CiteULike: nelmor's oscillations

Rate-specific synchrony: Using noisy oscillations to detect equally active neurons

David Markowitz — 2008-06-18T10:25:06-00:00

Proceedings of the National Academy of Sciences, Vol. 105, No. 24. (17 June 2008), pp. 8422-8427.

Although gamma frequency oscillations are common in the brain, their functional contributions to neural computation are not understood. Here we report in vitro electrophysiological recordings to evaluate how noisy gamma frequency oscillatory input interacts with the overall activation level of a neuron to determine the precise timing of its action potentials. The experiments were designed to evaluate spike synchrony in a neural circuit architecture in which a population of neurons receives a common noisy gamma oscillatory synaptic drive while the firing rate of each individual neuron is determined by a slowly varying independent input. We demonstrate that similarity of firing rate is a major determinant of synchrony under common noisy oscillatory input: Near coincidence of spikes at similar rates gives way to substantial desynchronization at larger firing rate differences. Analysis of this rate-specific synchrony phenomenon reveals distinct spike timing "fingerprints" at different firing rates that emerge through a combination of phase shifting and abrupt changes in spike patterns. We further demonstrate that rate-specific synchrony permits robust detection of rate similarity in a population of neurons through synchronous activation of a postsynaptic neuron, supporting the biological plausibility of a Many Are Equal computation. Our results reveal that spatially coherent noisy oscillations, which are common throughout the brain, can generate previously unknown relationships among neural rate codes, noisy interspike intervals, and precise spike synchrony codes. All of these can coexist in a self-consistent manner because of rate-specific synchrony. 10.1073/pnas.0803183105

Grid cell firing may arise from interference of theta frequency membrane potential oscillations in single neurons.

ME Hasselmo — 2008-06-12T10:07:59-00:00

Hippocampus, Vol. 17, No. 12. (2007), pp. 1252-1271.

Intracellular recording and computational modelling suggest that interactions of subthreshold membrane potential oscillation frequency in different dendritic branches of entorhinal cortex stellate cells could underlie the functional coding of continuous dimensions of space and time. Among other things, these interactions could underlie properties of grid cell field spacing. The relationship between experimental data on membrane potential oscillation frequency (f) and grid cell field spacing (G) indicates a constant scaling factor H = fG. This constant scaling factor between temporal oscillation frequency and spatial periodicity provides a starting constraint that is used to derive the model of Burgess et al. (Hippocampus, 2007). This model provides a consistent quantitative link between single cell physiological properties and properties of spiking units in awake behaving animals. Further properties and predictions of this model about single cell and network physiological properties are analyzed. In particular, the model makes quantitative predictions about the change in membrane potential, single cell oscillation frequency, and network oscillation frequency associated with speed of movement, about the independence of single cell properties from network theta rhythm oscillations, and about the effect of variations in initial oscillatory phase on the pattern of grid cell firing fields. These same mechanisms of subthreshold oscillations may play a more general role in memory function, by providing a method for learning arbitrary time intervals in memory sequences.

Temporal Frequency of Subthreshold Oscillations Scales with Entorhinal Grid Cell Field Spacing

Lisa Giocomo — 2007-03-23T21:59:27-00:00

Science, Vol. 315, No. 5819. (23 March 2007), pp. 1719-1722.

Grid cells in layer II of rat entorhinal cortex fire to spatial locations in a repeating hexagonal grid, with smaller spacing between grid fields for neurons inmore dorsal anatomical locations. Data from in vitro whole-cell patch recordings showed differences in frequency of subthreshold membrane potential oscillations in entorhinal neurons that correspond to different positions along the dorsal-to-ventral axis, supporting a model of physiological mechanisms for grid cell responses. 10.1126/science.1139207

Disrupted Dopamine Transmission and the Emergence of Exaggerated Beta Oscillations in Subthalamic Nucleus and Cerebral Cortex

