scholarly journals The Origin of Cortical Surround Receptive Fields Studied in the Barrel Cortex

2003 ◽  
Vol 23 (23) ◽  
pp. 8380-8391 ◽  
Author(s):  
Kevin Fox ◽  
Nicholas Wright ◽  
Helen Wallace ◽  
Stanislaw Glazewski
Keyword(s):  
Barrel Cortex ◽  
Receptive Fields

Spatial structure of multiwhisker receptive fields in the barrel cortex is stimulus dependent

2011 ◽  
Vol 106 (2) ◽  
pp. 986-998 ◽  
Author(s):  
Julie Le Cam ◽  
Luc Estebanez ◽  
Vincent Jacob ◽  
Daniel E. Shulz
Keyword(s):  
Spatial Structure ◽  
Barrel Cortex ◽  
Center Of Mass ◽  
Receptive Fields ◽  
Intrinsic Property ◽  
Spatial Separation ◽  
Cortical Layer ◽  
Trigeminal System ◽  
Response Latencies ◽  
Receptive Field Organization

The tactile sensations mediated by the whisker-trigeminal system allow rodents to efficiently detect and discriminate objects. These capabilities rely strongly on the temporal and spatial structure of whisker deflections. Subthreshold but also spiking receptive fields in the barrel cortex encompass a large number of vibrissae, and it seems likely that the functional properties of these multiwhisker receptive fields reflect the multiple-whisker interactions encountered by the animal during exploration of its environment. The aim of this study was to examine the dependence of the spatial structure of cortical receptive fields on stimulus parameters. Using a newly developed 24-whisker stimulation matrix, we applied a forward correlation analysis of spiking activity to randomized whisker deflections (sparse noise) to characterize the receptive fields that result from caudal and rostral directions of whisker deflection. We observed that the functionally determined principal whisker, the whisker eliciting the strongest response with the shortest latency, differed according to the direction of whisker deflection. Thus, for a given neuron, maximal responses to opposite directions of whisker deflections could be spatially separated. This spatial separation resulted in a displacement of the center of mass between the rostral and caudal subfields and was accompanied by differences between response latencies in rostral and caudal directions of whisker deflection. Such direction-dependent receptive field organization was observed in every cortical layer. We conclude that the spatial structure of receptive fields in the barrel cortex is not an intrinsic property of the neuron but depends on the properties of sensory input.

scholarly journals Spatiotemporal receptive fields of barrel cortex revealed by reverse correlation of synaptic input

2014 ◽  
Vol 17 (6) ◽  
pp. 866-875 ◽  
Author(s):  
Alejandro Ramirez ◽  
Eftychios A Pnevmatikakis ◽  
Josh Merel ◽  
Liam Paninski ◽  
Kenneth D Miller ◽  
...  
Keyword(s):  
Synaptic Input ◽  
Barrel Cortex ◽  
Receptive Fields ◽  
Reverse Correlation ◽  
Spatiotemporal Receptive Fields

Thalamocortical Specificity and the Synthesis of Sensory Cortical Receptive Fields

2005 ◽  
Vol 94 (1) ◽  
pp. 26-32 ◽  
Author(s):  
Jose-Manuel Alonso ◽  
Harvey A. Swadlow
Keyword(s):  
Visual Cortex ◽  
Barrel Cortex ◽  
Receptive Fields ◽  
High Specificity ◽  
Inhibitory Neurons ◽  
Simple Cells ◽  
Layer 4 ◽  
Different Response ◽  
Cortical Receptive Fields ◽  
Visual Cortical

A persistent and fundamental question in sensory cortical physiology concerns the manner in which receptive fields of layer-4 neurons are synthesized from their thalamic inputs. According to a hierarchical model proposed more than 40 years ago, simple receptive fields in layer 4 of primary visual cortex originate from the convergence of highly specific thalamocortical inputs (e.g., geniculate inputs with on-center receptive fields overlap the on subregions of layer 4 simple cells). Here, we summarize studies in the visual cortex that provide support for this high specificity of thalamic input to visual cortical simple cells. In addition, we review studies of GABAergic interneurons in the somatosensory “barrel” cortex with receptive fields that are generated by a very different mechanism: the nonspecific convergence of thalamic inputs with different response properties. We hypothesize that these 2 modes of thalamocortical connectivity onto subpopulations of excitatory and inhibitory neurons constitute a general feature of sensory neocortex and account for much of the diversity seen in layer-4 receptive fields.

