The Experts below are selected from a list of 43890 Experts worldwide ranked by ideXlab platform
György Buzsáki - One of the best experts on this subject based on the ideXlab platform.
-
Pyramidal Cell interneuron circuit architecture and dynamics in hippocampal networks
Neuron, 2017Co-Authors: Daniel F English, Sam Mckenzie, Talfan Evans, György Buzsáki, Euisik YoonAbstract:Summary Excitatory control of inhibitory neurons is poorly understood due to the difficulty of studying synaptic connectivity in vivo . We inferred such connectivity through analysis of spike timing and validated this inference using juxtaCellular and optogenetic control of presynaptic spikes in behaving mice. We observed that neighboring CA1 neurons had stronger connections and that superficial Pyramidal Cells projected more to deep interneurons. Connection probability and strength were skewed, with a minority of highly connected hubs. Divergent presynaptic connections led to synchrony between interneurons. Synchrony of convergent presynaptic inputs boosted postsynaptic drive. Presynaptic firing frequency was read out by postsynaptic neurons through short-term depression and facilitation, with individual Pyramidal Cells and interneurons displaying a diversity of spike transmission filters. Additionally, spike transmission was strongly modulated by prior spike timing of the postsynaptic Cell. These results bridge anatomical structure with physiological function.
-
Pyramidal Cell interneuron interactions underlie hippocampal ripple oscillations
Neuron, 2014Co-Authors: Eran Stark, Lisa Roux, Ronny Eichler, Yuta Senzai, Sebastien Royer, György BuzsákiAbstract:Summary High-frequency ripple oscillations, observed most prominently in the hippocampal CA1 Pyramidal layer, are associated with memory consolidation. The Cellular and network mechanisms underlying the generation, frequency control, and spatial coherence of the rhythm are poorly understood. Using multisite optogenetic manipulations in freely behaving rodents, we found that depolarization of a small group of nearby Pyramidal Cells was sufficient to induce high-frequency oscillations, whereas closed-loop silencing of Pyramidal Cells or activation of parvalbumin- (PV) or somatostatin-immunoreactive interneurons aborted spontaneously occurring ripples. Focal pharmacological blockade of GABA A receptors abolished ripples. Localized PV interneuron activation paced ensemble spiking, and simultaneous induction of high-frequency oscillations at multiple locations resulted in a temporally coherent pattern mediated by phase-locked interneuron spiking. These results constrain competing models of ripple generation and indicate that temporally precise local interactions between excitatory and inhibitory neurons support ripple generation in the intact hippocampus.
-
three dimensional reconstruction of the axon arbor of a ca3 Pyramidal Cell recorded and filled in vivo
Brain Structure & Function, 2007Co-Authors: Darrell A. Henze, Lucia Wittner, Laszlo Zaborszky, György BuzsákiAbstract:The three-dimensional intrahippocampal distribution of axon collaterals of an in vivo filled CA3c Pyramidal Cell was investigated. The neuron was filled with biocytin in an anesthetized rat and the collaterals were reconstructed with the aid of a NeuroLucida program from 48 coronal sections. The total length of the axon collaterals exceeded 0.5 m, with almost 40,000 synaptic boutons. The majority of the collaterals were present in the CA1 region (70.0%), whereas 27.6% constituted CA3 recurrent collaterals with the remaining minority of axons returning to the dentate gyrus. The axon arbor covered more than two thirds of the longitudinal axis of the hippocampus, and the terminals were randomly distributed both locally and distally from the soma. We suggest that the CA3 system can be conceptualized as a single-module, in which nearby and distant targets are contacted by the same probability (similar to a mathematically defined random graph). This arrangement, in combination with the parallel input granule Cells and parallel output CA1 Pyramidal Cells, appears ideal for segregation and integration of information and memories.
-
Hippocampal Pyramidal Cell-interneuron spike transmission is frequency dependent and responsible for place modulation of interneuron discharge.
