dopamine hippocampal CA1 medial prefrontal cortex rule switching VTA Significance Statement This study examines neural activity in mammalian brain networks that support the ability to respond flexibly to changing contexts. We use a rule-switching spatial task to examine whether the key reward-responsive and predictive dopamine (DA) activity changes in coordination with changes in rule representations in key cognitive regions, the medial prefrontal cortex (mPFC), and hippocampus.