scholarly journals Brain activity mapping at multiple scales with silicon microprobes containing 1,024 electrodes

2015 ◽  
Vol 114 (3) ◽  
pp. 2043-2052 ◽  
Author(s):  
Justin L. Shobe ◽  
Leslie D. Claar ◽  
Sepideh Parhami ◽  
Konstantin I. Bakhurin ◽  
Sotiris C. Masmanidis
Keyword(s):  
Multiple Scales ◽  
Functional Organization ◽  
Brain Activity ◽  
Three Dimensional ◽  
Field Potential ◽  
Neural Systems ◽  
Mammalian Brain ◽  
Neural Signals ◽  
Neural Ensembles ◽  
Potential Activity

The coordinated activity of neural ensembles across multiple interconnected regions has been challenging to study in the mammalian brain with cellular resolution using conventional recording tools. For instance, neural systems regulating learned behaviors often encompass multiple distinct structures that span the brain. To address this challenge we developed a three-dimensional (3D) silicon microprobe capable of simultaneously measuring extracellular spike and local field potential activity from 1,024 electrodes. The microprobe geometry can be precisely configured during assembly to target virtually any combination of four spatially distinct neuroanatomical planes. Here we report on the operation of such a device built for high-throughput monitoring of neural signals in the orbitofrontal cortex and several nuclei in the basal ganglia. We perform analysis on systems-level dynamics and correlations during periods of conditioned behavioral responding and rest, demonstrating the technology's ability to reveal functional organization at multiple scales in parallel in the mouse brain.

scholarly journals NFTsim: Theory and Simulation of Multiscale Neural Field Dynamics

2017 ◽  
Author(s):  
P. Sanz-Leon ◽  
P. A. Robinson ◽  
S. A. Knock ◽  
P. M. Drysdale ◽  
R. G. Abeysuriya ◽  
...  
Keyword(s):  
Large Scale ◽  
Multiple Scales ◽  
Brain Activity ◽  
Field Potential ◽  
Neural Field ◽  
Neural Systems ◽  
Unified Framework ◽  
Plain Text ◽  
Wide Range ◽  
Key Aspects

AbstractA user ready, portable, documented software package, NFTsim, is presented to facilitate numerical simulations of a wide range of brain systems using continuum neural field modeling. NFTsim enables users to simulate key aspects of brain activity at multiple scales. At the microscopic scale, it incorporates characteristics of local interactions between cells, neurotransmitter effects, synaptodendritic delays and feedbacks. At the mesoscopic scale, it incorporates information about medium to large scale axonal ranges of fibers, which are essential to model dissipative wave transmission and to produce synchronous oscillations and associated cross-correlation patterns as observed in local field potential recordings of active tissue. At the scale of the whole brain, NFTsim allows for the inclusion of long range pathways, such as thalamocortical projections, when generating macroscopic activity fields. The multiscale nature of the neural activity produced by NFTsim has the potential to enable the modeling of resulting quantities measurable via various neuroimaging techniques. In this work, we give a comprehensive description of the design and implementation of the software. Due to its modularity and flexibility, NFTsim enables the systematic study of an unlimited number of neural systems with multiple neural populations under a unified framework and allows for direct comparison with analytic and experimental predictions. The code is written in C++ and bundled with Matlab routines for a rapid quantitative analysis and visualization of the outputs. The output of NFTsim is stored in plain text file enabling users to select from a broad range of tools for offline analysis. This software enables a wide and convenient use of powerful physiologically-based neural field approaches to brain modeling. NFTsim is distributed under the Apache 2.0 license.

scholarly journals Emerging imaging methods to study whole-brain function in rodent models

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marija Markicevic ◽  
Iurii Savvateev ◽  
Christina Grimm ◽  
Valerio Zerbi
Keyword(s):  
Large Scale ◽  
Functional Organization ◽  
Imaging Techniques ◽  
Brain Activity ◽  
Research Question ◽  
Careful Consideration ◽  
Mammalian Brain ◽  
High Temporal Resolution ◽  
Imaging Methods ◽  
Evoked Activity

AbstractIn the past decade, the idea that single populations of neurons support cognition and behavior has gradually given way to the realization that connectivity matters and that complex behavior results from interactions between remote yet anatomically connected areas that form specialized networks. In parallel, innovation in brain imaging techniques has led to the availability of a broad set of imaging tools to characterize the functional organization of complex networks. However, each of these tools poses significant technical challenges and faces limitations, which require careful consideration of their underlying anatomical, physiological, and physical specificity. In this review, we focus on emerging methods for measuring spontaneous or evoked activity in the brain. We discuss methods that can measure large-scale brain activity (directly or indirectly) with a relatively high temporal resolution, from milliseconds to seconds. We further focus on methods designed for studying the mammalian brain in preclinical models, specifically in mice and rats. This field has seen a great deal of innovation in recent years, facilitated by concomitant innovation in gene-editing techniques and the possibility of more invasive recordings. This review aims to give an overview of currently available preclinical imaging methods and an outlook on future developments. This information is suitable for educational purposes and for assisting scientists in choosing the appropriate method for their own research question.