Nicolas Mallet — 2008-05-02T08:52:58-00:00

J. Neurosci., Vol. 28, No. 18. (30 April 2008), pp. 4795-4806.

In the subthalamic nucleus (STN) of Parkinson's disease (PD) patients, a pronounced synchronization of oscillatory activity at beta frequencies (15-30 Hz) accompanies movement difficulties. Abnormal beta oscillations and motor symptoms are concomitantly and acutely suppressed by dopaminergic therapies, suggesting that these inappropriate rhythms might also emerge acutely from disrupted dopamine transmission. The neural basis of these abnormal beta oscillations is unclear, and how they might compromise information processing, or how they arise, is unknown. Using a 6-hydroxydopamine-lesioned rodent model of PD, we demonstrate that beta oscillations are inappropriately exaggerated, compared with controls, in a brain-state-dependent manner after chronic dopamine loss. Exaggerated beta oscillations are expressed at the levels of single neurons and small neuronal ensembles, and are focally present and spatially distributed within STN. They are also expressed in synchronous population activities, as evinced by oscillatory local field potentials, in STN and cortex. Excessively synchronized beta oscillations reduce the information coding capacity of STN neuronal ensembles, which may contribute to parkinsonian motor impairment. Acute disruption of dopamine transmission in control animals with antagonists of D1/D2 receptors did not exaggerate STN or cortical beta oscillations. Moreover, beta oscillations were not exaggerated until several days after 6-hydroxydopamine injections. Thus, contrary to predictions, abnormally amplified beta oscillations in cortico-STN circuits do not result simply from an acute absence of dopamine receptor stimulation, but are instead delayed sequelae of chronic dopamine depletion. Targeting the plastic processes underlying the delayed emergence of pathological beta oscillations after continuing dopaminergic dysfunction may offer considerable therapeutic promise. 10.1523/JNEUROSCI.0123-08.2008

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

Roberto Galan — 2008-01-15T10:35:24-00:00

J Neurophysiol, Vol. 99, No. 1. (1 January 2008), pp. 277-283.

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 (25 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. 10.1152/jn.00563.2007

Assessing transient cross-frequency coupling in EEG data.

Michael X Cohen — 2007-12-20T10:30:55-00:00

J Neurosci Methods (30 October 2007)

Synchronization of oscillatory EEG signals across different frequency bands is receiving waxing interest in cognitive neuroscience and neurophysiology, and cross-frequency coupling is being increasingly linked to cognitive and perceptual processes. Several methods exist to examine cross-frequency coupling, although each has its limitations, typically by being flexible only over time or over frequency. Here, a method for assessing transient cross-frequency coupling is presented, which allows one to test for the presence of multiple, dynamic, and flexible cross-frequency coupling structure over both time and frequency. The method is applied to intracranial EEG data, and strong coupling between gamma ( approximately 40-80Hz) and upper theta ( approximately 7-9Hz) was observed. This method might have useful applications in uncovering the electrophysiological correlates of cognitive processes.

Automated characterization of multiple alpha peaks in multi-site electroencephalograms.

A K I Chiang — 2007-12-20T10:28:07-00:00

J Neurosci Methods (13 November 2007)

The identification of alpha rhythm in the human electroencephalogram (EEG) is generally a laborious task involving visual inspection of the spectrum. Moreover the occurrence of multiple alpha rhythms is often overlooked. This paper seeks to automate the process of identifying alpha peaks and quantifying their frequency, amplitude and width as a function of position on the scalp. Experimental EEG was fitted with parameterized spectra spanning the alpha range, with results categorized by multi-site criteria into three distinct classes: no distinguishable alpha peak, a single alpha peak, and two alpha peaks. The technique avoids visual bias, integrates spatial information, and is automated. We show that multiple alpha peaks are a common feature of many spectra.

