scholarly journals Visual epidural field potentials possess high functional specificity in single trials

2019 ◽  
Author(s):  
Benjamin Fischer ◽  
Andreas Schander ◽  
Andreas K. Kreiter ◽  
Walter Lang ◽  
Detlef Wegener

AbstractRecordings of epidural field potentials (EFPs) allow to acquire neuronal activity over a large region of cortical tissue with minimal invasiveness. Because electrodes are placed on top of the dura and do not enter the neuronal tissue, EFPs offer intriguing options for both clinical and basic science research. On the other hand, EFPs represent the integrated activity of larger neuronal populations, possess a higher trial-by-trial variability, and a reduced signal-to-noise ratio due the additional barrier of the dura. It is thus unclear whether and to what extent EFPs have sufficient spatial selectivity to allow for conclusions about the underlying functional cortical architecture, and whether single EFP trials provide enough information on the short time scales relevant for many clinical and basic neuroscience purposes. We here use the high spatial resolution of primary visual cortex to address these issues and investigate the extent to which very short EFP traces allow reliable decoding of spatial information. We briefly presented different visual objects at one out of nine closely adjacent locations and recorded neuronal activity with a high-density, epidural multi-electrode array in three macaque monkeys. Using receiver-operating characteristics to identify most-informative data, machine-learning algorithms provided close-to-perfect classification rates for all 27 stimulus conditions. A binary classifier applying a simple max function on ROC-selected data further showed that single trials might be classified with 100% performance even without advanced offline classifiers. Thus, although highly variable, EFPs constitute an extremely valuable source of information and offer new perspectives for minimally invasive recording of large-scale networks.

2019 ◽  
Vol 122 (4) ◽  
pp. 1634-1648 ◽  
Author(s):  
Benjamin Fischer ◽  
Andreas Schander ◽  
Andreas K. Kreiter ◽  
Walter Lang ◽  
Detlef Wegener

Recordings of epidural field potentials (EFPs) allow neuronal activity to be acquired over a large region of cortical tissue with minimal invasiveness. Because electrodes are placed on top of the dura and do not enter the neuronal tissue, EFPs offer intriguing options for both clinical and basic science research. On the other hand, EFPs represent the integrated activity of larger neuronal populations and possess a higher trial-by-trial variability and a reduced signal-to-noise ratio due the additional barrier of the dura. It is thus unclear whether and to what extent EFPs have sufficient spatial selectivity to allow for conclusions about the underlying functional cortical architecture, and whether single EFP trials provide enough information on the short timescales relevant for many clinical and basic neuroscience purposes. We used the high spatial resolution of primary visual cortex to address these issues and investigated the extent to which very short EFP traces allow reliable decoding of spatial information. We briefly presented different visual objects at one of nine closely adjacent locations and recorded neuronal activity with a high-density epidural multielectrode array in three macaque monkeys. With the use of receiver operating characteristics (ROC) to identify the most informative data, machine-learning algorithms provided close-to-perfect classification rates for all 27 stimulus conditions. A binary classifier applying a simple max function on ROC-selected data further showed that single trials might be classified with 100% performance even without advanced offline classifiers. Thus, although highly variable, EFPs constitute an extremely valuable source of information and offer new perspectives for minimally invasive recording of large-scale networks. NEW & NOTEWORTHY Epidural field potential (EFP) recordings provide a minimally invasive approach to investigate large-scale neural networks, but little is known about whether they possess the required specificity for basic and clinical neuroscience. By making use of the spatial selectivity of primary visual cortex, we show that single-trial information can be decoded with close-to-perfect performance, even without using advanced classifiers and based on very few data. This labels EFPs as a highly attractive and widely usable signal.


eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Andrea Antonini ◽  
Andrea Sattin ◽  
Monica Moroni ◽  
Serena Bovetti ◽  
Claudio Moretti ◽  
...  

Imaging neuronal activity with high and homogeneous spatial resolution across the field-of-view (FOV) and limited invasiveness in deep brain regions is fundamental for the progress of neuroscience, yet is a major technical challenge. We achieved this goal by correcting optical aberrations in gradient index lens-based ultrathin (≤500 µm) microendoscopes using aspheric microlenses generated through 3D-microprinting. Corrected microendoscopes had extended FOV (eFOV) with homogeneous spatial resolution for two-photon fluorescence imaging and required no modification of the optical set-up. Synthetic calcium imaging data showed that, compared to uncorrected endoscopes, eFOV-microendoscopes led to improved signal-to-noise ratio and more precise evaluation of correlated neuronal activity. We experimentally validated these predictions in awake head-fixed mice. Moreover, using eFOV-microendoscopes we demonstrated cell-specific encoding of behavioral state-dependent information in distributed functional subnetworks in a primary somatosensory thalamic nucleus. eFOV-microendoscopes are, therefore, small-cross-section ready-to-use tools for deep two-photon functional imaging with unprecedentedly high and homogeneous spatial resolution.


