Our research is aimed at understanding systems-level molecular mechanisms of selective retention of trivial memory through neuromodulation in the hippocampus (Takeuchi et al., Nature, 2016; Duszkiewicz et al., Trends in Neurosci., 2019). Further, we study the assimilation of this retained memory into the relevant knowledge structure, called schema (Tse, Takeuchi et al., Science, 2011), using sophisticated behavioural tests in rats combined with cutting-edge techniques.