Britt Lab for Neural Circuits, Motivation, and Reinforcement Learning

Welcome

We want to uncover the neurobiological mechanisms that underlie compulsive thoughts and actions. We are also interested in the neurobiological underpinnings of pleasure. Knowledge gained from these research endeavours will help efforts to resolve the pathophysiology of a variety of human psychiatric disorders, such as addiction, obsessive-compulsive disorder, schizophrenia, and Tourette's syndrome.

Jonathan Britt, Ph.D.

Densely labelled green fluorescent neurons and fibres on a black background. — Green fluorescent labelling · Britt Lab

Questions we're asking

One small structure where context, emotion and motivation meet.

Our research

What do the inputs to the nucleus accumbens encode?

Hippocampal, amygdala, thalamic and cortical inputs all converge on the nucleus accumbens. We record and manipulate each pathway to learn when it is active and when it matters for behaviour.

Reed et al., Neuron 2018 · Lafferty et al., Cell Rep. 2020
How does the brain decide to eat, and to enjoy it?

Eating coincides with a coordinated dip in excitatory input to the rostral accumbens shell, and hippocampal input to the shell makes food more palatable.

Reed et al., Neuron 2018 · Yang et al., Biol. Psychiatry 2020
What does dopamine actually teach?

Cue-evoked dopamine helps maintain cue–value associations without setting expected value, and accumbens shell dopamine both reinforces actions and limits how long they last.

Mendoza et al., Cell Rep. 2019 · Valyear et al., bioRxiv 2023
How is unproductive reward seeking held back?

Both major accumbens cell types, and both amygdala and thalamic inputs, are needed to stop responding when reward is unavailable: complementary roles rather than opposing ones.

Lafferty et al., Cell Rep. 2020

Pathway-specific innervation patterns in the nucleus accumbens.

Approach

Pathway-specific, with millisecond precision.

Our approach to uncovering the neurobiological processes that motivate and direct volitional behaviour is to combine state of the art methodologies (such as intracranial viral-mediated gene delivery, optogenetics, and calcium imaging) with simple rodent behavioural paradigms (such as Pavlovian and operant conditioning).

Our current efforts are largely focused on understanding the physiology and function of the nucleus accumbens, a forebrain structure that integrates contextual, emotional, and motivational cues to initiate and coordinate reward seeking behaviour.

Viral-mediated gene delivery
Light-sensitive proteins and calcium sensors, targeted to defined cell types and pathways.
Optogenetics
Switching specific pathways on or off with light, time-locked to behaviour.
Fiber photometry
Calcium activity recorded from pathway-defined axons in behaving mice.
Pavlovian and operant conditioning
Simple, well-controlled tasks that separate seeking, consuming and learning.

Selected work