Stephan Lammel
University of California-Berkeley, CA·Neuroscience
Why do we keep eating rich food when we are not hungry, and how does the brain decide which rewards to pursue? Both questions lead to the brain's reward system, a set of connected regions that drive motivation and learning.
- Fields
Neuroscience
Pharmacology
Physiology
- Topics
dopamine
ventral tegmental area
nucleus accumbens
- Grants
- 2 known grants, through Jun 2030
What they work on
- Test whether neurotensin signaling in the pathway from the lateral nucleus accumbens to the VTA drives hedonic feeding in mice, using optogenetics, NTS receptor blockers and a new neurotensin sensor that measures release in vitro and in vivo.
- Determine how a prolonged high-fat diet alters the NAcLat-to-VTA pathway before and after the synapse, using electrophysiology, fiber photometry and patch-seq, which pairs each neuron's electrical recording with its gene expression.
- Measure how different doses of nicotine change dopamine release in distinct nucleus accumbens subregions, and how nicotinic acetylcholine receptors contribute, using pharmacology and fiber photometry in mice.
- Compare dopamine cell body activity with dopamine release in separate VTA-to-NAc subcircuits during reward seeking and a two-armed bandit choice task, testing whether each subcircuit has a distinct role in reward learning and motivation.
- Establish Neuropixels recordings combined with optogenetics to record VTA dopamine neurons by cell type and projection target in head-fixed mice performing a reward-seeking task.
More about the research
Harmful changes in this system are linked to obesity and to substance use disorder. The lab studies the pathway between two parts of this system. The ventral tegmental area (VTA) is a midbrain region rich in dopamine neurons. The nucleus accumbens (NAc) is its main target. Working in mice, the lab links specific groups of cells and specific signaling molecules to specific behaviors.
Why it matters
Obesity and substance use disorder both involve harmful changes in the brain circuits that control reward and motivation. This work aims to show how a high-fat diet alters neurotensin signaling in the reward system, and which dopamine subcircuits drive reward learning and respond to nicotine. It may identify molecular and circuit-level targets that could guide the development of future treatments for obesity and addiction in humans.
Known grants
From NIH and NSF research grants. Labs often have other funding we can't see.
Closest labs
Elizabeth Mietlicki-Baase
University at Buffalo, NY·Neuroscience
Test whether activating amylin receptors in the ventral tegmental area suppresses rapid dopamine release in the nucleus accumbens core in response to fat in the mouth, measured with fast-scan cyclic voltammetry.
Christian Bravo-Rivera
University of Puerto Rico-Medical Sciences, PR·Neuroscience
Characterize how nucleus accumbens neurons and astrocytes encode the learning and expression of approach/avoidance conflict, using calcium fiber photometry in mice performing the platform-mediated avoidance task.
Marina Picciotto
Yale University, CT·Neuroscience
Define the role of nicotinic acetylcholine receptors in a ventral tegmental area to ventral pallidum GABA circuit and a medial septum to basolateral amygdala acetylcholine circuit that boost responding for rewards and reward-paired cues in mice.
The school
University of California-Berkeley: 46 labs on PI Pages, $1.1B a year on research, 825 research doctorates a year.
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