Somatotopic organization among parallel sensory pathways that promote a grooming sequence in .

Mechanosensory neurons located across the body surface respond to tactile stimuli and elicit diverse behavioral responses, from relatively simple stimulus location-aimed movements to complex movement sequences. How mechanosensory neurons and their postsynaptic circuits influence such diverse behaviors remains unclear. We previously discovered that perform a body location-prioritized grooming sequence when mechanosensory neurons at different locations on the head and body are simultaneously stimulated by dust (Hampel et al.

A leaky integrate-and-fire computational model based on the connectome of the entire adult brain reveals insights into sensorimotor processing.

The forthcoming assembly of the adult central brain connectome, containing over 125,000 neurons and 50 million synaptic connections, provides a template for examining sensory processing throughout the brain. Here, we create a leaky integrate-and-fire computational model of the entire brain, based on neural connectivity and neurotransmitter identity, to study circuit properties of feeding and grooming behaviors. We show that activation of sugar-sensing or water-sensing gustatory neurons in the computational model accurately predicts neurons that respond to tastes and are required for feeding initiation.

Somatotopic organization among parallel sensory pathways that promote a grooming sequence in .

Mechanosensory neurons located across the body surface respond to tactile stimuli and elicit diverse behavioral responses, from relatively simple stimulus location-aimed movements to complex movement sequences. How mechanosensory neurons and their postsynaptic circuits influence such diverse behaviors remains unclear. We previously discovered that perform a body location-prioritized grooming sequence when mechanosensory neurons at different locations on the head and body are simultaneously stimulated by dust (Hampel et al.

Distinct subpopulations of mechanosensory chordotonal organ neurons elicit grooming of the fruit fly antennae.

Diverse mechanosensory neurons detect different mechanical forces that can impact animal behavior. Yet our understanding of the anatomical and physiological diversity of these neurons and the behaviors that they influence is limited. We previously discovered that grooming of the antennae is elicited by an antennal mechanosensory chordotonal organ, the Johnston's organ (JO) (Hampel et al.

A Systematic Nomenclature for the Drosophila Ventral Nerve Cord.

Drosophila melanogaster is an established model for neuroscience research with relevance in biology and medicine. Until recently, research on the Drosophila brain was hindered by the lack of a complete and uniform nomenclature. Recognizing this, Ito et al.

Simultaneous activation of parallel sensory pathways promotes a grooming sequence in .

A central model that describes how behavioral sequences are produced features a neural architecture that readies different movements simultaneously, and a mechanism where prioritized suppression between the movements determines their sequential performance. We previously described a model whereby suppression drives a grooming sequence that is induced by simultaneous activation of different sensory pathways that each elicit a distinct movement (Seeds et al., 2014).

Axon Death Pathways Converge on Axundead to Promote Functional and Structural Axon Disassembly.

Axon degeneration is a hallmark of neurodegenerative disease and neural injury. Axotomy activates an intrinsic pro-degenerative axon death signaling cascade involving loss of the NAD biosynthetic enzyme Nmnat/Nmnat2 in axons, activation of dSarm/Sarm1, and subsequent Sarm-dependent depletion of NAD. Here we identify Axundead (Axed) as a mediator of axon death.

Inositol phosphate kinase 2 is required for imaginal disc development in Drosophila.

Inositol phosphate kinase 2 (Ipk2), also known as IP multikinase IPMK, is an evolutionarily conserved protein that initiates production of inositol phosphate intracellular messengers (IPs), which are critical for regulating nuclear and cytoplasmic processes. Here we report that Ipk2 kinase activity is required for the development of the adult fruit fly epidermis. Ipk2 mutants show impaired development of their imaginal discs, the primordial tissues that form the adult epidermis.

A neural command circuit for grooming movement control.

Animals perform many stereotyped movements, but how nervous systems are organized for controlling specific movements remains unclear. Here we use anatomical, optogenetic, behavioral, and physiological techniques to identify a circuit in Drosophila melanogaster that can elicit stereotyped leg movements that groom the antennae. Mechanosensory chordotonal neurons detect displacements of the antennae and excite three different classes of functionally connected interneurons, which include two classes of brain interneurons and different parallel descending neurons.

A suppression hierarchy among competing motor programs drives sequential grooming in Drosophila.

Motor sequences are formed through the serial execution of different movements, but how nervous systems implement this process remains largely unknown. We determined the organizational principles governing how dirty fruit flies groom their bodies with sequential movements. Using genetically targeted activation of neural subsets, we drove distinct motor programs that clean individual body parts.

BrainAligner: 3D registration atlases of Drosophila brains.

Analyzing Drosophila melanogaster neural expression patterns in thousands of three-dimensional image stacks of individual brains requires registering them into a canonical framework based on a fiducial reference of neuropil morphology. Given a target brain labeled with predefined landmarks, the BrainAligner program automatically finds the corresponding landmarks in a subject brain and maps it to the coordinate system of the target brain via a deformable warp. Using a neuropil marker (the antibody nc82) as a reference of the brain morphology and a target brain that is itself a statistical average of data for 295 brains, we achieved a registration accuracy of 2 μm on average, permitting assessment of stereotypy, potential connectivity and functional mapping of the adult fruit fly brain.

Inositol polyphosphate kinases: regulators of nuclear function.

Recent work has uncovered roles for inositide signalling pathways downstream of phospholipase C activation and inositol 1,4,5-trisphosphate in the regulation of nuclear processes including gene expression, mRNA export and DNA metabolism. The identification of several IPKs (inositol polyphosphate kinases) has renewed interest in the cellular roles of inositol tetra-, penta-, hexa- and pyro-phosphates. Discoveries of inositide receptors and novel mechanisms of inositide action have provided important insights into how such messengers couple to nuclear machinery.

Inositol phosphate metabolomics: merging genetic perturbation with modernized radiolabeling methods.

Recent discoveries that provide a link between inositol phosphate (IP) signaling and fundamental cellular processes evoke many exciting new hypotheses about IP function, and underscore the importance of understanding how IP synthesis is regulated. Central to studies of IP metabolism is the essential development of efficient, fast, and reproducible methods for quantitative analysis of IPs in systems ranging from simple cell cultures to more complex tissues and whole organisms. Additionally, in many cases there is a need to pharmacologically and/or genetically alter IP kinase and phosphatase activities in order to visualize low abundance inositol signaling messengers.

Molecular definition of a novel inositol polyphosphate metabolic pathway initiated by inositol 1,4,5-trisphosphate 3-kinase activity in Saccharomyces cerevisiae.

The production of inositol polyphosphate (IPs) and pyrophosphates (PP-IPs) from inositol 1,4,5-trisphosphate (I(1,4,5)P3) requires the 6-/3-/5-kinase activity of Ipk2 (also known as Arg82 and inositol polyphosphate multikinase). Here, we probed the distinct roles for I(1,4,5)P3 6- versus 3-kinase activities in IP metabolism and cellular functions reported for Ipk2. Expression of either I(1,4,5)P3 6- or 3-kinase activity rescued growth of ipk2-deficient yeast at high temperatures, whereas only 6-kinase activity enabled growth on ornithine as the sole nitrogen source.

A molecular basis for inositol polyphosphate synthesis in Drosophila melanogaster.

Metabolism of inositol 1,4,5-trisphosphate (I(1,4,5)P3) results in the production of diverse arrays of inositol polyphosphates (IPs), such as IP4, IP5, IP6) and PP-IP5. Insights into their synthesis in metazoans are reported here through molecular studies in the fruit fly, Drosophila melanogaster. Two I(1,4,5)P3 kinase gene products are implicated in initiating catabolism of these important IP regulators.