Cell-type specific signal processing in the medial entorhinal cortex deep layer micronetwork

• Applicant: Dr. Alexei Egorov
• Subject Area: Molecular Biology and Physiology of Neurons and Glial Cells
• Term: from 2019 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 430282670

Small neuronal networks express multi-neuronal activity patterns which are likely forming elementary representations. Typically, any complex cognitive or behavioral activity involves multiple local networks which are activated either simultaneously or sequentially. For some sensory and motor systems, there is considerable knowledge about the specific information contained in the activity of different local circuits. This is, however, much less clear for higher cognitive functions like spatial memory formation. Representations of spatial experiences are formed in the entorhinal-hippocampal formation. In the hippocampus they take the form of sharp wave-ripple complexes (SPW-R), which propagate into neocortical networks for long-term memory consolidation. The underlying mechanisms remain largely enigmatic. We want to study the first step in this chain of events, namely the propagation of SPW-R from the hippocampus to the medial entorhinal cortex (mEC) of mice. Our previous work shows that incoming hippocampal SPW-R activate two anatomically and functionally distinct sub-networks within mEC layer V. These parallel streams of activity are governed by two different sets of principal cells which form distinct intracortical micro-networks. We want to untangle the underlying connectivity and synaptic mechanisms, characterize the resulting multi-neuronal activity patterns and elucidate the role of inhibitory interneurons in structuring and separating the distinct pathways. Our work shall reveal basic mechanisms of a key example of segregated information processing in cortical networks.

• DFG Programme: Research Grants