scholarly journals Effects of Acoustic Stimuli on Neuronal Activity in the Auditory Cortex of the Rat

2011 ◽  
pp. 687-693 ◽  
Author(s):  
Y. ZHANG ◽  
L. HAN ◽  
X. XIAO ◽  
B. HU ◽  
H. RUAN ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Auditory Cortex ◽  
Neuronal Activity ◽  
Cortical Neurons ◽  
Slow Wave Sleep ◽  
Sound Stimulus ◽  
Sound Stimulation ◽  
Acoustic Stimuli ◽  
Spontaneous Neuronal Activity

Spontaneous activity of cortical neurons exhibits alternative fluctuations of membrane potential consisting of phased depolarization called "up-state" and persistent hyperpolarization called "down-state" during slow wave sleep and anesthesia. Here, we examined the effects of sound stimuli (noise bursts) on neuronal activity by intracellular recording in vivo from the rat auditory cortex (AC). Noise bursts increased the average time in the up-state by 0.81±0.65 s (range, 0.27-1.74 s) related to a 10 s recording duration. The rise times of the spontaneous up-events averaged 69.41±18.04 ms (range, 40.10-119.21 ms), while those of the sound-evoked up-events were significantly shorter (p<0.001) averaging only 22.54±8.81 ms (range, 9.31-45.74 ms). Sound stimulation did not influence ongoing spontaneous up-events. Our data suggest that a sound stimulus does not interfere with ongoing spontaneous neuronal activity in auditory cortex but can evoke new depolarizations in addition to the spontaneous ones.

Neural interaction in cat primary auditory cortex II. Effects of sound stimulation

1994 ◽  
Vol 71 (1) ◽  
pp. 246-270 ◽  
Author(s):  
J. J. Eggermont
Keyword(s):  
Auditory Cortex ◽  
Cortical Neurons ◽  
Relative Size ◽  
Primary Auditory Cortex ◽  
Mean Value ◽  
Neural Synchrony ◽  
Sound Stimulation ◽  
Common Input ◽  
Neural Correlation ◽  
The Mean

1. The effect of auditory stimulation with click trains, noise bursts, amplitude-modulated noise bursts, and amplitude-modulated tone bursts on the correlation of firing of 1,290 neuron pairs recorded on one or two electrodes in primary auditory cortex of the cat was investigated. A distinction was made between neural synchrony (the correlation under stimulus conditions) and neural correlation (the correlation under spontaneous or under stimulus conditions after correction for stimulus-related correlations). For neural correlation 63% of the single-electrode pairs showed a unilateral excitation component, often combined with a common-input peak, and only 11% of the dual electrode pairs showed this unilateral excitation. 2. Under poststimulus conditions the incidence of correlograms with clear peaks was high for single-electrode pairs (80–90% range) and somewhat lower for dual-electrode pairs (50–60% range). The strength of the neural correlation for poststimulus conditions, from 0.5 to 2 s after a 1-s stimulus, was comparable with that obtained for 15-min continuous silence, suggesting that aftereffects of stimulation had largely disappeared after 0.5 s. A stationary analysis of the correlation coefficient corroborated this. 3. Two stimulus-correction procedures, one based on the shift predictor and the other based on the joint peristimulus-time histogram (JPSTH) were compared. The mean value of the neural correlation under stimulus conditions obtained after applying the poststimulus time (PST) predictor was on average 20% larger than the mean value obtained after application of the shift predictor; however, this was not significantly different at the 0.05 level. There were no differences in the shape of the correlograms. This suggests that the less time-consuming shift predictor-based stimulus-correction procedure can be used for cortical neurons. 4. Under stimulus conditions neural correlation coefficients could be < or = 50% smaller than for spontaneous conditions. The strength of the stimulus-corrected neural correlation was inversely related to the relative size of the stimulus predictor (compared with the neural synchrony) and thus to the effectiveness of stimulation. This suggests that the assumption of additivity of stimulus and connectivity effects on neural synchrony is generally violated both for shift predictor and PST predictor procedures. 5. The neural correlogram peaks were narrower for single-electrode pairs than for dual-electrode pairs both under stimulus and spontaneous conditions. Under stimulus conditions the peaks were generally narrower than under spontaneous firing conditions.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Calculating Event-Triggered Average Synaptic Conductances From the Membrane Potential

