Dopamine Circuits in Reward and Aversion

Speaker: Stephan Lammel


The pursuit of reward and avoidance of pain might be one of the oldest ideas in the history of thought about behavior of organism. Indeed, learning to adapt to a constantly changing environment through reward and punishment is essential for survival of an organism. Midbrain dopamine neurons encode reward prediction errors which is thought to reinforce actions that are triggered by rewarding stimuli. However, whether dopamine acts as a unitary ‘reward signal’ has been controversial for decades. My research has sought to clarify this controversy by demonstrating that dopamine neurons can be divided into a much larger number of anatomically and functionally distinct cell populations (Lammel et al., 2008, 2011, 2015; Neuron; Lammel et al., 2012; Nature; Yang et al., 2018; Neuron). In my presentation, I will discuss recent work in which we provided the first incontrovertible evidence for a distinct, identifiable subset of dopamine neurons that are activated by aversive stimuli and cues that predict them (de Jong et al., 2019; Neuron). Moreover, I will discuss unpublished data showing how we developed an approach that allows us to perform large scale electrophysiological recordings (via ‘Neuropixels’) from optogenetically identified dopamine neurons in mice performing a reward seeking task. Our work reveals a previously unknown complexity in the dopamine system that is critical for explaining key aspects of reinforcement learning and motivated behavior.

About the speaker:

Stephan Lammel is an Associate Professor at the Department of Molecular and Cell Biology and the Helen Wills Neuroscience Institute at UC Berkeley.

He received his PhD in Neuroscience in 2008 from the Philipps University of Marburg under the supervision of Jochen Roeper and worked as a postdoctoral fellow under the guidance of Robert Malenka in Stanford from 2009 to 2014.

He first came to the University of California Berkeley in 2015 as an Assistant Professor.

His research explores how heterogeneity in the midbrain dopamine system contributes to key aspects of reinforcement learning and motivated behavior. 

Time and place:

May 18, 2021, 4:00 p.m. CEST

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