scholarly journals Sensory cortical dynamics during optical microstimulation training

2021 ◽  
Author(s):  
Ravi Pancholi ◽  
Lauren Ryan ◽  
Simon P Peron
Keyword(s):  
Somatosensory Cortex ◽  
Calcium Imaging ◽  
Pyramidal Neurons ◽  
Cortical Activity ◽  
Sensory Cortex ◽  
Cortical Processing ◽  
Cortical Dynamics ◽  
Two Photon ◽  
Primary Sensory Cortex ◽  
Impact Perception

Primary sensory cortex is a key locus of plasticity during learning. Exposure to novel stimuli often alters cortical activity, but isolating cortex-specific dynamics is challenging due to extensive pre-cortical processing. Here, we employ optical microstimulation of pyramidal neurons in layer (L) 2/3 of mouse primary vibrissal somatosensory cortex (vS1) to study cortical dynamics as mice learn to discriminate microstimulation intensity. Tracking activity over weeks using two-photon calcium imaging, we observe a rapid sparsification of the photoresponsive population, with the most responsive neurons exhibiting the largest declines in responsiveness. Following sparsification, the photoresponsive population attains a stable rate of neuronal turnover. At the same time, the photoresponsive population increasingly overlaps with populations encoding whisker movement and touch. Finally, we find that mice with larger declines in responsiveness learn the task more slowly than mice with smaller declines. Our results reveal that microstimulation-evoked cortical activity undergoes extensive reorganization during task learning and that the dynamics of this reorganization impact perception.

scholarly journals Long-term stability of cortical ensembles

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Jesús Pérez-Ortega ◽  
Tzitzitlini Alejandre-García ◽  
Rafael Yuste
Keyword(s):  
Calcium Imaging ◽  
Pyramidal Neurons ◽  
Evoked Responses ◽  
Single Session ◽  
Long Term Stability ◽  
Neuronal Ensembles ◽  
Two Photon ◽  
Layer 2 ◽  
Over Time

Neuronal ensembles, coactive groups of neurons found in spontaneous and evoked cortical activity, are causally related to memories and perception, but it still unknown how stable or flexible they are over time. We used two-photon multiplane calcium imaging to track over weeks the activity of the same pyramidal neurons in layer 2/3 of the visual cortex from awake mice and recorded their spontaneous and visually evoked responses. Less than half of the neurons were commonly active across any two imaging sessions. These 'common neurons' formed stable ensembles lasting weeks, but some ensembles were also transient and appeared only in one single session. Stable ensembles preserved ~68 % of their neurons up to 46 days, our longest imaged period, and these 'core' cells had stronger functional connectivity. Our results demonstrate that neuronal ensembles can last for weeks and could, in principle, serve as a substrate for long-lasting representation of perceptual states or memories.

In vivo two-photon calcium imaging of neuronal activities in primary somatosensory cortex in inflammatory chronic pain

2009 ◽  
Vol 65 ◽  
pp. S179
Author(s):  
Kei Eto ◽  
Hiroaki Wake ◽  
Hitoshi Ishibashi ◽  
Mami Noda ◽  
Junichi Nabekura
Keyword(s):  
Chronic Pain ◽  
Somatosensory Cortex ◽  
Calcium Imaging ◽  
Primary Somatosensory Cortex ◽  
Two Photon

scholarly journals Long-term Transverse Imaging of the Hippocampus with Glass Microperiscopes

2021 ◽  
Author(s):  
William T Redman ◽  
Nora S Wolcott ◽  
Luca Montelisciani ◽  
Gabriel Luna ◽  
Tyler D Marks ◽  
...  
Keyword(s):  
Cognitive Processes ◽  
Calcium Imaging ◽  
Pyramidal Neurons ◽  
Spatial Information ◽  
Anatomical Distribution ◽  
Two Photon ◽  
Information Finding ◽  
Apical Dendrites

