Fly Nervous System Research Articles

Introducing Pitt-Hopkins syndrome-associated mutations of TCF4 to Drosophila daughterless.

ABSTRACTPitt-Hopkins syndrome (PTHS) is caused by haploinsufficiency of Transcription factor 4 (TCF4), one of the three human class I basic helix-loop-helix transcription factors called E-proteins. Drosophila has a single E-protein, Daughterless (Da), homologous to all three mammalian counterparts. Here we show that human TCF4 can rescue Da deficiency during fruit fly nervous system development. Overexpression of Da or TCF4 specifically in adult flies significantly decreases their survival rates, indicating that these factors are crucial even after development has been completed. We generated da transgenic fruit fly strains with corresponding missense mutations R578H, R580W, R582P and A614V found in TCF4 of PTHS patients and studied the impact of these mutations in vivo. Overexpression of wild type Da as well as human TCF4 in progenitor tissues induced ectopic sensory bristles and the rough eye phenotype. By contrast, overexpression of DaR580W and DaR582P that disrupt DNA binding reduced the number of bristles and induced the rough eye phenotype with partial lack of pigmentation, indicating that these act dominant negatively. Compared to the wild type, DaR578H and DaA614V were less potent in induction of ectopic bristles and the rough eye phenotype, respectively, suggesting that these are hypomorphic. All studied PTHS-associated mutations that we introduced into Da led to similar effects in vivo as the same mutations in TCF4 in vitro. Consequently, our Drosophila models of PTHS are applicable for further studies aiming to unravel the molecular mechanisms of this disorder.

Drosophila Shep and C. elegans SUP-26 are RNA-binding proteins that play diverse roles in nervous system development.

The Caenorhabditis elegans gene sup-26 encodes a well-conserved RNA-recognition motif-containing RNA-binding protein (RBP) that functions in dendrite morphogenesis of the PVD sensory neuron. The Drosophila ortholog of sup-26, alan shepard (shep), is expressed throughout the nervous system and has been shown to regulate neuronal remodeling during metamorphosis. Here, we extend these studies to show that sup-26 and shep are required for the development of diverse cell types within the nematode and fly nervous systems during embryonic and larval stages. We ascribe roles for sup-26 in regulating dendrite number and the expression of genes involved in mechanosensation within the nematode peripheral nervous system. We also find that in Drosophila, shep regulates dendrite length and branch order of nociceptive neurons, regulates the organization of neuronal clusters of the peripheral nervous system and the organization of axons within the ventral nerve cord. Taken together, our results suggest that shep/sup-26 orthologs play diverse roles in neural development across animal species. Moreover, we discuss potential roles for shep/sup-26 orthologs in the human nervous system.

Differentiation of Drosophila glial cells.

Glial cells are important constituents of the nervous system and a hallmark of these cells are their pronounced migratory abilities. In Drosophila, glial lineages have been well described and some of the molecular mechanisms necessary to guide migrating glial cells to their final target sites have been identified. With the onset of migration, glial cells are already specified into one of five main glial cell types. The perineurial and subperineurial glial cells are eventually located at the outer surface of the Drosophila nervous system and constitute the blood-brain barrier. The cortex glial cells ensheath all neuroblasts and their progeny and reside within the central nervous system. Astrocyte-like cells invade the neuropil to control synaptic function and ensheathing glial cells encase the entire neuropil. Within the peripheral nervous system, wrapping glial cells ensheath individual axons or axon fascicles. Here, we summarize the current knowledge on how differentiation of glial cells into the specific subtypes is orchestrated. Furthermore, we discuss sequencing data that will facilitate further analyses of glial differentiation in the fly nervous system.

Aβ43 is neurotoxic and primes aggregation of Aβ40 in vivo.