The Journal of Neuroscience, 2002Co-Authors: Lisa Marshall, Darrell A. Henze, Xavier Leinekugel, George Drăgoi, Hajime Hirase, György BuzsákiAbstract:The interplay between principal Cells and interneurons plays an important role in timing the activity of individual Cells. We investigated the influence of single hippocampal CA1 Pyramidal Cells on putative interneurons. The activity of CA1 Pyramidal Cells was controlled intraCellularly by current injection, and the activity of neighboring interneurons was recorded extraCellularly in the urethane-anesthetized rat. Spike transmission probability between monosynaptically connected Pyramidal Cell‐ interneuron pairs was frequency dependent and highest between 5 and 25 Hz. In the awake animal, interneurons were found that had place-modulated firing rates, with place maps similar to their presynaptic Pyramidal neuron. Thus, single Pyramidal neurons can effectively determine the firing patterns of their interneuron targets.
Javier Defelipe - One of the best experts on this subject based on the ideXlab platform.
-
Branching angles of Pyramidal Cell dendrites follow common geometrical design principles in different cortical areas
Scientific Reports, 2014Co-Authors: Concha Bielza, Ruth Benavides-piccione, Pedro L. López-cruz, Pedro Larrañaga, Javier DefelipeAbstract:Unraveling Pyramidal Cell structure is crucial to understanding cortical circuit computations. Although it is well known that Pyramidal Cell branching structure differs in the various cortical areas, the principles that determine the geometric shapes of these Cells are not fully understood. Here we analyzed and modeled with a von Mises distribution the branching angles in 3D reconstructed basal dendritic arbors of hundreds of intraCellularly injected cortical Pyramidal Cells in seven different cortical regions of the frontal, parietal, and occipital cortex of the mouse. We found that, despite the differences in the structure of the Pyramidal Cells in these distinct functional and cytoarchitectonic cortical areas, there are common design principles that govern the geometry of dendritic branching angles of Pyramidal Cells in all cortical areas.
-
proximity of excitatory and inhibitory axon terminals adjacent to Pyramidal Cell bodies provides a putative basis for nonsynaptic interactions
Proceedings of the National Academy of Sciences of the United States of America, 2009Co-Authors: Angel Merchanperez, Joserodrigo Rodriguez, Charles E Ribak, Javier DefelipeAbstract:Although Pyramidal Cells are the main excitatory neurons in the cerebral cortex, it has recently been reported that they can evoke inhibitory postsynaptic currents in neighboring Pyramidal neurons. These inhibitory effects were proposed to be mediated by putative axo-axonic excitatory synapses between the axon terminals of Pyramidal Cells and perisomatic inhibitory axon terminals [Ren M, Yoshimura Y, Takada N, Horibe S, Komatsu Y (2007) Science 316:758–761]. However, the existence of this type of axo-axonic synapse was not found using serial section electron microscopy. Instead, we observed that inhibitory axon terminals synapsing on Pyramidal Cell bodies were frequently apposed by terminals that established excitatory synapses with neighbouring dendrites. We propose that a spillover of glutamate from these excitatory synapses can activate the adjacent inhibitory axo-somatic terminals.