scholarly journals Multi-scale mapping along the auditory hierarchy using high-resolution functional UltraSound in the awake ferret

2018 ◽  
Author(s):  
Célian Bimbard ◽  
Charlie Demené ◽  
Constantin Girard ◽  
Susanne Radtke-Schuller ◽  
Shihab Shamma ◽  
...  
Keyword(s):  
Cerebral Blood Volume ◽  
Multiple Scales ◽  
Functional Organization ◽  
Brain Activity ◽  
Spatial Scales ◽  
Auditory Pathway ◽  
Brain Regions ◽  
Sensory Response ◽  
Response Modulation ◽  
Sensory Responses

A major challenge in neuroscience is to longitudinally monitor whole brain activity across multiple spatial scales in the same animal. Functional UltraSound (fUS) is an emerging technology that offers images of cerebral blood volume over large brain portions. Here we show for the first time its capability to resolve the functional organization of sensory systems at multiple scales in awake animals, both within structures by precisely mapping sensory responses, and between structures by elucidating the connectivity scheme of top-down projections. We demonstrate that fUS provides stable (over days), yet rapid, highly-resolved 3D tonotopic maps in the auditory pathway of awake ferrets, with unprecedented sharp functional resolution (100μm). This was performed in four different brain regions, including small (1-2mm3 size), subcortical (8mm deep) and previously undescribed structures in the ferret. Furthermore, we used fUS to map longdistance projections from frontal cortex, a key source of sensory response modulation, to auditory cortex.

scholarly journals Differential effects of amplitude-modulated transcranial focused ultrasound on excitatory and inhibitory neurons

2020 ◽  
Author(s):  
Duc T. Nguyen ◽  
Destiny Berisha ◽  
Elisa Konofagou ◽  
Jacek P. Dmochowski
Keyword(s):  
Firing Rate ◽  
Focused Ultrasound ◽  
Multiple Scales ◽  
Brain Activity ◽  
Field Potential ◽  
Pyramidal Cells ◽  
Inhibitory Neurons ◽  
Specific Cell ◽  
Inhibitory Interneurons ◽  
Transcranial Focused Ultrasound

AbstractAlthough stimulation with ultrasound has been shown to modulate brain activity at multiple scales, it remains unclear whether transcranial focused ultrasound stimulation (tFUS) exerts its influence on specific cell types. Here we propose a novel form of tFUS where a continuous waveform is amplitude modulated (AM) at a slow rate (i.e., 40 Hz) targeting the temporal range of electrophysiological activity: AM-tFUS. We stimulated the rat hippocampus while recording multi-unit activity (MUA) followed by classification of spike waveforms into putative excitatory pyramidal cells and inhibitory interneurons. At low acoustic intensity, AM-tFUS selectively reduced firing rates of inhibitory interneurons. On the other hand, higher intensity AM-tFUS increased firing of putative excitatory neurons with no effect on inhibitory firing. Interestingly, firing rate was unchanged during AM-tFUS at intermediate intensity. Consistent with the observed changes in firing rate, power in the theta band (3-10 Hz) of the local field potential (LFP) decreased at low-intensity, was unchanged at intermediate intensity, and increased at higher intensity. Temperature increases at the AM-tFUS target were limited to 0.2°C. Our findings indicate that inhibitory interneurons exhibit greater sensitivity to ultrasound, and that cell-type specific neuromodulation may be achieved by calibrating the intensity of AM-tFUS.

scholarly journals Multi-scale mapping along the auditory hierarchy using high-resolution functional UltraSound in the awake ferret

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Célian Bimbard ◽  
Charlie Demene ◽  
Constantin Girard ◽  
Susanne Radtke-Schuller ◽  
Shihab Shamma ◽  
...  
Keyword(s):  
Cerebral Blood Volume ◽  
Multiple Scales ◽  
Functional Organization ◽  
Brain Activity ◽  
Spatial Scales ◽  
Auditory Pathway ◽  
Brain Regions ◽  
Sensory Response ◽  
Response Modulation ◽  
Long Distance

A major challenge in neuroscience is to longitudinally monitor whole brain activity across multiple spatial scales in the same animal. Functional UltraSound (fUS) is an emerging technology that offers images of cerebral blood volume over large brain portions. Here we show for the first time its capability to resolve the functional organization of sensory systems at multiple scales in awake animals, both within small structures by precisely mapping and differentiating sensory responses, and between structures by elucidating the connectivity scheme of top-down projections. We demonstrate that fUS provides stable (over days), yet rapid, highly-resolved 3D tonotopic maps in the auditory pathway of awake ferrets, thus revealing its unprecedented functional resolution (100/300µm). This was performed in four different brain regions, including very small (1–2 mm3 size), deeply situated subcortical (8 mm deep) and previously undescribed structures in the ferret. Furthermore, we used fUS to map long-distance projections from frontal cortex, a key source of sensory response modulation, to auditory cortex.

