Axonal topography of cortical basket cells in relation to orientation, direction, and ocular dominance maps

Buzás, Péter; Eysel, Ulf T.; Adorján, Péter; Kisvárday, Zoltán F.

doi:10.1002/cne.1282

Cited by 89 publications

(75 citation statements)

References 114 publications

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“…This is in broad agreement with a photostimulation study showing that short-range synaptic inputs of V1 neurons tend to be isooriented, whereas longer-range inputs are more evenly distributed across orientation domains (Roerig and Chen, 2002). Moreover, the (shorter) projections of medium-sized basket cells are mainly found in same-eye ocular dominance domains, whereas the long-distance projections of large basket cells contact both same-and opposite-eye domains (Buzás et al, 2001).…”

Section: Anatomical Substrates Of Intracortical Inhibitionsupporting

confidence: 90%

“…Although the specificity of Martinotti cell projections in the primary visual cortex is as yet unknown, a number of studies have related basket cell projections to the V1 functional architecture (for review, see Kisvárday et al, 2000). The exclusively local projections of layer 4 clutch cells, and the local projections of layer 2/3 medium-sized basket cells (which make up three-fourths of their total projections) are predominantly found in iso-orientation target sites (Buzás et al, 2001). In contrast, the long-distance (Ͼ500 m) projections of layer 3 large basket cells are somewhat biased toward cross-orientation sites.…”

Section: Anatomical Substrates Of Intracortical Inhibitionmentioning

confidence: 99%

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Intracortical Origins of Interocular Suppression in the Visual Cortex

Sengpiel¹,

Vorobyov²

2005

J. Neurosci.

104

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The response of neurons in the primary visual cortex to an optimally oriented grating is usually suppressed quite dramatically when a second grating of, for example, orthogonal orientation is superimposed. Such "cross-orientation suppression" has been implicated in the generation of cortical orientation selectivity and local response normalization. Until recently, little experimental evidence was available concerning the neurophysiological substrate of this phenomenon, although an involvement of intracortical inhibition was commonly assumed. However, Freeman et al. (2002) proposed that cortical cross-orientation suppression is caused by suppression in the thalamus and depression at geniculocortical synapses. Here, we examine a dichoptic form of cross-orientation suppression, termed interocular suppression and thought to be involved in binocular rivalry (Sengpiel et al., 1995a). We show that its dependency on the drift rate of the suppressing stimulus is consistent with a cortical origin; unlike monocular cross-orientation suppression, it cannot be evoked by very fast-moving stimuli. Moreover, we find that previous adaptation to the orthogonal stimulus essentially eliminates interocular suppression. Because adaptation is a cortical phenomenon, this result also argues in favor of a cortical locus of suppression, again unlike monocular cross-orientation suppression, which is not affected by adaptation to the suppressor (Freeman et al., 2002). Finally, interocular suppression is greatly reduced in the presence of the GABA antagonist bicuculline. Together, our study demonstrates that interocular suppression is substantially different from monocular cross-orientation suppression and is mediated by inhibitory circuitry within the visual cortex.

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Section: Anatomical Substrates Of Intracortical Inhibitionsupporting

confidence: 90%

Section: Anatomical Substrates Of Intracortical Inhibitionmentioning

confidence: 99%

Intracortical Origins of Interocular Suppression in the Visual Cortex

Sengpiel¹,

Vorobyov²

2005

J. Neurosci.

104

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“…Basket cells in layer 2/3 Ahmed et al, 1998;Buzás et al, 2001) (Fig. 2, b2/3) formed 93 Ϯ 6% of the synapses in layer 2/3.…”

Section: Synaptic Laminar Patterns Of Smooth Cell Typesmentioning

confidence: 99%

“…2, b2/3) formed 93 Ϯ 6% of the synapses in layer 2/3. Basket cells in layer 4 Kisvárday et al, 1985;Ahmed et al, 1997;Buzás et al, 2001) (Fig. 2, b4) formed 90 Ϯ 8% of their synapses in layer 4, and the layer 5 basket cells (Kisvárday et al, 1987) (Fig.…”

