How does the brain encode motivations? Why do we do what we do? Scott Sternson is trying to address these questions by looking at the origins of our most fundamental motivations –behaviors, such as hunger and thirst, that are physiologically imperative for survival. To decipher the neurobiology of these survival needs, his lab group uses a combination of advanced molecular and systems neuroscience approaches.
Ultimately, Sternson would like to understand how neural circuits mediate flexible, goal-directed behaviors. He focuses on circuits for specific survival needs that are under strong selective pressure. Nevertheless, satisfying these needs requires an organism to demonstrate flexible behaviors in a complex and dynamic environment. To simplify the complexity of this problem, Sternson’s team starts from small sets of specialized neurons whose activity is sufficient to trick the brain into thinking it’s in a state of physiological need. This enables the team to take a reductionist approach to elucidate circuits, neuronal computations, and motivational principles associated with physiological need states.
The primary focus of Sternson’s lab is on neurons that induce hunger. His team’s work starts in the hypothalamus and looks at its interactions with a variety of other brain areas. They have also developed many tools, especially chemogenetic tools, for investigating cell types in different brain areas. Currently, his group looks at cell type specification using RNA-Seq and cell-type-specific neural circuit function using opto/chemogenetics. They also use deep-brain calcium imaging to understand neuronal dynamics in appetite circuits. All of these technical approaches are applied in the context of behavioral paradigms and designed to deconstruct the motivational properties of need-sensing neurons.