@article {69092, title = {Different spectral sensitivities of ON- and OFF-motion pathways enhance the detection of approaching color objects in Drosophila.}, journal = {Nature Communications}, volume = {14}, year = {2023}, month = {2023 Nov 24}, pages = {7693}, abstract = {

Color and motion are used by many species to identify salient objects. They are processed largely independently, but color contributes to motion processing in humans, for example, enabling moving colored objects to be detected when their luminance matches the background. Here, we demonstrate an unexpected, additional contribution of color to motion vision in Drosophila. We show that behavioral ON-motion responses are more sensitive to UV than for OFF-motion, and we identify cellular pathways connecting UV-sensitive R7 photoreceptors to ON and OFF-motion-sensitive T4 and T5 cells, using neurogenetics and calcium imaging. Remarkably, this contribution of color circuitry to motion vision enhances the detection of approaching UV discs, but not green discs with the same chromatic contrast, and we show how this could generalize for systems with ON- and OFF-motion pathways. Our results provide a computational and circuit basis for how color enhances motion vision to favor the detection of saliently colored objects.

}, keywords = {Animals, Drosophila, Humans, Motion Perception, Photoreceptor Cells, Vision, Ocular}, issn = {2041-1723}, doi = {10.1038/s41467-023-43566-8}, author = {Longden, Kit D and Rogers, Edward M and Nern, Aljoscha and Dionne, Heather and Reiser, Michael B} } @article {69111, title = {Different spectral sensitivities of ON- and OFF-motion pathways enhance the detection of approaching color objects in Drosophila.}, journal = {Nature Communications}, volume = {14}, year = {2023}, month = {2023 Nov 24}, pages = {7693}, abstract = {

Color and motion are used by many species to identify salient objects. They are processed largely independently, but color contributes to motion processing in humans, for example, enabling moving colored objects to be detected when their luminance matches the background. Here, we demonstrate an unexpected, additional contribution of color to motion vision in Drosophila. We show that behavioral ON-motion responses are more sensitive to UV than for OFF-motion, and we identify cellular pathways connecting UV-sensitive R7 photoreceptors to ON and OFF-motion-sensitive T4 and T5 cells, using neurogenetics and calcium imaging. Remarkably, this contribution of color circuitry to motion vision enhances the detection of approaching UV discs, but not green discs with the same chromatic contrast, and we show how this could generalize for systems with ON- and OFF-motion pathways. Our results provide a computational and circuit basis for how color enhances motion vision to favor the detection of saliently colored objects.

}, keywords = {Animals, Drosophila, Humans, Motion Perception, Photoreceptor Cells, Vision, Ocular}, issn = {2041-1723}, doi = {10.1038/s41467-023-43566-8}, author = {Longden, Kit D and Rogers, Edward M and Nern, Aljoscha and Dionne, Heather and Reiser, Michael B} } @article {67952, title = {A functionally ordered visual feature map in the Drosophila brain.}, journal = {Neuron}, volume = {110}, year = {2022}, month = {2022 May 18}, pages = {1700}, abstract = {

Topographic maps, the systematic spatial ordering of neurons by response tuning, are common across species. In Drosophila, the lobula columnar (LC) neuron types project from the optic lobe to the central brain, where each forms a glomerulus in a distinct position. However, the advantages of this glomerular arrangement are unclear. Here, we examine the functional and spatial relationships of 10 glomeruli using single-neuron calcium imaging. We discover novel detectors for objects smaller than the lens resolution (LC18) and for complex line motion (LC25). We find that glomeruli are spatially clustered by selectivity for looming versus drifting object motion and ordered by size tuning to form a topographic visual feature map. Furthermore, connectome analysis shows that downstream neurons integrate from sparse subsets of possible glomeruli combinations, which are biased for glomeruli encoding similar features. LC neurons are thus an explicit example of distinct feature detectors topographically organized to facilitate downstream circuit integration.

}, issn = {1097-4199}, doi = {10.1016/j.neuron.2022.02.013}, author = {Klapoetke, Nathan C and Nern, Aljoscha and Rogers, Edward M and Rubin, Gerald M and Reiser, Michael B and Card, Gwyneth M} } @article {65847, title = {Spatial readout of visual looming in the central brain of Drosophila.}, journal = {eLife}, volume = {9}, year = {2020}, month = {2020 Nov 18}, abstract = {

Visual systems can exploit spatial correlations in the visual scene by using retinotopy. 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 , 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.

