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

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.

2006 ◽  
Vol 96 (3) ◽  
pp. 1658-1663 ◽  
Author(s):  
R. Haslinger ◽  
I. Ulbert ◽  
C. I. Moore ◽  
E. N. Brown ◽  
A. Devor

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.


2016 ◽  
Author(s):  
Katayun Cohen-Kashi Malina ◽  
Boaz Mohar ◽  
Akiva N. Rappaport ◽  
Miao Liu

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.


eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Baher A Ibrahim ◽  
Caitlin A Murphy ◽  
Georgiy Yudintsev ◽  
Yoshitaka Shinagawa ◽  
Matthew I Banks ◽  
...  

The mechanisms that govern thalamocortical transmission are poorly understood. Recent data have shown that sensory stimuli elicit activity in ensembles of cortical neurons that recapitulate stereotyped spontaneous activity patterns. Here, we elucidate a possible mechanism by which gating of patterned population cortical activity occurs. In this study, sensory-evoked all-or-none cortical population responses were observed in the mouse auditory cortex in vivo and similar stochastic cortical responses were observed in a colliculo-thalamocortical brain slice preparation. Cortical responses were associated with decreases in auditory thalamic synaptic inhibition and increases in thalamic synchrony. Silencing of corticothalamic neurons in layer 6 (but not layer 5) or the thalamic reticular nucleus linearized the cortical responses, suggesting that layer 6 corticothalamic feedback via the thalamic reticular nucleus was responsible for gating stochastic cortical population responses. These data implicate a corticothalamic-thalamic reticular nucleus circuit that modifies thalamic neuronal synchronization to recruit populations of cortical neurons for sensory representations.


2019 ◽  
Author(s):  
Hua-an Tseng ◽  
Xue Han

AbstractPrefrontal cortex (PFC) spike activity and local field potential (LFP) oscillation dynamics are broadly linked to various aspects of behavior. PFC neurons can encode the identity of sensory stimuli and related behavioral outcome in a range of sensory discrimination tasks. However, it remains largely unclear how different neuron subtypes and related LFP oscillation features are modulated in mice during sensory discrimination. To understand how excitatory and inhibitory neurons in PFC are selectively engaged during sensory discrimination and how they relate to LFPs oscillations, we used tetrode devices to probe well isolated individual PFC neurons, and LFP oscillations, in mice performing a three-choice auditory discrimination task. We found that a majority of the PFC neurons, 78% of a total of 711 individual neurons, exhibited sensory evoked responses that are context and task-progression dependent. Using spike waveforms, we classified these responsive neurons into excitatory and inhibitory neurons, and found that both neuron subtypes were transiently modulated, with individual neurons’ responses peaking throughout the entire task duration. While the number of responsive excitatory neurons remain largely constant throughout the task, an increasing fraction of inhibitory neurons were gradually recruited as trial progressed. Further examination of the coherences between individual neurons and LFPs revealed that inhibitory neurons in general exhibit higher spike-field coherence with LFP oscillations than excitatory neurons, first at higher gamma frequencies at the beginning of the task, and then at theta frequencies during the task, and finally across theta, beta and gamma frequencies at task completion. Together, our results demonstrate that while PFC excitatory neurons are continuously engaged during sensory discrimination, PFC inhibitory neurons are preferentially engaged as task progresses and selectively coordinated with distinct LFP oscillations. These results demonstrate increasing involvement of inhibitory neurons in shaping the overall PFC network dynamics as sensory discrimination progressed towards completion.


1998 ◽  
Vol 80 (2) ◽  
pp. 1006-1010 ◽  
Author(s):  
Mark T. Wallace ◽  
M. Alex Meredith ◽  
Barry E. Stein

Wallace, Mark T., M. Alex Meredith, and Barry E. Stein. Multisensory integration in the superior colliculus of the alert cat. J. Neurophysiol. 80: 1006–1010, 1998. The modality convergence patterns, sensory response properties, and principles governing multisensory integration in the superior colliculus (SC) of the alert cat were found to have fundamental similarities to those in anesthetized animals. Of particular interest was the observation that, in a manner indistinguishable from the anesthetized animal, combinations of two different sensory stimuli significantly enhanced the responses of SC neurons above those evoked by either unimodal stimulus. These observations are consistent with the speculation that there is a functional link among multisensory integration in individual SC neurons and cross-modality attentive and orientation behaviors.


2020 ◽  
Author(s):  
Subong Kim ◽  
Caroline Emory ◽  
Inyong Choi

AbstractSelective attention enhances cortical responses to attended sensory inputs while suppressing others, which can be an effective strategy for speech-in-noise (SiN) understanding. Here, we introduce a training paradigm designed to reinforce attentional modulation of auditory evoked responses. Subjects attended one of two speech streams while our EEG-based attention decoder provided online feedback. After four weeks of this neurofeedback training, subjects exhibited enhanced cortical response to target speech and improved performance during a SiN task. Such training effects were not found in the Placebo group that underwent attention training without neurofeedback. These results suggest an effective rehabilitation for SiN deficits.


