We are interested in how neuronal activity at the level of synapses, neurons, and neuronal circuits drives behaviour. To address this question, we focus on the hippocampus, a brain region that is critical for learning and memory. We combine novel physiological, optical, behavioural, and computational approaches to directly read out and manipulate the activity of individual neurons and neural circuits during behaviour.
A core question that drives our research is how the brain distinguishes between memories that closely resemble each other. A part of the hippocampus called the dentate gyrus has been suggested to serve this purpose by generating non-overlapping memory representations in a process termed “pattern separation”. An added twist is that, during adult life, the dentate gyrus is constantly supplied with new neurons, providing new circuit elements that can incorporate into the neuronal network. How the activity of these new adult-born neurons and mature granule cells combines to drive the production and storage of distinct memories represents a new frontier in understanding brain function. To tackle this task, we use intracellular patch-clamp recordings to assess how hippocampal neurons convert synaptic inputs into action potential output, 2-photon Ca2+ imaging to monitor the population activity of hippocampal circuits, and optogenetic tools to causally test theories of hippocampal function. Novel virtual-reality technologies allow us to directly probe cellular mechanisms of memory formation in vivo.