Description du sujet de thèse

Proper response to external stimuli is essential for survival. Upon aversive stimuli animals display a stereotypical defensive behavior consisting of flight and/or freeze followed before recovering to baseline activity. Aberrant response to aversive stimuli leads to depression, anxiety or addiction in humans. The evolutionarily conserved habenulo-interpeduncular nucleus (Hb-IPN) pathway has emerged as a crucial circuit that mediates fear and stress-related defensive behaviors. This pathway is composed of two distinct circuits, the cholinergic and the peptidergic non-cholinergic, that innervate adjacent domains in the IPN of zebrafish larvae (Hong et al., 2013). We recently found a hardwired mode of negatively correlated activity between the cholinergic and non-cholinergic circuits, whereby the synchronized activation of cholinergic neurons inhibits non-cholinergic neuron activity (Zaupa et al., 2021). The project aims to understand how different external stimuli interact with internal states to recruit the neuronal cicuits to modify defensive behavior.

Contexte de travail

The lab uses the transparent zebrafish larvae to record and manipulate neuronal activity in the Hb-IPN pathway. The candidate will study how external and internal states affect the activity in this brain region and locomotor behavior by calcium imaging, pharmacology, electrophysiology, optogenetics and computational analyses combined with behavioral studies. Candidates with a solid background in neuroscience focusing on neurophysiology with strong programming skills are encouraged to apply.