Generating oscillatory bursts from a network of regular spiking neurons without inhibition

Shao, Jing; Lai, Dihui; Meyer, Ulrike; Luksch, Harald; Weßel, Ralf

doi:10.1007/s10827-009-0171-5

Cited by 9 publications

(14 citation statements)

References 83 publications

(125 reference statements)

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“…The synchrony between the Ipc and SLu involves firing in rhythmic fashion at frequencies of 15-40 Hz, implying that shepherd-crook input to both nuclei is also rhythmic, as suggested by Shao et al (2009), but susceptible to feedback from the Ipc, because blocking visual responses in the Ipc suppresses visual responses in the SLu.…”

Section: Synchronized Feedback To the Teo From The Ipc And Slumentioning

confidence: 98%

Attentional Capture? Synchronized Feedback Signals from the Isthmi Boost Retinal Signals to Higher Visual Areas

Marı́n

Durán²,

Morales³

et al. 2012

J. Neurosci.

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When a salient object in the visual field captures attention, the neural representation of that object is enhanced at the expense of competing stimuli. How neural activity evoked by a salient stimulus evolves to take precedence over the neural activity evoked by other stimuli is a matter of intensive investigation. Here, we describe in pigeons (Columba livia) how retinal inputs to the optic tectum (TeO, superior colliculus in mammals), triggered by moving stimuli, are selectively relayed on to the rotundus (Rt, caudal pulvinar) in the thalamus, and to its pallial target, the entopallium (E, extrastriate cortex). We show that two satellite nuclei of the TeO, the nucleus isthmi parvocelullaris (Ipc) and isthmi semilunaris (SLu), send synchronized feedback signals across tectal layers. Preventing the feedback from Ipc but not from SLu to a tectal location suppresses visual responses to moving stimuli from the corresponding region of visual space in all Rt subdivisions. In addition, the bursting feedback from the Ipc imprints a bursting rhythm on the visual signals, such that the visual responses of the Rt and the E acquire a bursting modulation significantly synchronized to the feedback from Ipc. As the Ipc feedback signals are selected by competitive interactions, the visual responses within the receptive fields in the Rt tend to synchronize with the tectal location receiving the "winning" feedback from Ipc. We propose that this selective transmission of afferent activity combined with the cross-regional synchronization of the areas involved represents a bottom-up mechanism by which salient stimuli capture attention.

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Section: Synchronized Feedback To the Teo From The Ipc And Slumentioning

confidence: 98%

Attentional Capture? Synchronized Feedback Signals from the Isthmi Boost Retinal Signals to Higher Visual Areas

Marı́n

Durán²,

Morales³

et al. 2012

J. Neurosci.

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“…Each array contains 300 neurons. These neurons respond to somatic current injection with regular spiking and show spike-rate adaptation and linear frequencycurrent curves (Shao et al 2009). Therefore each neuron in the network is modeled as leaky integrate-and-fire type, including a spike-rate adaptation conductance.…”

Section: E T H O D Smentioning

confidence: 99%

“…The variable t j k represents the time at which neuron j generates the spike k. A summation is performed over all spikes generated by neuron j. Unless stated otherwise, parameter values of model neurons and synapses are based on previous studies (Shao et al 2009), where parameter values were tuned within their experimental constraints until the results of model neuron simulations matched results from in vitro intracellular recordings. All conductances are expressed in terms of an average membrane conductance, g m ϭ 2.78 nS.…”

Section: E T H O D Smentioning

confidence: 99%

“…The synaptic time constants for the excitatory synapses are: 1,L10¡Ipc ϭ 1,L10¡Imc ϭ7.6 ms, 2,L10¡Ipc ϭ 2,L10¡Imc ϭ0.47 ms, 1,Ipc¡L10 ϭ10.0 ms, 2,Ipc¡L10 ϭ1.0 ms (Shao et al 2009). The synaptic time constants for the Imc projections are 1,Imc¡L10/Ipc ϭ5.6 ms and 2,Imc¡L10/Ipc ϭ0.3 ms, which are commonly used for GABAergic synapses (Destexhe et al 1994).…”