The hippocampus consists of a stereotyped neuronal circuit repeated along the septal-temporal axis. This transverse circuit contains distinct subfields with stereotyped connectivity that support crucial cognitive processes, including episodic and spatial memory. However, comprehensive measurements across the transverse hippocampal circuit in vivo are intractable with existing techniques. Here, we developed an approach for two-photon imaging of the transverse hippocampal plane in awake mice via implanted glass microperiscopes, allowing optical access to the major hippocampal subfields and to the dendritic arbor of pyramidal neurons. Using this approach, we tracked dendritic morphological dynamics on CA1 apical dendrites and characterized spine turnover. We then used calcium imaging to quantify the prevalence of place and speed cells across subfields. Finally, we measured the anatomical distribution of spatial information, finding a non-uniform distribution of spatial selectivity along the DG-to-CA1 axis. This approach extends the existing toolbox for structural and functional measurements of hippocampal circuitry.

scholarly journals The influence of visual cortex on perception is modulated by behavioural state

2019 ◽  
Author(s):  
Lloyd E. Russell ◽  
Zidan Yang ◽  
Pei Lynn Tan ◽  
Mehmet Fişek ◽  
Adam M. Packer ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Visual Stimulus ◽  
Visual Stimulation ◽  
Cortical Activity ◽  
Cortical Stimulation ◽  
Sensory Cortex ◽  
Local Network ◽  
Low Contrast ◽  
Two Photon ◽  
Behavioural State

Our understanding of the link between neural activity and perception remains incomplete. Microstimulation and optogenetic experiments have shown that manipulating cortical activity can influence sensory-guided behaviour or elicit artificial percepts. And yet, some perceptual tasks can still be solved when sensory cortex is silenced or removed, suggesting that cortical activity may not always be essential. Reconciling these findings, and providing a quantitative framework linking cortical activity and behaviour, requires knowledge of the identity of the cells being activated during the behaviour, the engagement of the local and downstream networks, and the cortical and behavioural state. Here, we performed two-photon population calcium imaging in L2/3 primary visual cortex (V1) of headfixed mice performing a visual detection task while simultaneously activating specific groups of neurons using targeted two-photon optogenetics during low contrast visual stimulation. Only activation of groups of cells with similar tuning to the relevant visual stimulus led to a measurable bias of detection behaviour. Targeted photostimulation revealed signatures of centre-surround, predominantly inhibitory and like-to-like connectivity motifs in the local network which shaped the visual stimulus representation and partially explained the change in stimulus detectability. Moreover, the behavioural effects depended on overall performance: when the task was challenging for the mouse, V1 activity was more closely linked to performance, and cortical stimulation boosted perception. In contrast, when the task was easy, V1 activity was less informative about performance and cortical stimulation suppressed stimulus detection. Altogether, we find that both the selective routing of information through functionally specific circuits, and the prevailing cortical state, make similarly large contributions to explaining the behavioural response to photostimulation. Our results thus help to reconcile contradictory findings about the involvement of primary sensory cortex in behavioural tasks, suggesting that the influence of cortical activity on behaviour is dynamically reassigned depending on the demands of the task.

scholarly journals Three-dimensional Two-Photon Optogenetics and Imaging of Neural Circuits in vivo

2017 ◽  
Author(s):  
Weijian Yang ◽  
Luis Carrillo-Reid ◽  
Yuki Bando ◽  
Darcy S. Peterka ◽  
Rafael Yuste
Keyword(s):  
Visual Cortex ◽  
Neural Activity ◽  
Calcium Imaging ◽  
Pyramidal Neurons ◽  
Neural Circuits ◽  
Three Dimensional ◽  
Two Photon ◽  
Cellular Resolution ◽  
Photon Excitation

We demonstrate a holographic system for simultaneous three-dimensional (3D) two-photon stimulation and imaging of neural activity in the mouse neocortex in vivo with cellular resolution. Dual two-photon excitation paths are implemented with independent 3D targeting for calcium imaging and precision optogenetics. We validate the usefulness of the microscope by photoactivating local pools of interneurons in awake mice visual cortex in 3D, which suppress the nearby pyramidal neurons’ response to visual stimuli.

scholarly journals Motor cortical dynamics are shaped by multiple distinct subspaces during naturalistic behavior