-
Regional specialization in Pyramidal Cell structure in the limbic cortex of the vervet monkey (Cercopithecus pygerythrus): an intraCellular injection study of the anterior and posterior cingulate gyrus
Experimental Brain Research, 2005Co-Authors: Guy N. Elston, Ruth Benavides-piccione, Alejandra Elston, Paul R. Manger, Javier DefelipeAbstract:The Pyramidal Cell phenotype varies quite dramatically in structure among different cortical areas in the primate brain. Comparative studies in visual cortex, in particular, but also in sensorimotor and prefrontal cortex, reveal systematic trends for Pyramidal Cell specialization in functionally related cortical areas. Moreover, there are systematic differences in the extent of these trends between different primate species. Recently we demonstrated differences in Pyramidal Cell structure in the cingulate cortex of the macaque monkey; however, in the absence of other comparative data it remains unknown as to whether the neuronal phenotype differs in cingulate cortex between species. Here we extend the basis for comparison by studying the structure of the basal dendritic trees of layer III Pyramidal Cells in the posterior and anterior cingulate gyrus of the vervet monkey (Brodmann’s areas 23 and 24, respectively). Cells were injected with Lucifer Yellow in flat-mounted cortical slices, and processed for a light-stable DAB reaction product. Size, branching pattern, and spine density of basal dendritic arbors were determined, and somal areas measured. As in the macaque monkey, we found that Pyramidal Cells in anterior cingulate gyrus (area 24) were more branched and more spinous than those in posterior cingulate gyrus (area 23). In addition, the extent of the difference in Pyramidal Cell structure between these two cortical regions was less in the vervet monkey than in the macaque monkey.
-
Pyramidal Cell specialization in the occipitotemporal cortex of the Chacma baboon (Papio ursinus)
Experimental Brain Research, 2005Co-Authors: Guy N. Elston, Ruth Benavides-piccione, Alejandra Elston, Javier Defelipe, Paul R. MangerAbstract:Pyramidal Cell structure varies systematically in occipitotemporal visual areas in monkeys. The dendritic trees of Pyramidal Cells, on average, become larger, more branched and more spinous with progression from the primary visual area (V1) to the second visual area (V2), the fourth (V4, or dorsolateral DL visual area) and inferotemporal (IT) cortex. Presently available data reveal that the extent of this increase in complexity parallels the expansion of occipitotemporal cortex. Here we extend the basis for comparison by studying Pyramidal Cell structure in occipitotemporal cortical areas in the chacma baboon. We found a systematic increase in the size of and branching complexity in the basal dendritic trees, as well as a progressive increase in the spine density along the basal dendrites of layer III Pyramidal Cells through V1, V2 and V4. These data suggest that the trend for more complex Pyramidal Cells with anterior progression through occipitotemporal visual areas is not a feature restricted to monkeys and prosimians, but is a widespread feature of occipitotemporal cortex in primates.
-
Pyramidal Cell specialization in the occipitotemporal cortex of the vervet monkey.
Neuroreport, 2005Co-Authors: Guy N. Elston, Ruth Benavides-piccione, Alejandra Elston, Paul R. Manger, Javier DefelipeAbstract:Pyramidal Cells were injected intraCellularly in fixed, flat-mounted cortical slices taken from the first and fourth visual areas (VI and V4, respectively) and cytoarchitectonic areas TEO and TE of two age and gender-matched vervet monkeys and the size, branching complexity and spine density of their basal dendritic trees determined. In both animals, we found marked differences in the Pyramidal Cell phenotype between cortical areas. More specifically, a consistent trend for larger, more branched and more spinous Pyramidal Cells with progression through VI, V4, TEO and TE was observed. These findings support earlier reports of interareal specialization in Pyramidal Cell structure in occipitotemporal visual areas in the macaque monkey. (c) 2005 Lippincott Williams & Wilkins.
Richard B Miles - One of the best experts on this subject based on the ideXlab platform.
-
Single CA3 Pyramidal Cells trigger sharp waves in vitro by exciting interneurones.