Section: Synaptic Laminar Patterns Of Smooth Cell Typesmentioning

confidence: 99%

A Quantitative Map of the Circuit of Cat Primary Visual Cortex

Binzegger¹,

Douglas²,

Martin³

2004

J. Neurosci.

801

996

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We developed a quantitative description of the circuits formed in cat area 17 by estimating the "weight" of the projections between different neuronal types. To achieve this, we made three-dimensional reconstructions of 39 single neurons and thalamic afferents labeled with horseradish peroxidase during intracellular recordings in vivo. These neurons served as representatives of the different types and provided the morphometrical data about the laminar distribution of the dendritic trees and synaptic boutons and the number of synapses formed by a given type of neuron. Extensive searches of the literature provided the estimates of numbers of the different neuronal types and their distribution across the cortical layers. Applying the simplification that synapses between different cell types are made in proportion to the boutons and dendrites that those cell types contribute to the neuropil in a given layer, we were able to estimate the probable source and number of synapses made between neurons in the six layers. The predicted synaptic maps were quantitatively close to the estimates derived from the experimentalelectronmicroscopicstudiesforthecaseofthemainsourcesofexcitatoryandinhibitoryinputtothespinystellatecells,whichform a major target of layer 4 afferents. The map of the whole cortical circuit shows that there are very few "strong" but many "weak" excitatory projections, each of which may involve only a few percentage of the total complement of excitatory synapses of a single neuron.

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“…S4). Large basket cells in cat visual cortex extend a wide, horizontal axonal plexus that can span ocular dominance columns (27 ), which is useful for discriminating input coming from the two eyes. Among the great diversity of GABA A receptors (12), only those containing the α1 subunit drive the functional shift of ocular dominance following monocular deprivation in mice (28).…”

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confidence: 99%

Columnar Architecture Sculpted by GABA Circuits in Developing Cat Visual Cortex

Hensch

Stryker

2004

Science

167

115

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The mammalian visual cortex is organized into columns. Here, we examine cortical influences upon developing visual afferents in the cat by altering intrinsic γ-aminobutyric acid (GABA)-mediated inhibition with benzodiazepines. Local enhancement by agonist (diazepam) infusion did not perturb visual responsiveness, but did widen column spacing. An inverse agonist (DMCM) produced the opposite effect. Thus, intracortical inhibitory circuits shape the geometry of incoming thalamic arbors, suggesting that cortical columnar architecture depends on neuronal activity.Columnar architecture is the hallmark of the mammalian neocortex. What determines the final dimensions of individual columns, however, remains largely unknown. Manipulations of early visual experience indicate that the segregation of eye-specific columns is a competitive process between axons serving the two eyes in primary visual cortex (1,2). Cortical target neurons detect patterns of input activity to strengthen those connections correlated with their own firing, while weakening un-correlated afferent input. Gross disruption of postsynaptic activity supports such a correlation-based mechanism of refinement (3,4 ). Yet, recent reports have shown that initial clustering of individual thalamocortical arbors occurs at least a week before the critical period (5), leading to a suggestion that it may be largely genetically predetermined (6 ) rather than emerging from an initially overlapping configuration.Computational models based on traditional, self-organizing principles offer specific predictions about column spacing (7,8). Local excitatory connections within cortex may spread incoming afferent activity over a certain radius, which is ultimately limited by farther-reaching inhibition. Modulating the relative balance of excitation to inhibition alters the shape of this interaction function. Activity-dependent processes acting upon narrowed or broadened central excitatory regions would ultimately yield slender or wide columns, respectively (7,8). Here, we tested this hypothesis in developing kitten visual cortex.We measured the final size of ocular dominance columns after locally altering the inhibition intrinsic to visual cortex in vivo for 1 month starting 2 weeks after birth. At this age, physiological and anatomical data show that columns are beginning to segregate (5). Yet, individual thalamocortical arbors in the cat extend sparse, broadly distributed processes that have yet to focus their branching (9). Because direct activation of γ-aminobutyric acid (GABA) receptors with muscimol disrupts column formation (3), we used a local enhancement of intracortical inhibition during development that does not silence cortex (Fig. 1A) (10).

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Axonal topography of cortical basket cells in relation to orientation, direction, and ocular dominance maps

Cited by 89 publications

References 114 publications

Intracortical Origins of Interocular Suppression in the Visual Cortex

Intracortical Origins of Interocular Suppression in the Visual Cortex

A Quantitative Map of the Circuit of Cat Primary Visual Cortex

Columnar Architecture Sculpted by GABA Circuits in Developing Cat Visual Cortex

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