Rhythmic Spontaneous Activity in the Piriform Cortex

Sánchez-Vives, María V.; Descalzo, Vanessa F.; Reig, Ramón; Figueroa, Alejandra; Compte, Albert; Gallego, Roberto

doi:10.1093/cercor/bhm152

Cited by 36 publications

(30 citation statements)

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“…Such preferred states are particularly evident in the bimodal distribution of MUA during time in logarithmic scale in Fig. 3c, usually observed in Up/Down slow oscillations experiments (Sanchez-Vives et al 2008;Sanchez-Vives et al 2010;Reig et al 2010).…”

Section: Evidence Of Attractor Dynamics During Slow Up/down Oscillationsmentioning

confidence: 61%

“…1d, e is obtained, the residence times in one of the two preferred states (Up or Down) have approximately an exponential distribution (Gigante et al 2007;Martí et al 2008;Mejias et al 2010), in analogy to the problem of the diffusion over a barrier (Risken 1989). On the other hand, slow oscillation in vitro are quite regular with a relatively low coefficient of variation (Sanchez-Vives and McCormick 2000; Sanchez-Vives et al 2008;Sanchez-Vives et al 2010;Reig et al 2010), as shown in Fig. 3d for an example recording.…”

Section: In Vitro Experiments and Data Analysismentioning

confidence: 99%

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Exploring the spectrum of dynamical regimes and timescales in spontaneous cortical activity

2011

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Rhythms at slow (\1 Hz) frequency of alternating Up and Down states occur during slow-wave sleep states, under deep anaesthesia and in cortical slices of mammals maintained in vitro. Such spontaneous oscillations result from the interplay between network reverberations nonlinearly sustained by a strong synaptic coupling and a fatigue mechanism inhibiting the neurons firing in an activity-dependent manner. Varying pharmacologically the excitability level of brain slices we exploit the network dynamics underlying slow rhythms, uncovering an intrinsic anticorrelation between Up and Down state durations. Besides, a non-monotonic change of Down state duration is also observed, which shrinks the distribution of the accessible frequencies of the slow rhythms. Attractor dynamics with activity-dependent self-inhibition predicts a similar trend even when the system excitability is reduced, because of a stability loss of Up and Down states. Hence, such cortical rhythms tend to display a maximal size of the distribution of Up/Down frequencies, envisaging the location of the system dynamics on a critical boundary of the parameter space. This would be an optimal solution for the system in order to display a wide spectrum of dynamical regimes and timescales.

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Section: Evidence Of Attractor Dynamics During Slow Up/down Oscillationsmentioning

confidence: 61%

Section: In Vitro Experiments and Data Analysismentioning

confidence: 99%

Exploring the spectrum of dynamical regimes and timescales in spontaneous cortical activity

2011

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“…This could be unexpected since axonal conduction is known to increase with temperature (5%/deg) (Hodgkin and Katz 1949;Johnson and Olsen 1960). However, propagation of activity in the cortical network also depends on other factors such as excitatory/inhibitory balance, reverberation in the network, and excitability of the network (Compte et al 2003;Pinto et al 2005;Sanchez-Vives et al 2008). The larger excitability of neurons in the lower range of temperatures (Volgushev et al 2000b) and their closeness to threshold probably could compensate factors like the slower axonal conduction at cooler temperatures.…”

Section: Discussionmentioning

confidence: 99%

Temperature Modulation of Slow and Fast Cortical Rhythms

Reig

Mattia

Compte

et al. 2010

Journal of Neurophysiology

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Reig R, Mattia M, Compte A, Belmonte C, Sanchez-Vives MV. Temperature modulation of slow and fast cortical rhythms. J Neurophysiol 103: 1253-1261, 2010. First published December 23, 2009 doi:10.1152/jn.00890.2009. In the local cortical network, spontaneous emergent activity self-organizes in rhythmic patterns. These rhythms include a slow one (Ͻ1 Hz), consisting in alternation of up and down states, and also faster rhythms (10 -80 Hz) generated during up states. Varying the temperature in the bath between 26 and 41°C resulted in a strong modulation of the emergent network activity. Up states became shorter for warmer temperatures and longer with cooling, whereas down states were shortest at physiological (36 -37°C) temperature. The firing rate during up states was robustly modulated by temperature, increasing with higher temperatures. The sparse firing rate during down states hardly varied with temperature, thus resulting in a progressive merging of up and down states for temperatures around 30°C. Below 30°C and down to 26°C the firing lost rhythmicity, becoming progressively continuous. The slope of the down-to-up transitions, which reflects the speed of recruitment of the local network, was progressively steeper for higher temperatures, whereas wave-propagation speed exhibited only a moderate increase. Fast rhythms were particularly sensitive to temperature. Broadband highfrequency fluctuations in the local field potential were maximal for recordings at 36 -38°C. Overall, we found that maintaining cortical slices at physiological temperature is critical for the generated activity to be analogous to that in vivo. We also demonstrate that changes in activity with temperature were not secondary to oxygenation changes. Temperature variation sets the in vitro cortical network at different functional regimes, allowing the exploration of network activity generation and control mechanisms.