The involvement of Amyloid-β (Aβ) in the pathogenesis of Alzheimer’s disease (AD) is well established. However, it is becoming clear that the amyloid load in AD brains consists of a heterogeneous mixture of Aβ peptides, implying that a thorough understanding of their respective role and toxicity is crucial for the development of efficient treatments. Besides the well-studied Aβ40 and Aβ42 species, recent data have raised the possibility that Aβ43 peptides might be instrumental in AD pathogenesis, because they are frequently observed in both dense and diffuse amyloid plaques from human AD brains and are highly amyloidogenic in vitro. However, whether Aβ43 is toxic in vivo is currently unclear. Using Drosophila transgenic models of amyloid pathology, we show that Aβ43 peptides are mainly insoluble and highly toxic in vivo, leading to the progressive loss of photoreceptor neurons, altered locomotion and decreased lifespan when expressed in the adult fly nervous system. In addition, we demonstrate that Aβ43 species are able to trigger the aggregation of the typically soluble and non-toxic Aβ40, leading to synergistic toxic effects on fly lifespan and climbing ability, further suggesting that Aβ43 peptides could act as a nucleating factor in AD brains. Altogether, our study demonstrates high pathogenicity of Aβ43 species in vivo and supports the idea that Aβ43 contributes to the pathological events leading to neurodegeneration in AD.Electronic supplementary materialThe online version of this article (doi:10.1007/s00401-015-1419-y) contains supplementary material, which is available to authorized users.

Mapping Behavior to Neural Anatomy Using Machine Vision and Thermogenetics

To understand the relationship between neural anatomy and behavior, the ultimate output of the nervous system, we performed a high-throughput, thermogenetic screen of 2,200 transgenic Drosophila lines from the Janelia GAL4 collection. Each GAL4 line drives expression in a different, sparse subset of neurons in the fly nervous system. Using genetic techniques, we selectively activated these sparse subsets of neurons, and measured the behavioral effects. We developed a high-throughput, automated system for measuring the flies’ locomotion and social behavior with breadth and depth. We recorded 20,000 videos of groups of flies freely behaving in an open-field walking arena, totaling ∼400 TB of raw data. From the video, we tracked the flies’ body and wing positions using our tracking software, Ctrax. We used our machine learning-based behavior classification system, JAABA, to create 15 behavior classifiers (e.g. walking, chasing) that input trajectories from Ctrax and output predictions for each frame of each fly's behaviors (totaling ∼175 billion annotations of behavior). For each line of flies, we computed ∼200 behavior statistics, such as the fraction of time spent chasing, or average speed while walking, summarizing the behavioral effects of activating the targeted neurons in a concise, interpretable manner. Concurrent with our screen, the Janelia Fly Light project imaged the expression pattern of each GAL4 line, producing image stacks indicating which neurons are likely being activated in each line. By jointly analyzing these behavior and anatomy measurements, we created brain-behavior maps suggesting neural substrates for the generation and/or regulation of each behavior. This study is groundbreaking on two technological fronts. It represents the application of video-based behavior recognition to a highly phenotypically diverse data set of thousands of Drosophila genotypes, and the largest unbiased screen to assign function to neurons throughout the nervous system.

Neurophysiology ofDrosophilaModels of Parkinson’s Disease

We provide an insight into the role Drosophila has played in elucidating neurophysiological perturbations associated with Parkinson's disease- (PD-) related genes. Synaptic signalling deficits are observed in motor, central, and sensory systems. Given the neurological impact of disease causing mutations within these same genes in humans the phenotypes observed in fly are of significant interest. As such we observe four unique opportunities provided by fly nervous system models of Parkinson's disease. Firstly, Drosophila models are instrumental in exploring the mechanisms of neurodegeneration, with several PD-related mutations eliciting related phenotypes including sensitivity to energy supply and vesicular deformities. These are leading to the identification of plausible cellular mechanisms, which may be specific to (dopaminergic) neurons and synapses rather than general cellular phenotypes. Secondly, models show noncell autonomous signalling within the nervous system, offering the opportunity to develop our understanding of the way pathogenic signalling propagates, resembling Braak's scheme of spreading pathology in PD. Thirdly, the models link physiological deficits to changes in synaptic structure. While the structure-function relationship is complex, the genetic tractability of Drosophila offers the chance to separate fundamental changes from downstream consequences. Finally, the strong neuronal phenotypes permit relevant first in vivo drug testing.