The Journal of Physiology, 2016Co-Authors: Michael Bazelot, Maria Teleńczuk, Richard B MilesAbstract:KEY POINTS The CA3 hippocampal region generates sharp waves (SPW), a population activity associated with neuronal representations. The synaptic mechanisms responsible for the generation of these events still require clarification. Using slices maintained in an interface chamber, we found that the firing of single CA3 Pyramidal Cells triggers SPW like events at short latencies, similar to those for the induction of firing in interneurons. Multi-electrode records from the CA3 stratum Pyramidale showed that Pyramidal Cells triggered events consisting of putative interneuron spikes followed by field IPSPs. SPW fields consisted of a repetition of these events at intervals of 4-8 ms. Although many properties of induced and spontaneous SPWs were similar, the triggered events tended to be initiated close to the stimulated Cell. These data show that the initiation of SPWs in vitro is mediated via Pyramidal Cell synapses that excite interneurons. They do not indicate why interneuron firing is repeated during a SPW. ABSTRACT Sharp waves (SPWs) are a hippocampal population activity that has been linked to neuronal representations. We show that SPWs in the CA3 region of rat hippocampal slices can be triggered by the firing of single Pyramidal Cells. Single action potentials in almost one-third of Pyramidal Cells initiated SPWs at latencies of 2-5 ms with probabilities of 0.07-0.76. Initiating Pyramidal Cells evoked field IPSPs (fIPSPs) at similar latencies when SPWs were not initiated. Similar spatial profiles for fIPSPs and middle components of SPWs suggested that SPW fields reflect repeated fIPSPs. Multiple extraCellular records showed that the initiated SPWs tended to start near the stimulated Pyramidal Cell, whereas spontaneous SPWs could emerge at multiple sites. Single Pyramidal Cells could initiate two to six field IPSPs with distinct amplitude distributions, typically preceeded by a short-duration extraCellular action potential. Comparison of these initiated fields with spontaneously occurring inhibitory field motifs allowed us to identify firing in different interneurones during the spread of SPWs. Propagation away from an initiating Pyramidal Cell was typically associated with the recruitment of interneurones and field IPSPs that were not activated by the stimulated Pyramidal Cell. SPW fields initiated by single Cells were less variable than spontaneous events, suggesting that more stereotyped neuronal ensembles were activated, although neither the spatial profiles of fields, nor the identities of interneurone firing were identical for initiated events. The effects of single Pyramidal Cell on network events are thus mediated by different sequences of interneurone firing.
-
Cellular anatomy physiology and epileptiform activity in the ca3 region of dcx knockout mice a neuronal lamination defect and its consequences
European Journal of Neuroscience, 2012Co-Authors: Elodie Brueljungerman, Michael Bazelot, Jean Simonnet, Celine Dinocourt, Richard B MilesAbstract:We report data on the neuronal form, synaptic connectivity, neuronal excitability and epileptiform population activities generated by the hippocampus of animals with an inactivated doublecortin gene. The protein product of this gene affects neuronal migration during development. Human doublecortin (DCX) mutations are associated with lissencephaly, subcortical band heterotopia, and syndromes of intellectual disability and epilepsy. In Dcx ) ⁄ Y mice, CA3 hippocampal Pyramidal Cells are abnormally laminated. The lamination defect was quantified by measuring the extent of the double, dispersed or single Pyramidal Cell layer in the CA3 region of Dcx ) ⁄ Y mice. We investigated how this abnormal lamination affected two groups of synapses that normally innervate defined regions of the CA3 Pyramidal Cell membrane. Numbers of parvalbumin (PV)-containing interneurons, which contact peri-somatic sites, were not reduced in Dcx ) ⁄ Y animals. Pyramidal Cells in double, dispersed or single layers received PV-containing terminals. Excitatory mossy fibres which normally target proximal CA3 Pyramidal Cell apical dendrites apparently contact CA3 Cells of both layers in Dcx ) ⁄ Y animals but sometimes on basilar rather than apical dendrites. The dendritic form of Pyramidal Cells in Dcx ) ⁄ Y animals was altered and Pyramidal Cells of both layers were more excitable than their counterparts in wild-type animals. Unitary inhibitory field events occurred at higher frequency in Dcx ) ⁄ Y animals. These differences may contribute to a susceptibility to epileptiform activity: a modest increase in excitability induced both interictal and ictal-like discharges more effectively in tissue from Dcx ) ⁄ Y mice than from wild-type animals.
