinal Sensory Processing and Pain Control

2012 ◽  
Vol 92 (1) ◽  
pp. 193-235 ◽  
Author(s):  
Hanns Ulrich Zeilhofer ◽  
Hendrik Wildner ◽  
Gonzalo E. Yévenes
Keyword(s):  
Chronic Pain ◽  
Dorsal Horn ◽  
Sensory Processing ◽  
Temporal Discrimination ◽  
Sensory Nerve ◽  
Nerve Fibers ◽  
Sensory Stimuli ◽  
Inhibitory Neurotransmission ◽  
Pain Syndromes ◽  
Chronic Pain Syndromes

The two amino acids GABA and glycine mediate fast inhibitory neurotransmission in different CNS areas and serve pivotal roles in the spinal sensory processing. Under healthy conditions, they limit the excitability of spinal terminals of primary sensory nerve fibers and of intrinsic dorsal horn neurons through pre- and postsynaptic mechanisms, and thereby facilitate the spatial and temporal discrimination of sensory stimuli. Removal of fast inhibition not only reduces the fidelity of normal sensory processing but also provokes symptoms very much reminiscent of pathological and chronic pain syndromes. This review summarizes our knowledge of the molecular bases of spinal inhibitory neurotransmission and its organization in dorsal horn sensory circuits. Particular emphasis is placed on the role and mechanisms of spinal inhibitory malfunction in inflammatory and neuropathic chronic pain syndromes.

Magnetoencephalography

2017 ◽  
Author(s):  
Riitta Hari
Keyword(s):  
Sensory Processing ◽  
Quantum Interference ◽  
Sensor Technology ◽  
Brain Dynamics ◽  
Clinical Neuroscience ◽  
Sensory Stimuli ◽  
Superconducting Quantum Interference Devices ◽  
Brain Signals ◽  
Basic Characteristics ◽  
The Brain

This chapter introduces magnetoencephalography (MEG), a tool to study brain dynamics in basic and clinical neuroscience. MEG picks up brain signals with millisecond resolution, as does electroencephalography, but without distortion by skull and scalp. The chapter describes current instrumentation based on superconducting quantum interference devices (SQUIDs). It delineates basic characteristics of measured signals: (1) brain rhythms and their reactivity during sensory processing and various tasks and (2) evoked responses elicited by sensory stimuli, and the dependence of these responses on various stimulus characteristics. Signals are described from healthy and diseased brains. The chapter presents studies of the brain basis of cognition and social interaction studied in dual-MEG setups and describes how MEG applications can be broadened by innovative setups, including frequency tagging. Progress in the field is predicted regarding sensor technology, data analysis, and multimodal brain imaging, all of which could strengthen MEG’s role in the study of brain dynamics.

State-Dependent Performance of Optic-Flow Processing Interneurons

2009 ◽  
Vol 102 (6) ◽  
pp. 3606-3618 ◽  
Author(s):  
Kit D. Longden ◽  
Holger G. Krapp
Keyword(s):  
Sensory Processing ◽  
Optic Flow ◽  
Visual Processing ◽  
Metabolic Cost ◽  
Sensory Stimuli ◽  
State Dependent ◽  
Directional Motion ◽  
Save Energy ◽  
Self Motion ◽  
The Impact

Active locomotive states are metabolically expensive and require efficient sensory processing both to avoid wasteful movements and to cope with an extended bandwidth of sensory stimuli. This is particularly true for flying animals because flight, as opposed to walking or resting, imposes a steplike increase in metabolism for the precise execution and control of movements. Sensory processing itself carries a significant metabolic cost, but the principles governing the adjustment of sensory processing to different locomotor states are not well understood. We use the blowfly as a model system to study the impact on visual processing of a neuromodulator, octopamine, which is known to be involved in the regulation of flight physiology. We applied an octopamine agonist and recorded the directional motion responses of identified visual interneurons known to process self-motion–induced optic flow to directional motion stimuli. The neural response range of these neurons is increased and the response latency is reduced. We also found that, due to an elevated spontaneous spike rate, the cells' negative signaling range is increased. Meanwhile, the preferred self-motion parameters the cells encode were state independent. Our results indicate that in the blowfly energetically expensive sensory coding strategies, such as rapid, large responses, and high spontaneous spike activity could be adjusted by the neuromodulator octopamine, likely to save energy during quiet locomotor states.

Cilia Not Only Move, but also Have Taste!

2010 ◽  
Vol 18 (2) ◽  
pp. 6-8
Author(s):  
Stephen W. Carmichael
Keyword(s):  
Molecular Machines ◽  
Sensory Function ◽  
Mechanical Activity ◽  
Sensory Receptors ◽  
Pulmonary Infections ◽  
Immotile Cilia ◽  
Specific Direction ◽  
Motile Cilia ◽  
First Time ◽  
Sensory Functions

Motile cilia are organelles that contain amazing molecular machines that bend each cilium in a rhythmic and coordinated movement. This allows a liquid film, perhaps with particles embedded within, to move in a specific direction. The classic example is the cilia of the respiratory passages that move a layer of debris-carrying mucus out of the lungs. When this mechanism is not working properly, recurrent pulmonary infections result. The classic example of this is immotile cilia syndrome that results in chronic bronchitis and related problems. However, no sensory function has been assigned to these classic motile cilia until now (although nodal cilia have both mechanical activity and sensory functions). Alok Shah, Yehuda Ben-Shahar, Thomas Moninger, Joel Kline, and Michael Welsh have demonstrated sensory receptors on motile cilia for the first time.

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