caesar Seminar Series
Sercan Sayin, School of Life Sciences Weihenstephan, Technical University of Munich
caesar seminar series
Aminergic neurons arbitrate between perseverance and reward in hungry Drosophila
An animal must show perseverance to achieve survival in its precarious environment. Faced with starvation, it will exhaust its already depleted energy resources for food-seeking until it finds the food reward. However, disengagement from a task is equally essential. Getting trapped at an attractor state in its behavioral space will result in failure to exploit other potential action sequences for an animal. How the balance is achieved is poorly understood. Here, we used Drosophila melanogaster as a model to study internal state dependent generation and control of perseverance in appetitive odor tracking and underlying aminergic neuronal substrates. Taking advantage of a new generation of a spherical treadmill for olfaction, we found hungry wild-type flies strove more for finding food over time despite lack of a reward. The absence of relief must accumulate prediction errors, as flies without dopamine failed to integrate negative drive and did not persevere. Reward presentation asserted control over perseverance in a transient or persistent manner, depending on the inherent value of the reward. We identified specific octopaminergic neurons residing in SEZ, a primary taste region, as the mediator of this brake control. Since the mushroom body receives input from both aminergic populations, we propose mushroom body as a convergence network for perseverance and showed its output acts as the motivational switch for food-seeking. This convergent hub provides a framework to study the interplay between two attractor states that confer behavioral perseverance and flexibility.