scholarly journals Action Potential Timing Precision in Dorsal Cochlear Nucleus Pyramidal Cells

2007 ◽  
Vol 97 (6) ◽  
pp. 4162-4172 ◽  
Author(s):  
Sarah E. Street ◽  
Paul B. Manis
Keyword(s):  
Firing Rate ◽  
Cochlear Nucleus ◽  
Pyramidal Neurons ◽  
Pyramidal Cells ◽  
Spike Trains ◽  
Spike Timing ◽  
Dorsal Cochlear Nucleus ◽  
Information Encoding ◽  
Temporal Precision ◽  
Noise Current

Many studies of the dorsal cochlear nucleus (DCN) have focused on the representation of acoustic stimuli in terms of average firing rate. However, recent studies have emphasized the role of spike timing in information encoding. We sought to ascertain whether DCN pyramidal cells might employ similar strategies and to what extent intrinsic excitability regulates spike timing. Gaussian distributed low-pass noise current was injected into pyramidal cells in a brain slice preparation. The shuffled autocorrelation-based analysis was used to compute a correlation index of spike times across trials. The noise causes the cells to fire with temporal precision (SD ≅ 1–2 ms) and high reproducibility. Increasing the coefficient of variation of the noise improved the reproducibility of the spike trains, whereas increasing the firing rate of the neuron decreased the neurons' ability to respond with predictable patterns of spikes. Simulated inhibitory postsynaptic potentials superimposed on the noise stimulus enhanced spike timing for >300 ms, although the enhancement was greatest during the first 100 ms. We also found that populations of pyramidal neurons respond to the same noise stimuli with correlated spike trains, suggesting that ensembles of neurons in the DCN receiving shared input can fire with similar timing. These results support the hypothesis that spike timing can be an important aspect of information coding in the DCN.

scholarly journals Self-tuning of inhibition by endocannabinoids shapes spike-time precision in CA1 pyramidal neurons

2013 ◽  
Vol 110 (8) ◽  
pp. 1930-1944 ◽  
Author(s):  
Franck Dubruc ◽  
David Dupret ◽  
Olivier Caillard
Keyword(s):  
Pyramidal Neurons ◽  
Pyramidal Cells ◽  
Memory Formation ◽  
Spike Timing ◽  
Excitatory Postsynaptic Potential ◽  
Spike Time ◽  
Transient Improvement ◽  
Self Tuning ◽  
Feedforward Inhibition

In the hippocampus, activity-dependent changes of synaptic transmission and spike-timing coordination are thought to mediate information processing for the purpose of memory formation. Here, we investigated the self-tuning of intrinsic excitability and spiking reliability by CA1 hippocampal pyramidal cells via changes of their GABAergic inhibitory inputs and endocannabinoid (eCB) signaling. Firing patterns of CA1 place cells, when replayed in vitro, induced an eCB-dependent transient reduction of spontaneous GABAergic activity, sharing the main features of depolarization-induced suppression of inhibition (DSI), and conditioned a transient improvement of spike-time precision during consecutive burst discharges. When evaluating the consequences of DSI on excitatory postsynaptic potential (EPSP)-spike coupling, we found that transient reductions of uncorrelated (spontaneous) or correlated (feedforward) inhibition improved EPSP-spike coupling probability. The relationship between EPSP-spike-timing reliability and inhibition was, however, more complex: transient reduction of correlated (feedforward) inhibition disrupted or improved spike-timing reliability according to the initial spike-coupling probability. Thus eCB-mediated tuning of pyramidal cell spike-time precision is governed not only by the initial level of global inhibition, but also by the ratio between spontaneous and feedforward GABAergic activities. These results reveal that eCB-mediated self-tuning of spike timing by the discharge of pyramidal cells can constitute an important contribution to place-cell assemblies and memory formation in the hippocampus.

Two separate inhibitory mechanisms shape the responses of dorsal cochlear nucleus type IV units to narrowband and wideband stimuli

1994 ◽  
Vol 71 (6) ◽  
pp. 2446-2462 ◽  
Author(s):  
I. Nelken ◽  
E. D. Young
Keyword(s):  
Firing Rate ◽  
Cochlear Nucleus ◽  
Inhibitory Effect ◽  
Broadband Noise ◽  
Dorsal Cochlear Nucleus ◽  
Inhibitory Input ◽  
Inhibitory Influence ◽  
Type Ii ◽  
Rate Level ◽  
Type Iv