scholarly journals Origins of Cortical Layer V Surround Receptive Fields in the Rat Barrel Cortex

2010 ◽  
Vol 103 (2) ◽  
pp. 709-724 ◽  
Author(s):  
Nicholas Wright ◽  
Kevin Fox
Keyword(s):  
Barrel Cortex ◽  
Receptive Fields ◽  
Sensory Stimulation ◽  
Cortical Layer ◽  
Sensory Response ◽  
Sources Of Information ◽  
Thalamic Input ◽  
Whisker Pad ◽  
Layer V ◽  
Different Sources

Layer IV of the barrel cortex contains an anatomical map of the contralateral whisker pad, which serves as a useful reference in relating receptive field properties of cells to the cortical columns in which they reside. Recent studies have shown that the degree to which the surround receptive fields of layer IV cells are generated intracortically or subcortically depends on whether they lie in barrel or septal columns. To investigate whether this is true for layer V cells, we blocked intracortical activity in the barrel cortex by infusing muscimol from the cortical surface and measuring spike responses to sensory stimulation in the presence of locally iontophoresed bicuculline. Layer V cells beneath barrels had small subcortically generated single- or double-whisker center receptive fields and larger intracortically generated six to seven whisker surround receptive fields. Conversely, septally located cells received multiwhisker input from both subcortical and cortical sources. Most properties of layer Va and layer Vb cells were very similar. However, layer Vb barrel neurons showed a relative lack of phasic inhibition evoked from sensory input compared with layer Va cells. The direct thalamic input to the layer V cells was not sufficient to evoke a sensory response in the absence of input from superficial layers. These findings suggest that despite the apparent overt similarity of layer V receptive fields, barrel and septal subdivisions process different sources of information within the barrel cortex.

scholarly journals Influence of Subcortical Inhibition on Barrel Cortex Receptive Fields

2009 ◽  
Vol 102 (1) ◽  
pp. 437-450 ◽  
Author(s):  
Akio Hirata ◽  
Juan Aguilar ◽  
Manuel A. Castro-Alamancos
Keyword(s):  
Receptive Field ◽  
High Frequency ◽  
Gaba Receptor ◽  
Barrel Cortex ◽  
Receptive Fields ◽  
Neural Responses ◽  
Sensory Stimuli ◽  
Long Latency ◽  
Actual Degree ◽  
Sensory Responses

Influence of subcortical inhibition on barrel cortex receptive fields. By the time neural responses driven by vibrissa stimuli reach the barrel cortex, they have undergone significant spatial and temporal transformations within subcortical relays. A major regulator of these transformations is thought to be subcortical GABA-mediated inhibition, but the actual degree of this influence is unknown. We used disinhibition produced by GABA receptor antagonists to unmask the excitatory sensory responses that are normally suppressed by inhibition in the main subcortical sensory relays to barrel cortex; principal trigeminal (Pr5) and primary thalamic (VPM) nuclei. We found that, within subcortical relays, inhibition only slightly suppresses short-latency receptive field responses, but robustly suppresses long-latency center and surround receptive field responses. However, the long-latency subcortical effects of inhibition are mostly not reflected in the barrel cortex. The most robust effect of subcortical inhibition on barrel cortex responses is to transiently suppress the receptive field responses of high-frequency sensory stimuli. This transient adaptation caused by subcortical inhibition recovers within a few stimuli and gives way to a steady-state adaptation that is independent of subcortical inhibition.

scholarly journals Cross-Whisker Adaptation of Neurons in Layer 2/3 of the Rat Barrel Cortex

2021 ◽  
Vol 15 ◽  
Author(s):  
Yonatan Katz ◽  
Ilan Lampl
Keyword(s):  
Cortical Neurons ◽  
Barrel Cortex ◽  
Receptive Fields ◽  
Repetitive Stimulation ◽  
Complex Environments ◽  
Cortical Cells ◽  
High Responsiveness ◽  
Layer 2 ◽  
Layer 4 ◽  
Stimulation Of

Neurons in the barrel cortex respond preferentially to stimulation of one principal whisker and weakly to several adjacent whiskers. Such integration exists already in layer 4, the pivotal recipient layer of thalamic inputs. Previous studies show that cortical neurons gradually adapt to repeated whisker stimulations and that layer 4 neurons exhibit whisker specific adaptation and no apparent interactions with other whiskers. This study aimed to study the specificity of adaptation of layer 2/3 cortical cells. Towards this aim, we compared the synaptic response of neurons to either repetitive stimulation of one of two responsive whiskers or when repetitive stimulation of the two whiskers was interleaved. We found that in most layer 2/3 cells adaptation is whisker-specific. These findings indicate that despite the multi-whisker receptive fields in the cortex, the adaptation process for each whisker-pathway is mostly independent of other whiskers. A mechanism allowing high responsiveness in complex environments.