Balance between efficiency and stability in a neural circuit model of the Drosophila brain

Event Abstract Back to Event Balance between efficiency and stability in a neural circuit model of the Drosophila brain Cheng-Te Wang1, Yu-Chi Huang1 and Chung-Chuan Lo1* 1 National Tsing Hua University, Institute of Systems Neuroscience, Taiwan Fruit fly (Drosophila melanogaster) is becoming a promising model animal in computational neuroscience for its small brain size, complex cognitive behavior and abundant data from genes to circuits. Although much has being learned about the functions of individual sensory systems, how do they operated and integrated at the brain-wide level in Drosophila remains poorly understood. To provide a platform for studying computation of the fly nervous system, we initiated the Flysim project with a goal to construct a full-brain neural circuit model with a single-neuron resolution based on the data obtained from the flycircuit database. Although containing only ~28,000 neurons (account for 22% of the fly brain) at the current stage, our fly brain model already exhibits unexpectedly rich dynamics. Due to the strongly recurrent excitation, the brain model is inherently unstable and epilepsy-like activity frequently arose from the baseline state. We further found that the epilepsy-like activity cannot be suppressed by solely strengthening the inhibitory synapses but can be eliminated by implementing short-term depression. However, depressed synapses strongly attenuate the propagation of signals and lead to an inefficient neural circuit. Therefore, a functioning nervous system requires fine balance between stability and efficiency. Additional analyses revealed that the epilepsy-like activity originates from a group of specific brain regions that are functionally less understood but seem to play roles in integrating signals from different sensory modules. By a large-scale screening through the inhibitory system of the brain model, we further discovered that the epilepsy-like activity can be suppressed by a small number of inhibitory neurons if they are manually activated. Interestingly, the epilepsy-suppressing ability of these neurons does not come from their inhibitory strength, but from their unique innervating patterns over the excitatory system. In conclusion, despite being in an early stage of the model development, our fly brain model has already shown its strength in providing insights into brain-wide neural dynamics which may not be revealed by analyzing the random or simple small-world neural networks. Acknowledgements This work is supported by the Ministry of Science and Technology and by the Ministry of Education, Taiwan. We thank the National Center for High-performance Computing for providing computational resources and Dr. Ann-Shyn Chiang for helpful comments. Keywords: Drosophila, Epilepsy, network stability, fruit fly, balanced networks, Efficiency, short-term depression, short-term synaptic plasticity, Inhibitory Control Conference: Neuroinformatics 2015, Cairns, Australia, 20 Aug - 22 Aug, 2015. Presentation Type: Poster, to be considered for oral presentation Topic: Computational neuroscience Citation: Wang C, Huang Y and Lo C (2015). Balance between efficiency and stability in a neural circuit model of the Drosophila brain. Front. Neurosci. Conference Abstract: Neuroinformatics 2015. doi: 10.3389/conf.fnins.2015.91.00035 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 07 Apr 2015; Published Online: 05 Aug 2015. * Correspondence: Dr. Chung-Chuan Lo, National Tsing Hua University, Institute of Systems Neuroscience, Hsinchu city, US & Canada only, 300, Taiwan, cclo@life.nthu.edu.tw Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Cheng-Te Wang Yu-Chi Huang Chung-Chuan Lo Google Cheng-Te Wang Yu-Chi Huang Chung-Chuan Lo Google Scholar Cheng-Te Wang Yu-Chi Huang Chung-Chuan Lo PubMed Cheng-Te Wang Yu-Chi Huang Chung-Chuan Lo Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

MANF silencing, immunity induction or autophagy trigger an unusual cell type in metamorphosing Drosophila brain.

Glia are abundant cells in the brain of animals ranging from flies to humans. They perform conserved functions not only in neural development and wiring, but also in brain homeostasis. Here we show that by manipulating gene expression in glia, a previously unidentified cell type appears in the Drosophila brain during metamorphosis. More specifically, this cell type appears in three contexts: (1) after the induction of either immunity, or (2) autophagy, or (3) by silencing of neurotrophic factor DmMANF in glial cells. We call these cells MANF immunoreactive Cells (MiCs). MiCs are migratory based on their shape, appearance in brain areas where no cell bodies exist and the nuclear localization of dSTAT. They are labeled with a unique set of molecular markers including the conserved neurotrophic factor DmMANF and the transcription factor Zfh1. They possess the nuclearly localized protein Relish, which is the hallmark of immune response activation. They also express the conserved engulfment receptor Draper, therefore indicating that they are potentially phagocytic. Surprisingly, they do not express any of the common glial and neuronal markers. In addition, ultrastructural studies show that MiCs are extremely rich in lysosomes. Our findings reveal critical molecular and functional components of an unusual cell type in the Drosophila brain. We suggest that MiCs resemble macrophages/hemocytes and vertebrate microglia based on their appearance in the brain upon genetically challenged conditions and the expression of molecular markers. Interestingly, macrophages/hemocytes or microglia-like cells have not been reported in the fly nervous system before.Electronic supplementary materialThe online version of this article (doi:10.1007/s00018-014-1789-7) contains supplementary material, which is available to authorized users.