Modulation of CA3 Afferent Inputs by Novelty and Theta Rhythm

Desiree Villarreal — 2007-12-06T10:24:22-00:00

J. Neurosci., Vol. 27, No. 49. (5 December 2007), pp. 13457-13467.

Models of hippocampal function suggest that the modulation of CA3 afferent input during theta rhythm allows for a rapid alternation between encoding and retrieval states, with each phase enhancing either extrinsic or intrinsic CA3 afferents, favoring either encoding or retrieval, respectively. Here, we show that during the initial exploration of a novel environment by rats, intrinsic CA3-CA3 synaptic inputs are attenuated on CA3 theta peaks, favoring extrinsic CA3 inputs, whereas extrinsic perforant path-CA3 synaptic inputs are attenuated on CA3 theta troughs, favoring intrinsic CA3 inputs. This modulation is absent when animals are re-exposed to the same environment 2 or 48 h later and thus habituates with familiarity, suggesting a process involved in learning. Modulation of CA3 synaptic inputs during novelty was blocked by atropine at a dose that blocks type 2 theta rhythm. Re-exposure to the same novel environment 48 h later in the absence of atropine did not result in habituation, but instead modulated CA3 synaptic responses as though the environment were novel and explored for the first time. The NMDA receptor antagonist (+/-)-3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid (CPP), administered in a dose that blocks long-term potentiation induction, did not alter CA3 synaptic modulation during initial exploration. However, like atropine, CPP blocked the habituation of synaptic modulation normally observed with re-exposure, as though the environment were novel and explored for the first time. Thus, as predicted theoretically, recurrent and cortical CA3 afferents are differentially modulated during phases of theta rhythm. This modulation is atropine sensitive and habituates in an NMDA receptor-dependent manner, suggesting an NMDA receptor-dependent process that, in conjunction with theta rhythm, contributes to encoding of novel information in the hippocampus. 10.1523/JNEUROSCI.3702-07.2007

Measuring fundamental frequencies in local field potentials.

B Masimore — 2007-12-04T10:10:00-00:00

J Neurosci Methods, Vol. 138, No. 1-2. (30 September 2004), pp. 97-105.

Neural processes display rhythmic oscillations in local field potentials; identification of their characteristic frequencies is complicated due to their highly non-stationary nature. A simple technique, combining Fourier transforms and correlation coefficients yields unambiguous determinations of the frequencies without a priori filtering. This procedure also provides quantitative information concerning interactions between frequencies. Fundamental frequencies in local field potential data acquired from the hippocampus, cortex, and striatum from awake, behaving rats were calculated using this technique. Characteristic frequencies identified using this technique from hippocampus and cortex agreed with known oscillations. Application to dorsal striatal local field potentials identified a low-frequency theta component as well as a narrow gamma band oscillation at 50-55 Hz.

An Olfacto-Hippocampal Network Is Dynamically Involved in Odor-Discrimination Learning

Claire Martin — 2007-10-16T03:51:23-00:00

J Neurophysiol, Vol. 98, No. 4. (1 October 2007), pp. 2196-2205.

Several studies have shown that memory consolidation relies partly on interactions between sensory and limbic areas. The functional loop formed by the olfactory system and the hippocampus represents an experimentally tractable model that can provide insight into this question. It had been shown previously that odor-learning associated beta band oscillations (1530 Hz) of the local field potential in the rat olfactory system are enhanced with criterion performance, but it was unknown if these involve networks beyond the olfactory system. We recorded local field potentials from the olfactory bulb (OB) and dorsal and ventral hippocampus during acquisition of odor discriminations in a go/no-go task. These regions showed increased beta oscillation power during odor sampling, accompanied by a coherence increase in this frequency band between the OB and both hippocampal subfields. This coherence between the OB and the hippocampus increased with the onset of the first rule transfer to a new odor set and remained high for all learning phases and subsequent odor sets. However, coherence between the two hippocampal fields reset to baseline levels with each new odor set and increased again with criterion performance. These data support hippocampal involvement in the network underlying odor-discrimination learning and also suggest that cooperation between the dorsal and ventral hippocampus varies with learning progress. Oscillatory activity in the beta range may thus provide a mechanism by which these areas are linked during memory consolidation, similar to proposed roles of beta oscillations in other systems with long-range connections. 10.1152/jn.00524.2007

