The vision posited by Ivan Pavlov about 100 years ago has more or less become reality today.

Yet, it is still not clear how such activity patterns in the brain are encoded at the synaptic level. Synapses are the major sites of information exchange between neurons and can be regarded as the principal information-encoding units. Information may be encoded and stored both in the weights and in the wiring pattern of synapses.

However, whether individual synapses contribute to lasting alterations of neuronal circuits evoked by learning and memory formation is still not clear. We are interested in resolving how synapses participate in the formation and storage of memory engrams in the brain. To this end we develop and use optical methods to investigate Shaffer collateral synapses of the hippocampus in vitro and in vivo.

Experimental Set-Up

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Synaptic wiring of hippocampal circuits

How does synaptic plasticity affect synaptic connectivity? We are trying to answer this question by following individual functionally identified Schaffer collateral synapses in time. By controlling plasticity and circuit activity in slice cultures we test how synaptic function and synaptic stability are changed. See also DFG Research Unit 2419 .

Schaffer Collateral Synapses

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Schaffer collateral synapses in vivo

One of our central goals is to understand if and how memory traces - or engrams - can be encoded and stored in synaptic networks. To address this goal, we image identified synapses that are associated with a specific memory in the hippocampus of living mice. This project is supported by an ERC Starting Grant.

Optogenetic Tools

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Development of optogenetic tools

Improved optogenetic tools are required for the precise manipulation of neuronal circuits. Especially neuronal silencing needs to become more efficient. In collaboration with the lab of Peter Hegemann, we develop novel light-gated anion channels and apply them in neurons and neuronal circuits. See also DFG priority program SPP 1926 .