2020 ◽  
Author(s):  
Matthew G. Perich ◽  
Sara Conti ◽  
Marion Badi ◽  
Andrew Bogaard ◽  
Beatrice Barra ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Somatosensory Cortex ◽  
Sensory Information ◽  
Cortical Activity ◽  
The Body ◽  
Cortical Dynamics ◽  
Object Interaction ◽  
Driven System ◽  
Flexible Integration ◽  
Motor Cortical

ABSTRACTBehavior relies on continuous influx of sensory information about the body and the environment. In primates, cortex integrates somatic feedback to accurately reach and manipulate objects. Yet, in many experimental regimes motor cortex seems paradoxically to operate as a feedforward, rather than feedback-driven, system. Here, we recorded simultaneously from motor and somatosensory cortex as monkeys performed a naturalistic reaching and object interaction behavior. We studied how unexpected feedback from behavioral errors influences cortical dynamics. Motor cortex generally exhibited robust feedforward dynamics, yet displayed feedback-driven dynamics surrounding correction of behavioral errors. We then decomposed motor cortical activity into orthogonal subspaces capturing communication with somatosensory cortex or behavior-generating dynamics. During error correction, the communication subspace became feedback-driven, while the behavioral subspace maintained feedforward dynamics. We therefore demonstrate that cortical activity is compartmentalized within distinct subspaces that shape the population dynamics, enabling flexible integration of salient inputs with ongoing activity for robust behavior.

scholarly journals Dynamic perceptual feature selectivity in primary somatosensory cortex upon reversal learning

2019 ◽  
Author(s):  
Ronan Chéreau ◽  
Tanika Bawa ◽  
Leon Fodoulian ◽  
Alan Carleton ◽  
Stéphane Pagès ◽  
...  
Keyword(s):  
Perceptual Learning ◽  
Somatosensory Cortex ◽  
Sensory Cortex ◽  
Primary Somatosensory Cortex ◽  
Primary Sensory Cortex ◽  
Before And After ◽  
Feature Selectivity ◽  
Stimulus Value ◽  
Reward Contingencies ◽  
Stimulus Features

ABSTRACTNeurons in primary sensory cortex encode a variety of stimulus features upon perceptual learning. However, it is unclear whether the acquired stimulus selectivity remains stable when the same input is perceived in a different context. Here, we monitored the activity of individual neurons in the mouse primary somatosensory cortex in a reward-based texture discrimination task. We tracked their stimulus selectivity before and after changing reward contingencies, which allowed us to identify various classes of neurons. We found neurons that stably represented a texture or the upcoming behavioral choice, but the majority was dynamic. Among those, a subpopulation of neurons regained selectivity contingent on stimulus-value. These value-sensitive neurons forecasted the onset of learning by displaying a distinct and transient increase in activity, depending on past behavioral experience. Thus, stimulus selectivity of excitatory neurons during perceptual learning is dynamic and largely relies on behavioral contingencies, even in primary sensory cortex.

scholarly journals How many neurons are sufficient for perception of cortical activity?

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Henry WP Dalgleish ◽  
Lloyd E Russell ◽  
Adam M Packer ◽  
Arnd Roth ◽  
Oliver M Gauld ◽  
...  
Keyword(s):  
Lower Bound ◽  
Pyramidal Neurons ◽  
Barrel Cortex ◽  
Cortical Activity ◽  
Network Activity ◽  
Local Network ◽  
Two Photon ◽  
All Optical ◽  
The Face ◽  
The Impact

Many theories of brain function propose that activity in sparse subsets of neurons underlies perception and action. To place a lower bound on the amount of neural activity that can be perceived, we used an all-optical approach to drive behaviour with targeted two-photon optogenetic activation of small ensembles of L2/3 pyramidal neurons in mouse barrel cortex while simultaneously recording local network activity with two-photon calcium imaging. By precisely titrating the number of neurons stimulated, we demonstrate that the lower bound for perception of cortical activity is ~14 pyramidal neurons. We find a steep sigmoidal relationship between the number of activated neurons and behaviour, saturating at only ~37 neurons, and show this relationship can shift with learning. Furthermore, activation of ensembles is balanced by inhibition of neighbouring neurons. This surprising perceptual sensitivity in the face of potent network suppression supports the sparse coding hypothesis, and suggests that cortical perception balances a trade-off between minimizing the impact of noise while efficiently detecting relevant signals.

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