scholarly journals Laminar Population Analysis: Estimating Firing Rates and Evoked Synaptic Activity From Multielectrode Recordings in Rat Barrel Cortex

2007 ◽  
Vol 97 (3) ◽  
pp. 2174-2190 ◽  
Author(s):  
Gaute T. Einevoll ◽  
Klas H. Pettersen ◽  
Anna Devor ◽  
Istvan Ulbert ◽  
Eric Halgren ◽  
...  
Keyword(s):  
Frequency Band ◽  
Barrel Cortex ◽  
Population Analysis ◽  
Current Source ◽  
Field Potential ◽  
Synaptic Activity ◽  
Data Sets ◽  
Synaptic Connections ◽  
Firing Activity ◽  
Forward Solution

We present a new method, laminar population analysis (LPA), for analysis of laminar-electrode (linear multielectrode) data, where physiological constraints are explicitly incorporated in the mathematical model: the high-frequency band [multiunit activity (MUA)] is modeled as a sum over contributions from firing activity of multiple cortical populations, whereas the low-frequency band [local field potential (LFP)] is assumed to reflect the dendritic currents caused by synaptic inputs evoked by this firing. The method is applied to stimulus-averaged laminar-electrode data from barrel cortex of anesthetized rat after single whisker flicks. Two sample data sets, distinguished by stimulus paradigm, type of applied anesthesia, and electrical boundary conditions, are studied in detail. These data sets are well accounted for by a model with four cortical populations: one supragranular, one granular, and two infragranular populations. Population current source densities (CSDs; the CSD signatures after firing in a particular population) provided by LPA are further used to estimate the synaptic connection pattern between the various populations using a new LFP template-fitting technique, where LFP population templates are found by the electrostatic forward solution based on results from compartmental modeling of morphologically reconstructed neurons. Our analysis confirms previous experimental findings regarding the synaptic connections from neurons in the granular layer onto neurons in the supragranular layers and provides predictions about other synaptic connections. Furthermore, the time dependence of the stimulus-evoked population firing activity is predicted, and the temporal ordering of response onset is found to be compatible with earlier findings.

scholarly journals Stereotyped large amplitude cortical LFP events can be clustered and reveal precisely ordered phase-locking in neuronal populations

2019 ◽  
Author(s):  
Catalin C. Mitelut ◽  
Martin A. Spacek ◽  
Allen W. Chan ◽  
Tim H. Murphy ◽  
Nicholas V. Swindale
Keyword(s):  
Visual Cortex ◽  
Barrel Cortex ◽  
Slow Wave Sleep ◽  
Current Source ◽  
Field Potential ◽  
State Transitions ◽  
Stimulus Processing ◽  
Cortical Areas ◽  
Up States ◽  
Firing Order

AbstractDuring quiet wakefulness, slow-wave sleep and anesthesia, mammalian cortex exhibits a synchronised state during which transient changes in the local field potential (LFP) accompany periods of increased single neuron firing, known as UP-states. While UP-state genesis is still debated (Crunelli and Hughes, 2010) such transitions may constitute the default activity pattern of the entire cortex (Neske, 2016). Recent findings of preserved firing order between UP-state transitions and stimulus processing in high-firing rate (>2Hz) rat auditory and barrel cortex neurons (Luczak et al., 2015) support this hypothesis. Yet it is unknown whether UP-states are homogeneous and whether neurons with firing rates <2Hz in visual cortex or other species exhibit spiking order. Using extracellular recordings during anesthetized states in cat visual cortex and mouse visual, auditory and barrel cortex, we show that UP-states can be tracked and clustered based on the shape of the LFP waveform. We show that LFP event clusters (LECs) have current-source-density profiles that are common across different recordings or animals and using simultaneous electrophysiology and widefield voltage and calcium imaging in mouse we confirm that LEC transitions are cortex-wide phenomena. Individual LEC events can be resolved in time to within 1 – 4 ms and they elicit synchronous firing of over 75% of recorded neurons with most neurons synchronizing their firing to within ±5 – 15 ms relative LECs. Firing order of different neurons during LEC events was preserved over periods of ~30 minutes enabling future studies of UP-state transitions and firing order with near millisecond precision.Significant StatementDuring sleep and anesthetic states mammalian cortex undergoes substantial changes from awake active states. Recent studies show that single neurons in some cortical areas in rats undergo increased spiking during sleep and anesthetic states (called UP-state transitions) with some neurons firing in an order similar to awake states. This suggests that sensory processing may be similar across all states and that firing order is important for stimulus processing. Yet UP-state transitions remain poorly understood and it is unclear whether firing order is present in other cortical areas or species. Here we describe multiple classes of UP-state transitions and show most neurons in visual cortex in cats and visual, barrel and auditory cortex in mice exhibit firing order during such transitions.

