scholarly journals Connectivity establishes spatial readout of visual looming in a glomerulus lacking retinotopy

2020 ◽  
Author(s):  
Mai M. Morimoto ◽  
Aljoscha Nern ◽  
Arthur Zhao ◽  
Edward M. Rogers ◽  
Allan M. Wong ◽  
...  
Keyword(s):  
Visual Field ◽  
Visual Information ◽  
Spatial Information ◽  
Behavioral Control ◽  
Cell Types ◽  
Spatial Correlations ◽  
Contralateral Suppression ◽  
Central Brain ◽  
Retinotopic Organization ◽  
Spatial Locations

AbstractVisual systems can exploit spatial correlations in the visual scene by using retinotopy, the organizing principle by which neighboring cells encode neighboring spatial locations. However, retinotopy is often lost, such as when visual pathways are integrated with other sensory modalities. How is spatial information processed in the absence of retinotopy? Here, we focused on visual looming responsive LC6 cells in Drosophila, a population whose dendrites collectively tile the visual field, but whose axons form a single glomerulus—a structure lacking retinotopic organization—in the central brain. We identified multiple glomerulus neurons and found that they respond to looming in different portions of the visual field, unexpectedly preserving spatial information. Through EM reconstruction of all LC6 synaptic inputs to the glomerulus, we found that LC6 and downstream cell types form circuits within the glomerulus that establish spatial readout of visual features and contralateral suppression—mechanisms that transform visual information for behavioral control.

scholarly journals Spatial readout of visual looming in the central brain of Drosophila

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Mai M Morimoto ◽  
Aljoscha Nern ◽  
Arthur Zhao ◽  
Edward M Rogers ◽  
Allan M Wong ◽  
...  
Keyword(s):  
Visual Field ◽  
Visual Information ◽  
Spatial Information ◽  
Behavioral Control ◽  
Cell Types ◽  
Spatial Correlations ◽  
Central Brain ◽  
Retinotopic Organization ◽  
Multiple Cell ◽  
Spatial Locations

Visual systems can exploit spatial correlations in the visual scene by using retinotopy, the organizing principle by which neighboring cells encode neighboring spatial locations. However, retinotopy is often lost, such as when visual pathways are integrated with other sensory modalities. How is spatial information processed outside of strictly visual brain areas? Here, we focused on visual looming responsive LC6 cells in Drosophila, a population whose dendrites collectively cover the visual field, but whose axons form a single glomerulus—a structure without obvious retinotopic organization—in the central brain. We identified multiple cell types downstream of LC6 in the glomerulus and found that they more strongly respond to looming in different portions of the visual field, unexpectedly preserving spatial information. Through EM reconstruction of all LC6 synaptic inputs to the glomerulus, we found that LC6 and downstream cell types form circuits within the glomerulus that enable spatial readout of visual features and contralateral suppression—mechanisms that transform visual information for behavioral control.

scholarly journals Parallel visual pathways with topographic versus non-topographic organization connect the Drosophila eyes to the central brain

2020 ◽  
Author(s):  
Lorin Timaeus ◽  
Laura Geid ◽  
Gizem Sancer ◽  
Mathias F. Wernet ◽  
Thomas Hummel
Keyword(s):  
Visual Information ◽  
Visual Cues ◽  
Spatial Information ◽  
Central Complex ◽  
Structural Basis ◽  
Projection Neurons ◽  
Central Brain ◽  
Retinotopic Organization ◽  
Dendritic Fields ◽  
Parallel Visual Pathways

SummaryOne hallmark of the visual system is the strict retinotopic organization from the periphery towards the central brain, spanning multiple layers of synaptic integration. Recent Drosophila studies on the computation of distinct visual features have shown that retinotopic representation is often lost beyond the optic lobes, due to convergence of columnar neuron types onto optic glomeruli. Nevertheless, functional imaging revealed a spatially accurate representation of visual cues in the central complex (CX), raising the question how this is implemented on a circuit level. By characterizing the afferents to a specific visual glomerulus, the anterior optic tubercle (AOTU), we discovered a spatial segregation of topographic versus non-topographic projections from molecularly distinct classes of medulla projection neurons (medullo-tubercular, or MeTu neurons). Distinct classes of topographic versus non-topographic MeTus form parallel channels, terminating in separate AOTU domains. Both types then synapse onto separate matching topographic fields of tubercular-bulbar (TuBu) neurons which relay visual information towards the dendritic fields of central complex ring neurons in the bulb neuropil, where distinct bulb sectors correspond to a distinct ring domain in the ellipsoid body. Hence, peripheral topography is maintained due to stereotypic circuitry within each TuBu class, providing the structural basis for spatial representation of visual information in the central complex. Together with previous data showing rough topography of lobula projections to a different AOTU subunit, our results further highlight the AOTUs role as a prominent relay station for spatial information from the retina to the central brain.

