scholarly journals Synaptic targets of photoreceptors specialized to detect color and skylight polarization in Drosophila

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Emil Kind ◽  
Kit D Longden ◽  
Aljoscha Nern ◽  
Arthur Zhao ◽  
Gizem Sancer ◽  
...  
Keyword(s):  
Neural Circuits ◽  
Polarized Light ◽  
Cell Types ◽  
Brain Regions ◽  
Complementary Information ◽  
Color Processing ◽  
Optic Lobes ◽  
Skylight Polarization ◽  
The World ◽  
Central Brain

Color and polarization provide complementary information about the world and are detected by specialized photoreceptors. However, the downstream neural circuits that process these distinct modalities are incompletely understood in any animal. Using electron microscopy, we have systematically reconstructed the synaptic targets of the photoreceptors specialized to detect color and skylight polarization in Drosophila, and we have used light microscopy to confirm many of our findings. We identified known and novel downstream targets that are selective for different wavelengths or polarized light, and followed their projections to other areas in the optic lobes and the central brain. Our results revealed many synapses along the photoreceptor axons between brain regions, new pathways in the optic lobes, and spatially segregated projections to central brain regions. Strikingly, photoreceptors in the polarization-sensitive dorsal rim area target fewer cell types, and lack strong connections to the lobula, a neuropil involved in color processing. Our reconstruction identifies shared wiring and modality-specific specializations for color and polarization vision, and provides a comprehensive view of the first steps of the pathways processing color and polarized light inputs.

scholarly journals Synaptic targets of functionally specialized R7 and R8 photoreceptors in the central eye and dorsal rim area of Drosophila

2021 ◽  
Author(s):  
Emil Kind ◽  
Kit D. Longden ◽  
Aljoscha Nern ◽  
Arthur Zhao ◽  
Gizem Sancer ◽  
...  
Keyword(s):  
Neural Circuits ◽  
Light And Electron Microscopy ◽  
Polarized Light ◽  
Cell Types ◽  
Polarization Vision ◽  
Complementary Information ◽  
Color Processing ◽  
Dorsal Rim Area ◽  
The World ◽  
Central Brain

Color and polarization provide complementary information about the world and are detected by specialized photoreceptors. However, the downstream neural circuits that process these distinct modalities are incompletely understood in any animal. We have systematically reconstructed, using light and electron microscopy, the synaptic targets of the photoreceptors specialized to detect color and polarized light in Drosophila. We identified known and novel downstream targets that are selective for different wavelengths as well as for polarized light and followed their projections to other areas in the optic lobes and the central brain. Strikingly, photoreceptors in the polarization-sensitive dorsal rim area target fewer cell types, that lack strong connections to the lobula, a neuropil with a proposed role in color processing. Our reconstruction identifies shared wiring and modality-specific specializations for color and polarization vision, and provides a comprehensive view of the first steps of the pathways processing color and polarized light inputs.

scholarly journals Cellular and synaptic adaptations of neural circuits processing skylight polarization in the fly

2019 ◽  
Author(s):  
Gizem Sancer ◽  
Emil Kind ◽  
Juliane Uhlhorn ◽  
Julia Volkmann ◽  
Johannes Hammacher ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Functional Role ◽  
Neural Circuits ◽  
Cell Types ◽  
Neuronal Morphology ◽  
Synaptic Membranes ◽  
Polarization Vision ◽  
Optic Lobes ◽  
Skylight Polarization ◽  
Central Brain

AbstractSpecialized ommatidia harboring polarization-sensitive photoreceptors exist in the ‘dorsal rim area’ (DRA) of virtually all insects. Although downstream elements have been described both anatomically and physiologically throughout the optic lobes and the central brain of different species, little is known about their cellular and synaptic adaptations and how these shape their functional role in polarization vision. We have previously shown that in the DRA of Drosophila melanogaster, two distinct types of modality-specific ‘distal medulla’ cell types (Dm-DRA1 and Dm-DRA2) are post-synaptic to long visual fiber photoreceptors R7 and R8, respectively. Here we describe additional neuronal elements in the medulla neuropil that manifest modality-specific differences in the DRA region, including DRA-specific neuronal morphology, as well as differences in the structure of pre- or post-synaptic membranes. Furthermore, we show that certain cell types (medulla tangential cells and octopaminergic neuromodulatory cells) specifically avoid contacts with polarization-sensitive photoreceptors. Finally, while certain transmedullary cells are specifically absent from DRA medulla columns, other subtypes show specific wiring differences while still connecting the DRA to the lobula complex, as previously been described in larger insects. This hints towards a complex circuit architecture with more than one pathway connecting polarization-sensitive DRA photoreceptors with the central brain.