Gamma Oscillations Coordinate Amygdalo-Rhinal Interactions during Learning

Elizabeth Bauer — 2007-08-29T17:39:41-00:00

J. Neurosci., Vol. 27, No. 35. (29 August 2007), pp. 9369-9379.

The rhinal cortices contribute to memory formation by integrating and transferring neocortical information to the hippocampus. Rhinal contributions to memory are likely influenced by the amygdala because strong reciprocal connections exist between these structures. In light of previous data showing that oscillations regulate neuronal activity during memory formation and recall, we tested the possibility that coherent oscillations serve to coordinate amygdalo-rhinal activity during learning. To this end, we performed simultaneous extracellular recordings of basolateral amygdala (BLA), perirhinal, and entorhinal activity. We first tested whether there are correlated fluctuations in the power of BLA and rhinal field activity during the waking state. Correlated power fluctuations were most pronounced in the 3545 Hz band. Within each structure, firing probability fluctuated rhythmically with the fast oscillations, indicating that they were not volume conducted. To test whether fast oscillations coordinate BLA and rhinal activity during learning, animals were trained on a trace-conditioning task in which a visual conditioned stimulus (CS) predicted a food reward after a delay. The predictive value of the CS was learned gradually over 9 d. As learning progressed, the 3545 Hz power increased in the BLA and rhinal cortices, particularly during the late part of the CS and delay. Moreover, the firing of BLA and rhinal neurons became rhythmically entrained by BLA oscillations at that time. Thus, our data suggest that neuronal interactions are coordinated by fast oscillations in the BLArhinal network. By telescoping the periods of effective neuronal interactions in short recurring time windows, these fast oscillations may facilitate rhinal interactions and synaptic plasticity. 10.1523/JNEUROSCI.2153-07.2007

Gamma oscillations dynamically couple hippocampal CA3 and CA1 regions during memory task performance

Sean Montgomery — 2007-08-29T08:22:58-00:00

PNAS (28 August 2007), 0701826104.

Edited by Fred H. Gage, The Salk Institute for Biological Sciences, San Diego, CA, and approved July 20, 2007 (received for review February 27, 2007)The hippocampal formation is believed to be critical for the encoding, consolidation, and retrieval of episodic memories. Yet, how these processes are supported by the anatomically diverse hippocampal networks is still unknown. To examine this issue, we tested rats in a hippocampus-dependent delayed spatial alternation task on a modified T maze while simultaneously recording local field potentials from dendritic and somatic layers of the dentate gyrus, CA3, and CA1 regions by using high-density, 96-site silicon probes. Both the power and coherence of gamma oscillations exhibited layer-specific changes during task performance. Peak increases in the gamma power and coherence were found in the CA3CA1 interface on the maze segment approaching the T junction, independent of motor aspects of task performance. These results show that hippocampal networks can be dynamically coupled by gamma oscillations according to specific behavioral demands. Based on these findings, we propose that gamma oscillations may serve as a physiological mechanism by which CA3 output can coordinate CA1 activity to support retrieval of hippocampus-dependent memories. 10.1073/pnas.0701826104

Olfactory Bulb Gamma Oscillations Are Enhanced with Task Demands

Jennifer Beshel — 2007-08-03T06:54:13-00:00

J. Neurosci., Vol. 27, No. 31. (1 August 2007), pp. 8358-8365.

Fast oscillations in neural assemblies have been proposed as a mechanism to facilitate stimulus representation in a variety of sensory systems across animal species. In the olfactory system, intervention studies suggest that oscillations in the gamma frequency range play a role in fine odor discrimination. However, there is still no direct evidence that such oscillations are intrinsically altered in intact systems to aid in stimulus disambiguation. Here we show that gamma oscillatory power in the rat olfactory bulb during a two-alternative choice task is modulated in the intact system according to task demands with dramatic increases in gamma power during discrimination of molecularly similar odorants in contrast to dissimilar odorants. This elevation in power evolves over the course of criterion performance, is specific to the gamma frequency band (6585 Hz), and is independent of changes in the theta or beta frequency band range. Furthermore, these high amplitude gamma oscillations are restricted to the olfactory bulb, such that concurrent piriform cortex recordings show no evidence of enhanced gamma power during these high-amplitude events. Our results display no modulation in the power of beta oscillations (1528 Hz) shown previously to increase with odor learning in a Go/No-go task, and we suggest that the oscillatory profile of the olfactory system may be influenced by both odor discrimination demands and task type. The results reported here indicate that enhancement of local gamma power may reflect a switch in the dynamics of the system to a strategy that optimizes stimulus resolution when input signals are ambiguous. 10.1523/JNEUROSCI.1199-07.2007

Role of experience and oscillations in transforming a rate code into a temporal code.

MR Mehta — 2005-02-17T21:47:07-00:00

Nature, Vol. 417, No. 6890. (13 June 2002), pp. 741-746.