Closing the Gap between Glia and Neuroblast Proliferation

Reporting in this issue of Developmental Cell, Spéder and Brand (2014) show that gap junctions are required in blood-brain barrier glial cells to reactivate proliferation of quiescent neuroblasts. Gap junctions allow synchronous Ca(2+) waves and control insulin-like protein Dipl6 expression and secretion to trigger neuroblast division.

Divergent and convergent roles for insulin-like peptides in the worm, fly and mammalian nervous systems

Insulin signaling plays a critical role in coupling external changes to animal physiology and behavior. Despite remarkable conservation in the insulin signaling pathway components across species, divergence in the mechanism and function of the signal is evident. Focusing on recent findings from C. elegans, D. melanogaster and mammals, we discuss the role of insulin signaling in regulating adult neuronal function and behavior. In particular, we describe the transcription-dependent and transcription-independent aspects of insulin signaling across these three species. Interestingly, we find evidence of diverse mechanisms underlying complex networks of peptide action in modulating nervous system function.

Proteomic profiling in Drosophila reveals potential Dube3a regulation of the actin cytoskeleton and neuronal homeostasis.

The molecular defects associated with Angelman syndrome (AS) and 15q duplication autism are directly correlated to expression levels of the E3 ubiquitin ligase protein UBE3A. Here we used Drosophila melanogaster to screen for the targets of this ubiquitin ligase under conditions of both decreased (as in AS) or increased (as in dup(15)) levels of the fly Dube3a or human UBE3A proteins. Using liquid phase isoelectric focusing of proteins from whole fly head extracts we identified a total of 50 proteins that show changes in protein, and in some cases transcriptional levels, when Dube3a fluctuates. We analyzed head extracts from cytoplasmic, nuclear and membrane fractions for Dube3a regulated proteins. Our results indicate that Dube3a is involved in the regulation of cellular functions related to ATP synthesis/metabolism, actin cytoskeletal integrity, both catabolism and carbohydrate metabolism as well as nervous system development and function. Sixty-two percent of the proteins were >50% identical to homologous human proteins and 8 have previously be shown to be ubiquitinated in the fly nervous system. Eight proteins may be regulated by Dube3a at the transcript level through the transcriptional co-activation function of Dube3a. We investigated one autism-associated protein, ATPα, and found that it can be ubiquitinated in a Dube3a dependent manner. We also found that Dube3a mutants have significantly less filamentous actin than wild type larvae consistent with the identification of actin targets regulated by Dube3a. The identification of UBE3A targets is the first step in unraveling the molecular etiology of AS and duplication 15q autism.

Making sense out of nonsense to visualize editing in the fly nervous system

In vivo methods to capture processing events such as RNA editing in specific cell types are sparse. Researchers have now developed a method to visualize adenosine-to-inosine editing activity in individual fruit fly neurons using a reverse-engineered fluorescent reporter.