scholarly journals Direct comparison of category and spatial selectivity in human occipitotemporal cortex

2021 ◽  
Author(s):  
Edward H Silson ◽  
Iris Isabelle Anna Groen ◽  
Chris I Baker
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Visual Information ◽  
Large Scale ◽  
Spatial Information ◽  
Temporal Cortex ◽  
Occipital Cortex ◽  
Right Visual Field ◽  
Ventral Temporal Cortex ◽  
Category Bias

Human visual cortex is organised broadly according to two major principles: retinotopy (the spatial mapping of the retina in cortex) and category-selectivity (preferential responses to specific categories of stimuli). Historically, these principles were considered anatomically separate, with retinotopy restricted to the occipital cortex and category-selectivity emerging in lateral-occipital and ventral-temporal cortex. Contrary to this assumption, recent studies show that category-selective regions exhibit systematic retinotopic biases. It is unclear, however, whether responses within these regions are more strongly driven by retinotopic location or by category preference, and if there are systematic differences between category-selective regions in the relative strengths of these preferences. Here, we directly compare spatial and category preferences by measuring fMRI responses to scene and face stimuli presented in the left or right visual field and computing two bias indices: a spatial bias (response to the contralateral minus ipsilateral visual field) and a category bias (response to the preferred minus non-preferred category). We compare these biases within and between scene- and face-selective regions across the lateral and ventral surfaces of visual cortex. We find an interaction between surface and bias: lateral regions show a stronger spatial than category bias, whilst ventral regions show the opposite. These effects are robust across and within subjects, and reflect large-scale, smoothly varying gradients across both surfaces. Together, these findings support distinct functional roles for lateral and ventral category-selective regions in visual information processing in terms of the relative importance of spatial information.

Auditory Spatial Information and Head-Coupled Display Systems

1988 ◽  
Vol 32 (2) ◽  
pp. 75-75
Author(s):  
Thomas Z. Strybel
Keyword(s):  
Visual Field ◽  
Visual Information ◽  
Spatial Information ◽  
Three Dimensional ◽  
Field Of View ◽  
Auditory Modality ◽  
Auditory Information ◽  
Display System ◽  
Direct Head ◽  
Display Systems

Developments of head-coupled control/display systems have focused primarily on the display of three dimensional visual information, as the visual system is the optimal sensory channel for the aquisition of spatial information in humans. The auditory system improves the efficiency of vision, however, by obtaining spatial information about relevant objects outside of the visual field of view. This auditory information can be used to direct head and eye movements. Head-coupled display systems, can also benefit from the addition of auditory spatial information, as it provides a natural method of signaling the location of important events outside of the visual field of view. This symposium will report on current efforts in the developments of head-coupled display systems, with an emphasis on the auditory spatial component. The first paper “Virtual Interface Environment Workstations”, by Scott S. Fisher, will report on the development of a prototype virtual environment. This environment consists of a head-mounted, wide-angle, stereoscopic display system which is controlled by operator position, voice, and gesture. With this interface, an operator can virtually explore a 360 degree synthesized environment, and viscerally interact with its components. The second paper, “A Virtual Display System For Conveying Three-Dimensional Acoustic Information” by Elizabeth M. Wenzel, Frederic L. Wightman and Scott H. Foster, will report on the development of a method of synthetically generating three-dimensional sound cues for the above-mentioned interface. The development of simulated auditory spatial cues is limited to some extent, by our knowlege of auditory spatial processing. The remaining papers will report on two areas of auditory space perception that have recieved little attention until recently. “Perception of Real and Simulated Motion in the Auditory Modality”, by Thomas Z. Strybel, will review recent research on auditory motion perception, because a natural acoustic environment must contain moving sounds. This review will consider applications of this knowledge to head-coupled display systems. The last paper, “Auditory Psychomotor Coordination”, will examine the interplay between the auditory, visual and motor systems. The specific emphasis of this paper is the use of auditory spatial information in the regulation of motor responses so as to provide efficient application of the visual channel.

scholarly journals A topographic visual pathway into the central brain of Drosophila