scholarly journals Comprehensive mapping of whisker-evoked responses reveals broad, sharply tuned thalamocortical input to layer 4 of barrel cortex

2011 ◽  
Vol 105 (5) ◽  
pp. 2421-2437 ◽  
Author(s):  
Noah C. Roy ◽  
Thomas Bessaih ◽  
Diego Contreras
Keyword(s):  
Cortical Neurons ◽  
Barrel Cortex ◽  
Current Source ◽  
Field Potential ◽  
Fundamental Information ◽  
Layer 4 ◽  
Density Analysis ◽  
Evoked Activity ◽  
Rats And Mice

Cortical neurons are organized in columns, distinguishable by their physiological properties and input-output organization. Columns are thought to be the fundamental information-processing modules of the cortex. The barrel cortex of rats and mice is an attractive model system for the study of cortical columns, because each column is defined by a layer 4 (L4) structure called a barrel, which can be clearly visualized. A great deal of information has been collected regarding the connectivity of neurons in barrel cortex, but the nature of the input to a given L4 barrel remains unclear. We measured this input by making comprehensive maps of whisker-evoked activity in L4 of rat barrel cortex using recordings of multiunit activity and current source density analysis of local field potential recordings of animals under light isoflurane anesthesia. We found that a large number of whiskers evoked a detectable response in each barrel (mean of 13 suprathreshold, 18 subthreshold) even after cortical activity was abolished by application of muscimol, a GABAA agonist. We confirmed these findings with intracellular recordings and single-unit extracellular recordings in vivo. This constitutes the first direct confirmation of the hypothesis that subcortical mechanisms mediate a substantial multiwhisker input to a given cortical barrel.

scholarly journals Psychosocial Crowding Stress-Induced Changes in Synaptic Transmission and Glutamate Receptor Expression in the Rat Frontal Cortex

Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 294
Author(s):  
Agnieszka Zelek-Molik ◽  
Bartosz Bobula ◽  
Anna Gądek-Michalska ◽  
Katarzyna Chorązka ◽  
Adam Bielawski ◽  
...  
Keyword(s):  
Frontal Cortex ◽  
Primary Motor Cortex ◽  
Interleukin 1 ◽  
Field Potential ◽  
Long Term Potentiation ◽  
Plasma Corticosterone ◽  
Receptor Expression ◽  
Synaptic Activity ◽  
Common Mechanism ◽  
Crowding Stress

This study demonstrates how exposure to psychosocial crowding stress (CS) for 3, 7, and 14 days affects glutamate synapse functioning and signal transduction in the frontal cortex (FC) of rats. CS effects on synaptic activity were evaluated in FC slices of the primary motor cortex (M1) by measuring field potential (FP) amplitude, paired-pulse ratio (PPR), and long-term potentiation (LTP). Protein expression of GluA1, GluN2B mGluR1a/5, VGLUT1, and VGLUT2 was assessed in FC by western blot. The body’s response to CS was evaluated by measuring body weight and the plasma level of plasma corticosterone (CORT), adrenocorticotropic hormone (ACTH), and interleukin 1 beta (IL1B). CS 3 14d increased FP and attenuated LTP in M1, while PPR was augmented in CS 14d. The expression of GluA1, GluN2B, and mGluR1a/5 was up-regulated in CS 3d and downregulated in CS 14d. VGLUTs expression tended to increase in CS 7d. The failure to blunt the effects of chronic CS on FP and LTP in M1 suggests the impairment of habituation mechanisms by psychosocial stressors. PPR augmented by chronic CS with increased VGLUTs level in the CS 7d indicates that prolonged CS exposure changed presynaptic signaling within the FC. The CS bidirectional profile of changes in glutamate receptors’ expression seems to be a common mechanism evoked by stress in the FC.

Reverse Optical Trawling for Synaptic Connections In Situ

2009 ◽  
Vol 102 (1) ◽  
pp. 636-643 ◽  
Author(s):  
Takuya Sasaki ◽  
Genki Minamisawa ◽  
Naoya Takahashi ◽  
Norio Matsuki ◽  
Yuji Ikegaya
Keyword(s):  
Network Connectivity ◽  
Synaptic Activity ◽  
Calcium Transients ◽  
Synaptic Connections ◽  
False Positive Error ◽  
Presynaptic Neuron ◽  
Promising Tool ◽  
On Line ◽  
False Positive Error Rate ◽  
Presynaptic Neurons