Genetic manipulations in the fruit fly fight club: role of amine neurons studied at a single neuron level

Event Abstract Back to Event Genetic manipulations in the fruit fly fight club: role of amine neurons studied at a single neuron level Edward A Kravitz1* 1 Harvard Medical School, Neurobiology, United States Aggression is a nearly universal feature of the social behavior of animals. In the wild, it is used for access to food and shelter, for protection from predation and for selection of mates. Although not well known until about a decade ago, fighting behavior exists in same sex pairings of male and female fruit flies (Drosophila melanogaster). With the genome sequenced and with a wealth of powerful genetic tools available, fruit flies serve as a unique experimental model for the study of complex behaviors like aggression. In early experiments, a quantitative analysis of the behavioral patterns seen during fights revealed that some of the patterns observed were similar in male and female fights while others were unique to male or to female flies. A single gene, fruitless, of the sex determination hierarchy of genes, determined whether flies fought using male or female patterns of aggression. At the end of male fights hierarchical relationships usually were established while at the end of female fights resources were shared. Via inbreeding winners, we could generate highly aggressive “bullies” who fought at higher intensity levels and who always won fights against the parent Canton-S strain. After a single loss to another bully, however, these highly aggressive flies lost all competitive advantage against other flies. Learning and memory accompanied the establishment of hierarchical relationships in male fights, with defeated flies showing a “loser mentality” that influenced the outcomes of future fights. As in other species, amines including serotonin, dopamine and octopamine (the fly homologue of norepinephrine) all exert influences on multiple aspects of behavior, including aggression. Serotonin, for example, is not required to initiate aggression, but does facilitate going to higher intensity levels in fights. However, serotonin also influences learning and memory, courtship, feeding behavior, etc. There are about 100 of each subtype of amine neurons in the fruit fly nervous system. In this talk, recent studies will be described that take an intersectional genetics approach to allow us to reliably alter the function of single identified amine neurons in living animals and to observe the resultant behavioral phenotypes. In addition, studies will be presented asking how male flies choose between courtship and aggression when approaching a conspecific. Finally data will be presented describing experimental approaches towards unraveling the circuitry concerned with the identified neurons. (supported by NIGMS) Keywords: Aggression, Dopamine, Drosophila, Genes, Octopamine, Serotonin Conference: Tenth International Congress of Neuroethology, College Park. Maryland USA, United States, 5 Aug - 10 Aug, 2012. Presentation Type: Plenary Address (including special lectures) (Note, these individuals have already been invited) Topic: Genes and Behavior Citation: Kravitz E (2012). Genetic manipulations in the fruit fly fight club: role of amine neurons studied at a single neuron level. Conference Abstract: Tenth International Congress of Neuroethology. doi: 10.3389/conf.fnbeh.2012.27.00060 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 08 May 2012; Published Online: 07 Jul 2012. * Correspondence: Prof. Edward A Kravitz, Harvard Medical School, Neurobiology, Boston, MA, 02115, United States, edward_kravitz@hms.harvard.edu Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Edward A Kravitz Google Edward A Kravitz Google Scholar Edward A Kravitz PubMed Edward A Kravitz Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Complexity at large

Complexity at large

New tools for the analysis of glial cell biology in Drosophila

Because of its genetic, molecular, and behavioral tractability, Drosophila has emerged as a powerful model system for studying molecular and cellular mechanisms underlying the development and function of nervous systems. The Drosophila nervous system has fewer neurons and exhibits a lower glia:neuron ratio than is seen in vertebrate nervous systems. Despite the simplicity of the Drosophila nervous system, glial organization in flies is as sophisticated as it is in vertebrates. Furthermore, fly glial cells play vital roles in neural development and behavior. In addition, powerful genetic tools are continuously being created to explore cell function in vivo. In taking advantage of these features, the fly nervous system serves as an excellent model system to study general aspects of glial cell development and function in vivo. In this article, we review and discuss advanced genetic tools that are potentially useful for understanding glial cell biology in Drosophila.

A dimorphic pheromone circuit in Drosophila from sensory input to descending output

Drosophila show innate olfactory-driven behaviours that are observed in naive animals without previous learning or experience, suggesting that the neural circuits that mediate these behaviours are genetically programmed. Despite the numerical simplicity of the fly nervous system, features of the anatomical organization of the fly brain often confound the delineation of these circuits. Here we identify a neural circuit responsive to cVA, a pheromone that elicits sexually dimorphic behaviours. We have combined neural tracing using an improved photoactivatable green fluorescent protein (PA-GFP) with electrophysiology, optical imaging and laser-mediated microlesioning to map this circuit from the activation of sensory neurons in the antennae to the excitation of descending neurons in the ventral nerve cord. This circuit is concise and minimally comprises four neurons, connected by three synapses. Three of these neurons are overtly dimorphic and identify a male-specific neuropil that integrates inputs from multiple sensory systems and sends outputs to the ventral nerve cord. This neural pathway suggests a means by which a single pheromone can elicit different behaviours in the two sexes.