Section: E T H O D Smentioning

confidence: 99%

“…To study the dynamics of stimulus competition in the isthmotectal system, we represent the available anatomical (Wang et al 2004 and physiological (Shao et al 2009) information about the avian isthmotectal circuit ( Fig. 2A) in a model network (see METHODS) consisting of four interacting populations of spiking model neurons (Fig.…”

Section: Structure Of the Isthmotectal Model Networkmentioning

confidence: 99%

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Recurrent Antitopographic Inhibition Mediates Competitive Stimulus Selection in an Attention Network

Lai

Brandt

Luksch

et al. 2011

Journal of Neurophysiology

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Topographically organized neurons represent multiple stimuli within complex visual scenes and compete for subsequent processing in higher visual centers. The underlying neural mechanisms of this process have long been elusive. We investigate an experimentally constrained model of a midbrain structure: the optic tectum and the reciprocally connected nucleus isthmi. We show that a recurrent antitopographic inhibition mediates the competitive stimulus selection between distant sensory inputs in this visual pathway. This recurrent antitopographic inhibition is fundamentally different from surround inhibition in that it projects on all locations of its input layer, except to the locus from which it receives input. At a larger scale, the model shows how a focal top-down input from a forebrain region, the arcopallial gaze field, biases the competitive stimulus selection via the combined activation of a local excitation and the recurrent antitopographic inhibition. Our findings reveal circuit mechanisms of competitive stimulus selection and should motivate a search for anatomical implementations of these mechanisms in a range of vertebrate attentional systems.

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Laminar segregation of GABAergic neurons in the avian nucleus isthmi pars magnocellularis: A retrograde tracer and comparative study

Faunes

Fernández

Gutiérrez-Ibáñez

et al. 2013

J of Comparative Neurology

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The isthmic complex is part of a visual midbrain circuit thought to be involved in stimulus selection and spatial attention. In birds, this circuit is composed of the nuclei isthmi pars magnocellularis (Imc), pars parvocellularis (Ipc), and pars semilunaris (SLu), all of them reciprocally connected to the ipsilateral optic tectum (TeO). The Imc conveys heterotopic inhibition to the TeO, Ipc, and SLu via widespread γ-aminobutyric acid (GABA)ergic axons that allow global competitive interactions among simultaneous sensory inputs. Anatomical studies in the chick have described a cytoarchitectonically uniform Imc nucleus containing two intermingled cell types: one projecting to the Ipc and SLu and the other to the TeO. Here we report that in passerine species, the Imc is segregated into an internal division displaying larger, sparsely distributed cells, and an external division displaying smaller, more densely packed cells. In vivo and in vitro injections of neural tracers in the TeO and the Ipc of the zebra finch demonstrated that neurons from the external and internal subdivisions project to the Ipc and the TeO, respectively, indicating that each Imc subdivision contains one of the two cell types hodologically defined in the chick. In an extensive survey across avian orders, we found that, in addition to passerines, only species of Piciformes and Rallidae exhibited a segregated Imc, whereas all other groups exhibited a uniform Imc. These results offer a comparative basis to investigate the functional role played by each Imc neural type in the competitive interactions mediated by this nucleus.

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Generating oscillatory bursts from a network of regular spiking neurons without inhibition

Cited by 9 publications

References 83 publications

Attentional Capture? Synchronized Feedback Signals from the Isthmi Boost Retinal Signals to Higher Visual Areas

Attentional Capture? Synchronized Feedback Signals from the Isthmi Boost Retinal Signals to Higher Visual Areas

Recurrent Antitopographic Inhibition Mediates Competitive Stimulus Selection in an Attention Network

Laminar segregation of GABAergic neurons in the avian nucleus isthmi pars magnocellularis: A retrograde tracer and comparative study

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