scholarly journals CA1 20-40 Hz oscillatory dynamics reflect trial-specific information processing supporting nonspatial sequence memory

2020 ◽  
Author(s):  
Sandra Gattas ◽  
Gabriel A. Elias ◽  
Michael A. Yassa ◽  
Norbert J. Fortin
Keyword(s):  
Functional Organization ◽  
Critical Role ◽  
Memory Task ◽  
Field Potential ◽  
Specific Information ◽  
Oscillatory Dynamics ◽  
Processing Information ◽  
Potential Activity ◽  
Sequence Memory ◽  
40 Hz

AbstractThe hippocampus is known to play a critical role in processing information about temporal context. However, it remains unclear how hippocampal oscillations are involved, and how their functional organization is influenced by connectivity gradients. We examined local field potential activity in CA1 as rats performed a complex odor sequence memory task. We find that odor sequence processing epochs were characterized by increased power in the 4-8 Hz and 20-40 Hz range, with 20-40 Hz oscillations showing a power gradient increasing toward proximal CA1. Running epochs were characterized by increased power in the 8-12 Hz range and across higher frequency ranges (>24 Hz), with power gradients increasing toward proximal and distal CA1, respectively. Importantly, 20-40 Hz power increased with knowledge of the sequence and carried trial-type-specific information. These results suggest that 20-40 Hz oscillations are associated with trial-specific processing of nonspatial information critical for order memory judgments.

scholarly journals Testing for functional organization of three-dimensional surface tilt encoding within visual cortex

2020 ◽  
Author(s):  
Reuben Rideaux ◽  
Andrew E Welchman
Keyword(s):  
Visual Cortex ◽  
Binocular Disparity ◽  
Multiple Scales ◽  
Functional Organization ◽  
3D Structure ◽  
Three Dimensional ◽  
Planar Surfaces ◽  
Grasping And Manipulation ◽  
Use Phase ◽  
The Brain

ABSTRACTVisual perception of three-dimensional (3D) structure is important for object recognition, grasping, and manipulation. The 3D structure of a surface can be defined in terms of its slant and tilt. Previous work has shown that slant and tilt are represented in the posterior and ventral intraparietal sulcus of the human brain; however, it is unclear whether the representation of these features is functionally organized within this region. Here we use phase-encoded presentation of 3D planar surfaces with linear gradients defined by horizontal binocular disparity while measuring fMRI activity to test whether the representation of 3D surface tilt is functionally organized within visual cortex. We find functionally defined structures within V3A and V7. Most notably, in one participant we find that the tilt preference is unilaterally organized in a pinwheel-like structure, similar to those observed for orientation preference in V1, which encompasses most of area V3A. These findings indicate that 3D orientation is functionally organized within the human visual cortex, and the evidence suggesting the presence of a large pinwheel-like structure indicates that this type of organization may be applied canonically within the brain at multiple scales.

scholarly journals Optoacoustic Calcium Imaging of Deep Brain Activity in an Intracardially Perfused Mouse Brain Model

Photonics ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 67 ◽  
Author(s):  
Oleksiy Degtyaruk ◽  
Benedict Mc Larney ◽  
Xosé Deán-Ben ◽  
Shy Shoham ◽  
Daniel Razansky
Keyword(s):  
Mouse Brain ◽  
Large Scale ◽  
Near Infrared ◽  
Brain Activity ◽  
Three Dimensional ◽  
Mammalian Brain ◽  
Visible Range ◽  
Light Spectrum ◽  
Optoacoustic Imaging

One main limitation of established neuroimaging methods is the inability to directly visualize large-scale neural dynamics in whole mammalian brains at subsecond speeds. Optoacoustic imaging has advanced in recent years to provide unique advantages for real-time deep-tissue observations, which have been exploited for three-dimensional imaging of both cerebral hemodynamic parameters and direct calcium activity in rodents. Due to a lack of suitable calcium indicators excitable in the near-infrared window, optoacoustic imaging of neuronal activity at deep-seated areas of the mammalian brain has been impeded by the strong absorption of blood in the visible range of the light spectrum. To overcome this, we have developed and validated an intracardially perfused mouse brain preparation labelled with genetically encoded calcium indicator GCaMP6f that closely resembles in vivo conditions. By overcoming the limitations of hemoglobin-based light absorption, this new technique was used to observe stimulus-evoked calcium dynamics in the brain at penetration depths and spatio-temporal resolution scales not attainable with existing neuroimaging techniques.

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