scholarly journals A Connectome of the Adult Drosophila Central Brain

2020 ◽  
Author(s):  
C. Shan Xu ◽  
Michal Januszewski ◽  
Zhiyuan Lu ◽  
Shin-ya Takemura ◽  
Kenneth J. Hayworth ◽  
...  
Keyword(s):  
Large Fraction ◽  
Large Data ◽  
Fruit Fly ◽  
Cell Types ◽  
Brain Regions ◽  
Central Complex ◽  
Data Set ◽  
New Methods ◽  
Central Brain ◽  
The Brain

AbstractThe neural circuits responsible for behavior remain largely unknown. Previous efforts have reconstructed the complete circuits of small animals, with hundreds of neurons, and selected circuits for larger animals. Here we (the FlyEM project at Janelia and collaborators at Google) summarize new methods and present the complete circuitry of a large fraction of the brain of a much more complex animal, the fruit fly Drosophila melanogaster. Improved methods include new procedures to prepare, image, align, segment, find synapses, and proofread such large data sets; new methods that define cell types based on connectivity in addition to morphology; and new methods to simplify access to a large and evolving data set. From the resulting data we derive a better definition of computational compartments and their connections; an exhaustive atlas of cell examples and types, many of them novel; detailed circuits for most of the central brain; and exploration of the statistics and structure of different brain compartments, and the brain as a whole. We make the data public, with a web site and resources specifically designed to make it easy to explore, for all levels of expertise from the expert to the merely curious. The public availability of these data, and the simplified means to access it, dramatically reduces the effort needed to answer typical circuit questions, such as the identity of upstream and downstream neural partners, the circuitry of brain regions, and to link the neurons defined by our analysis with genetic reagents that can be used to study their functions.Note: In the next few weeks, we will release a series of papers with more involved discussions. One paper will detail the hemibrain reconstruction with more extensive analysis and interpretation made possible by this dense connectome. Another paper will explore the central complex, a brain region involved in navigation, motor control, and sleep. A final paper will present insights from the mushroom body, a center of multimodal associative learning in the fly brain.

scholarly journals A visual pathway for skylight polarization processing in Drosophila

2020 ◽  
Author(s):  
Ben J. Hardcastle ◽  
Jaison J. Omoto ◽  
Pratyush Kandimalla ◽  
Bao-Chau M. Nguyen ◽  
Mehmet F. Keleş ◽  
...  
Keyword(s):  
Polarized Light ◽  
Fruit Fly ◽  
Visual Pathway ◽  
Central Complex ◽  
Reduced Representation ◽  
Central Processing ◽  
Use Patterns ◽  
Sense Of Direction ◽  
Skylight Polarization ◽  
Central Brain

SUMMARYMany insects use patterns of polarized light in the sky to orient and navigate. Here we functionally characterize neural circuitry in the fruit fly, Drosophila melanogaster, that conveys polarized light signals from the eye to the central complex, a brain region essential for the fly’s sense of direction. Neurons tuned to the angle of polarization of ultraviolet light are found throughout the anterior visual pathway, connecting the optic lobes with the central complex via the anterior optic tubercle and bulb, in a homologous organization to the ‘sky compass’ pathways described in other insects. We detail how a consistent, map-like organization of neural tunings in the peripheral visual system is transformed into a reduced representation suited to flexible processing in the central brain. This study identifies computational motifs of the transformation, enabling mechanistic comparisons of multisensory integration and central processing for navigation in the brains of insects.

scholarly journals Classification and genetic targeting of cell types in the primary taste and premotor center of the Drosophila brain

2021 ◽  
Author(s):  
Gabriella R Sterne ◽  
Hideo Otsuna ◽  
Barry J Dickson ◽  
Kristin Scott
Keyword(s):  
Sensory Processing ◽  
Neural Circuits ◽  
Cell Types ◽  
Brain Regions ◽  
Projection Neurons ◽  
Sensorimotor Transformations ◽  
Drosophila Brain ◽  
Genetic Targeting ◽  
And Behavior ◽  
Insight Into