2007 ◽  
Vol 97 (3) ◽  
pp. 2544-2552 ◽  
Author(s):  
Martin Pospischil ◽  
Zuzanna Piwkowska ◽  
Michelle Rudolph ◽  
Thierry Bal ◽  
Alain Destexhe
Keyword(s):  
Membrane Potential ◽  
Cortical Neurons ◽  
Time Course ◽  
Spike Generation ◽  
Nonlinear Contribution ◽  
Central Neurons ◽  
Time Courses ◽  
Model Subject ◽  
Synaptic Conductances

The optimal patterns of synaptic conductances for spike generation in central neurons is a subject of considerable interest. Ideally such conductance time courses should be extracted from membrane potential ( Vm) activity, but this is difficult because the nonlinear contribution of conductances to the Vm renders their estimation from the membrane equation extremely sensitive. We outline here a solution to this problem based on a discretization of the time axis. This procedure can extract the time course of excitatory and inhibitory conductances solely from the analysis of Vm activity. We test this method by calculating spike-triggered averages of synaptic conductances using numerical simulations of the integrate-and-fire model subject to colored conductance noise. The procedure was also tested successfully in biological cortical neurons using conductance noise injected with dynamic clamp. This method should allow the extraction of synaptic conductances from Vm recordings in vivo.

Characteristic Membrane Potential Trajectories in Primate Sensorimotor Cortex Neurons Recorded In Vivo

2005 ◽  
Vol 94 (4) ◽  
pp. 2713-2725 ◽  
Author(s):  
Daofen Chen ◽  
Eberhard E. Fetz
Keyword(s):  
Membrane Potential ◽  
Sensorimotor Cortex ◽  
High Frequency ◽  
Cortical Neurons ◽  
Type I ◽  
Type Ii ◽  
Interspike Intervals ◽  
Cortical Oscillations ◽  
Firing Properties

We examined the membrane potentials and firing properties of motor cortical neurons recorded intracellularly in awake, behaving primates. Three classes of neuron were distinguished by 1) the width of their spikes, 2) the shape of the afterhyperpolarization (AHP), and 3) the distribution of interspike intervals. Type I neurons had wide spikes, exhibited scoop-shaped AHPs, and fired irregularly. Type II neurons had narrower spikes, showed brief postspike afterdepolarizations before the AHP, and sometimes fired high-frequency doublets. Type III neurons had the narrowest spikes, showed a distinct post-AHP depolarization, or “rebound AHP” (rAHP), lasting nearly 30 ms, and tended to fire at 25–35 Hz. The evidence suggests that an intrinsic rAHP may confer on these neurons a tendency to fire at a preferred frequency governed by the duration of the rAHP and may contribute to a “pacemaking” role in generating cortical oscillations.

scholarly journals Network activity influences the subthreshold and spiking visual responses of pyramidal neurons in a three-layer cortex

2016 ◽  
Author(s):  
Nathaniel C. Wright ◽  
Ralf Wessel
Keyword(s):  
Membrane Potential ◽  
Cortical Neurons ◽  
Visual Stimulation ◽  
Ex Vivo ◽  
Network Activity ◽  
Visual Responses ◽  
Cortical Function ◽  
Sensory Evoked ◽  
High Conductance

A primary goal of systems neuroscience is to understand cortical function, which typically involves studying spontaneous and sensory-evoked cortical activity. Mounting evidence suggests a strong and complex relationship between the ongoing and evoked state. To date, most work in this area has been based on spiking in populations of neurons. While advantageous in many respects, this approach is limited in scope; it records the activities of a minority of neurons, and gives no direct indication of the underlying subthreshold dynamics. Membrane potential recordings can fill these gaps in our understanding, but are difficult to obtain in vivo. Here, we record subthreshold cortical visual responses in the ex vivo turtle eye-attached whole-brain preparation, which is ideally-suited to such a study. In the absence of visual stimulation, the network is “synchronous”; neurons display network-mediated transitions between low- and high-conductance membrane potential states. The prevalence of these slow-wave transitions varies across turtles and recording sessions. Visual stimulation evokes similar high-conductance states, which are on average larger and less reliable when the ongoing state is more synchronous. Responses are muted when immediately preceded by large, spontaneous high-conductance events. Evoked spiking is sparse, highly variable across trials, and mediated by concerted synaptic inputs that are in general only very weakly correlated with inputs to nearby neurons. Together, these results highlight the multiplexed influence of the cortical network on the spontaneous and sensory-evoked activity of individual cortical neurons.

scholarly journals Long-Lasting Context Dependence Constrains Neural Encoding Models in Rodent Auditory Cortex

