scholarly journals Local and thalamic origins of ongoing and sensory evoked cortical correlations

2016 ◽  
Author(s):  
Katayun Cohen-Kashi Malina ◽  
Boaz Mohar ◽  
Akiva N. Rappaport ◽  
Miao Liu
Keyword(s):  
Barrel Cortex ◽  
Field Potential ◽  
Sensory Response ◽  
Cortical Cells ◽  
Synaptic Inputs ◽  
Correlated Activity ◽  
Layer 4 ◽  
Lower Variability ◽  
Intact Cortex ◽  
Sensory Evoked

Thalamic inputs of layer 4 (L4) cells in sensory cortices are outnumbered by local connections. Thus, it was suggested that robust sensory response in L4 emerges due to synchronized thalamic activity. In order to investigate the role of both inputs in generation of cortical synchronization, we isolated the thalamic excitatory inputs of cortical cells by optogenetically silencing cortical firing. In anesthetized mice, we measured the correlation between isolated thalamic synaptic inputs of simultaneously patched nearby L4 cells of the barrel cortex. In contrast to correlated activity of excitatory synaptic inputs in the intact cortex, isolated thalamic inputs exhibit lower variability and asynchronous spontaneous and sensory evoked inputs. These results were further supported in awake mice when we recorded the excitatory inputs of individual cortical cells simultaneously with the local field potential (LFP) in a nearby site. Our results therefore indicate that cortical synchronization emerges by intracortical coupling.

Analysis of LFP Phase Predicts Sensory Response of Barrel Cortex

2006 ◽  
Vol 96 (3) ◽  
pp. 1658-1663 ◽  
Author(s):  
R. Haslinger ◽  
I. Ulbert ◽  
C. I. Moore ◽  
E. N. Brown ◽  
A. Devor
Keyword(s):  
Barrel Cortex ◽  
Temporal Dynamics ◽  
Field Potential ◽  
Electrode Array ◽  
Sensory Response ◽  
Strong Function ◽  
Large Populations ◽  
Up And Down States ◽  
Sensory Evoked ◽  
Local Field Potential Lfp

Several previous studies have shown the existence of Up and Down states and have linked their magnitude (e.g., depolarization level) to the size of sensory-evoked responses. Here, we studied how the temporal dynamics of such states influence the sensory-evoked response to vibrissa deflection. Under α-chloralose anesthesia, barrel cortex exhibits strong quasi-periodic ∼1-Hz local field potential (LFP) oscillations generated by the synchronized fluctuation of large populations of neurons between depolarized (Up) and hyperpolarized (Down) states. Using a linear depth electrode array, we recorded the LFP and multiunit activity (MUA) simultaneously across multiple layers of the barrel column and used the LFP to approximate the subthreshold Up–Down fluctuations. Our central finding is that the MUA response is a strong function of the LFP oscillation’s phase. When only ongoing LFP magnitude was considered, the response was largest in the Down state, in agreement with previous studies. However, consideration of the LFP phase revealed that the MUA response varied smoothly as a function of LFP phase in a manner that was not monotonically dependent on LFP magnitude. The LFP phase is therefore a better predictor of the MUA response than the LFP magnitude is. Our results suggest that, in the presence of ongoing oscillations, there can be a continuum of response properties and that each phase may, at times, need to be considered a distinct cortical state.

scholarly journals Membrane potential correlates of network decorrelation and improved SNR by cholinergic activation in the somatosensory cortex

2017 ◽  
Author(s):  
Inbal Meir ◽  
Yonatan Katz ◽  
Ilan Lampl
Keyword(s):  
Membrane Potential ◽  
Differential Effect ◽  
Barrel Cortex ◽  
Signal To Noise Ratio ◽  
Nucleus Basalis ◽  
Sensory Response ◽  
Layer 4 ◽  
Underlying Mechanisms ◽  
Sensory Evoked ◽  
Cholinergic Activation

AbstractThe nucleus basalis (NB) projects cholinergic axons to the cortex where they play a major role in arousal, attention and learning. Cholinergic inputs shift cortical dynamics from synchronous to asynchronous and improves the signal to noise ratio (SNR) of sensory response. Yet, the underlying mechanisms of these changes remain unclear. Using simultaneous extracellular and whole cell patch recordings in layer 4 barrel cortex we show that activation of the cholinergic system has a differential effect on ongoing and sensory evoked activities. Cholinergic activation eliminated the large and correlated spontaneous synaptic fluctuations in membrane potential while sparing the synaptic response to whisker stimulation. This differential effect of cholinergic activation provides a unified explanation for the increased SNR of sensory response and for the reduction in both trial to trial variability and noise correlations as well as explaining the shift into desynchronized cortical state which are the hallmarks of arousal and attention.

scholarly journals Simultaneous Two-Photon Voltage or Calcium Imaging and Multi-Channel Local Field Potential Recordings in Barrel Cortex of Awake and Anesthetized Mice