Coding efficiency of fly motion processing is set by firing rate, not firing precision.

To comprehend the principles underlying sensory information processing, it is important to understand how the nervous system deals with various sources of perturbation. Here, we analyze how the representation of motion information in the fly's nervous system changes with temperature and luminance. Although these two environmental variables have a considerable impact on the fly's nervous system, they do not impede the fly to behave suitably over a wide range of conditions. We recorded responses from a motion-sensitive neuron, the H1-cell, to a time-varying stimulus at many different combinations of temperature and luminance. We found that the mean firing rate, but not firing precision, changes with temperature, while both were affected by mean luminance. Because we also found that information rate and coding efficiency are mainly set by the mean firing rate, our results suggest that, in the face of environmental perturbations, the coding efficiency is improved by an increase in the mean firing rate, rather than by an increased firing precision.

Sensorimotor Transformation: From Visual Responses to Motor Commands

A recent study reveals how vision-based estimates of self-motion are passed on to premotor descending neurons which connect to various motor centres in the fly nervous system.

A principal skeleton algorithm for standardizing confocal images of fruit fly nervous systems

Motivation: The fruit fly (Drosophila melanogaster) is a commonly used model organism in biology. We are currently building a 3D digital atlas of the fruit fly larval nervous system (LNS) based on a large collection of fly larva GAL4 lines, each of which targets a subset of neurons. To achieve such a goal, we need to automatically align a number of high-resolution confocal image stacks of these GAL4 lines. One commonly employed strategy in image pattern registration is to first globally align images using an affine transform, followed by local non-linear warping. Unfortunately, the spatially articulated and often twisted LNS makes it difficult to globally align the images directly using the affine method. In a parallel project to build a 3D digital map of the adult fly ventral nerve cord (VNC), we are confronted with a similar problem.Results: We proposed to standardize a larval image by best aligning its principal skeleton (PS), and thus used this method as an alternative of the usually considered affine alignment. The PS of a shape was defined as a series of connected polylines that spans the entire shape as broadly as possible, but with the shortest overall length. We developed an automatic PS detection algorithm to robustly detect the PS from an image. Then for a pair of larval images, we designed an automatic image registration method to align their PSs and the entire images simultaneously. Our experimental results on both simulated images and real datasets showed that our method does not only produce satisfactory results for real confocal larval images, but also perform robustly and consistently when there is a lot of noise in the data. We also applied this method successfully to confocal images of some other patterns such as the adult fruit fly VNC and center brain, which have more complicated PS. This demonstrates the flexibility and extensibility of our method.Availability: The supplementary movies, full size figures, test data, software, and tutorial on the software can be downloaded freely from our website http://penglab.janelia.org/proj/principal_skeletonContact: pengh@janelia.hhmi.orgSupplementary information: Supplementary data are available at Bioinformatics online.

Protein kinase C deficiency-induced alcohol insensitivity and underlying cellular targets in Drosophila

Multiple subtypes of protein kinase C (PKC) isozymes are implicated in various neurological disorders including alcohol insensitivity, a trait strongly associated with alcoholism in humans, but molecular and cellular mechanisms underlying the PKC activities remain poorly understood. Here we show that functional knockdown of conventional, novel or atypical PKC in the fly nervous system each resulted in alcohol insensitivity. Neuroanatomical mapping of conventional Ca 2+-sensitive PKC53E activity uncovers a previously uncharacterized role of Drosophila serotonin neurons in alcohol sensitivity. The deficiency of PKC53E but not novel Ca 2+-independent PKC98E appears to reduce synaptic serotonin levels, since acute inhibition of serotonin reuptake by citalopram and Prozac reversed alcohol insensitivity in flies expressing PKC53E double-stranded RNA in serotonin neurons. Together, findings from this and our previous studies indicate that PKC53E and PKC98E differentially regulate fly alcohol sensitivity through independent modulation of conserved serotonin and neuropeptide Y-like systems.