2009 ◽  
Vol 102 (5) ◽  
pp. 2638-2656 ◽  
Author(s):  
Hiroki Asari ◽  
Anthony M. Zador
Keyword(s):  
Auditory Cortex ◽  
Auditory Processing ◽  
Cortical Neurons ◽  
Stream Segregation ◽  
Context Dependence ◽  
Neural Encoding ◽  
Response Component ◽  
Presynaptic Mechanisms ◽  
Acoustic Processing

Acoustic processing requires integration over time. We have used in vivo intracellular recording to measure neuronal integration times in anesthetized rats. Using natural sounds and other stimuli, we found that synaptic inputs to auditory cortical neurons showed a rather long context dependence, up to ≥4 s (τ ∼ 1 s), even though sound-evoked excitatory and inhibitory conductances per se rarely lasted ≳100 ms. Thalamic neurons showed only a much faster form of adaptation with a decay constant τ <100 ms, indicating that the long-lasting form originated from presynaptic mechanisms in the cortex, such as synaptic depression. Restricting knowledge of the stimulus history to only a few hundred milliseconds reduced the predictable response component to about half that of the optimal infinite-history model. Our results demonstrate the importance of long-range temporal effects in auditory cortex and suggest a potential neural substrate for auditory processing that requires integration over timescales of seconds or longer, such as stream segregation.

scholarly journals Wide-field imaging of cortical neuronal activity with red-shifted functional indicators during motor task execution

2018 ◽  
Author(s):  
Elena Montagni ◽  
Francesco Resta ◽  
Emilia Conti ◽  
Alessandro Scaglione ◽  
Maria Pasquini ◽  
...  
Keyword(s):  
Neuronal Activity ◽  
Cortical Neurons ◽  
Fluorescent Protein ◽  
Fluorescent Microscopy ◽  
Motor Task ◽  
Free Calcium ◽  
Wide Field ◽  
Task Execution ◽  
Additional Advantage

AbstractIntracellular concentration of free calcium ions in neuronal populations can be longitudinally evaluated by using fluorescent protein indicators, called genetically encoded calcium indicators (GECIs). GECIs with long emission wavelengths are particularly attractive for deep tissue microscopy in vivo, and have the additional advantage of avoiding spectral overlap with commonly used neuronal actuators like Channelrhodopsin.Here we investigated the performances of selected red-shifted GECIs through an ex vivo characterization and in vivo imaging of cortical mouse activity during motor task execution. Cortical neurons were infected with adeno-associated virus (AAV) expressing one of the red GECI variants (jRCaMP1a, jRCaMP1b, jRGECO1a, jRGECO1b). First we characterized the transfection in terms of extension and intensity using wide-field fluorescence microscopy. Next, we used RCaMP1a to analyse the cortical neuronal activity during motor behaviour. To that end, wide-field fluorescent microscopy and a robotic device for motor control were combined for simultaneous recording of cortical neuronal-activity, force applied and forelimb position during task execution.Our results show that jRCaMP1a has sufficient sensitivity to monitor in vivo neuronal activity over multiple functional areas, and can be successfully used to perform longitudinal imaging in awake mice.

scholarly journals Corticothalamic gating of population auditory thalamocortical transmission in mouse

2019 ◽  
Author(s):  
Baher A. Ibrahim ◽  
Caitlin Murphy ◽  
Guido Muscioni ◽  
Aynaz Taheri ◽  
Georgiy Yudintsev ◽  
...  
Keyword(s):  
Receptive Field ◽  
Auditory Cortex ◽  
Cortical Neurons ◽  
Feedback Inhibition ◽  
Thalamic Reticular Nucleus ◽  
Reticular Nucleus ◽  
Linear Filter ◽  
Sensory Stimuli