Integration of Synaptic Responses to Neighboring Whiskers in Rat Barrel Cortex In Vivo

2005 ◽  
Vol 93 (4) ◽  
pp. 1920-1934 ◽  
Author(s):  
Michael J. Higley ◽  
Diego Contreras
Keyword(s):  
Barrel Cortex ◽  
Single Cells ◽  
Receptive Fields ◽  
Synaptic Integration ◽  
Synaptic Response ◽  
Cortical Function ◽  
Sensory Stimuli ◽  
Paired Stimulation ◽  
The Individual

Characterizing input integration at the single-cell level is a critical step to understanding cortical function, particularly when sensory stimuli are represented over wide cortical areas and single cells exhibit large receptive fields. To study synaptic integration of sensory inputs, we made intracellular recordings from the barrel cortex of anesthetized rats in vivo. For each cell, we deflected the principal whisker (PW) either alone or preceded by the deflection of a single adjacent whisker (AW) at an interval of 20 or 3 ms. At the 20-ms interval in all cases, prior AW deflection significantly suppressed the PW-evoked spike output and caused the underlying synaptic response to reach a peak Vm less depolarized than that arising from PW deflection alone. The decrease in peak Vm was not attributed to hyperpolarizing inhibition but to a divisive reduction in PW-evoked PSP amplitude. The reduction in amplitude was not a result of shunting inhibition but was mostly a result of removal of the synaptic drive, or disfacilitation. When the AW–PW interval was shortened to 3 ms, spike suppression was observed in a subset of the cells studied. In most cases, a divisive reduction in synaptic response amplitude was offset by summation with the preceding AW-evoked depolarization. To determine whether suppression is a general feature of synaptic integration by barrel cortex neurons, we also characterized the interaction of responses evoked by local electrical stimulation. In contrast to the whisker data, we found that responses to paired stimulation at the same intervals produced more spikes and reached a peak Vm more depolarized than the individual responses alone, suggesting that whisker-evoked suppression is not a result of postsynaptic mechanisms. Instead, we propose that cross-whisker response suppression depends on sensory-specific mechanisms at cortical and subcortical levels.

Flow of excitation within rat barrel cortex on striking a single vibrissa

1992 ◽  
Vol 68 (4) ◽  
pp. 1345-1358 ◽  
Author(s):  
M. Armstrong-James ◽  
K. Fox ◽  
A. Das-Gupta
Keyword(s):  
Information Transfer ◽  
Statistical Difference ◽  
Barrel Cortex ◽  
Single Cells ◽  
Receptive Fields ◽  
Response Magnitude ◽  
Adult Rats ◽  
Single Column ◽  
Mystacial Vibrissae ◽  
Stimulation Of

1. Extracellular spike recordings were made from single cells in various layers of barrel cortex in adult rats anesthetized with urethan. Response magnitude and latency differences to brief 1.14 degrees deflections of mystacial vibrissae of center (principal) and surround receptive-field vibrissae were measured. Latency differences for pairs of cells in the same penetration to stimulation of the principal vibrissa were also collected. In separate experiments the domains of layer IV cells were mapped for their influence by a single vibrissa and their latencies to this vibrissa were recorded. In all experiments precise locations of layer IV cells in each penetration were identified using dye-lesioning and cytochrome oxidase staining of tangential sections. 2. The results suggest that principal vibrissa data are relayed radially in a column of neurons before parallel relay to adjacent columns. To the principal vibrissa, layers IV and Vb neurons discharged earliest, with layers II and III on average 2 and 3 ms later, respectively. Serial relay from layers IV to III to II was suggested to be the most common event. Although layer Va cells fired next, a single-column organization is not suggested for them because differences in latency or response magnitude to their principal and immediate surround vibrissae were not significant. Layer II, III and IV cells showed no statistical difference in latency to the nearest surround vibrissa but fired significantly later than to their principal input. 3. Because, from our previous studies, surround receptive fields of barrel cells in rat S1 cortex appear to be constructed intracortically, these data suggest a parallel column-column relay for their construction. Horizontal relay between barrels occurred first within the septae between barrels. Mean intracortical transmission velocities were calculated at approximately 0.05 m/s for column-column information transfer.

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