2020 ◽  
Author(s):  
Andrea Antonini ◽  
Andrea Sattin ◽  
Monica Moroni ◽  
Serena Bovetti ◽  
Claudio Moretti ◽  
...  

AbstractImaging neuronal activity with high and homogeneous spatial resolution across the field-of-view (FOV) and limited invasiveness in deep brain regions is fundamental for the progress of neuroscience, yet is a major technical challenge. We achieved this goal by correcting optical aberrations in gradient index lens-based ultrathin (≤ 500 µm) microendoscopes using aspheric microlenses generated through 3D-microprinting. Corrected microendoscopes had extended FOV (eFOV) with homogeneous spatial resolution for two-photon fluorescence imaging and required no modification of the optical set-up. Synthetic calcium imaging data showed that, compared to uncorrected endoscopes, eFOV-microendoscopes led to improved signal-to-noise ratio and more precise evaluation of correlated neuronal activity. We experimentally validated these predictions in awake head-fixed mice. Moreover, using eFOV-microendoscopes we demonstrated cell-specific encoding of behavioral state-dependent information in distributed functional subnetworks in a primary somatosensory thalamic nucleus. eFOV-microendoscopes are, therefore, small-cross-section ready-to-use tools for deep two-photon functional imaging with unprecedentedly high and homogeneous spatial resolution.


BME Frontiers ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-20
Author(s):  
Richard H. Roth ◽  
Jun B. Ding

Understanding how brain activity encodes information and controls behavior is a long-standing question in neuroscience. This complex problem requires converging efforts from neuroscience and engineering, including technological solutions to perform high-precision and large-scale recordings of neuronal activity in vivo as well as unbiased methods to reliably measure and quantify behavior. Thanks to advances in genetics, molecular biology, engineering, and neuroscience, in recent decades, a variety of optical imaging and electrophysiological approaches for recording neuronal activity in awake animals have been developed and widely applied in the field. Moreover, sophisticated computer vision and machine learning algorithms have been developed to analyze animal behavior. In this review, we provide an overview of the current state of technology for neuronal recordings with a focus on optical and electrophysiological methods in rodents. In addition, we discuss areas that future technological development will need to cover in order to further our understanding of the neural activity underlying behavior.


2009 ◽  
Vol 101 (3) ◽  
pp. 1671-1678 ◽  
Author(s):  
Jiangang Du ◽  
Ingmar H. Riedel-Kruse ◽  
Janna C. Nawroth ◽  
Michael L. Roukes ◽  
Gilles Laurent ◽  
...  

Microelectrode array recordings of neuronal activity present significant opportunities for studying the brain with single-cell and spike-time precision. However, challenges in device manufacturing constrain dense multisite recordings to two spatial dimensions, whereas access to the three-dimensional (3D) structure of many brain regions appears to remain a challenge. To overcome this limitation, we present two novel recording modalities of silicon-based devices aimed at establishing 3D functionality. First, we fabricated a dual-side electrode array by patterning recording sites on both the front and back of an implantable microstructure. We found that the majority of single-unit spikes could not be simultaneously detected from both sides, suggesting that in addition to providing higher spatial resolution measurements than that of single-side devices, dual-side arrays also lead to increased recording yield. Second, we obtained recordings along three principal directions with a multilayer array and demonstrated 3D spike source localization within the enclosed measurement space. The large-scale integration of such dual-side and multilayer arrays is expected to provide massively parallel recording capabilities in the brain.


Author(s):  
L. Alonso ◽  
J. Picos ◽  
J. Armesto

Abstract. Advances in remote sensing technologies are generating new perspectives concerning the role of and methods used for National Forestry Inventories (NFIs). The increase in computation capabilities over the last several decades and the development of new statistical techniques have allowed for the automation of forest resource map generation through image analysis techniques and machine learning algorithms. The availability of large-scale data and the high temporal resolution that satellite platforms provide mean that it is possible to obtain updated information about forest resources at the stand level, thus increasing the quality of the spatial information. However, photointerpretation of satellite and aerial images is still the most common way that remote sensing information is used for NFIs or forest management purposes. This study describes a methodology that automatically maps the main forest covers in Galicia (Eucalyptus spp., conifers and broadleaves) using Worldview-2 and the random forest classifier. Furthermore, the method also evaluates the separate mapping of the three most abundant Pinus tree species in Galicia (Pinus pinaster, Pinus radiata and Pinus sylvestris). According to the results, Worldview-2 multispectral images allow for the efficient differentiation between the main forest classes that are present in Galicia with a very high degree of accuracy (91%) and ample spatial detail. Pinus species can also be efficiently differentiated (83%).


