scholarly journals Development of Columnar Topography in the Excitatory Layer 4 to Layer 2/3 Projection in Rat Barrel Cortex

2003 ◽  
Vol 23 (25) ◽  
pp. 8759-8770 ◽  
Author(s):  
Kevin J. Bender ◽  
Juliana Rangel ◽  
Daniel E. Feldman
Keyword(s):  
Barrel Cortex ◽  
Layer 2 ◽  
Layer 4

Layer- and Cell-Type-Specific Effects of Neonatal Whisker-Trimming in Adult Rat Barrel Cortex

2007 ◽  
Vol 97 (6) ◽  
pp. 4380-4385 ◽  
Author(s):  
Soo-Hyun Lee ◽  
Peter W. Land ◽  
Daniel J. Simons
Keyword(s):  
Barrel Cortex ◽  
Sensory Deprivation ◽  
Cell Type ◽  
Growth Layer ◽  
Adult Rat ◽  
Specific Effects ◽  
Layer 2 ◽  
Layer 4 ◽  
Cell Type Specific ◽  
Fast Spike

Tactile deprivation in rats produced by whisker-trimming early in life leads to abnormally robust responses of excitatory neurons in layer 4 of primary somatosensory cortex when the re-grown whiskers are stimulated. Present findings from fast-spike neurons indicate that presumed inhibitory cells fire less robustly under the same conditions. These contrasting effects may reflect altered patterns of thalamocortical input to excitatory versus inhibitory cells and/or changes in the strength of intracortical connections. Despite increased excitability of layer 4, neurons in layer 2/3 respond at control levels even after full whisker re-growth. Layer 4 synapses onto supragranular neurons may be permanently depressed as a result of neonatal sensory deprivation.

Temporal Frequency of Whisker Movement. II. Laminar Organization of Cortical Representations

2001 ◽  
Vol 86 (1) ◽  
pp. 354-367 ◽  
Author(s):  
Ehud Ahissar ◽  
Ronen Sosnik ◽  
Knarik Bagdasarian ◽  
Sebastian Haidarliu
Keyword(s):  
Barrel Cortex ◽  
Temporal Frequency ◽  
Spike Count ◽  
Thalamic Nuclei ◽  
Laminar Organization ◽  
Coding Schemes ◽  
Layer 2 ◽  
Layer 4 ◽  
Cortical Representations ◽  
Latency Coding

Part of the information obtained by rodent whiskers is carried by the frequency of their movement. In the thalamus of anesthetized rats, the whisker frequency is represented by two different coding schemes: by amplitude and spike count (i.e., response amplitudes and spike counts decrease as a function of frequency) in the lemniscal thalamus and by latency and spike count (latencies increase and spike counts decrease as a function of frequency) in the paralemniscal thalamus (see accompanying paper). Here we investigated neuronal representations of the whisker frequency in the primary somatosensory (“barrel”) cortex of the anesthetized rat, which receives its input from both the lemniscal and paralemniscal thalamic nuclei. Single and multi-units were recorded from layers 2/3, 4 (barrels only), 5a, and 5b during vibrissal stimulation. Typically, the input frequency was represented by amplitude and spike count in the barrels of layer 4 and in layer 5b (the “lemniscal layers”) and by latency and spike count in layer 5a (the “paralemniscal layer”). Neurons of layer 2/3 displayed a mixture of the two coding schemes. When the pulse width of the stimulus was reduced from 50 to 20 ms, the latency coding in layers 5a and 2/3 was dramatically reduced, while the spike-count coding was not affected; in contrast, in layers 4 and 5b, the latencies remained constant, but the spike counts were reduced with 20-ms stimuli. The same effects were found in the paralemniscal and lemniscal thalamic nuclei, respectively (see accompanying paper). These results are consistent with the idea that thalamocortical loops of different pathways, although terminating within the same cortical columns, perform different computations in parallel. Furthermore, the mixture of coding schemes in layer 2/3 might reflect an integration of lemniscal and paralemniscal outputs.

scholarly journals The Timing of Sensory-Guided Behavioral Response is Represented in the Mouse Primary Somatosensory Cortex

2018 ◽  
Vol 29 (7) ◽  
pp. 3034-3047
Author(s):  
Jérémy Camon ◽  
Sandrine Hugues ◽  
Melissa A Erlandson ◽  
David Robbe ◽  
Sabria Lagoun ◽  
...  
Keyword(s):  
Somatosensory Cortex ◽  
Behavioral Response ◽  
Barrel Cortex ◽  
Ex Vivo ◽  
Primary Somatosensory Cortex ◽  
Cortical Columns ◽  
Reward Delivery ◽  
Wide Range ◽  
Layer 2 ◽  
Layer 4

Abstract Whisker-guided decision making in mice is thought to critically depend on information processing occurring in the primary somatosensory cortex. However, it is not clear if neuronal activity in this “early” sensory region contains information about the timing and speed of motor response. To address this question we designed a new task in which freely moving mice learned to associate a whisker stimulus to reward delivery. The task was tailored in such a way that a wide range of delays between whisker stimulation and reward collection were observed due to differences of motivation and perception. After training, mice were anesthetized and neuronal responses evoked by stimulating trained and untrained whiskers were recorded across several cortical columns of barrel cortex. We found a strong correlation between the delay of the mouse behavioral response and the timing of multiunit activity evoked by the trained whisker, outside its principal cortical column, in layers 4 and 5A but not in layer 2/3. Circuit mapping ex vivo revealed this effect was associated with a weakening of layer 4 to layer 2/3 projection. We conclude that the processes controlling the propagation of key sensory inputs to naive cortical columns and the timing of sensory-guided action are linked.

