Interneuron plasticity during spatial learning

The hippocampus is a complex neuronal network, which is important for spatial memories. Hippocampal principal cells encode space by firing in a location-dependent manner. Together these place cells form an allocentric map representation of space so that each environment corresponds with an entirely different map. New maps can be formed as a result of spatial learning and this new map formation is accompanied by plastic changes of pyramidal cell-interneuron connections. Here, combined in vivo electrophysiology and optogenetic approaches will be used to test whether these plastic changes are interneuron type-specific. Moreover, we will examine the molecular mechanisms behind this type of plasticity and test how these plastic changes might promote map stabilisation. In these experiments the use of optogentics techniques will enable us to differentiate different interneuron types and to identify those that underwent c-fos-expression.

The hippocampus is a complex neuronal network, which is important for spatial memories. Hippocampal principal cells encode space by firing in a location-dependent manner. Together these place cells form an allocentric map representation of space so that each environment corresponds with an entirely different map. New maps can be formed as a result of spatial learning and this new map formation is accompanied by plastic changes of pyramidal cell-interneuron connections. Here, combined in vivo electrophysiology and optogenetic approaches were used to test plastic changes on interneurons. Moreover, we examined how synchronized activity regulated this type of plasticity and tested how these plastic changes promoted map stabilization. In these experiments the use of optogentics techniques enabled us to differentiate specific interneuron types. In using these approaches, our work revealed that optogenetic activation triggers synchronization changes, leading to the reorganization of connections between pyramidal cells and interneurons.