Balint Lasztoczi (Medical University of Vienna) talk on the 10th October at 11 am in the KOKI Lecture room

Summary: Cortical circuits of any particular brain area receive inputs from multiple sources carrying different information often directly converging onto single cells. For circuits to appropriately process incoming information the integration and segregation of these inputs has to be under tight temporal control, with the balance dynamically adjusted to fit the current computational task. In my presentation I will summarize our understanding of some mechanisms involved in input selection in the rodent hippocampus based on our recordings of electrical activity in head-fixed mice.
In the CA1 area afferents carrying mnemonic and sensory information from the CA3 area and the entorhinal cortex converge on CA1 pyramidal cells. During exploration, cycles of a constant 8 - 12 Hz theta oscillation organize the firing of CA1 pyramidal cells into short, discrete sequences where the order of cellular activation reflects the temporal organization of firing during behavioural episodes on a compressed time scale (theta firing sequences). By exploring the interaction between the spike timing of CA1 pyramidal cells and different layer-specific gamma oscillations associated with various CA1 afferent pathways, I will show how theta-paced shifts in the efficiency and activity of afferent pathways may shape theta firing sequences. In the second part of my talk, I will address the role of hippocampal GABAergic cells in the regulation of information transfer from the entorhinal cortex to CA1 pyramidal cells via the temporoammonic pathway. Neurogliaform cells are a peculiar GABAergic cell type residing in the stratum lacunosum-moleculare associated with the temporoammonic pathway. I will present our recent data supporting that neurogliaform cells are key players in regulating cortico-hippocampal communication by temporarily disconnecting CA1 pyramidal cells from their cortical inputs. I will discuss the potential implications of our findings in the healthy brain circuitry as well as in neuropsychiatric disorders.

All are welcome.