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.

scholarly journals Cellular and synaptic phenotypes lead to disrupted information processing in Fmr1-KO mouse layer 4 barrel cortex

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Aleksander P. F. Domanski ◽  
Sam A. Booker ◽  
David J. A. Wyllie ◽  
John T. R. Isaac ◽  
Peter C. Kind
Keyword(s):  
Neurodevelopmental Disorders ◽  
Barrel Cortex ◽  
Fragile X ◽  
Developmental Changes ◽  
Neuronal Function ◽  
Sensory Hypersensitivity ◽  
Layer 2 ◽  
Layer 4 ◽  
Network Simulations ◽  
Sensory Encoding

Abstract Sensory hypersensitivity is a common and debilitating feature of neurodevelopmental disorders such as Fragile X Syndrome (FXS). How developmental changes in neuronal function culminate in network dysfunction that underlies sensory hypersensitivities is unknown. By systematically studying cellular and synaptic properties of layer 4 neurons combined with cellular and network simulations, we explored how the array of phenotypes in Fmr1-knockout (KO) mice produce circuit pathology during development. We show that many of the cellular and synaptic pathologies in Fmr1-KO mice are antagonistic, mitigating circuit dysfunction, and hence may be compensatory to the primary pathology. Overall, the layer 4 network in the Fmr1-KO exhibits significant alterations in spike output in response to thalamocortical input and distorted sensory encoding. This developmental loss of layer 4 sensory encoding precision would contribute to subsequent developmental alterations in layer 4-to-layer 2/3 connectivity and plasticity observed in Fmr1-KO mice, and circuit dysfunction underlying sensory hypersensitivity.

scholarly journals Loss of Calretinin in L5a impairs the formation of the barrel cortex leading to abnormal whisker-mediated behaviors

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Mingzhao Su ◽  
Junhua Liu ◽  
Baocong Yu ◽  
Kaixing Zhou ◽  
Congli Sun ◽  
...  
Keyword(s):  
Information Integration ◽  
Pyramidal Neurons ◽  
Barrel Cortex ◽  
Sensory Information ◽  
Membrane Excitability ◽  
Novelty Preference ◽  
Layer 4 ◽  
Dendritic Complexity ◽  
Cortex System

AbstractThe rodent whisker-barrel cortex system has been established as an ideal model for studying sensory information integration. The barrel cortex consists of barrel and septa columns that receive information input from the lemniscal and paralemniscal pathways, respectively. Layer 5a is involved in both barrel and septa circuits and play a key role in information integration. However, the role of layer 5a in the development of the barrel cortex remains unclear. Previously, we found that calretinin is dynamically expressed in layer 5a. In this study, we analyzed calretinin KO mice and found that the dendritic complexity and length of layer 5a pyramidal neurons were significantly decreased after calretinin ablation. The membrane excitability and excitatory synaptic transmission of layer 5a neurons were increased. Consequently, the organization of the barrels was impaired. Moreover, layer 4 spiny stellate cells were not able to properly gather, leading to abnormal formation of barrel walls as the ratio of barrel/septum size obviously decreased. Calretinin KO mice exhibited deficits in exploratory and whisker-associated tactile behaviors as well as social novelty preference. Our study expands our knowledge of layer 5a pyramidal neurons in the formation of barrel walls and deepens the understanding of the development of the whisker-barrel cortex system.

scholarly journals Mechanisms underlying the response of mouse cortical networks to optogenetic manipulation

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Alexandre Mahrach ◽  
Guang Chen ◽  
Nuo Li ◽  
Carl van Vreeswijk ◽  
David Hansel
Keyword(s):  
Motor Cortex ◽  
Numerical Simulations ◽  
Barrel Cortex ◽  
Population Models ◽  
Gabaergic Interneurons ◽  
Paradoxical Effect ◽  
Form Complex ◽  
Recurrent Excitation ◽  
Layer 2

GABAergic interneurons can be subdivided into three subclasses: parvalbumin positive (PV), somatostatin positive (SOM) and serotonin positive neurons. With principal cells (PCs) they form complex networks. We examine PCs and PV responses in mouse anterior lateral motor cortex (ALM) and barrel cortex (S1) upon PV photostimulation in vivo. In ALM layer five and S1, the PV response is paradoxical: photoexcitation reduces their activity. This is not the case in ALM layer 2/3. We combine analytical calculations and numerical simulations to investigate how these results constrain the architecture. Two-population models cannot explain the results. Four-population networks with V1-like architecture account for the data in ALM layer 2/3 and layer 5. Our data in S1 can be explained if SOM neurons receive inputs only from PCs and PV neurons. In both four-population models, the paradoxical effect implies not too strong recurrent excitation. It is not evidence for stabilization by inhibition.

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