-
Pyramidal Cell to inhibitory Cell spike transduction explicable by active dendritic conductances in inhibitory Cell
Journal of Computational Neuroscience, 1995Co-Authors: Rodney D. Traub, Richard B MilesAbstract:In the guinea-pig hippocampal CA3 region, the synaptic connection from Pyramidal neurons tostratum Pyramidale inhibitory neurons is remarkable. Anatomically, the connection usually consists of a single release site on an interneuronal dendrite, sometimes 200 μm or more from the soma. Nevertheless, the connection is physiologically powerful, in that a single presynaptic action potential can evoke, with probability 0.1 to 0.6, a postsynaptic action potential with latency 2 to 6 ms. We construct a model interneuron and show that the anatomical and physiological observations can be reconciled if the interneuron dendrites are electrically excitable. Excitable dendrites could also account for depolarization-induced amplification of the Pyramidal Cell-interneuron EPSP in the voltage range subthreshold for spike generation.
Guy N. Elston - One of the best experts on this subject based on the ideXlab platform.
-
Specialization of the Neocortical Pyramidal Cell during Primate Evolution
Evolution of Nervous Systems, 2007Co-Authors: Guy N. ElstonAbstract:In a recent series of investigations, dramatic differences in Pyramidal Cell structure have been demonstrated in the primate neocortex. Initial studies in the cortex of the macaque monkey revealed a remarkable degree of heterogeneity in the structure of Pyramidal Cells sampled from homologous cortical layers among functionally related cortical areas. For example, there was, on average, a 13-fold difference in the number of spines in the dendritic trees of layer III Pyramidal Cells involved in visual processing. Moreover, the differences in the complexity of Pyramidal Cell structure among cortical areas were not random: Cells involved in what are generally accepted to be more complex aspects of visual processing had more complex structure. Similar systematic trends in Pyramidal Cell specialization were found among cortical areas involved in somatosensation, locomotion, emotion, and even in executive cortical functions such as conceptualization, planning, and prioritizing. These studies revealed up to a 16-fold difference in the number of dendritic spines (putative excitatory inputs) in the dendritic trees of Pyramidal Cells in different cortical areas of the adult macaque monkey brain. Moreover, there are systematic and dramatic differences in the branching structure of Pyramidal Cells in the macaque cerebral cortex, with neurons in executive cortical areas having significantly more branches than those in sensory or motor cortex. Comparative studies of Pyramidal Cell structure have revealed some interesting similarities, and some striking differences, in the structure of Pyramidal Cells in the brains of various primate species. With up to a 30-fold difference in the estimates of the total number of dendritic spines in the dendritic trees of Pyramidal Cells in the primate cerebral cortex there is considerable scope for receiving different numbers of excitatory inputs. Moreover, the most branched Pyramidal Cells observed to date are found in the human prefrontal cortex, being, on average, more than twice as branched as those in the galago prefrontal cortex. Thus, species differences in Pyramidal Cell structure not only influence the number of inputs received within the dendritic tree, but how these inputs are integrated. Here we present an overview of the comparative data obtained from visual, somatosensory, motor, cingulate, and prefrontal cortex of the human, baboon, macaque monkey, vervet monkey, owl monkey, marmoset monkey, and galago. From these data, and those obtained from the archontan tree shrew, one can speculate on the functional consequences of specialization of the Pyramidal Cell phenotype, and how these may vary between species. New insights into evolutionary and developmental pressures that may shape the Pyramidal Cell phenotype in the adult brain are presented.