1. The principal cells of the dorsal cochlear nucleus (DCN) are mostly inhibited by best frequency (BF) tones but are mostly excited by broadband noise (BBN), producing the so-called type IV response characteristic. The narrowband inhibitory responses can be explained by the inhibitory influence of interneurons with type II response characteristics. However, it is not clear that all the details of the type IV responses can be accounted for by this neural circuit. In particular, many type IV units are inhibited by band-reject noise (notch noise); type II units tend to be only weakly excited by these stimuli, if at all. In this paper we study the relationships between the narrowband, inhibitory and the wideband, excitatory regimens of the type IV responses and present the case for the existence of a second inhibitory source in DCN, called the wideband inhibitor (WBI) below. 2. Type IV units were studied using pure tones, noise bands arithmetically centered on BF, notch noise centered on BF, and BBN. We measured the rate-level function (response rate as function of stimulus level) for each stimulus. This paper is based on the responses of 28 type IV units. 3. Evidence for low-threshold inhibitory input to type IV units is derived from analysis of rate-level functions at sound levels just above threshold. Notch noise stimuli of the appropriate notch width produce inhibition at threshold in this regime. When BBN is presented, this inhibition appears to summate with excitation produced by energy in the band of noise centered on BF, resulting in BBN rate-level functions with decreased slope and maximum firing rate. A range of slopes and maximal firing rates is observed, but these variables are strongly correlated and they are negatively correlated with the strength of the inhibition produced by notch noise; this result supports the conclusion that a single inhibitory source is responsible for these effects. 4. By contrast, there is a weak (nonsignificant) positive correlation between the strength of the inhibitory effect of notch noise and the slope/maximal firing rate in response to narrowband stimuli, including BF tones. The contrast between this positive nonsignificant correlation and the significant negative correlation mentioned above suggests that more than one inhibitory effect operates: specifically, the type II input is responsible for inhibition by narrowband stimuli and a different inhibitory source, the WBI, produces inhibition by notch stimuli. 5. Several lines of evidence are given to show that type II units cannot produce the inhibition seen with notch noise stimuli.(ABSTRACT TRUNCATED AT 400 WORDS)

Cell-specific, spike timing–dependent plasticities in the dorsal cochlear nucleus

2004 ◽  
Vol 7 (7) ◽  
pp. 719-725 ◽  
Author(s):  
Thanos Tzounopoulos ◽  
Yuil Kim ◽  
Donata Oertel ◽  
Laurence O Trussell
Keyword(s):  
Cochlear Nucleus ◽  
Spike Timing ◽  
Dorsal Cochlear Nucleus

Model of auditory prediction in the dorsal cochlear nucleus via spike-timing dependent plasticity

2006 ◽  
Vol 69 (10-12) ◽  
pp. 1191-1194 ◽  
Author(s):  
Patrick D. Roberts ◽  
Christine V. Portfors ◽  
Nathaniel Sawtell ◽  
Richard Felix II
Keyword(s):  
Cochlear Nucleus ◽  
Spike Timing ◽  
Dorsal Cochlear Nucleus ◽  
Spike Timing Dependent Plasticity ◽  
Dependent Plasticity

Intrinsic oscillations in spike trains indicate non-renewal statistics due to convergence of inputs in dorsal cochlear nucleus neurons

2005 ◽  
Vol 200 (1-2) ◽  
pp. 10-28 ◽  
Author(s):  
Prateek S. Aggarwal ◽  
Steven B. Lowen ◽  
H. Steven Colburn ◽  
William F. Dolphin
Keyword(s):  
Cochlear Nucleus ◽  
Spike Trains ◽  
Dorsal Cochlear Nucleus

scholarly journals Designing optimal stimuli to control neuronal spike timing

2011 ◽  
Vol 106 (2) ◽  
pp. 1038-1053 ◽  
Author(s):  
Yashar Ahmadian ◽  
Adam M. Packer ◽  
Rafael Yuste ◽  
Liam Paninski
Keyword(s):  
Spike Train ◽  
Laser Light ◽  
Pyramidal Cells ◽  
Electrical Current ◽  
Optimization Methods ◽  
Spike Trains ◽  
Spike Timing ◽  
Safety Measures ◽  
Physiological Constraints ◽  
Cortical Slices

Recent advances in experimental stimulation methods have raised the following important computational question: how can we choose a stimulus that will drive a neuron to output a target spike train with optimal precision, given physiological constraints? Here we adopt an approach based on models that describe how a stimulating agent (such as an injected electrical current or a laser light interacting with caged neurotransmitters or photosensitive ion channels) affects the spiking activity of neurons. Based on these models, we solve the reverse problem of finding the best time-dependent modulation of the input, subject to hardware limitations as well as physiologically inspired safety measures, that causes the neuron to emit a spike train that with highest probability will be close to a target spike train. We adopt fast convex constrained optimization methods to solve this problem. Our methods can potentially be implemented in real time and may also be generalized to the case of many cells, suitable for neural prosthesis applications. With the use of biologically sensible parameters and constraints, our method finds stimulation patterns that generate very precise spike trains in simulated experiments. We also tested the intracellular current injection method on pyramidal cells in mouse cortical slices, quantifying the dependence of spiking reliability and timing precision on constraints imposed on the applied currents.