We introduce a new method to unveil the network connectivity among dozens of neurons in brain slice preparations. While synaptic inputs were whole cell recorded from given postsynaptic neurons, the spatiotemporal firing patterns of presynaptic neuron candidates were monitored en masse with functional multineuron calcium imaging, an optical technique that records action potential–evoked somatic calcium transients with single-cell resolution. By statistically screening the neurons that exhibited calcium transients immediately before the postsynaptic inputs, we identified the presynaptic cells that made synaptic connections onto the patch-clamped neurons. To enhance the detection power, we devised the following points: 1) [K+]e was lowered and [Ca2+]e and [Mg2+]e were elevated, to reduce background synaptic activity and minimize the failure rate of synaptic transmission; and 2) a small fraction of presynaptic neurons was specifically activated by glutamate applied iontophoretically through a glass pipette that was moved to survey the presynaptic network of interest (“trawling”). Then we could theoretically detect 96% of presynaptic neurons activated in the imaged regions with a 1% false-positive error rate. This on-line probing technique would be a promising tool in the study of the wiring topography of neuronal circuits.

scholarly journals on and off Channels of the Frog Optic Tectum Revealed by Current Source Density Analysis

1998 ◽  
Vol 80 (4) ◽  
pp. 1886-1899 ◽  
Author(s):  
Hideki Nakagawa ◽  
Nobuyoshi Matsumoto
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Current Source ◽  
Current Source Density ◽  
Synaptic Activity ◽  
Diffuse Light ◽  
Retinal Ganglion ◽  
Source Density ◽  
Current Source Density Analysis ◽  
Density Analysis

Nakagawa, Hideki and Nobuyoshi Matsumoto. on and off channels of the frog optic tectum revealed by current source density analysis. J. Neurophysiol. 80: 1886–1899, 1998. The spatiotemporal patterns of excitatory synaptic activity in response to diffuse light on and off stimuli were examined by means of current source density (CSD) analysis. The qualitative and quantitative analyses obtained from 24 depth profiles for each stimulus revealed obviously different distributions of synaptic activity in the laminar structure. Two or three dominant current sinks I, II, and III were evoked in response to diffuse light on stimulation. Sink I was observed at the bottom of the retinorecipient layer. Both sinks II and III, showing an identical spatial pattern, were observed just above sink I. On the other hand, diffuse light off stimulation elicited up to six current sinks IV, V, VI, VII, VIII, and IX. Sink IV was observed at the bottom of the retinorecipient layer. Sink V was observed in the most superficial layer. Both sinks VI and VIII were located between the two preceding sinks. Finally, sinks VII and IX occurred below the retinorecipient layer. Five electrically evoked current sinks A, B, C, D, and E, characterized in our previous study, were also recognized in the present quantitative analysis. A statistical analysis revealed that, in visually evoked responses, statistical differences in the spatial distribution were not present between sinks I and IV, and sinks II and VIII ( P < 0.05). The analysis also showed that, in electrically evoked responses, only a pair of sinks C and E exhibit virtually identical spatial distribution ( P < 0.05). Based on well-known properties of the retinal ganglion cells, possible neuronal mechanisms underlying each of current sinks in the on and off channels and their functional meanings were considered. Sink I reflects the excitatory monosynaptic activity derived from R3 retinal ganglion cells. Sink IV reflects the excitatory monosynaptic activity derived from both R3 and R4 cells. Sinks V, VI, VII, and IX may be composed of successive polysynaptic excitatory potentials derived from convergence of inputs from both R3 and R4 cells. We concluded that the early four sinks play in particular an important role in eliciting avoidance behavior. On the other hand, sinks II, III, and VIII reflect excitatory synaptic activities derived from on-off retinal fibers of another type having slow conduction velocity. These late current sinks were suggested to mediate prey catching and its facilitation.

scholarly journals Multi-objective Informative Frequency Band Selection Based on Negentropy-induced Grey Wolf Optimizer for Fault Diagnosis of Rolling Element Bearings

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 1845 ◽  
Author(s):  
Xiaohui Gu ◽  
Shaopu Yang ◽  
Yongqiang Liu ◽  
Rujiang Hao ◽  
Zechao Liu
Keyword(s):  
Frequency Band ◽  
Background Noise ◽  
Grey Wolf Optimizer ◽  
Data Sets ◽  
Rolling Element Bearings ◽  
Grey Wolf ◽  
Objective Functions ◽  
Multi Objective ◽  
Rolling Element ◽  
Envelope Spectrum

Informative frequency band (IFB) selection is a challenging task in envelope analysis for the localized fault detection of rolling element bearings. In previous studies, it was often conducted with a single indicator, such as kurtosis, etc., to guide the automatic selection. However, in some cases, it is difficult for that to fully depict and balance the fault characters from impulsiveness and cyclostationarity of the repetitive transients. To solve this problem, a novel negentropy-induced multi-objective optimized wavelet filter is proposed in this paper. The wavelet parameters are determined by a grey wolf optimizer with two independent objective functions i.e., maximizing the negentropy of squared envelope and squared envelope spectrum to capture impulsiveness and cyclostationarity, respectively. Subsequently, the average negentropy is utilized in identifying the IFB from the obtained Pareto set, which are non-dominated by other solutions to balance the impulsive and cyclostationary features and eliminate the background noise. Two cases of real vibration signals with slight bearing faults are applied in order to evaluate the performance of the proposed methodology, and the results demonstrate its effectiveness over some fast and optimal filtering methods. In addition, its stability in tracking the IFB is also tested by a case of condition monitoring data sets.

