Being able to learn and to adapt to a changing environment through learning is fundamental for the survival of living organisms. Furthermore, the capacity of learning, to a large extent, defines the successfulness of both biological and artificial intelligence. In the brain, synaptic plasticity, by virtue of its capability of altering the connectivity and thus dynamics of neuronal circuits based on neuronal activity, serves as a cellular substrate of learning and memory. In this talk, I will describe several observations of learning and plasticity made with hippocampal neurons in culture, including the properties of spike-timing-dependent synaptic plasticity, the features of quasi-rhythmic network dynamics with conserved temporal patterns, and the intricate interactions between the two that is reminiscent of Hebb’s cell assembly theory.