Neural circuits carry out complex computations that allow animals to evaluate food, select mates, move toward attractive stimuli, and move away from threats. In insects, the subesophageal zone (SEZ) is a brain region that receives gustatory, pheromonal, and mechanosensory inputs and contributes to the control of diverse behaviors, including feeding, grooming, and locomotion. Despite its importance in sensorimotor transformations, the study of SEZ circuits has been hindered by limited knowledge of the underlying diversity of SEZ neurons. Here, we generate a collection of split-GAL4 lines that provides precise genetic targeting of 138 different SEZ cell types in adult D. melanogaster, comprising approximately one third of all SEZ neurons. We characterize the single cell anatomy of these neurons and find that they cluster by morphology into six supergroups that organize the SEZ into discrete anatomical domains. We find that the majority of local SEZ interneurons are not classically polarized, suggesting rich local processing, whereas SEZ projection neurons tend to be classically polarized, conveying information to a limited number of higher brain regions. This study provides insight into the anatomical organization of the SEZ and generates resources that will facilitate further study of SEZ neurons and their contributions to sensory processing and behavior.

Conscious Mind, Resonant Brain

2021 ◽  
Author(s):  
Stephen Grossberg
Keyword(s):  
Artificial Intelligence ◽  
Machine Learning ◽  
Large Scale ◽  
Neural Circuits ◽  
Physical World ◽  
Brain Regions ◽  
Human Condition ◽  
Learning Technology ◽  
Large Scale Problems ◽  
The World

The book is the culmination of 50 years of intensive research by the author, who is broadly acknowledged to be the most important pioneer and current research leader who models how brains give rise to minds, notably how neural circuits in multiple brain regions interact together to generate psychological functions. The book provides a unified understanding of how, where, and why our brains can consciously see, hear, feel, and know about the world, and effectively plan and act within it. It hereby embodies a revolutionary Principia of Mind that clarifies how autonomous adaptive intelligence is achieved, thereby providing mechanistic explanations of multiple mental disorders, biological bases of morality, religion, and the human condition, as well as solutions to large-scale problems in machine learning, technology, and Artificial Intelligence. Because brains embody a universal developmental code, unifying insights also emerge about all living cellular tissues and about how mental laws reflect laws of the physical world.

scholarly journals Distinct transcriptomic cell types and neural circuits of the subiculum and prosubiculum along the dorsal-ventral axis

2019 ◽  
Author(s):  
Song-Lin Ding ◽  
Zizhen Yao ◽  
Karla E. Hirokawa ◽  
Thuc Nghi Nguyen ◽  
Lucas T. Graybuck ◽  
...  
Keyword(s):  
Neural Circuits ◽  
Cell Types ◽  
Brain Regions ◽  
Spatial Processing ◽  
List Type ◽  
Cell Type ◽  
Functional Studies ◽  
Hybridization Data ◽  
Cell Type Specific ◽  
Subcortical Regions

SummarySubicular region plays important roles in spatial processing and many cognitive functions and these were mainly attributed to subiculum (Sub) rather than prosubiculum (PS). Using single-cell RNA-sequencing (scRNA-seq) technique we have identified up to 27 distinct transcriptomic clusters/cell types, which were registered to anatomical sub-domains in Sub and PS. Based on reliable molecular markers derived from transcriptomic clustering and in situ hybridization data, the precise boundaries of Sub and PS have been consistently defined along the dorsoventral (DV) axis. Using these borders to evaluate Cre-line specificity and tracer injections, we have found bona fide Sub projections topographically to structures important for spatial processing and navigation. In contrast, PS along DV axis sends its outputs to widespread brain regions crucial for motivation, emotion, reward, stress, anxiety and fear. Brain-wide cell-type specific projections of Sub and PS have also been revealed using specific Cre-lines. These results reveal two molecularly and anatomically distinct circuits centered in Sub and PS, respectively, providing a consistent explanation to historical data and a clearer foundation for future functional studies.Highlights27 transcriptomic cell types identified in and spatially registered to “subicular” regions.Anatomic borders of “subicular” regions reliably determined along dorsal-ventral axis.Distinct cell types and circuits of full-length subiculum (Sub) and prosubiculum (PS).Brain-wide cell-type specific projections of Sub and PS revealed with specific Cre-lines.In BriefDing et al. show that mouse subiculum and prosubiculum are two distinct regions with differential transcriptomic cell types, subtypes, neural circuits and functional correlation. The former has obvious topographic projections to its main targets while the latter exhibits widespread projections to many subcortical regions associated with reward, emotion, stress and motivation.