-
Regional specialization in Pyramidal Cell structure in the limbic cortex of the vervet monkey (Cercopithecus pygerythrus): an intraCellular injection study of the anterior and posterior cingulate gyrus
Experimental Brain Research, 2005Co-Authors: Guy N. Elston, Ruth Benavides-piccione, Alejandra Elston, Paul R. Manger, Javier DefelipeAbstract:The Pyramidal Cell phenotype varies quite dramatically in structure among different cortical areas in the primate brain. Comparative studies in visual cortex, in particular, but also in sensorimotor and prefrontal cortex, reveal systematic trends for Pyramidal Cell specialization in functionally related cortical areas. Moreover, there are systematic differences in the extent of these trends between different primate species. Recently we demonstrated differences in Pyramidal Cell structure in the cingulate cortex of the macaque monkey; however, in the absence of other comparative data it remains unknown as to whether the neuronal phenotype differs in cingulate cortex between species. Here we extend the basis for comparison by studying the structure of the basal dendritic trees of layer III Pyramidal Cells in the posterior and anterior cingulate gyrus of the vervet monkey (Brodmann’s areas 23 and 24, respectively). Cells were injected with Lucifer Yellow in flat-mounted cortical slices, and processed for a light-stable DAB reaction product. Size, branching pattern, and spine density of basal dendritic arbors were determined, and somal areas measured. As in the macaque monkey, we found that Pyramidal Cells in anterior cingulate gyrus (area 24) were more branched and more spinous than those in posterior cingulate gyrus (area 23). In addition, the extent of the difference in Pyramidal Cell structure between these two cortical regions was less in the vervet monkey than in the macaque monkey.
-
Pyramidal Cell specialization in the occipitotemporal cortex of the Chacma baboon (Papio ursinus)
Experimental Brain Research, 2005Co-Authors: Guy N. Elston, Ruth Benavides-piccione, Alejandra Elston, Javier Defelipe, Paul R. MangerAbstract:Pyramidal Cell structure varies systematically in occipitotemporal visual areas in monkeys. The dendritic trees of Pyramidal Cells, on average, become larger, more branched and more spinous with progression from the primary visual area (V1) to the second visual area (V2), the fourth (V4, or dorsolateral DL visual area) and inferotemporal (IT) cortex. Presently available data reveal that the extent of this increase in complexity parallels the expansion of occipitotemporal cortex. Here we extend the basis for comparison by studying Pyramidal Cell structure in occipitotemporal cortical areas in the chacma baboon. We found a systematic increase in the size of and branching complexity in the basal dendritic trees, as well as a progressive increase in the spine density along the basal dendrites of layer III Pyramidal Cells through V1, V2 and V4. These data suggest that the trend for more complex Pyramidal Cells with anterior progression through occipitotemporal visual areas is not a feature restricted to monkeys and prosimians, but is a widespread feature of occipitotemporal cortex in primates.
-
Pyramidal Cell specialization in the occipitotemporal cortex of the vervet monkey.
Neuroreport, 2005Co-Authors: Guy N. Elston, Ruth Benavides-piccione, Alejandra Elston, Paul R. Manger, Javier DefelipeAbstract:Pyramidal Cells were injected intraCellularly in fixed, flat-mounted cortical slices taken from the first and fourth visual areas (VI and V4, respectively) and cytoarchitectonic areas TEO and TE of two age and gender-matched vervet monkeys and the size, branching complexity and spine density of their basal dendritic trees determined. In both animals, we found marked differences in the Pyramidal Cell phenotype between cortical areas. More specifically, a consistent trend for larger, more branched and more spinous Pyramidal Cells with progression through VI, V4, TEO and TE was observed. These findings support earlier reports of interareal specialization in Pyramidal Cell structure in occipitotemporal visual areas in the macaque monkey. (c) 2005 Lippincott Williams & Wilkins.