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“…The pEN, also called area tempestas, is a highly epileptogenic locus (16,17). However, the physiological role of its dense connectivity is unknown (15,18).To probe excitatory connectivity in the olfactory cortex, we isolated excitatory synaptic activity in a tailored brain slice containing the ventral anterior piriform cortex (APC V ), the pEN, the anterior olfactory cortex (AOC; also called anterior olfactory nucleus). Using weak stimulation of the lateral olfactory tract (LOT) input while blocking GABAergic inhibition and NMDA receptors, we evoked transient, all-or-none, network-wide bursts of excitation.…”

mentioning

confidence: 99%

“…The pEN, also called area tempestas, is a highly epileptogenic locus (16,17). However, the physiological role of its dense connectivity is unknown (15,18).…”

mentioning

confidence: 99%

Hierarchical excitatory synaptic connectivity in mouse olfactory cortex

McGinley

Westbrook

2013

Proc. Natl. Acad. Sci. U.S.A.

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Topological motifs in synaptic connectivity-such as the cortical column-are fundamental to processing of information in cortical structures. However, the mesoscale topology of cortical networks beyond columns remains largely unknown. In the olfactory cortex, which lacks an obvious columnar structure, sensory-evoked patterns of activity have failed to reveal organizational principles of the network and its structure has been considered to be random. We probed the excitatory network in the mouse olfactory cortex using variance analysis of paired whole-cell recording in olfactory cortex slices. On a given trial, triggered network-wide bursts in disinhibited slices had remarkably similar time courses in widely separated and randomly selected cell pairs of pyramidal neurons despite significant trial-to-trial variability within each neuron. Simulated excitatory network models with random topologies only partially reproduced the experimental burst-variance patterns. Network models with local (columnar) or distributed subnetworks, which have been predicted as the basis of encoding odor objects, were also inconsistent with the experimental data, showing greater variability between cells than across trials. Rather, network models with power-law and especially hierarchical connectivity showed the best fit. Our results suggest that distributed subnetworks are weak or absent in the olfactory cortex, whereas a hierarchical excitatory topology may predominate. A hierarchical excitatory network organization likely underlies burst generation in this epileptogenic region, and may also shape processing of sensory information in the olfactory cortex.piriform cortex | endopiriform nucleus | small world | functional connectome | network topology S tructural and functional plasticity at excitatory synapses in cortical networks represents a fundamental mechanism for encoding sensory representations and memory. As a result, neuronal ensembles that are connected with high probability emerge as functional units to produce a population code of the environment. The topology of such excitatory circuits should contain signatures-as global topological motifs-that reflect the encoding strategy. The cortical column is a well-studied example of such a motif (1). Columnar cortices contain substantial distributed connectivity and some brain areas, such as association cortex, high-order cortices, and the piriform cortex, lack a pronounced columnar structure. In the piriform (olfactory) cortex, there exists only a rudimentary understanding of the relationship between network structure and cortical function. The axons of individual piriform pyramidal neurons ramify widely throughout the olfactory cortex, and only show patchiness on a very broad scale (2-4). Consistent with this architecture, neural activity in response to individual odorants is distributed broadly across the olfactory cortex as detected by 2-deoxyglucose, c-fos expression, multiunit recording, and population calcium imaging (5-8). Likewise, the receptive fields of individual neurons i...

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Rhythmic Spontaneous Activity in the Piriform Cortex

Cited by 36 publications

References 58 publications

Exploring the spectrum of dynamical regimes and timescales in spontaneous cortical activity

Exploring the spectrum of dynamical regimes and timescales in spontaneous cortical activity

Temperature Modulation of Slow and Fast Cortical Rhythms

Hierarchical excitatory synaptic connectivity in mouse olfactory cortex

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