Ulises Rey, Ph.D.

As an undergraduate, Ulises Rey studied human biology at the University Pompeu Fabra in Barcelona before moving to Berlin to join Stephan Sigrist’s group at the Free University of Berlin for his master’s and doctoral degrees. To understand how neurons exchange information with each other, he focused on the process of how proteins are organized at the synaptic terminal. For the last three years he has been a postdoctoral fellow in Manuel Zimmer’s group at the University of Vienna, trying to understand the organization of behavior using the nematode C. elegans. In his project, he developed a new behavioral assay compatible with whole brain imaging recordings. The behavioral data is quantitatively analyzed to find transitions between different behaviors. At the same time, the activity of every single neuron in the central nervous system of the C. elegans is recorded to understand how the transitions are implemented at the level of global brain dynamics.

Principal Investigator: Manuel Zimmer

Fellow: Josefine Meyer and Lisa Sippl

Project
Fasted C. elegans worms perform exploratory behavior to find food sources like bacteria. At the same time these worms have to avoid toxic environments like areas with low oxygen levels. In normal conditions when worms find a food patch they enter it to maximally exploit its resources, even if the oxygen concentration is lower. However, observations in the Zimmer Lab have shown that when the presence of food (appetitive) is coupled to extra low oxygen levels (aversive) the worms adapt their behavior to find an equilibrium between food exploitation and minimal hypoxia exposure. In the current project, we want to investigate the parameters that control this decision making by modifying the levels of the two contradictory inputs. Moreover, the implicated neural circuits could be uncovered using single neuron calcium imaging. Optogenetic activation/inhibition of the sensory pathways could bring the circuit out of balance to change the behavioral output.