2006 ◽  
Vol 95 (2) ◽  
pp. 1263-1273 ◽  
Author(s):  
Alexei L. Vyssotski ◽  
Andrei N. Serkov ◽  
Pavel M. Itskov ◽  
Giacomo Dell'Omo ◽  
Alexander V. Latanov ◽  
...  

To study the neurophysiology of large-scale spatial cognition, we analyzed the neuronal activity of navigating homing pigeons. This is not possible using conventional radio-telemetry suitable for short distances only. Therefore we developed a miniaturized data logger (“neurologger”) that can be carried by a homing pigeon on its back, in conjunction with a micro-global position system (GPS) logger recording the spatial position of the bird. In its present state, the neurologger permits recording from up to eight single-ended or differential electrodes in a walking or flying pigeon. Inputs from eight independent channels are preamplified, band-pass filtered, and directed to an eight-channel, 10-bit analog-digital converter of the microcontroller storing data on a “Multimedia” or “Secure Digital” card. For electroencephalography (EEG), the logger permits simultaneous recordings of up to eight channels during maximally 47 h, depending on memory, while single unit activity from two channels can be stored over 9 h. The logger permits single unit separation from recorded multiunit signals. The neurologger with GPS represents a better alternative to telemetry that will eventually permit to record neuronal activity during cognitive and innate behavior of many species moving freely in their habitats but will also permit automated high-throughput screening of EEG in the laboratory.


2016 ◽  
Vol 113 (23) ◽  
pp. 6556-6561 ◽  
Author(s):  
Teppei Matsui ◽  
Tomonari Murakami ◽  
Kenichi Ohki

Resting-state functional connectivity (FC), which measures the correlation of spontaneous hemodynamic signals (HemoS) between brain areas, is widely used to study brain networks noninvasively. It is commonly assumed that spatial patterns of HemoS-based FC (Hemo-FC) reflect large-scale dynamics of underlying neuronal activity. To date, studies of spontaneous neuronal activity cataloged heterogeneous types of events ranging from waves of activity spanning the entire neocortex to flash-like activations of a set of anatomically connected cortical areas. However, it remains unclear how these various types of large-scale dynamics are interrelated. More importantly, whether each type of large-scale dynamics contributes to Hemo-FC has not been explored. Here, we addressed these questions by simultaneously monitoring neuronal calcium signals (CaS) and HemoS in the entire neocortex of mice at high spatiotemporal resolution. We found a significant relationship between two seemingly different types of large-scale spontaneous neuronal activity—namely, global waves propagating across the neocortex and transient coactivations among cortical areas sharing high FC. Different sets of cortical areas, sharing high FC within each set, were coactivated at different timings of the propagating global waves, suggesting that spatial information of cortical network characterized by FC was embedded in the phase of the global waves. Furthermore, we confirmed that such transient coactivations in CaS were indeed converted into spatially similar coactivations in HemoS and were necessary to sustain the spatial structure of Hemo-FC. These results explain how global waves of spontaneous neuronal activity propagating across large-scale cortical network contribute to Hemo-FC in the resting state.


Coronaviruses ◽  
2020 ◽  
Vol 01 ◽  
Author(s):  
Yam Nath Paudel ◽  
Efthalia Angelopoulou ◽  
Bhupendra Raj Giri ◽  
Christina Piperi ◽  
Iekhsan Othman ◽  
...  

: COVID-19 has emerged as a devastating pandemic of the century that the current generations have ever experienced. The COVID-19 pandemic has infected more than 12 million people around the globe and 0.5 million people have succumbed to death. Due to the lack of effective vaccines against the COVID-19, several nations throughout the globe has imposed a lock-down as a preventive measure to lower the spread of COVID-19 infection. As a result of lock-down most of the universities and research institutes has witnessed a long pause in basic science research ever. Much has been talked about the long-term impact of COVID-19 in economy, tourism, public health, small and large-scale business of several kind. However, the long-term implication of these research lab shutdown and its impact in the basic science research has not been much focused. Herein, we provide a perspective that portrays a common problem of all the basic science researchers throughout the globe and its long-term consequences.


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