2017 ◽  
Author(s):  
Lorin Timaeus ◽  
Laura Geid ◽  
Thomas Hummel
Keyword(s):  
Visual Information ◽  
Spatial Representation ◽  
Spatial Information ◽  
Complex Structure ◽  
Central Complex ◽  
Structural Basis ◽  
Projection Neurons ◽  
Optic Lobes ◽  
Central Brain ◽  
Dendritic Fields

SummaryThe visual system is characterized by a strict topographic organization from the retina towards multiple layers of synaptic integration. Recent studies in Drosophila have shown that in the transition from the optic lobes to the central brain, due to convergence of columnar neurons onto optic glomeruli, distinct synaptic units employed in the computation of different visual features, the retinotopic representation is lost in these circuits. However, functional imaging revealed a spatial representation of visual cues in the Drosophila central complex, raising the question about the underlying circuitry, which bypasses optic glomerulus convergence.While characterizing afferent arborizations within Drosophila visual glomeruli, we discovered a spatial segregation of topographic and non-topographic projections from distinct molecular classes of medulla projection neurons, medullo-tubercular (MeTu) neurons, into a specific central brain glomerulus, the anterior optic tubercle (AOTu). Single cell analysis revealed that topographic information is organized by ensembles of MeTu neurons (type 1), forming parallel channels within the AOTu, while a separate class of MeTu neurons (type 2) displays convergent projection, associated with a loss of spatial resolution. MeTu afferents in the AOTu synapse onto a matching topographic field of output projection neurons, these tubercular-bulbar (TuBu) neurons relay visual information towards dendritic fields of central complex ring neurons in the bulb neuropil. Within the bulb, neuronal proximity of the topographic AOTu map as well as channel identity is maintained despite the absence of a stereotyped map organization, providing the structural basis for spatial representation of visual information in the central complex (CX). TuBu neurons project onto dendritic fields of efferent ring neurons, where distinct sectors of the bulb correspond to a distinct ring domain in the ellipsoid body. We found a stereotypic circuitry for each analyzed TuBu class, thus the individual channels of peripheral topography are maintained in the central complex structure. Together with previous data showing rough topography within the lobula AOTu domain, our results on the organization of medulla projection neurons define the AOTu neuropil as the main relay station for spatial information from the optic lobes into the central brain.

Retinal ganglion cell density of the black rhinoceros (Diceros bicornis): Calculating visual resolution

2008 ◽  
Vol 25 (2) ◽  
pp. 215-220 ◽  
Author(s):  
JOHN D. PETTIGREW ◽  
PAUL R. MANGER
Keyword(s):  
Visual Field ◽  
Ganglion Cell ◽  
Cell Density ◽  
Visual Information ◽  
Ganglion Cells ◽  
Cell Types ◽  
Domestic Cat ◽  
Retinal Ganglion ◽  
Black Rhinoceros ◽  
Visual Resolution

AbstractA single right retina from a black rhinoceros was whole mounted, stained and analyzed to determine the visual resolution of the rhinoceros, an animal with reputedly poor eyesight. A range of small (15-μm diameter) to large (100-μm diameter) ganglion cell types was seen across the retina. We observed two regions of high density of retinal ganglion cells at either end of a long, but thin, horizontal streak. The temporal specialization, which receives light from the anterior visual field, exhibited a ganglion cell density of approximately 2000/mm2, while the nasal specialization exhibited a density of approximately 1500/mm2. The retina exhibited a ganglion cell density bias toward the upper half, especially so, the upper temporal quadrant, indicating that the rhinoceros would be processing visual information from the visual field below the anterior horizon for the most part. Our calculations indicate that the rhinoceros has a visual resolution of 6 cycles/degree. While this resolution is one-tenth that of humans (60 cycles/deg) and less than that of the domestic cat (9 cycles/deg), it is comparable to that of the rabbit (6 cycles/deg), and exceeds that seen in a variety of other mammals including seals, dolphins, microbats, and rats. Thus, the reputation of the rhinoceros as a myopic, weakly visual animal is not supported by our observations of the retina. We calculate that the black rhinoceros could readily distinguish a 30 cm wide human at a distance of around 200 m given the appropriate visual background.

scholarly journals Cell types and neuronal circuitry underlying female aggression in Drosophila

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Catherine E Schretter ◽  
Yoshinori Aso ◽  
Alice A Robie ◽  
Marisa Dreher ◽  
Michael-John Dolan ◽  
...  
Keyword(s):  
Social Interactions ◽  
Visual Information ◽  
Internal State ◽  
Cell Types ◽  
Female Aggression ◽  
Sexually Dimorphic ◽  
Neuronal Circuitry ◽  
Genetic Inactivation ◽  
Descending Neurons ◽  
Central Brain

