He is a fellow of the Korean Academy of Science and Technology and co-director of the IBS Center for Cognition and Sociality with Changjoon Justin Lee.

He investigated the molecular mechanisms of learning and memory using a simple animal, the marine snail Aplysia.

Moreover, he found that multiple pulses of serotonin stimulate gene expression that is mediated by the cAMP-response element (CRE).

Combining molecular, electrophysiological, and behavioral experimental tools, he began to explore the mechanisms of learning and memory in mice.

One of the major findings from his group was proving the importance of synaptic protein degradation in memory reorganization.

He found that postsynaptic proteins were degraded in the hippocampus by polyubiquitination after the retrieval of contextual fear memory.

In collaboration with Min Zhuo from the University of Toronto, he showed that the phosphorylation of PKMζ was increased in a neuropathic pain model in the anterior cingulate cortex.

Lee and E. Kim, he demonstrated that NMDAR-dependent synaptic plasticity in the hippocampus is impaired in a mouse model of autism, the Shank2 knockout.