-
Areal specialization of Pyramidal Cell structure in the visual cortex of the tree shrew: a new twist revealed in the evolution of cortical circuitry
Experimental Brain Research, 2005Co-Authors: Guy N. Elston, Alejandra Elston, Vivien Casagrande, Jon H. KaasAbstract:Cortical Pyramidal Cells, while having a characteristic morphology, show marked phenotypic variation in primates. Differences have been reported in their size, branching structure and spine density between cortical areas. In particular, there is a systematic increase in the complexity of the structure of Pyramidal Cells with anterior progression through occipito-temporal cortical visual areas. These differences reflect area-specific specializations in cortical circuitry, which are believed to be important for visual processing. However, it remains unknown as to whether these regional specializations in Pyramidal Cell structure are restricted to primates. Here we investigated Pyramidal Cell structure in the visual cortex of the tree shrew, including the primary (V1), second (V2) and temporal dorsal (TD) areas. As in primates, there was a trend for more complex branching structure with anterior progression through visual areas in the tree shrew. However, contrary to the trend reported in primates, Cells in the tree shrew tended to become smaller with anterior progression through V1, V2 and TD. In addition, Pyramidal Cells in V1 of the tree shrew are more than twice as spinous as those in primates. These data suggest that variables that shape the structure of adult cortical Pyramidal Cells differ among species.
Giorgio A Ascoli - One of the best experts on this subject based on the ideXlab platform.
-
CA3 Cells: Detailed and Simplified Pyramidal Cell Models
Hippocampal Microcircuits, 2010Co-Authors: Michele Migliore, Giorgio A Ascoli, David B. JaffeAbstract:From rodents to humans, the hippocampus has been implicated in a variety of cognitive functions, including spatial navigation, memory storage, and recall (Holscher, 2003). The classic anatomical representation of the hippocampal circuitry is organized around the synaptic loop from the entorhinal cortex to the dentate gyrus, to area CA3, to CA1, to the subicular complex, and back to the entorhinal cortex. In this pathway, area CA3 constitutes a pivotal crossroad of synaptic convergence and integration. In particular, the principal neurons of this region, CA3 Pyramidal Cells, receive monosynaptic excitatory inputs from the entorhinal stellate Cells (via the perforant pathway), dentate granule Cells (mossy fibers), and from other CA3 Pyramidal Cells (recurrent collaterals). These afferents pathways are laminated, with mossy fibers synapsing on the most proximal apical dendrites, recurrent collaterals on basal trees and medial apical dendrites, and perforant pathway on the distal apical branches. In order to understand the computational function of the hippocampus, it is important to relate its structure and activity at the Cellular level. The electrophysiological repertoire of CA3 Pyramidal Cells includes single spiking and bursting, spanning a broad range of firing frequencies (∼1–200 Hz). This activity is mediated in part by a number of voltage-gated channels, each with specific properties and dendritic distributions.
-
effects of dendritic morphology on ca3 Pyramidal Cell electrophysiology a simulation study
Brain Research, 2002Co-Authors: Jeffrey L Krichmar, Slawomir J Nasuto, Ruggero Scorcioni, Stuart D Washington, Giorgio A AscoliAbstract:We investigated the effect of morphological differences on neuronal firing behavior within the hippocampal CA3 Pyramidal Cell family by using three-dimensional reconstructions of dendritic morphology in computational simulations of electrophysiology. In this paper, we report for the first time that differences in dendritic structure within the same morphological class can have a dramatic influence on the firing rate and firing mode (spiking versus bursting and type of bursting). Our method consisted of converting morphological measurements from three-dimensional neuroanatomical data of CA3 Pyramidal Cells into a computational simulator format. In the simulation, active channels were distributed evenly across the Cells so that the electrophysiological differences observed in the neurons would only be due to morphological differences. We found that differences in the size of the dendritic tree of CA3 Pyramidal Cells had a significant qualitative and quantitative effect on the electrophysiological response. Cells with larger dendritic trees: (1) had a lower burst rate, but a higher spike rate within a burst, (2) had higher thresholds for transitions from quiescent to bursting and from bursting to regular spiking and (3) tended to burst with a plateau. Dendritic tree size alone did not account for all the differences in electrophysiological responses. Differences in apical branching, such as the distribution of branch points and terminations per branch order, appear to effect the duration of a burst. These results highlight the importance of considering the contribution of morphology in electrophysiological and simulation studies.
