Comprehensive map of visual projection neurons for processing ultraviolet information in the Drosophila brain

Previously, we demonstrated that visual and olfactory associative memories of Drosophila share mushroom body (MB) circuits (<xref ref-type="bibr" rid="bib46">Vogt et al., 2014</xref>). Unlike for odor representation, the MB circuit for visual information has not been characterized. Here, we show that a small subset of MB Kenyon cells (KCs) selectively responds to visual but not olfactory stimulation. The dendrites of these atypical KCs form a ventral accessory calyx (vAC), distinct from the main calyx that receives olfactory input. We identified two types of visual projection neurons (VPNs) directly connecting the optic lobes and the vAC. Strikingly, these VPNs are differentially required for visual memories of color and brightness. The segregation of visual and olfactory domains in the MB allows independent processing of distinct sensory memories and may be a conserved form of sensory representations among insects.

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

eLife ◽

10.7554/elife.71679 ◽

2021 ◽

Vol 10 ◽

Author(s):

Gabriella R Sterne ◽

Hideo Otsuna ◽

Barry J Dickson ◽

Kristin Scott

Keyword(s):

Sensory Processing ◽

Cell Types ◽

Brain Regions ◽

Projection Neurons ◽

Sensorimotor Transformations ◽

Drosophila Brain ◽

Genetic Targeting ◽

And Behavior ◽

Insight Into ◽

Adult Drosophila

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.

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Morphology of visual projection neurons supplying premotor area in the brain of the silkmoth Bombyx mori

Cell and Tissue Research ◽

10.1007/s00441-018-2892-0 ◽

2018 ◽

Vol 374 (3) ◽

pp. 497-515 ◽

Cited By ~ 4

Author(s):

Shigehiro Namiki ◽

Ryohei Kanzaki

Keyword(s):

Bombyx Mori ◽

Projection Neurons ◽

Premotor Area ◽

Visual Projection ◽

The Brain

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Decision letter: Visual projection neurons in the Drosophila lobula link feature detection to distinct behavioral programs

10.7554/elife.21022.043 ◽

2016 ◽

Keyword(s):

Feature Detection ◽

Projection Neurons ◽

Visual Projection

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Decoding odor quality and intensity in the Drosophila brain

eLife ◽

10.7554/elife.04147 ◽

2014 ◽

Vol 3 ◽

Cited By ~ 82

Author(s):

Antonia Strutz ◽

Jan Soelter ◽

Amelie Baschwitz ◽

Abu Farhan ◽

Veit Grabe ◽

...

Keyword(s):

Relevant Information ◽

Projection Neurons ◽

Third Order ◽

Odor Quality ◽

Intensity Information ◽

Drosophila Brain ◽

Feature Based ◽

Vinegar Fly ◽

Attraction Behavior ◽

Neural Maps

To internally reflect the sensory environment, animals create neural maps encoding the external stimulus space. From that primary neural code relevant information has to be extracted for accurate navigation. We analyzed how different odor features such as hedonic valence and intensity are functionally integrated in the lateral horn (LH) of the vinegar fly, Drosophila melanogaster. We characterized an olfactory-processing pathway, comprised of inhibitory projection neurons (iPNs) that target the LH exclusively, at morphological, functional and behavioral levels. We demonstrate that iPNs are subdivided into two morphological groups encoding positive hedonic valence or intensity information and conveying these features into separate domains in the LH. Silencing iPNs severely diminished flies' attraction behavior. Moreover, functional imaging disclosed a LH region tuned to repulsive odors comprised exclusively of third-order neurons. We provide evidence for a feature-based map in the LH, and elucidate its role as the center for integrating behaviorally relevant olfactory information.

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

10.1101/2021.08.06.455433 ◽

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.

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Non-thalamic origin of zebrafish sensory nuclei implies convergent evolution of visual pathways in amniotes and teleosts

eLife ◽

10.7554/elife.54945 ◽

2020 ◽

Vol 9 ◽

Author(s):

Solal Bloch ◽

Hanako Hagio ◽

Manon Thomas ◽

Aurélie Heuzé ◽

Jean-Michel Hermel ◽

...

Keyword(s):

Convergent Evolution ◽

Cell Lineage ◽

Projection Neurons ◽

Vertebrate Species ◽

Thalamic Nuclei ◽

Sensory Structure ◽

Wide Range ◽

Visual Projection ◽

Juvenile Stages ◽

Lateral Nucleus

Ascending visual projections similar to the mammalian thalamocortical pathway are found in a wide range of vertebrate species, but their homology is debated. To get better insights into their evolutionary origin, we examined the developmental origin of a thalamic-like sensory structure of teleosts, the preglomerular complex (PG), focusing on the visual projection neurons. Similarly to the tectofugal thalamic nuclei in amniotes, the lateral nucleus of PG receives tectal information and projects to the pallium. However, our cell lineage study in zebrafish reveals that the majority of PG cells are derived from the midbrain, unlike the amniote thalamus. We also demonstrate that the PG projection neurons develop gradually until late juvenile stages. Our data suggest that teleost PG, as a whole, is not homologous to the amniote thalamus. Thus, the thalamocortical-like projections evolved from a non-forebrain cell population, which indicates a surprising degree of variation in the vertebrate sensory systems.

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