Boosting of Action Potential Backpropagation by Neocortical Network Activity<i>In Vivo</i>

Waters, Jack; Helmchen, Fritjof

doi:10.1523/jneurosci.2933-04.2004

Cited by 99 publications

(86 citation statements)

References 48 publications

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“…The [Ca 2ϩ ] i transients evoked by pairing an EPSP with a single AP in our experimental conditions indicated that the rise in [Ca 2ϩ ] i was not sufficient to induce LTP. This might be different for other connections, depending on the ion channel distribution in dendrites and spines, which influence the backpropagation of APs and Ca 2ϩ signaling (Magee and Johnston, 1995;Spruston et al, 1995;Sabatini and Svoboda, 2000;Sabatini et al, 2001;Waters and Helmchen, 2004;Gasparini and Magee, 2006). The requirement for AP bursts to induce synaptic modifications might provide stability of connectivity (Lisman and Spruston, 2005), because in vivo cortical activity is sparse and single APs occur more frequently than bursts (Lee et al, 2006;Waters and Helmchen, 2006).…”

Section: Discussionmentioning

confidence: 99%

Spine Ca²⁺Signaling in Spike-Timing-Dependent Plasticity

Nevian¹,

Sakmann²

2006

J. Neurosci.

421

552

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Section: Discussionmentioning

confidence: 99%

Spine Ca²⁺Signaling in Spike-Timing-Dependent Plasticity

Nevian¹,

Sakmann²

2006

J. Neurosci.

421

552

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“…Lastly, it is possible that invasion of the distal apical dendrites by BPAPs is enhanced in the awake state so that the AP activity of the pyramidal neurons themselves can contribute to dendritic Ca 2ϩ responses. For instance, BPAPs cause enhance dendritic Ca 2ϩ influx into the tufts of L2/3 neurons during upstates induced by urethane anesthesia (26).…”

Section: Discussionmentioning

confidence: 99%

Enhanced dendritic activity in awake rats

Murayama

Larkum

2009

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

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Almost nothing is known about dendritic activity in awake animals and even less about its relationship to behavior. The tuft dendrites of layer 5 (L5) pyramidal neurons lie in layer 1, where long-range axons from secondary thalamic nuclei and higher cortical areas arrive. This class of input is very dependent on active thalamocortical loops and activity in higher brain areas and so is likely to be heavily influenced by the conscious state of the animal. If, as has been suggested, the dendrites of pyramidal neurons actively participate in this process, dendritic activity should greatly increase in the awake state. Here, we measured calcium activity in L5 pyramidal neuron dendrites using the ''periscope'' fiberoptic system. Recordings were made in the sensorimotor cortex of awake and anesthetized rats following sensory stimulation of the hindlimb. Bi-phasic dendritic responses evoked by hindlimb stimulation were extremely dependent on brain state. In the awake state, there was a prominent slow, delayed response whose integral was on average 14-fold larger than in the anesthetized state. Moreover, the dramatic increases in dendritic activity closely correlated to the strength of subsequent hindlimb movement. These changes were confined to L5 pyramidal dendrites and were not reflected in the response of layer 2/3 (L2/3) neurons to air-puff stimuli in general (which actually decreased in the awake state). The results demonstrate that the activity of L5 pyramidal dendrites is a neural correlate of awake behavior.calcium imaging ͉ calcium spike ͉ fiberoptics ͉ layer 5 pyramidal neuron ͉ neocortex T he changes that occur at the neuronal level from the anesthetized to the awake brain states is one of the most fundamental questions remaining in neuroscience (1-3). One leading hypothesis is that during awake sensory processing, thalamo-cortical interactions involving deep-layer pyramidal neurons result in non-specific thalamic nuclei projecting feedback input to the tuft dendrites of L5 pyramidal neurons (4). It is also hypothesized that higher cortical areas (more active during conscious processing) project to the same tuft dendrites in L1 in primary sensory areas (5, 6). Both these hypotheses predict specific input to pyramidal cell dendrites during the awake state. Given the intrinsic excitability of pyramidal tuft dendrites with their ability to sustain regenerative Ca 2ϩ activity (7,8), these hypotheses also predict that dendritic activity in these neurons should increase in the awake state.So far, it has only been possible to test the effectiveness of feedback input to L1 in vitro (9, 10). In vivo recordings of dendritic calcium activity has been restricted to anesthetized animals. In these studies, there is evidence for sensory stimulusevoked dendritic Ca 2ϩ spikes in the apical dendrites (11, 12), which is, however, suppressed by powerful dendritic inhibitory mechanisms (13) that are more active during anesthesia (14). These studies also predict that dendritic activity should increase in the awake preparation; howe...

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“…Single whisker deflections have been reported to induce zero or one, rarely two, APs in L2/3 neurons [12,26,27,32,49]. APs cause Ca 2þ accumulations in somata and dendrites that can be detected with Ca 2þ imaging in vivo [49,90,97]. Since individual dendrites were difficult to identify, we performed fluorescence measurements in somata.…”

Section: Methodsmentioning

confidence: 99%

The functional microarchitecture of the mouse barrel cortex

Satō

Gray

Mainen³

et al. 2007

Neuroscience Research

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Cortical maps, consisting of orderly arrangements of functional columns, are a hallmark of the organization of the cerebral cortex. However, the microorganization of cortical maps at the level of single neurons is not known, mainly because of the limitations of available mapping techniques. Here, we used bulk loading of Ca 2þ indicators combined with two-photon microscopy to image the activity of multiple single neurons in layer (L) 2/3 of the mouse barrel cortex in vivo. We developed methods that reliably detect single action potentials in approximately half of the imaged neurons in L2/3. This allowed us to measure the spiking probability following whisker deflection and thus map the whisker selectivity for multiple neurons with known spatial relationships. At the level of neuronal populations, the whisker map varied smoothly across the surface of the cortex, within and between the barrels. However, the whisker selectivity of individual neurons recorded simultaneously differed greatly, even for nearest neighbors. Trial-to-trial correlations between pairs of neurons were high over distances spanning multiple cortical columns. Our data suggest that the response properties of individual neurons are shaped by highly specific subcolumnar circuits and the momentary intrinsic state of the neocortex.Citation: Sato TR, Gray NW, Mainen ZF, Svoboda K (2007) The functional microarchitecture of the mouse barrel cortex. PLoS Biol 5(7): e189.

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Boosting of Action Potential Backpropagation by Neocortical Network ActivityIn Vivo

Cited by 99 publications

References 48 publications

Spine Ca²⁺Signaling in Spike-Timing-Dependent Plasticity

Spine Ca²⁺Signaling in Spike-Timing-Dependent Plasticity

Enhanced dendritic activity in awake rats

The functional microarchitecture of the mouse barrel cortex

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Boosting of Action Potential Backpropagation by Neocortical Network ActivityIn Vivo

Cited by 99 publications

References 48 publications

Spine Ca2+Signaling in Spike-Timing-Dependent Plasticity

Spine Ca2+Signaling in Spike-Timing-Dependent Plasticity

Enhanced dendritic activity in awake rats

The functional microarchitecture of the mouse barrel cortex

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Product

Resources

About

Spine Ca²⁺Signaling in Spike-Timing-Dependent Plasticity

Spine Ca²⁺Signaling in Spike-Timing-Dependent Plasticity