Our goal is to understand the fundamental principles for the function and organization of neural circuits involved in estimating an animal’s own movement, especially in the context of visually guided locomotion. Many basic functions of our brain, from motor control, to more cognitive operations such as navigation, critically depend on self-movement estimation. We investigate which circuits are involved in this representation, and what computations these circuits perform. In addition, we aim to identify the activity dynamics and mechanisms by which these computations are generated.

Our strategy focuses on connecting neural activity dynamics to the locomotive behavior of the fruitfly, Drosophila melanogaster. We employ multiple methods to record and reversible perturb neural activity in behaving flies, to analyze the structure of interconnected neurons, to quantify different aspects of the fly’s locomotive behavior, and to model functional networks. This multidisciplinary approach, together with the ever-expanding genetic toolkit of the fruitfly, allows us to find mechanistic explanations for how multisensory and sensorimotor integration processes in the brain are used to guide adaptive behavior.

Overview

Sensory processing and motor actions are intimately linked in many aspects of brain function. Examples include active sensing, goal-directed locomotion and motor learning. We use these behavioral contexts to investigate the underlying operational principles of sensorimotor processing.
Our projects are divided in three inter-related lines of research:

Development of behavioral paradigms to study sensorimotor integration

We are currently developing “freely moving” and “tethered” behavioral paradigms in virtual reality-like worlds designed to probe the computational capacities of the fly’s brain during visually guided orientation behaviors. These shall form a platform for studying: a) how the fly uses its own movements and the generated visual motion cues to explore an environment, b) how her brain incorporates sensory signals to correct locomotion during orientation towards objects, and c) how do past experiences inform ongoing behavior.

Colaborators: Gonçalo Lopez, José Cruz and Matthieu Pasquet

Identification of neurons and circuits involved in sensorimotor processing

The aim of this project is to understand how components in the circuit are linked and how the activity patterns of neurons arise from their synaptic connectivity. We identify neuronal components of a network using behavioral, physiological and anatomical methods. We then map connectivity among candidate neurons by combining chemical, optical and electrical techniques. Importantly, in the brain of the fruitfly it is possible to systematically identify the same class of neurons across different individuals. This allows investigating variability in synaptic connectivity and circuit function across different flies.

Probing neural processing during sensorimotor tasks

In simultaneous with head-fixed, tethered locomotion, we use electrophysiological and imaging techniques to monitor the activity dynamics of populations of genetically- or anatomically-defined groups of neurons. We apply quantitative analytical tools to correlate neural population activity with the behaviors described above, and to make predictions about the contribution of different groups of neurons to such behaviors. We examine the roles of different groups of neurons in the circuit by precise manipulations of their activity with genetic and optical techniques. These experiments are aimed at defining the functional logic of the circuitry in the context of a specific behavior. By comparing different visual-motor tasks, our research attempts to identify common principles of visual-motor transformations.

Eugenia Chiappe, PhD
Principal Investigator
eugenia.chiappe@neuro.fchampalimaud.org

Biography

Kathrin Steck, PhD
Postdoctoral Researcher
kathrin.steck@neuro.fchampalimaud.org

Mert Erginkaya
2012 INDP PhD Student
mert.erginkaya@neuro.fchampalimaud.org

Nélia Varela, PhD
Senior Research Assistant
nelia.varela@neuro.fchampalimaud.org

Nuno Rito
Masters Student
nuno.rito@neuro.fchampalimaud.org

Rita Saraiva
Lab Administrator
rita.saraiva@research.fchampalimaud.org

Saliha Ece Sönmez
Research Technician
ece.sonmez@research.fchampalimaud.org

Sebastián Malagón Pérez
Research Technician
sebastian.malagon@research.fchampalimaud.org

Terufumi Fujiwara, PhD
Postdoctoral Researcher
terufumi.fujiwara@neuro.fchampalimaud.org

Tomás Cruz
2014 INDP PhD Student
tomas.cruz@neuro.fchampalimaud.org

Wynne Stagnaro
Research Technician
wynne.stagnaro@research.fchampalimaud.org

Busse L, Cardin JA, Chiappe ME, Halassa MM, McGinley MJ, Yamashita T, Saleem AB. (2017) Sensation during Active Behaviors. J. Neurosci. 37 (45), 10826-10834.

Terufumi Fujiwara, Tomás L Cruz, James P. Bohnslav, and M Eugenia Chiappe (2016) A faithful internal representation of walking movements in the Drosophila visual system Nat. Neurosci. (doi:doi:10.1038/nn.4435)

Tuthill JC, Chiappe ME, Reiser MB (2011) Neural correlates of illusory motion perception in Drosophila. Proc. Natl. Acad. Sci. U.S.A. 108 (23), 9685-9690 (doi:10.1073/pnas.1100062108)

Chiappe ME, Seelig JD, Reiser MB, Jayaraman V (2010) Walking Modulates Speed Sensitivity in Drosophila Motion Vision. Curr. Biol. 20 (16), 1470-1475 (doi:10.1016/j.cub.2010.06.072)

Seelig JD, Chiappe ME, Lott GK, Dutta A, Osborne JE, Reiser MB, Jayaraman V (2010) Two-photon calcium imaging from head-fixed Drosophila during optomotor walking behavior. Nat. Methods 7 (7), 535-534 (doi:10.1038/nmeth.1468)

Tian L, Hires SA, Mao T, Huber D, Chiappe ME, Chalasani SH, Petreanu L, Akerboom J, McKinney SA, Schreiter ER, Bargmann CI, Jayaraman V, Svoboda K and Looger LL (2009) Imaging neural activity in worms, flies and mice with improved GCaMP calcium indicators. Nat. Methods 6 , 875 - 881 (doi:doi:10.1038/nmeth.1398 )

Chiappe ME, Kozlov AS and Hudspeth AJ (2007) The Structural and Functional Differentiation of Hair Cells in a Lizard's Basilar Papilla Suggests an Operational Principle of Amniote Cochleas. J. Neurosci. 27 (44), 11978-11985 (doi:10.1523/JNEUROSCI.3679-07.2007)

Larsson MC, Domingos AI, Jones WD, Chiappe ME, Amrein H, Vosshall LB. (2004) Or83b encodes a broadly expressed odorant receptor essential for Drosophila olfaction. Neuron 43 (5), 703-714 (doi:10.1016/j.neuron.2004.08.019)

Chiappe ME, Lattanzi ML, Colman-Lerner AA, Barañao JL, Saragüeta P (2002) Expression of 3 beta-hydroxysteroid dehydrogenase in early bovine embryo development. Mol. Reprod. Dev. 61 (2), 135-141 (doi:10.1002/mrd.1140)

Lerner AA, Salamone DF, Chiappe ME, Barañao JL (1995) Comparative studies between freshly isolated and spontaneously immortalized bovine granulosa cells: protein secretion, steroid metabolism, and responsiveness to growth factors. J. Cell. Physiol. 164 (2), 395-403 (doi:10.1002/jcp.1041640220)