2021 ◽  
Vol 15 ◽  
Author(s):  
Claudia Cecchetto ◽  
Stefano Vassanelli ◽  
Bernd Kuhn
Keyword(s):  
Local Field ◽  
Calcium Imaging ◽  
Local Field Potential ◽  
Barrel Cortex ◽  
Field Potential ◽  
Imaging Data ◽  
Spatiotemporal Resolution ◽  
Two Photon ◽  
Cranial Window ◽  
Sensory Evoked

Neuronal population activity, both spontaneous and sensory-evoked, generates propagating waves in cortex. However, high spatiotemporal-resolution mapping of these waves is difficult as calcium imaging, the work horse of current imaging, does not reveal subthreshold activity. Here, we present a platform combining voltage or calcium two-photon imaging with multi-channel local field potential (LFP) recordings in different layers of the barrel cortex from anesthetized and awake head-restrained mice. A chronic cranial window with access port allows injecting a viral vector expressing GCaMP6f or the voltage-sensitive dye (VSD) ANNINE-6plus, as well as entering the brain with a multi-channel neural probe. We present both average spontaneous activity and average evoked signals in response to multi-whisker air-puff stimulations. Time domain analysis shows the dependence of the evoked responses on the cortical layer and on the state of the animal, here separated into anesthetized, awake but resting, and running. The simultaneous data acquisition allows to compare the average membrane depolarization measured with ANNINE-6plus with the amplitude and shape of the LFP recordings. The calcium imaging data connects these data sets to the large existing database of this important second messenger. Interestingly, in the calcium imaging data, we found a few cells which showed a decrease in calcium concentration in response to vibrissa stimulation in awake mice. This system offers a multimodal technique to study the spatiotemporal dynamics of neuronal signals through a 3D architecture in vivo. It will provide novel insights on sensory coding, closing the gap between electrical and optical recordings.

scholarly journals Comprehensive mapping of whisker-evoked responses reveals broad, sharply tuned thalamocortical input to layer 4 of barrel cortex

2011 ◽  
Vol 105 (5) ◽  
pp. 2421-2437 ◽  
Author(s):  
Noah C. Roy ◽  
Thomas Bessaih ◽  
Diego Contreras
Keyword(s):  
Cortical Neurons ◽  
Barrel Cortex ◽  
Current Source ◽  
Field Potential ◽  
Fundamental Information ◽  
Layer 4 ◽  
Density Analysis ◽  
Evoked Activity ◽  
Rats And Mice

Cortical neurons are organized in columns, distinguishable by their physiological properties and input-output organization. Columns are thought to be the fundamental information-processing modules of the cortex. The barrel cortex of rats and mice is an attractive model system for the study of cortical columns, because each column is defined by a layer 4 (L4) structure called a barrel, which can be clearly visualized. A great deal of information has been collected regarding the connectivity of neurons in barrel cortex, but the nature of the input to a given L4 barrel remains unclear. We measured this input by making comprehensive maps of whisker-evoked activity in L4 of rat barrel cortex using recordings of multiunit activity and current source density analysis of local field potential recordings of animals under light isoflurane anesthesia. We found that a large number of whiskers evoked a detectable response in each barrel (mean of 13 suprathreshold, 18 subthreshold) even after cortical activity was abolished by application of muscimol, a GABAA agonist. We confirmed these findings with intracellular recordings and single-unit extracellular recordings in vivo. This constitutes the first direct confirmation of the hypothesis that subcortical mechanisms mediate a substantial multiwhisker input to a given cortical barrel.

Angular Tuning and Velocity Sensitivity in Different Neuron Classes Within Layer 4 of Rat Barrel Cortex

2004 ◽  
Vol 91 (1) ◽  
pp. 223-229 ◽  
Author(s):  
Soo-Hyun Lee ◽  
Daniel J. Simons
Keyword(s):  
Cortical Neurons ◽  
Barrel Cortex ◽  
Deflection Angle ◽  
Field Potential ◽  
Response Dynamics ◽  
Velocity Sensitivity ◽  
Deflection Amplitude ◽  
Layer 4 ◽  
Local Circuitry ◽  
Local Circuits

Local circuitry within layer IV whisker-related barrels is preferentially sensitive to thalamic population firing synchrony, and neurons respond most vigorously to stimuli, such as high-velocity whisker deflections, that evoke it. Field potential recordings suggest that thalamic barreloid neurons having similar angular preferences fire synchronously. To examine whether angular tuning of cortical neurons might also be affected by thalamic firing synchrony, we characterized responses of layer IV units to whisker deflections that varied in angular direction and velocity. Barrel regular-spike units (RSUs) became more tuned for deflection angle with slower whisker movements. Deflection amplitude had no affect. Barrel fast-spike units (FSUs) were poorly tuned for deflection angle, and their responses remained constant with different deflection velocity. The dependence of angular tuning on deflection velocity among barrel RSUs appears to reflect the same underlying response dynamics that determine their velocity sensitivity and receptive field focus. Unexpectedly, septal RSUs and FSUs are largely similar to their barrel counterparts despite available evidence suggesting that they receive different afferent inputs and are embedded within different local circuits.

