Tihana Jovanic Team

Neural Circuits and Behavior

In brief

All animals are constantly confronted with multiple behavioural options that they need to choose from depending on the context and on their internal state. We study how a group of neural cells interacts to ensures that appropriate behaviours are chosen and correctly ordered in an ever-changing environment using a powerful system with a compact and tractable nervous system: the fruitfly larva. We combine multiple approaches from detailed behavioral and connectivity analysis to in vivo imaging of neuronal activity.

Our research

Making appropriate behavioral choices depending on the environment and one’s internal state is essential for survival. In addition, a key feature of behavior is that it is frequently organized in sequences of actions. The neural bases of the decision-making process that leads to appropriate behavioral choices and of the sequence generation mechanism that ensure the proper ordering of individual elements in an action sequence are poorly understood at a circuit and single neuron level.

In our research, we exploit the advantages of the exquisite genetic tools available in Drosophila for manipulation and monitoring of neuronal activity at single neuron level and the numerical simplicity of the larval nervous system that allows the reconstruction of synaptic connectivity across the nervous system using large-scale electron microscopy to study the structure and function of the neural circuits for sensorimotor decisions and action sequences. We focus on three main aims :

• Aim 1. Determine how contextual information modulates behavioral choices.
• Aim 2. Define the brain-wide mechanism underlying competitive interactions between multiple actions.
• Aim 3. Determine the circuit mechanism underlying the production of longer innate sequences.

Circuit underlying the selection between a hunch and a bend. Schematic representation of the circuit based on EM reconstruction data. The width of the line is proportional to synaptic strength. (Jovanic, Scheinder-Mizell and al., cell, 2016).

If you are interested in our research, you are welcome to contact us by email.
We are interested in applications from motivated graduate students and postdocs. We will also consider internship requests of undergraduates, both in the field of biology, engineering and computational methods for data analysis.

Selected Publications

> Masson, J.-B.°, Laurent, F., Cardona, A., Barre, C., Skatchkovsky, N., Truman, J.W., Zlatic, M.°, and Jovanic, T.° Identifying neural substrates of competitive interactions and sequence transitions during mechanosensory responses in Drosophila. (PLos genetics, 2020, vol 16(2) e1008589) (https://doi.org/10.1371/journal.pgen.1008589)

> Tihana Jovanic, Studying decision-making in Drosophila larvae, a perspective (Journal of Neurogenetics, 2020, vol.55, p.1-9) (https://doi.org/10.1080/01677063.2020.1719407)

> T. Jovanic°, M.Winding, J.Truman, A.Cardona, M. Gershow° and M. Zlatic° Neural substrates of Drosophila larval anemotaxis (Current Biology, 2019 Feb 18;29(4):554–4.) (https://doi.org/10.1101/244608)

> T. Jovanic*, C. Schneider-Mizell*, M. Shao, JB Masson, G. Dennisov, R. Fetter, B. Mensch, J. Truman, A. Cardona, and M. Zlatic - Competitive disinhibition mediates behavioral choice and sequences in Drosophila, Cell, 2016 (http://dx.doi.org/10.1016/j.cell.2016.09.009)

° Highlighted in a Dispatch in Current biology by Kristan WB: Functional Connectomics: How Maggots Make Up Their Minds, Current biology, 2017 (http://dx.doi.org/10.1016/j.cub.2016.11.031)

* these authors contributed equally

Team members

 

Alumni

Maryam Remdane, étudiante de Master
Alexandre Petitmangin,
Erwan Maury