Encoding the Timing of Inhibitory Inputs

2005 ◽  
Vol 93 (5) ◽  
pp. 2887-2897 ◽  
Author(s):  
Patrick O. Kanold ◽  
Paul B. Manis
Keyword(s):  
Spike Timing ◽  
Dorsal Cochlear Nucleus ◽  
Heterogeneous Distribution ◽  
Information Encoding ◽  
Neuronal Populations ◽  
Voltage Change ◽  
Voltage Dependent ◽  
Inhibitory Potential ◽  
Neuronal Systems

Many neuronal systems represent information by the timing of individual spikes, and it is generally assumed that spike timing predominantly encodes excitatory inputs. We show here that the timing of inhibition can also be explicitly encoded in spike times using time-dependent and voltage-dependent properties of a rapidly inactivating potassium channel ( IKIF). In vitro recordings in rat dorsal cochlear nucleus show that the effects of inhibition on spike timing can long outlast the duration of the inhibitory potential and that this depends only on the membrane voltage change during the inhibitory postsynaptic potential. Modeling results show that small neuronal populations with a heterogeneous distribution of IKIF voltage dependence can robustly encode intervals of >100 ms between inhibition and excitation. Thus neuronal systems can detect and represent the precise timing of inhibition, suggesting the importance of inhibition in information encoding.

scholarly journals Rapid Temporal Modulation of Synchrony by Competition in Cortical Interneuron Networks

2004 ◽  
Vol 16 (2) ◽  
pp. 251-275 ◽  
Author(s):  
P.H.E. Tiesinga ◽  
T. J. Sejnowski
Keyword(s):  
Cortical Neurons ◽  
Pyramidal Neurons ◽  
Background Activity ◽  
Pyramidal Cells ◽  
Spike Timing ◽  
Network Activity ◽  
Local Networks ◽  
Rapid Changes ◽  
Asynchronous State ◽  
The Impact

The synchrony of neurons in extrastriate visual cortex is modulated by selective attention even when there are only small changes in firing rate (Fries, Reynolds, Rorie, & Desimone, 2001). We used Hodgkin-Huxley type models of cortical neurons to investigate the mechanism by which the degree of synchrony can be modulated independently of changes in firing rates. The synchrony of local networks of model cortical interneurons interacting through GABAA synapses was modulated on a fast timescale by selectively activating a fraction of the interneurons. The activated interneurons became rapidly synchronized and suppressed the activity of the other neurons in the network but only if the network was in a restricted range of balanced synaptic background activity. During stronger background activity, the network did not synchronize, and for weaker background activity, the network synchronized but did not return to an asynchronous state after synchronizing. The inhibitory output of the network blocked the activity of pyramidal neurons during asynchronous network activity, and during synchronous network activity, it enhanced the impact of the stimulus-related activity of pyramidal cells on receiving cortical areas (Salinas & Sejnowski, 2001). Synchrony by competition provides a mechanism for controlling synchrony with minor alterations in rate, which could be useful for information processing. Because traditional methods such as cross-correlation and the spike field coherence require several hundred milliseconds of recordings and cannot measure rapid changes in the degree of synchrony, we introduced a new method to detect rapid changes in the degree of coincidence and precision of spike timing.

scholarly journals Optimal Time Scale for Spike-Time Reliability: Theory, Simulations, and Experiments

2008 ◽  
Vol 99 (1) ◽  
pp. 277-283 ◽  
Author(s):  
Roberto F. Galán ◽  
G. Bard Ermentrout ◽  
Nathaniel N. Urban
Keyword(s):  
Time Scale ◽  
High Reliability ◽  
Pyramidal Cells ◽  
Spike Timing ◽  
Optimal Time ◽  
Spike Time ◽  
Neuron Models ◽  
Temporal Precision ◽  
Gamma Range ◽  
Theoretical Predictions

Use of spike timing to encode information requires that neurons respond with high temporal precision and with high reliability. Fast fluctuating stimuli are known to result in highly reproducible spike times across trials, whereas constant stimuli result in variable spike times. Here, we first studied mathematically how spike-time reliability depends on the rapidness of aperiodic stimuli. Then, we tested our theoretical predictions in computer simulations of neuron models (Hodgkin-Huxley and modified quadratic integrate-and-fire), as well as in patch-clamp experiments with real neurons (mitral cells in the olfactory bulb and pyramidal cells in the neocortex). As predicted by our theory, we found that for firing frequencies in the beta/gamma range, spike-time reliability is maximal when the time scale of the input fluctuations (autocorrelation time) is in the range of a few milliseconds (2–5 ms), coinciding with the time scale of fast synapses, and decreases substantially for faster and slower inputs. Finally, we comment how these findings relate to mechanisms causing neuronal synchronization.

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