2012 ◽  
Vol 108 (10) ◽  
pp. 2679-2688 ◽  
Author(s):  
Zhiyin Liang ◽  
Michael A. Freed

The retina is divided into parallel and mostly independent ON and OFF pathways, but the ON pathway “cross” inhibits the OFF pathway. Cross inhibition was thought to improve signal processing by the OFF pathway, but its effect on contrast encoding had not been tested experimentally. To quantify the effect of cross inhibition on the encoding of contrast, we presented a dark flash to an in vitro preparation of the mammalian retina. We then recorded excitatory currents, inhibitory currents, membrane voltages, and spikes from OFF α-ganglion cells. The recordings were subjected to an ideal observer analysis that used Bayesian methods to determine how accurately the recordings detected the dark flash. We found that cross inhibition increases the detection accuracy of currents and membrane voltages. Yet these improvements in encoding do not fully reach the spike train, because cross inhibition also hyperpolarizes the OFF α-cell below spike threshold, preventing small signals in the membrane voltages at low contrast from reaching the spike train. The ultimate effect of cross inhibition is to increase the accuracy with which the spike train detects moderate contrast, but reduce the accuracy with which it detects low contrast. In apparent compensation for the loss of accuracy at low contrast, cross inhibition, by hyperpolarizing the OFF α-cell, reduces the number of spikes required to detect the dark flash and thereby increases encoding efficiency.


2020 ◽  
Vol 60 (1) ◽  
pp. 33-42
Author(s):  
Piyumika S Suriyampola ◽  
Melissa Lopez ◽  
Brontë E Ellsworth ◽  
Emília P Martins

Synopsis Animals can shift their reliance on different sensory modalities in response to environmental conditions, and knowing the degree to which traits are reversible may help us to predict their chances of survival in a changing environment. Here, using adult zebrafish (Danio rerio), we found that 6 weeks in different light environments alone were sufficient to shift whether fish approached visual or chemical cues first, and that a subsequent reversal of lighting conditions also reversed their sensory preferences. In addition, we measured simple behavioral responses to sensory stimuli presented alone, and found that zebrafish housed in dim light for 6 weeks responded weakly to an optomotor assay, but strongly to an olfactory cue, whereas fish experiencing bright light for 6 weeks responded strongly to the visual optomotor stimulus and weakly in an olfactory assay. Visual and olfactory responses were equally reversible, and shifted to the opposite pattern when we reversed lighting conditions for 6 weeks. In contrast, we did not find a change in activity level, suggesting that changes in multiple sensory modalities can buffer animals from changes in more complex forms of behavior. This reversal of sensory response provides insight into how animals may use sensory shifts to keep up with environmental change.


1979 ◽  
Vol 57 (2) ◽  
pp. 174-184 ◽  
Author(s):  
Y. C. Wong ◽  
H. C. Kwan ◽  
J. T. Murphy

In monkeys performing a handle-repositioning task involving primarily wrist flexion–extension (F–E) movements after a torque perturbation was delivered to the handle, single units were recorded extracellularly in the contralateral precentral cortex. Precentral neurons were identified by passive somatosensory stimulation, and were classified into five somatotopically organized populations. Based on electromyographic recordings, it was observed that flexors and extensors about the wrist joint were specifically involved in the repositioning of the handle, while many other muscles which act at the wrist and other forelimb joints were involved in the task in a supportive role. In precentral cortex, all neuronal responses observed were temporally correlated to both the sensory stimuli and the motor responses. Visual stimuli, presented simultaneously with torque perturbations, did not affect the early portion of cortical responses to such torque perturbations. In each of the five somatotopically organized neuronal populations, task-related neurons as well as task-unrelated ones were observed. A significantly larger proportion of wrist (F–E) neurons was related to the task, as compared with the other, nonwrist (F–E) populations. The above findings were discussed in the context of a hypothesis for the function of precentral cortex during voluntary limb movement in awake primates. This hypothesis incorporates a relationship between activities of populations of precentral neurons, defined with respect to their responses to peripheral events at or about single joints, and movements about the same joint.


2018 ◽  
Vol 115 (6) ◽  
pp. 1352-1357 ◽  
Author(s):  
Jayakrishnan Nair ◽  
Arndt-Lukas Klaassen ◽  
Jozsef Arato ◽  
Alexei L. Vyssotski ◽  
Michael Harvey ◽  
...  

The default mode network (DMN) is a collection of cortical brain regions that is active during states of rest or quiet wakefulness in humans and other mammalian species. A pertinent characteristic of the DMN is a suppression of local field potential gamma activity during cognitive task performance as well as during engagement with external sensory stimuli. Conversely, gamma activity is elevated in the DMN during rest. Here, we document that the rat basal forebrain (BF) exhibits the same pattern of responses, namely pronounced gamma oscillations during quiet wakefulness in the home cage and suppression of this activity during active exploration of an unfamiliar environment. We show that gamma oscillations are localized to the BF and that gamma-band activity in the BF has a directional influence on a hub of the rat DMN, the anterior cingulate cortex, during DMN-dominated brain states. The BF is well known as an ascending, activating, neuromodulatory system involved in wake–sleep regulation, memory formation, and regulation of sensory information processing. Our findings suggest a hitherto undocumented role of the BF as a subcortical node of the DMN, which we speculate may be important for switching between internally and externally directed brain states. We discuss potential BF projection circuits that could underlie its role in DMN regulation and highlight that certain BF nuclei may provide potential target regions for up- or down-regulation of DMN activity that might prove useful for treatment of DMN dysfunction in conditions such as epilepsy or major depressive disorder.


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