Aggressive social interactions are used to compete for limited resources and are regulated by complex sensory cues and the organism’s internal state. While both sexes exhibit aggression, its neuronal underpinnings are understudied in females. Here, we identify a population of sexually dimorphic aIPg neurons in the adult Drosophila melanogaster central brain whose optogenetic activation increased, and genetic inactivation reduced, female aggression. Analysis of GAL4 lines identified in an unbiased screen for increased female chasing behavior revealed the involvement of another sexually dimorphic neuron, pC1d, and implicated aIPg and pC1d neurons as core nodes regulating female aggression. Connectomic analysis demonstrated that aIPg neurons and pC1d are interconnected and suggest that aIPg neurons may exert part of their effect by gating the flow of visual information to descending neurons. Our work reveals important regulatory components of the neuronal circuitry that underlies female aggressive social interactions and provides tools for their manipulation.

scholarly journals Cognitive map formation through haptic and visual exploration of tactile city-like maps

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Loes Ottink ◽  
Marit Hoogendonk ◽  
Christian F. Doeller ◽  
Thea M. Van der Geest ◽  
Richard J. A. Van Wezel
Keyword(s):  
Visual Information ◽  
Spatial Information ◽  
Cognitive Map ◽  
Visual Exploration ◽  
Distinct Advantage ◽  
Small Scale ◽  
Map Learning ◽  
Scale Models ◽  
Spatial Tasks ◽  
Tactile Maps

AbstractIn this study, we compared cognitive map formation of small-scale models of city-like environments presented in visual or tactile/haptic modalities. Previous research often addresses only a limited amount of cognitive map aspects. We wanted to combine several of these aspects to elucidate a more complete view. Therefore, we assessed different types of spatial information, and consider egocentric as well as allocentric perspectives. Furthermore, we compared haptic map learning with visual map learning. In total 18 sighted participants (9 in a haptic condition, 9 visuo-haptic) learned three tactile maps of city-like environments. The maps differed in complexity, and had five marked locations associated with unique items. Participants estimated distances between item pairs, rebuilt the map, recalled locations, and navigated two routes, after learning each map. All participants overall performed well on the spatial tasks. Interestingly, only on the complex maps, participants performed worse in the haptic condition than the visuo-haptic, suggesting no distinct advantage of vision on the simple map. These results support ideas of modality-independent representations of space. Although it is less clear on the more complex maps, our findings indicate that participants using only haptic or a combination of haptic and visual information both form a quite accurate cognitive map of a simple tactile city-like map.

Retinal input influences pace of neurogenesis but not cell-type configuration of the visual forebrain

2021 ◽  
Author(s):  
Shachar Sherman ◽  
Koichi Kawakami ◽  
Herwig Baier
Keyword(s):  
Visual Information ◽  
Visual Stimulation ◽  
Ganglion Cells ◽  
Neuronal Cell ◽  
Cell Types ◽  
Vertebrate Brain ◽  
Relative Contribution ◽  
Retinal Input ◽  
And Migration ◽  
The Brain

The brain is assembled during development by both innate and experience-dependent mechanisms1-7, but the relative contribution of these factors is poorly understood. Axons of retinal ganglion cells (RGCs) connect the eye to the brain, forming a bottleneck for the transmission of visual information to central visual areas. RGCs secrete molecules from their axons that control proliferation, differentiation and migration of downstream components7-9. Spontaneously generated waves of retinal activity, but also intense visual stimulation, can entrain responses of RGCs10 and central neurons11-16. Here we asked how the cellular composition of central targets is altered in a vertebrate brain that is depleted of retinal input throughout development. For this, we first established a molecular catalog17 and gene expression atlas18 of neuronal subpopulations in the retinorecipient areas of larval zebrafish. We then searched for changes in lakritz (atoh7-) mutants, in which RGCs do not form19. Although individual forebrain-expressed genes are dysregulated in lakritz mutants, the complete set of 77 putative neuronal cell types in thalamus, pretectum and tectum are present. While neurogenesis and differentiation trajectories are overall unaltered, a greater proportion of cells remain in an uncommitted progenitor stage in the mutant. Optogenetic stimulation of a pretectal area20,21 evokes a visual behavior in blind mutants indistinguishable from wildtype. Our analysis shows that, in this vertebrate visual system, neurons are produced more slowly, but specified and wired up in a proper configuration in the absence of any retinal signals.

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