AbstractSince the discovery of the receptive field, scientists have tracked receptive field structure to gain insights about mechanisms of sensory processing. At the level of the thalamus and cortex, this linear filter approach has been challenged by findings that populations of cortical neurons respond in a stereotyped fashion to sensory stimuli. Here, we elucidate a possible mechanism by which gating of cortical representations occurs. All-or-none population responses (here called “ON” and “OFF” responses) were observed in vivo and in vitro in the mouse auditory cortex at near-threshold acoustic or electrical stimulation. ON-responses were associated with previously-described UP states in the auditory cortex. OFF-responses in the cortex were only eliminated by blocking GABAergic inhibition in the thalamus. Opto- and chemogenetic silencing of NTSR-positive corticothalamic layer 6 (CTL6) neurons as well as the pharmacological blocking of the thalamic reticular nucleus (TRN) retrieved the missing cortical responses, suggesting that the corticothalamic feedback inhibition via TRN controls the gating of thalamocortical activity. Moreover, the oscillation of the pre-stimulus activity of corticothalamic cells predicted the cortical ON vs. OFF responses, suggesting that underlying cortical oscillation controls thalamocortical gating. These data suggest that the thalamus may recruit cortical ensembles rather than linearly encoding ascending stimuli and that corticothalamic projections play a key role in selecting cortical ensembles for activation.

Pharmacological and Model-based Interpretation of Neuronal Dynamics Transitions during Sleep-Waking Cycle

1994 ◽  
Vol 33 (01) ◽  
pp. 125-128 ◽  
Author(s):  
M. Nakao ◽  
Y. Mizutani ◽  
T. Takahashi ◽  
K. Watanabe ◽  
H. Arai ◽  
...  
Keyword(s):  
Neuronal Activity ◽  
Slow Wave Sleep ◽  
Low Frequency ◽  
Power Spectral Analysis ◽  
Neuronal Dynamics ◽  
Brain Functions ◽  
Limbic Systems ◽  
Power Spectral ◽  
Spontaneous Activities ◽  
Spontaneous Neuronal Activity

Abstract:Power spectral analysis has been applied to spontaneous single neuronal activities during the sleep-waking cycle in various regions of the cat’s central nervous system. During slow-wave sleep (SWS), the spontaneous activities of many neurons had a white noise-like power-spectral density profile in a very low frequency range (0.01-1.0 Hz) whereas, during rapid-eye-movement sleep (REMS), they showed a 1/f-like spectral pattern. This spectral transition between SWS and REMS was hypothesized to depend on the influence of serotonergic and cholinergic neuronal activity which is considered to modulate various brain functions. According to both pharmacological experiments and simulation studies with a neural network model, it was concluded that the serotonergic system may have a function to eliminate slow fluctuations in neuronal activity in wide areas, from the reticulothalamo-neocortical to the limbic systems. Consequently, simple signal processing of spontaneous neuronal activity has elucidated an important neurophysiological fact, which may lead to a principle of the basic brain function and its mechanism.

scholarly journals Impaired State-Dependent Potentiation of GABAergic Synaptic Currents Triggers Seizures in a Genetic Generalized Epilepsy Model

2020 ◽  
Author(s):  
Chun-Qing Zhang ◽  
Mackenzie A Catron ◽  
Li Ding ◽  
Caitlyn M Hanna ◽  
Martin J Gallagher ◽  
...  
Keyword(s):  
Slow Wave ◽  
Cortical Neurons ◽  
Slow Wave Sleep ◽  
Brain Slices ◽  
Epileptic Activity ◽  
Epilepsy Syndrome ◽  
Synaptic Currents ◽  
State Dependent ◽  
Generalized Epilepsy

Abstract Epileptic activity in genetic generalized epilepsy (GGE) patients preferentially appears during sleep and its mechanism remains unknown. Here, we found that sleep-like slow-wave oscillations (0.5 Hz SWOs) potentiated excitatory and inhibitory synaptic currents in layer V cortical pyramidal neurons from wild-type (wt) mouse brain slices. In contrast, SWOs potentiated excitatory, but not inhibitory, currents in cortical neurons from a heterozygous (het) knock-in (KI) Gabrg2+Q/390X model of Dravet epilepsy syndrome. This created an imbalance between evoked excitatory and inhibitory currents to effectively prompt neuronal action potential firings. Similarly, physiologically similar up-/down-state induction (present during slow-wave sleep) in cortical neurons also potentiated excitatory synaptic currents within brain slices from wt and het KI mice. Moreover, this state-dependent potentiation of excitatory synaptic currents entailed some signaling pathways of homeostatic synaptic plasticity. Consequently, in het KI mice, in vivo SWO induction (using optogenetic methods) triggered generalized epileptic spike-wave discharges (SWDs), being accompanied by sudden immobility, facial myoclonus, and vibrissa twitching. In contrast, in wt littermates, SWO induction did not cause epileptic SWDs and motor behaviors. To our knowledge, this is the first mechanism to explain why epileptic SWDs preferentially happen during non rapid eye-movement sleep and quiet-wakefulness in human GGE patients.

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