scholarly journals Astrocyte subdomains respond independently in vivo

2019 ◽  
Author(s):  
Mónica López-Hidalgo ◽  
Vered Kellner ◽  
James Schummers
Keyword(s):  
Visual Cortex ◽  
Neuronal Activity ◽  
Visual Stimulus ◽  
Calcium Concentration ◽  
Neural Circuit ◽  
Functional Unit ◽  
Spatial Interaction ◽  
Topographic Organization ◽  
Orientation Maps

AbstractAstrocytes contact thousands of synapses throughout the territory covered by its fine bushy processes. Astrocytes respond to neuronal activity with an increase in calcium concentration that is in turn linked to their capacity to modulate neuronal activity. It remains unclear whether astrocytes behave as a single functional unit that integrates all of these inputs, or if multiple functional subdomains reside within an individual astrocyte. We utilized the topographic organization of ferret visual cortex to test whether local neuronal activity can elicit spatially restricted events within an individual astrocyte. We monitored calcium activity throughout the extent of astrocytes in ferret visual cortex while presenting visual stimuli that elicit coordinated neuronal activity spatially restricted to functional columns. We found visually-driven calcium responses throughout the entire astrocyte that was largely independent in individual subdomains, often responding to different visual stimulus orientations. A model of the spatial interaction of astrocytes and neuronal orientation maps recapitulated these measurements, consistent with the hypothesis that astrocyte subdomains integrate local neuronal activity. Together, these results suggest that astrocyte responses to neural circuit activity are dominated by functional subdomains that respond locally and independently to neuronal activity.

scholarly journals An Intracortical Implantable Brain-Computer Interface for Telemetric Real-Time Recording and Manipulation of Neuronal Circuits for Closed-Loop Intervention

2021 ◽  
Vol 15 ◽  
Author(s):  
Hamed Zaer ◽  
Ashlesha Deshmukh ◽  
Dariusz Orlowski ◽  
Wei Fan ◽  
Pierre-Hugues Prouvot ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Real Time ◽  
Neuronal Activity ◽  
Closed Loop ◽  
Neural Circuit ◽  
Radio Communication ◽  
Computer Interfaces ◽  
Cerebral Mri ◽  
High Bandwidth ◽  
And Behavior

Recording and manipulating neuronal ensemble activity is a key requirement in advanced neuromodulatory and behavior studies. Devices capable of both recording and manipulating neuronal activity brain-computer interfaces (BCIs) should ideally operate un-tethered and allow chronic longitudinal manipulations in the freely moving animal. In this study, we designed a new intracortical BCI feasible of telemetric recording and stimulating local gray and white matter of visual neural circuit after irradiation exposure. To increase the translational reliance, we put forward a Göttingen minipig model. The animal was stereotactically irradiated at the level of the visual cortex upon defining the target by a fused cerebral MRI and CT scan. A fully implantable neural telemetry system consisting of a 64 channel intracortical multielectrode array, a telemetry capsule, and an inductive rechargeable battery was then implanted into the visual cortex to record and manipulate local field potentials, and multi-unit activity. We achieved a 3-month stability of the functionality of the un-tethered BCI in terms of telemetric radio-communication, inductive battery charging, and device biocompatibility for 3 months. Finally, we could reliably record the local signature of sub- and suprathreshold neuronal activity in the visual cortex with high bandwidth without complications. The ability to wireless induction charging combined with the entirely implantable design, the rather high recording bandwidth, and the ability to record and stimulate simultaneously put forward a wireless BCI capable of long-term un-tethered real-time communication for causal preclinical circuit-based closed-loop interventions.

scholarly journals A neural circuit for gamma-band coherence across the retinotopic map in mouse visual cortex

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Richard Hakim ◽  
Kiarash Shamardani ◽  
Hillel Adesnik
Keyword(s):  
Visual Cortex ◽  
Neural Circuit ◽  
Brain Slices ◽  
Pyramidal Cells ◽  
Gamma Oscillations ◽  
Gamma Band ◽  
Neuron Activity ◽  
Mouse Visual Cortex ◽  
Retinotopic Map

Cortical gamma oscillations have been implicated in a variety of cognitive, behavioral, and circuit-level phenomena. However, the circuit mechanisms of gamma-band generation and synchronization across cortical space remain uncertain. Using optogenetic patterned illumination in acute brain slices of mouse visual cortex, we define a circuit composed of layer 2/3 (L2/3) pyramidal cells and somatostatin (SOM) interneurons that phase-locks ensembles across the retinotopic map. The network oscillations generated here emerge from non-periodic stimuli, and are stimulus size-dependent, coherent across cortical space, narrow band (30 Hz), and depend on SOM neuron but not parvalbumin (PV) neuron activity; similar to visually induced gamma oscillations observed in vivo. Gamma oscillations generated in separate cortical locations exhibited high coherence as far apart as 850 μm, and lateral gamma entrainment depended on SOM neuron activity. These data identify a circuit that is sufficient to mediate long-range gamma-band coherence in the primary visual cortex.

