Job ID: 80917

PHD position in Neural Circuits and Behavior in Drosophila

Position: Ph.D. Student

Deadline: 7 May 2022

City: Saclay

Country: France

Institution: Institut des Neurosciences Paris-Saclay

Department:

Description:

A PhD position is available to join the Neural circuits and Behavior team headed by Tihana Jovanic in the Cognition and Neural Network Department at Paris Saclay Institute of Neuroscience (NeuroPSI).

The team uses Drosophila larva as a model system to map neural circuits using a multidisciplinary approach that combines neural manipulation during behavior, electron microscopy (EM) reconstruction of neuronal connectivity at a synaptic level and recording of neuronal activity using Calcium imaging in the Drosophila larva with the goal of understanding computational principles underlying complex behaviours and their modulation by the context and internal state.

Investigation of the role of ascending and descending pathways in sensorimotor decisions and behavioral control.

In order to survive animal’s constantly need to adjust their behavioral output to the dynamic changes in the environment and their internal needs. Across the animal the brain performs computations essential for behavior such multisensory integration, learning, decision-making etc that then need to be transmitted to the motor circuits that control the behavior output and that are located close to the muscles that they control, which is in spinal cord in the vertebrate and ventral nerve cord (VNC) in insects. In addition, the higher order brain regions also need to receive information about animal’s behavioral and locomotor state to efficiently process relevant information. The communication between higher order regions and sensorimotor circuits is mediated via ascending and descending pathways across species, however the exact mechanism by which the information from higher order regions conveyed to sensorimotor circuits and vice versa and how is this information integrated to produce appropriate behavioral output is not well understood. We propose to fill this gap in a powerful model organism for neural circuit analysis: the Drosophila larva. Drosophila larvae are ideally suited for combining comprehensive, synaptic-resolution circuit mapping across the nervous system with targeted manipulation of uniquely identified circuit motifs at the individual neuron level, which makes it possible to establish a causal relationship between circuit structure and function in brain-wide.

We have previously identified the neural substrates and neural circuits underlying sensorimotor decisions in the ventral nerve cord of the Drosophila larva that allowed to determine the neural circuits bases underlying competitive interactions and navigational decision-making (Jovanic et al, 2016, 2019, Masson 2020).  Our published and unpublished preliminary studies have also identified ascending pathways to the brain as well descending pathways from the higher order to the VNC. In order to investigate the modulation of sensorimotor circuit activity in the VNC  by descending neurons and the influence of animal’s behavioral state on higher-order processing we will combine multiple approaches for neural circuit analysis. We will use synaptic-resolution connectomics (reconstruction of neurons and synapses in electron microscopy) to determine what types of information do descending neurons from  the higher order regions convey to the VNC and what regions do ascending pathways from the VNC contact in higher order regions. . We will use immunocytochemistry to determine the neurotransmitters (and co-transmitters) they express. Furthermore, we will perform neuronal manipulation (silencing/activation) of ascending/descending neurons during behavior and quantify behavioral changes that occur upon these manipulations using automated algorithms. Finally, we will monitor the activity of ascending/descending neurons using calcium-imaging in response to different type of stimuli and /or while optogenetically activating their upstream partners to determine whether pairs of neurons activate/inhibit each other. Altogether this will allow us to determine the role and mechanism of action of the ascending and descending pathways in modulating central processing and behavior with cellular and synaptic resolution.

 

More details about the team can be found here: https://neuropsi.cnrs.fr/departements/cnn/equipe-tihana-jovanic/

 

We are seeking applications of highly motivated individuals, preferably with background in

Neuroscience or related fields. Master in neuroscience, biology, engineering or related fields is required. Experience in Calcium-ˇimaging and/or programming will be appreciated.

 

The work will include connectivity analyses based on EM reconstruction as well as optogenetics and Calcium-imaging and there will be opportunities for national and international collaborations specifically on modelling.

 

Anticipated start date is fall 2022

 

Paris Saclay Institute of Neuroscience (NeuroPSI) is located in Saclay (20 km south of Paris) and is dedicated to fundamental research in Neuroscience. NeuroPSI has state-of the art core facilities and the Saclay campus provides a highly interdisciplinary and collaborative environment mixing university and engineering schools, with excellent laboratories in fundamental and applied science.

 

For more details about the project and position please contact Tihana Jovanic tihana.jovanic@cnrs.fr

Candidates should send a CV, a motivation letter and contacts of two references

tihana.jovanic@cnrs.fr by May 7th

Review of applications will begin immediately and will continue until the position is filled.