scholarly journals A visual pathway for skylight polarization processing in Drosophila

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Ben J Hardcastle ◽  
Jaison J Omoto ◽  
Pratyush Kandimalla ◽  
Bao-Chau M Nguyen ◽  
Mehmet F Keleş ◽  
...  
Keyword(s):  
Polarized Light ◽  
Fruit Fly ◽  
Visual Pathway ◽  
Central Complex ◽  
Reduced Representation ◽  
Central Processing ◽  
Use Patterns ◽  
Sense Of Direction ◽  
Skylight Polarization ◽  
Central Brain

Many insects use patterns of polarized light in the sky to orient and navigate. Here we functionally characterize neural circuitry in the fruit fly, Drosophila melanogaster, that conveys polarized light signals from the eye to the central complex, a brain region essential for the fly's sense of direction. Neurons tuned to the angle of polarization of ultraviolet light are found throughout the anterior visual pathway, connecting the optic lobes with the central complex via the anterior optic tubercle and bulb, in a homologous organization to the 'sky compass' pathways described in other insects. We detail how a consistent, map-like organization of neural tunings in the peripheral visual system is transformed into a reduced representation suited to flexible processing in the central brain. This study identifies computational motifs of the transformation, enabling mechanistic comparisons of multisensory integration and central processing for navigation in the brains of insects.

Synaptic organization of the gustatory NST

1994 ◽  
Vol 52 ◽  
pp. 150-151
Author(s):  
M. C. Whitehead
Keyword(s):  
Central Nervous System ◽  
Dendritic Spines ◽  
Fundamental Problem ◽  
Cell Types ◽  
Brain Regions ◽  
Excitatory Synapses ◽  
Solitary Tract ◽  
Synaptic Organization ◽  
Synaptic Junctions ◽  
Afferent Terminals

A fundamental problem in taste research is to determine how gustatory signals are processed and disseminated in the mammalian central nervous system. An important first step toward understanding information processing is the identification of cell types in the nucleus of the solitary tract (NST) and their synaptic relationships with oral primary afferent terminals. Facial and glossopharyngeal (LIX) terminals in the hamster were labelled with HRP, examined with EM, and characterized as containing moderate concentrations of medium-sized round vesicles, and engaging in asymmetrical synaptic junctions. Ultrastructurally the endings resemble excitatory synapses in other brain regions.Labelled facial afferent endings in the RC subdivision synapse almost exclusively with distal dendrites and dendritic spines of NST cells. Most synaptic relationships between the facial synapses and the dendrites are simple. However, 40% of facial endings engage in complex synaptic relationships within glomeruli containing unlabelled axon endings particularly ones termed "SP" endings. SP endings are densely packed with small, pleomorphic vesicles and synapse with both the facial endings and their postsynaptic dendrites by means of nearly symmetrical junctions.

Subsurface imaging for panel paintings inspection: A comparative study of the ultraviolet, the visible, the infrared and the terahertz spectra

2015 ◽  
Vol 23 (1) ◽  
Author(s):  
A. Bendada ◽  
S. Sfarra ◽  
C. Ibarra−Castanedo ◽  
M. Akhloufi ◽  
J.−P. Caumes ◽  
...  
Keyword(s):  
Subsurface Imaging ◽  
Wide Spread ◽  
Ir Thermography ◽  
Complementary Information ◽  
Ir Sensors ◽  
The World ◽  
Panel Paintings ◽  
Temperature Maps ◽  
Illumination Source ◽  
Ir Reflectography

AbstractInfrared (IR) reflectography has been used for many years for the detection of underdrawings on panel paintings. Advances in the fields of IR sensors and optics have impelled the wide spread use of IR reflectography by several recognized Art Museums and specialized laboratories around the World. The transparency or opacity of a painting is the result of a complex combination of the optical properties of the painting pigments and the underdrawing material, as well as the type of illumination source and the sensor characteristics. For this reason, recent researches have been directed towards the study of multispectral approaches that could provide simultaneous and complementary information of an artwork. The present work relies on non−simultaneous multispectral inspection using a set of detectors covering from the ultraviolet to the terahertz spectra. It is observed that underdrawings contrast increases with wavelength up to 1700 nm and, then, gradually decreases. In addition, it is shown that IR thermography, i.e., temperature maps or thermograms, could be used simultaneously as an alternative technique for the detection of underdrawings besides the detection of subsurface defects.

Sign in / Sign up

Export Citation Format

Share Document