scholarly journals In Vivo Optogenetic Modulation with Simultaneous Neural Detection Using Microelectrode Array Integrated with Optical Fiber

Sensors ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 4526
Author(s):  
Penghui Fan ◽  
Yilin Song ◽  
Shengwei Xu ◽  
Yuchuan Dai ◽  
Yiding Wang ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Neuronal Activity ◽  
Microelectrode Array ◽  
Adhesive Bonding ◽  
Neural Circuit ◽  
Low Frequency ◽  
Depth Range ◽  
Light Power ◽  
The Brain

The detection of neuroelectrophysiology while performing optogenetic modulation can provide more reliable and useful information for neural research. In this study, an optical fiber and a microelectrode array were integrated through hot-melt adhesive bonding, which combined optogenetics and electrophysiological detection technology to achieve neuromodulation and neuronal activity recording. We carried out the experiments on the activation and electrophysiological detection of infected neurons at the depth range of 900–1250 μm in the brain which covers hippocampal CA1 and a part of the upper cortical area, analyzed a possible local inhibition circuit by combining opotogenetic modulation and electrophysiological characteristics and explored the effects of different optical patterns and light powers on the neuromodulation. It was found that optogenetics, combined with neural recording technology, could provide more information and ideas for neural circuit recognition. In this study, the optical stimulation with low frequency and large duty cycle induces more intense neuronal activity and larger light power induced more action potentials of neurons within a certain power range (1.032 mW–1.584 mW). The present study provided an efficient method for the detection and modulation of neurons in vivo and an effective tool to study neural circuit in the brain.

scholarly journals Novel System to Monitor In Vivo Neural Graft Activity After Spinal Cord Injury

2021 ◽  
Author(s):  
Kentaro Ago ◽  
Narihito Nagoshi ◽  
Kent Imaizumi ◽  
Takahiro Kitagawa ◽  
Momotaro Kawai ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Neuronal Activity ◽  
Neural Circuit ◽  
Imaging System ◽  
Non Invasive ◽  
Cord Injury ◽  
Neural Graft ◽  
Host Behaviour

AbstractExpectations for neural stem/progenitor cell (NS/PC) transplantation as a treatment for spinal cord injury (SCI) are increasing. However, whether and how grafted cells are incorporated into the host neural circuit and contribute to motor function recovery remain unknown. The aim of this project was to establish a novel non-invasive in vivo imaging system to visualize the activity of neural grafts by which we can simultaneously demonstrate the circuit-level integration between the graft and host, and the contribution of graft neuronal activity to host behaviour. We introduced Akaluc, a newly engineered luciferase, under control of a potent neuronal activity-dependent synthetic promoter, E-SARE, into NS/PCs and engrafted the cells into SCI model mice. Through the use of this system, we reveal that the activity of grafted cells was integrated with host behaviour and driven by host neural circuit inputs. This non-invasive system is expected to help elucidate the therapeutic mechanism of cell transplantation treatment for SCI and determine better therapy techniques that maximize the function of cells in the host circuit.

scholarly journals Novel System to Monitor In Vivo Neural Graft Activity After Spinal Cord Injury

2021 ◽  
Author(s):  
Kentaro Ago ◽  
Narihito Nagoshi ◽  
Kent Imaizumi ◽  
Takahiro Kitagawa ◽  
Momotaro Kawai ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Neuronal Activity ◽  
Neural Circuit ◽  
Imaging System ◽  
Non Invasive ◽  
Cord Injury ◽  
Neural Graft ◽  
Host Behaviour

Abstract Expectations for neural stem/progenitor cell (NS/PC) transplantation as a treatment for spinal cord injury (SCI) are increasing. However, whether and how grafted cells are incorporated into the host neural circuit and contribute to motor function recovery remain unknown. The aim of this project was to establish a novel non-invasive in vivo imaging system to visualize the activity of neural grafts by which we can simultaneously demonstrate the circuit-level integration between the graft and host, and the contribution of graft neuronal activity to host behaviour. We introduced Akaluc, a newly engineered luciferase, under control of a potent neuronal activity-dependent synthetic promoter, E-SARE, into NS/PCs and engrafted the cells into SCI model mice. Through the use of this system, we reveal that the activity of grafted cells was integrated with host behaviour and driven by host neural circuit inputs. This non-invasive system is expected to help elucidate the therapeutic mechanism of cell transplantation treatment for SCI and determine better therapy techniques that maximize the function of cells in the host circuit.

scholarly journals Reward timing and its expression by inhibitory interneurons in the mouse primary visual cortex