The dendritic origins of penicillin-induced epileptogenesis in CA3 hippocampal pyramidal cells

1986 ◽  
Vol 56 (6) ◽  
pp. 1718-1738 ◽  
Author(s):  
J. W. Swann ◽  
R. J. Brady ◽  
R. J. Friedman ◽  
E. J. Smith
Keyword(s):  
Cell Body ◽  
Average Distance ◽  
Hippocampal Slices ◽  
Current Source ◽  
Field Potential ◽  
Pyramidal Cells ◽  
Large Current ◽  
Hippocampal Ca3 ◽  
Ca3 Pyramidal Cells ◽  
Negative Field

Experiments were performed in order to identify the sites of epileptiform burst generation in rat hippocampal CA3 pyramidal cells. A subsequent slow field potential was studied, which is associated with afterdischarge generation. Laminar field potential and current source-density (CSD) methods were employed in hippocampal slices exposed to penicillin. Simultaneous intracellular and extracellular field recordings from the CA3 pyramidal cell body layer showed that whenever an epileptiform burst was recorded extracellularly, individual CA3 neurons underwent an intense depolarization shift. In extracellular records a slow negative field potential invariably followed epileptiform burst generation. In approximately 10% of slices, synchronous afterdischarges rode on the envelope of this negative field potential. Intracellularly a depolarizing afterpotential followed the depolarization shift and was coincident with the extracellular slow negative field potential. A one-dimensional CSD analysis performed perpendicular to the CA3 cell body layer showed that during epileptiform burst generation large current sinks occur simultaneously in the central portions of both the apical and basilar dendrites. The average distance of the peak amplitude for these sinks from the center of the cell body layer was 175 +/- 46.8 microns and 158 +/- 25.0 microns, respectively. A large current source was recorded in the cell body layer. Smaller current sources were observed in the distal portions of the dendritic layers. During the postburst slow field potential a current sink was recorded at the edge of the cell body layer in stratum oriens--a region referred to as the infrapyramidal zone. Simultaneous with the current sink recorded there, smaller sinks were often observed in the dendritic layers that appeared to be "tails" or prolongations of the currents underlying burst generation. Two-dimensional analyses of these field potentials were performed on planes parallel and perpendicular to the exposed surface of the slice. Isopotential contours showed that the direction of extracellular current is mainly orthogonal to the CA3 laminae. Correction of CSD estimates made perpendicular to the cell body layer for current flowing in the other direction did not alter the location of computed current sources and sinks. In order to show that the dendritic currents associated with epileptiform burst generation were active sinks, tetrodotoxin (TTX) was applied locally to the dendrites where the current sinks were recorded.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Long Duration Stimuli and Nonlinearities in the Neural–Haemodynamic Coupling

2005 ◽  
Vol 25 (5) ◽  
pp. 651-661 ◽  
Author(s):  
John Martindale ◽  
Jason Berwick ◽  
Chris Martin ◽  
Yazhuo Kong ◽  
Ying Zheng ◽  
...  
Keyword(s):  
Blood Flow ◽  
Impulse Response ◽  
Neural Activity ◽  
Barrel Cortex ◽  
Current Source ◽  
Impulse Response Function ◽  
Good Prediction ◽  
Doppler Flowmetry ◽  
Linear Convolution ◽  
Convolution Model

Recent studies have shown that the haemodynamic responses to brief (<2 secs) stimuli can be well characterised as a linear convolution of neural activity with a suitable haemodynamic impulse response. In this paper, we show that the linear convolution model cannot predict measurements of blood flow responses to stimuli of longer duration (>2 secs), regardless of the impulse response function chosen. Modifying the linear convolution scheme to a nonlinear convolution scheme was found to provide a good prediction of the observed data. Whereas several studies have found a nonlinear coupling between stimulus input and blood flow responses, the current modelling scheme uses neural activity as an input, and thus implies nonlinearity in the coupling between neural activity and blood flow responses. Neural activity was assessed by current source density analysis of depth-resolved evoked field potentials, while blood flow responses were measured using laser Doppler flowmetry. All measurements were made in rat whisker barrel cortex after electrical stimulation of the whisker pad for 1 to 16 secs at 5 Hz and 1.2 mA (individual pulse width 0.3 ms).

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