Our Emmy Noether group investigates how long-term memory formation is altered by addictive drugs such as amphetamine and cocaine. Specifically, we examine how these substances, along with endogenous dopamine from the mesolimbic system, influence neuronal network activity in the hippocampus and entorhinal cortex at different stages of memory formation. To achieve this, we use in vivo electrophysiological recordings from large ensembles of neurons in mice performing memory tasks during and after repeated drug exposure. To further dissect the neural circuits linking addiction and memory, we integrate these recordings with optogenetic and chemogenetic manipulations of genetically defined cell types and pathways. Our research is supported by the DFG Emmy Noether program and an ERC Starting Grant.