2019 ◽  
Author(s):  
Kevin J Monk ◽  
Simon Allard ◽  
Marshall G Hussain Shuler
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Visual Stimulus ◽  
Network Architecture ◽  
Sensory Cortex ◽  
Inhibitory Interneurons ◽  
Feature Detector ◽  
Primary Sensory Cortex ◽  
Fixed Delay

AbstractPrimary sensory cortex has historically been studied as a low-level feature detector, but has more recently been implicated in many higher-level cognitive functions. For instance, after an animal learns that a light predicts water at a fixed delay, neurons in primary visual cortex (V1) can produce “reward timing activity” (i.e., spike modulation of various forms that relate the interval between the visual stimulus and expected reward). The manner by which V1 produces these representations is unknown. Here, we combine behavior, in vivo electrophysiology, and optogenetics to investigate the characteristics of and circuit mechanisms underlying V1 reward timing in the head-fixed mouse. We find that reward timing activity is present in mouse V1, that inhibitory interneurons participate in reward timing, and that these representations are consistent with a theorized network architecture. Together, these results deepen our understanding of V1 reward timing and the manner by which it is produced.

scholarly journals Sound improves neuronal encoding of visual stimuli in mouse primary visual cortex

2021 ◽  
Author(s):  
Aaron M. Williams ◽  
Christopher F. Angeloni ◽  
Maria Neimark Geffen
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Neuronal Activity ◽  
Visual Stimulus ◽  
Visual Stimuli ◽  
Audiovisual Integration ◽  
Neuronal Firing ◽  
Auditory Information ◽  
Visual Responses ◽  
Neuronal Encoding

In everyday life, we integrate visual and auditory information in routine tasks such as navigation and communication. While it is known that concurrent sound can improve visual perception, the neuronal correlates of this audiovisual integration are not fully understood. Specifically, it remains unknown whether improvement of the detection and discriminability of visual stimuli due to sound is reflected in the neuronal firing patterns in the primary visual cortex (V1). Furthermore, presentation of the sound can induce movement in the subject, but little is understood about whether and how sound-induced movement contributes to V1 neuronal activity. Here, we investigated how sound and movement interact to modulate V1 visual responses in awake, head-fixed mice and whether this interaction improves neuronal encoding of the visual stimulus. We presented visual drifting gratings with and without simultaneous auditory white noise to awake mice while recording mouse movement and V1 neuronal activity. Sound modulated the light-evoked activity of 80% of light-responsive neurons, with 95% of neurons exhibiting increased activity when the auditory stimulus was present. Sound consistently induced movement. However, a generalized linear model revealed that sound and movement had distinct and complementary effects of the neuronal visual responses. Furthermore, decoding of the visual stimulus from the neuronal activity was improved with sound, an effect that persisted even when controlling for movement. These results demonstrate that sound and movement modulate visual responses in complementary ways, resulting in improved neuronal representation of the visual stimulus. This study clarifies the role of movement as a potential confound in neuronal audiovisual responses, and expands our knowledge of how multi-modal processing is mediated at a neuronal level in the awake brain.

scholarly journals In vivo magnetic recording of neuronal activity

2016 ◽  
Author(s):  
Laure Caruso ◽  
Thomas Wunderle ◽  
Christopher Murphy Lewis ◽  
Joao Valadeiro ◽  
Vincent Trauchessec ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Visual Cortex ◽  
Magnetic Fields ◽  
Neuronal Activity ◽  
Field Measurements ◽  
Magnetic Sensors ◽  
List Type ◽  
Spin Electronics ◽  
Magnetic Field Measurements

SUMMARYNeuronal activity generates ionic flows and thereby both magnetic fields and electric potential differences, i.e. voltages. Voltage measurements are widely used, but suffer from isolating and smearing properties of tissue between source and sensor, are blind to ionic flow direction, and reflect the difference between two electrodes, complicating interpretation. Magnetic field measurements could overcome these limitations, but have been essentially limited to magnetoencephalography (MEG), using centimeter-sized, helium-cooled extracranial sensors. Here, we report on in vivo magnetic recordings of neuronal activity from visual cortex of cats with magnetrodes, specially developed needle-shaped probes carrying micron-sized, non-cooled magnetic sensors based on spin electronics. Event-related magnetic fields inside the neuropil were on the order of several nanoteslas, informing MEG source models and efforts for magnetic field measurements through MRI. Though the signal-to-noise ratio is still inferior to electrophysiology, this proof of concept demonstrates the potential to exploit the fundamental advantages of magnetophysiology.HIGHLIGHTSSpin-electronics based probes achieve local magnetic recordings inside the neuropilMagnetic field recordings were performed in vivo, in anesthetized cat visual cortexEvent-related fields (ERFs) to visual stimuli were up to several nanoteslas in sizeERFs could be detected after averaging less than 20 trialsIN BRIEFCaruso et al. report in vivo, intra-cortical recordings of magnetic fields that reflect neuronal activity, using magnetrodes, i.e. micron size magnetic sensors based on spin electronics.

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