Physiology I

A fundamental and fascinating feature of the mammalian brain is its capacity to acquire and store novel information. However, little progress has been made on how memory is represented in neuronal networks. Our research is focused on understanding the mechanisms underlying the emergence of learning-associated active cell populations, so called cell assemblies, representing new memories. We aim to focus this question on the rodent dentate gyrus (DG), the input region of the hippocampus, known to be functionally vital for acquiring new memories in humans, nonhuman primates and rodents. So far our group efforts have been clarifying the cellular and synaptic properties of neurons and synapses in the DG circuitry and the mechanisms underlying the synchronization of neuronal networks for the encoding of information. Moreover, we have investigated the cellular, synaptic and network mechanisms important for the development of neuronal networks, specifically of GABAergic inhibitory cells. Our major questions which have been brought into sharp focus based on recent scientific observations are as follows:

1. understand the spatial and temporal emergence of learning-associated cell assemblies representing new memories,
2. delineate the nature and relevance of the major functional (cellular, synaptic, plasticity) and structural  changes underlying cell assembly formation
3. understand the functional and dynamic characteristics of synaptic communication among cells and their role in information processing in cortical microcircuits
4. identify the role of the high variety of GABAergic cells in neuronal network function and cell assembly formation
5. examine dysfunction of cellular components in specific mouse models underlying neuronal diseases

To address these questions we use state-of-the-art techniques which include:

1. imaging and manipulating activity of neuron populations during behaviour at high spatial and temporal resolution
2. dissect and manipulate the mechanisms underlying synaptic transmission and plasticity on a cell-type and synapse-specific manner in the living animal
3. 3. record from pairs of neurons in acute slice preparations
4. perform behavioural analysis during in vivo single unit and local field potential recordings
5. apply optophysiological techniques to recruit or silence defined neuron types in specific brain areas
6. combine electrophysiological with computational approaches