Research

Animal studies are essential to understanding the neural circuitries responsible for responding to and learning about stimuli in the environment that are emotionally significant, either because they are aversive (e.g. threatening, uncontrollable) or rewarding (e.g. interesting, pleasurable). Of those brain regions that constitute these neural circuitries, a number contain a combination of neurons specialized for either aversion processing or reward processing. Identifying and studying these “aversion” and “reward” neurons specifically is essential to understand how neural circuits for aversion and reward processing function and, furthermore, how they are altered by chronic exposure to aversion.

Our research focuses on the neural circuits involving amygdala-hippocampus in aversion processing and amygdala-nucleus accumbens-ventral tegmentum-nucleus accumbens in aversion and reward processing. Methods include neuronal tracing; pathway-specific measurement of neuronal activity and neurotransmitter signalling during aversion- or reward-directed behaviour using fibre photometry; laser capture microdissection of specific neuronal populations for transcriptome expression; brain histology and quantification of specific genes or proteins; environmental perturbations including chronic social stress and adolescent social isolation; neuropharmacological targeting of specific receptors (e.g. orphan receptors) and processes (e.g. glutamate synaptogenesis).

Examples of current studies:

(1) Aversion and reward signalling in the basal amygdala-nucleus accumbens pathway and changes induced by chronic social stress.

(2) Reward signalling in the nucleus accumbens-ventral tegmentum-nucleus accumbens circuit and changes induced by chronic social stress.

(3) Neural circuit changes underlying the reversal of chronic stress-induced excessive aversion reactivity by inhibition of transient receptor potential cation channels.

(4) Effects of psilocybin on aversion memory extinction and glutamate synapse status in control and chronic-stressed mice.

(5) Effects of adolescent social isolation on cortical circuits underlying flexible learning processes.