In the vast majority of brain areas, the firing rates of neurons, averaged over several hundred milliseconds to several seconds, can be strongly modulated by, and provide accurate information about, properties of their inputs. This is referred to as the rate code. However, the biophysical laws of synaptic plasticity require precise timing of spikes over short timescales (<10 ms). Hence it is critical to understand the physiological mechanisms that can generate precise spike timing in vivo, and the relationship between such a temporal code and a rate code. Here we propose a mechanism by which a temporal code can be generated through an interaction between an asymmetric rate code and oscillatory inhibition. Consistent with the predictions of our model, the rate and temporal codes of hippocampal pyramidal neurons are highly correlated. Furthermore, the temporal code becomes more robust with experience. The resulting spike timing satisfies the temporal order constraints of hebbian learning. Thus, oscillations and receptive field asymmetry may have a critical role in temporal sequence learning.

Pathological synchronization in Parkinson's disease: networks, models and treatments

Constance Hammond — 2007-07-03T08:13:20-00:00

Trends in Neurosciences, Vol. 30, No. 7. (July 2007), pp. 357-364.

Parkinson's disease is a common and disabling disorder of movement owing to dopaminergic denervation of the striatum. However, it is still unclear how this denervation perverts normal functioning to cause slowing of voluntary movements. Recent work using tissue slice preparations, animal models and in humans with Parkinson's disease has demonstrated abnormally synchronized oscillatory activity at multiple levels of the basal ganglia-cortical loop. This excessive synchronization correlates with motor deficit, and its suppression by dopaminergic therapies, ablative surgery or deep-brain stimulation might provide the basic mechanism whereby diverse therapeutic strategies ameliorate motor impairment in patients with Parkinson's disease. This review is part of the INMED/TINS special issue, Physiogenic and pathogenic oscillations: the beauty and the beast, based on presentations at the annual INMED/TINS symposium (http://inmednet.com/).

Network and intrinsic cellular mechanisms underlying theta phase precession of hippocampal neurons

Andrew Maurer — 2007-07-03T08:00:23-00:00

Trends in Neurosciences, Vol. 30, No. 7. (July 2007), pp. 325-333.

Hippocampal `place cells' systematically shift their phase of firing in relation to the theta rhythm as an animal traverses the `place field'. These dynamics imply that the neural ensemble begins each theta cycle at a point in its state-space that might `represent' the current location of the rat, but that the ensemble `looks ahead' during the rest of the cycle. Phase precession could result from intrinsic cellular dynamics involving interference of two oscillators of different frequencies, or from network interactions, similar to Hebb's `phase sequence' concept, involving asymmetric synaptic connections. Both models have difficulties accounting for all of the available experimental data, however. A hybrid model, in which the look-ahead phenomenon implied by phase precession originates in superficial entorhinal cortex by some form of interference mechanism and is enhanced in the hippocampus proper by asymmetric synaptic plasticity during sequence encoding, seems to be consistent with available data, but as yet there is no fully satisfactory theoretical account of this phenomenon. This review is part of the INMED/TINS special issue Physiogenic and pathogenic oscillations: the beauty and the beast, based on presentations at the annual INMED/TINS symposium (http://inmednet.com).

Modulation of Neuronal Interactions Through Neuronal Synchronization

Thilo Womelsdorf — 2007-06-15T08:56:16-00:00

Science, Vol. 316, No. 5831. (15 June 2007), pp. 1609-1612.

Brain processing depends on the interactions between neuronal groups. Those interactions are governed by the pattern of anatomical connections and by yet unknown mechanisms that modulate the effective strength of a given connection. We found that the mutual influence among neuronal groups depends on the phase relation between rhythmic activities within the groups. Phase relations supporting interactions between the groups preceded those interactions by a few milliseconds, consistent with a mechanistic role. These effects were specific in time, frequency, and space, and we therefore propose that the pattern of synchronization flexibly determines the pattern of neuronal interactions. 10.1126/science.1139597

Cortical oscillations and temporal interactions in a computer simulation of piriform cortex

M Wilson — 2007-04-02T08:51:22-00:00

J Neurophysiol, Vol. 67, No. 4. (1 April 1992), pp. 981-995.

The role of acetylcholine in learning and memory.