}, issn = {2050-084X}, doi = {10.7554/eLife.57685}, author = {Morimoto, Mai M and Nern, Aljoscha and Zhao, Arthur and Rogers, Edward M and Wong, Allan and Isaacson, Mathew D and Bock, Davi and Rubin, Gerald M and Reiser, Michael B} } @article {48982, title = {Behavioral state modulates the ON visual motion pathway of Drosophila.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {115}, year = {2017}, month = {2017 Dec 18}, pages = {E102-11}, abstract = {

The behavioral state of an animal can dynamically modulate visual processing. In flies, the behavioral state is known to alter the temporal tuning of neurons that carry visual motion information into the central brain. However, where this modulation occurs and how it tunes the properties of this neural circuit are not well understood. Here, we show that the behavioral state alters the baseline activity levels and the temporal tuning of the first directionally selective neuron in the ON motion pathway (T4) as well as its primary input neurons (Mi1, Tm3, Mi4, Mi9). These effects are especially prominent in the inhibitory neuron Mi4, and we show that central octopaminergic neurons provide input to Mi4 and increase its excitability. We further show that octopamine neurons are required for sustained behavioral responses to fast-moving, but not slow-moving, visual stimuli in walking flies. These results indicate that behavioral-state modulation acts directly on the inputs to the directionally selective neurons and supports efficient neural coding of motion stimuli.

}, issn = {1091-6490}, doi = {10.1073/pnas.1703090115}, author = {Strother, James A and Wu, Shiuan-Tze and Rogers, Edward M and Eliason, Jessica L M and Wong, Allan M and Nern, Aljoscha and Reiser, Michael B} } @article {48414, title = {The emergence of directional selectivity in the visual motion pathway of Drosophila.}, journal = {Neuron}, volume = {94}, year = {2017}, month = {2017 Apr 05}, pages = {168-182.e10}, abstract = {

The perception of visual motion is critical for animal navigation, and flies are a prominent model system for exploring this neural computation. In Drosophila, the T4 cells of the medulla are directionally selective and necessary for ON motion behavioral responses. To examine the emergence of directional selectivity, we developed genetic driver lines for the neuron types with the most synapses onto T4 cells. Using calcium imaging, we found that these neuron types are not directionally selective and that selectivity arises in the T4 dendrites. By silencing each input neuron type, we identified which neurons are necessary for T4 directional selectivity and ON motion behavioral responses. We then determined the sign of the connections between these neurons and T4 cells using neuronal photoactivation. Our results indicate a computational architecture for motion detection that is a hybrid of classic theoretical models.

}, issn = {1097-4199}, doi = {10.1016/j.neuron.2017.03.010}, author = {Strother, James A and Wu, Shiuan-Tze and Wong, Allan M and Nern, Aljoscha and Rogers, Edward M and Le, Jasmine Q and Rubin, Gerald M and Reiser, Michael B} } @article {48934, title = {Ultra-selective looming detection from radial motion opponency.}, journal = {Nature}, volume = {551}, year = {2017}, month = {2017 Nov 08}, pages = {237-241}, abstract = {

Nervous systems combine lower-level sensory signals to detect higher-order stimulus features critical to survival, such as the visual looming motion created by an imminent collision or approaching predator. Looming-sensitive neurons have been identified in diverse animal species. Different large-scale visual features such as looming often share local cues, which means loom-detecting neurons face the challenge of rejecting confounding stimuli. Here we report the discovery of an ultra-selective looming detecting neuron, lobula plate/lobula columnar, type II (LPLC2) in Drosophila, and show how its selectivity is established by radial motion opponency. In the fly visual system, directionally selective small-field neurons called T4 and T5 form a spatial map in the lobula plate, where they each terminate in one of four retinotopic layers, such that each layer responds to motion in a different cardinal direction. Single-cell anatomical analysis reveals that each arm of the LPLC2 cross-shaped primary dendrites ramifies in one of these layers and extends along that layer{\textquoteright}s preferred motion direction. In vivo calcium imaging demonstrates that, as their shape predicts, individual LPLC2 neurons respond strongly to outward motion emanating from the centre of the neuron{\textquoteright}s receptive field. Each dendritic arm also receives local inhibitory inputs directionally selective for inward motion opposing the excitation. This radial motion opponency generates a balance of excitation and inhibition that makes LPLC2 non-responsive to related patterns of motion such as contraction, wide-field rotation or luminance change. As a population, LPLC2 neurons densely cover visual space and terminate onto the giant fibre descending neurons, which drive the jump muscle motor neuron to trigger an escape take off. Our findings provide a mechanistic description of the selective feature detection that flies use to discern and escape looming threats.

}, issn = {1476-4687}, doi = {10.1038/nature24626}, author = {Klapoetke, Nathan C and Nern, Aljoscha and Peek, Martin Y and Rogers, Edward M and Breads, Patrick and Rubin, Gerald M and Reiser, Michael B and Card, Gwyneth M} }