Understanding the mechanisms that underlie learning is one of the most fascinating and central aims of neurobiological research. Hippocampal long-term potentiation (LTP) is widely regarded as a prime candidate for the cellular mechanism of learning. The receptor tyrosine kinase TrkB (also known as NTRK2), known primarily for its function during PNS and CNS development, has emerged in recent years as a potent regulator of hippocampal LTP. Here I describe efforts to understand the signalling pathways and molecular mechanisms that underlie the involvement of TrkB in LTP and learning.