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 Modulation of Sensory Response at Different Time Lags after Locus Coeruleus Micro-stimulation

2020 ◽  
Author(s):  
Zeinab Fazlali ◽  
Yadollah Ranjbar-Slamloo ◽  
Ehsan Arabzadeh
Keyword(s):  
Locus Coeruleus ◽  
Sensory Input ◽  
Barrel Cortex ◽  
Temporal Integration ◽  
Time Lag ◽  
Evoked Response ◽  
Sensory Response ◽  
Time Lags ◽  
Biphasic Effect ◽  
Sensory Evoked

AbstractLocus Coeruleus (LC) noradrenergic system has widespread projections throughout the brain and affects sensory processing in various modalities. Inhibition of both spontaneous and sensory-evoked cortical activity is well-documented in early experiments by either LC electrical micro-stimulation or local application of norepinephrine (NE). However, the temporal profile of LC modulation of sensory response is not well-established. Here, we recorded neuronal activity from the rat barrel cortex under urethane anesthesia and coupled LC micro-stimulation with brief mechanical deflection of whiskers at 10 different time lags (50-500 ms). LC micro-stimulation exhibited a biphasic effect on BC spontaneous activity: a period of suppression (∼100 ms) followed by a period of excitation (∼200 ms). This profile was highly consistent across BC units: 82% of BC units showed early suppression and 91% of BC units showed late excitation. We observed a similar effect on the sensory-evoked response: at 50-ms lag, the evoked response (1-75 ms after deflection onset) decreased in 77% of units and at 150-ms lag, the early evoked response was facilitated in 85% of units. At 150 to 350-ms time lags, LC micro-stimulation caused a combined facilitation followed by suppression on the evoked response. For lags of 400-ms and higher, the effect was pure facilitation. Additionally, response latency was significantly decreased at 250 ms time lag. In summary, we found that LC modulation affects the cortical processing of sensory inputs in a complex manner which critically depends on the time lag between LC activation and sensory input. These results have clear implications for temporal integration of sensory input and its noradrenergic modulation in a behavioral setting.

scholarly journals State-aware detection of sensory stimuli in the cortex of the awake mouse

2018 ◽  
Author(s):  
Audrey Sederberg ◽  
Aurelie Pala ◽  
He J. V. Zheng ◽  
Biyu J. He ◽  
Garrett B. Stanley
Keyword(s):  
Field Potential ◽  
Ideal Observer ◽  
Sensory Response ◽  
Detection Accuracy ◽  
Sensory Stimuli ◽  
Robust Detection ◽  
Sensory Inputs ◽  
Cortical Responses ◽  
Brain States ◽  
Sensory Evoked

Cortical responses to sensory inputs vary across repeated presentations of identical stimuli, but how this trial-to-trial variability impacts detection of sensory inputs is not fully understood. Using multi-channel local field potential (LFP) recordings in primary somatosensory cortex (S1) of the awake mouse, we optimized a data-driven cortical state classifier to predict single-trial sensory-evoked responses, based on features of the spontaneous, ongoing LFP recorded across cortical layers. Our findings show that, by utilizing an ongoing prediction of the sensory response generated by this state classifier, an ideal observer improves overall detection accuracy and generates robust detection of sensory inputs across various states of ongoing cortical activity in the awake brain, which could have implications for variability in the performance of detection tasks across brain states.

scholarly journals Contribution of interneuron subtype-specific GABAergic signalling to emergent sensory processing in somatosensory whisker barrel cortex in mouse

2021 ◽  
Author(s):  
Liad J. Baruchin ◽  
Michael M. Kohl ◽  
Simon J.B Butt
Keyword(s):  
Sensory Processing ◽  
Barrel Cortex ◽  
Sensory Information ◽  
Gaba Release ◽  
Gabaergic Interneuron ◽  
Dependent Manner ◽  
Sensory Adaptation ◽  
Layer 4 ◽  
Evoked Activity ◽  
Sensory Evoked

AbstractMammalian neocortex is important for conscious processing of sensory information. Fundamental to this function is balanced glutamatergic and GABAergic signalling. Yet little is known about how this interaction arises in the developing forebrain despite increasing insight into early GABAergic interneuron (IN) circuits. To further study this, we assessed the contribution of specific INs to the development of sensory processing in the mouse whisker barrel cortex. Specifically we explored the role of INs in speed coding and sensory adaptation. In wild-type animals, both speed processing and adaptation were present as early as the layer 4 critical period of plasticity, and showed refinement over the period leading to active whisking onset. We then conditionally silenced action-potential-dependent GABA release in either somatostatin (SST) or vasoactive intestinal peptide (VIP) INs. These genetic manipulations influenced both spontaneous and sensory-evoked activity in an age and layer-dependent manner. Silencing SST+ INs reduced early spontaneous activity and abolished facilitation in sensory adaptation observed in control pups. In contrast, VIP+ IN silencing had an effect towards the onset of active whisking. Silencing either IN subtype had no effect on speed coding. Our results reveal how these IN subtypes differentially contribute to early sensory processing over the first few postnatal weeks.

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