Michael E Hasselmo — 2006-10-11T08:30:58-00:00

Curr Opin Neurobiol (28 September 2006)

Pharmacological data clearly indicate that both muscarinic and nicotinic acetylcholine receptors have a role in the encoding of new memories. Localized lesions and antagonist infusions demonstrate the anatomical locus of these cholinergic effects, and computational modeling links the function of cholinergic modulation to specific cellular effects within these regions. Acetylcholine has been shown to increase the strength of afferent input relative to feedback, to contribute to theta rhythm oscillations, activate intrinsic mechanisms for persistent spiking, and increase the modification of synapses. These effects might enhance different types of encoding in different cortical structures. In particular, the effects in entorhinal and perirhinal cortex and hippocampus might be important for encoding new episodic memories.

Propagating waves mediate information transfer in the motor cortex

Doug Rubino — 2006-11-27T14:33:18-00:00

Nature Neuroscience, Vol. 9, No. 12. (19 November 2006), pp. 1549-1557.

Cannabinoids reveal importance of spike timing coordination in hippocampal function

David Robbe — 2006-11-27T14:33:19-00:00

Nature Neuroscience, Vol. 9, No. 12. (19 November 2006), pp. 1526-1533.

Hippocampal CA1 spiking during encoding and retrieval: Relation to theta phase.

Joseph R Manns — 2006-08-29T14:20:09-00:00

Neurobiol Learn Mem (11 July 2006)

The hippocampal theta rhythm is a prominent oscillation in the field potential observed throughout the hippocampus as a rat investigates stimuli in the environment. A recent computational model [Hasselmo, M. E., Bodelon, C., & Wyble, B. P. (2002a). A proposed function for hippocampal theta rhythm: separate phases of encoding and retrieval enhance reversal of prior learning. Neural Computation, 14, 793-817. Neuromodulation, theta rhythm and rat spatial navigation. Neural Networks, 15, 689-707] suggested that the theta rhythm allows the hippocampal formation to alternate rapidly between conditions that promote memory encoding (strong synaptic input from entorhinal cortex to areas CA3 and CA1) and conditions that promote memory retrieval (strong synaptic input from CA3 to CA1). That model predicted that the preferred theta phase of CA1 spiking should differ for information being encoded versus information being retrieved. In the present study, the spiking activity of CA1 pyramidal cells was recorded while rats performed either an odor-cued delayed nonmatch-to-sample recognition memory test or an object recognition memory task based on the animal's spontaneous preference for novelty. In the test period of both tasks, the preferred theta phase exhibited by CA1 pyramidal cells differed between moments when the rat inspected repeated (match) and non-repeated (nonmatch) items. Also in the present study, additional modeling work extended the previous model to address the mean phase of CA1 spiking associated with stimuli inducing varying levels of retrieval relative to encoding, ranging from novel nonmatch stimuli with no retrieval to highly familiar repeated stimuli with extensive retrieval. The modeling results obtained here demonstrated that the experimentally observed phase differences are consistent with different levels of CA3 synaptic input to CA1 during recognition of repeated items.

Distinct Roles for the Kainate Receptor Subunits GluR5 and GluR6 in Kainate-Induced Hippocampal Gamma Oscillations

Andre Fisahn — 2006-10-18T12:19:29-00:00

J. Neurosci., Vol. 24, No. 43. (27 October 2004), pp. 9658-9668.

Kainate receptors (KARs) play an important role in synaptic physiology, plasticity, and pathological phenomena such as epilepsy. However, the physiological implications for neuronal networks of the distinct expression patterns of KAR subunits are unknown. Using KAR knock-out mice, we show that subunits glutamate receptor (GluR) 5 and GluR6 play distinct roles in kainate-induced gamma oscillations and epileptiform burst activity. Ablation of GluR5 leads to a higher susceptibility of the network to the oscillogenic and epileptogenic effects of kainate, whereas lack of GluR6 prevents kainate-induced gamma oscillations or epileptiform bursts. Based on experimental and simulated neuronal network data as well as the consequences of GluR5 and GluR6 expression for cellular and synaptic physiology, we propose that the functional interplay of GluR5-containing KARs on axons of interneurons and GluR6-containing KARs in the somatodendritic region of both interneurons and pyramidal cells underlie the oscillogenic and epileptogenic effects of kainate. 10.1523/JNEUROSCI.2973-04.2004

Olfactory Computations and Network Oscillation

Alan Gelperin — 2006-02-08T23:53:23-00:00

J. Neurosci., Vol. 26, No. 6. (8 February 2006), pp. 1663-1668.