@article {46557, title = {A multilevel multimodal circuit enhances action selection in Drosophila.}, journal = {Nature}, volume = {520}, year = {2015}, month = {2015 Apr 20}, pages = {633-9}, abstract = {

Natural events present multiple types of sensory cues, each detected by a specialized sensory modality. Combining information from several modalities is essential for the selection of appropriate actions. Key to understanding multimodal computations is determining the structural patterns of multimodal convergence and how these patterns contribute to behaviour. Modalities could converge early, late or at multiple levels in the sensory processing hierarchy. Here we show that combining mechanosensory and nociceptive cues synergistically enhances the selection of the fastest mode of escape locomotion in Drosophila larvae. In an electron microscopy volume that spans the entire insect nervous system, we reconstructed the multisensory circuit supporting the synergy, spanning multiple levels of the sensory processing hierarchy. The wiring diagram revealed a complex multilevel multimodal convergence architecture. Using behavioural and physiological studies, we identified functionally connected circuit nodes that trigger the fastest locomotor mode, and others that facilitate it, and we provide evidence that multiple levels of multimodal integration contribute to escape mode selection. We propose that the multilevel multimodal convergence architecture may be a general feature of multisensory circuits enabling complex input{\textendash}output functions and selective tuning to ecologically relevant combinations of cues.

}, doi = {10.1038/nature14297}, author = {Ohyama, Tomoko and Schneider-Mizell, Casey M. and Fetter, Richard D. and Aleman, Javier Valdes and Franconville, Romain and Rivera-Alba, Marta and Mensh, Brett D. and Branson, Kristin M. and Simpson, Julie H. and Truman, James W. and Cardona, Albert and Zlatic, Marta} } @article {6881, title = {Wiring economy can account for cell body placement across species and brain areas.}, journal = {Current biology : CB}, volume = {24}, year = {2014}, month = {2014 Feb 3}, pages = {R109-10}, abstract = {The placement of neuronal cell bodies relative to the neuropile differs among species and brain areas. Cell bodies can be either embedded as in mammalian cortex or segregated as in invertebrates and some other vertebrate brain areas. Why are there such different arrangements? Here we suggest that the observed arrangements may simply be a reflection of wiring economy, a general principle that tends to reduce the total volume of the neuropile and hence the volume of the inclusions in it. Specifically, we suggest that the choice of embedded versus segregated arrangement is determined by which neuronal component - the cell body or the neurite connecting the cell body to the arbor - has a smaller volume. Our quantitative predictions are in agreement with existing and new measurements.}, issn = {1879-0445}, doi = {10.1016/j.cub.2013.12.012}, author = {Rivera-Alba, Marta and Peng, Hanchuan and de Polavieja, Gonzalo G and Chklovskii, Dmitri B} } @article {5763, title = {JAABA: interactive machine learning for automatic annotation of animal behavior.}, journal = {Nature Methods}, volume = {10}, year = {2013}, month = {2012 Dec}, pages = {64-7}, abstract = {

We present a machine learning{\textendash}based system for automatically computing interpretable, quantitative measures of animal behavior. Through our interactive system, users encode their intuition about behavior by annotating a small set of video frames. These manual labels are converted into classifiers that can automatically annotate behaviors in screen-scale data sets. Our general-purpose system can create a variety of accurate individual and social behavior classifiers for different organisms, including mice and adult and larval Drosophila.

}, issn = {1548-7091}, author = {Kabra, Mayank and Robie, Alice A and Rivera-Alba, Marta and Branson, Steven and Branson, Kristin} } @article {4327, title = {Wiring economy and volume exclusion determine neuronal placement in the Drosophila brain.}, journal = {Current Biology}, volume = {21}, year = {2011}, month = {2011 Dec}, pages = {2000-5}, abstract = {

Wiring economy has successfully explained the individual placement of neurons in simple nervous systems like that of Caenorhabditis elegans [1-3] and the locations of coarser structures like cortical areas in complex vertebrate brains [4]. However, it remains unclear whether wiring economy can explain the placement of individual neurons in brains larger than that of C.\ elegans. Indeed, given the greater number of neuronal interconnections in larger brains, simply minimizing the length of connections results in unrealistic configurations, with multiple neurons occupying the same position in space. Avoiding such configurations, or volume exclusion, repels neurons from each other, thus counteracting wiring economy. Here we test whether wiring economy together with volume exclusion can explain the placement of neurons in a module of the Drosophila melanogaster brain known as lamina cartridge [5-13]. We used newly developed techniques for semiautomated reconstruction from serial electron microscopy (EM) [14] to obtain the shapes of neurons, the location of synapses, and the resultant synaptic connectivity. We show that wiring length minimization and volume exclusion together can explain the structure of the lamina microcircuit. Therefore, even in brains larger than that of C.\ elegans, at least for some circuits, optimization can play an important role in individual neuron placement.

}, issn = {1879-0445}, doi = {10.1016/j.cub.2011.10.022}, author = {Rivera-Alba, Marta and Vitaladevuni, Shiv N. and Mischenko, Yuriy and Lu, Zhiyuan and Takemura, Shin-ya and Scheffer, Lou and Meinertzhagen, Ian and Chklovskii, Dmitri and Polavieja, Gonzalo} }