Project description
Profiling inhibitory projections to hippocampal-entorhinal networks
The brain’s interconnected networks are carefully orchestrated to enable high-level functions. The hippocampus and entorhinal cortex are interconnected and play a role in learning and memory. The septum, a subcortical structure near the brain’s midline, sends inhibitory inputs to the hippocampal and entorhinal networks. These GABAergic neurons, named for the neurotransmitter they release, modulate neuronal spiking in hippocampal and entorhinal networks that supports spatial- and object-coding. These neurons are vulnerable to degeneration; moreover, medial septum inactivation is associated with cognitive impairments. Funded by the European Research Council, the VulnerableInhibition project aims to elucidate the role of the septal-entorhinal GABAergic projections in episodic memory and spatial navigation dysfunction and investigate mitochondrial dysfunction as a source of their enhanced vulnerability.
Objective
Septal GABAergic projection neurons are considered “pacemaker” cells as they enable the temporal organization of neuronal spike firing in hippocampal and entorhinal networks that support spatial- and object-coding. Accordingly, medial septum inactivation is associated with cognitive impairments, but the specific role of the septal-entorhinal GABAergic projections therein has remained unexplored. This is a pressing question, as we have evidence that septal GABAergic projections exhibit enhanced vulnerability. In mouse models with neurodegeneration, we found that septal GABAergic axons exhibit signs of degeneration when target cells in the entorhinal cortices are not yet impaired. Furthermore, we have evidence for mitochondrial pathology in the degenerating axons. These results prompt the following questions: How does malfunction of septal GABAergic projections translate into dysfunction of downstream networks involved in episodic memory and spatial navigation? What are the mechanisms that render septal GABAergic projections prone to vulnerability?
Employing in vivo electrophysiology combined with optogenetics, behavioral studies, 2-photon imaging of axons and mitochondria in live mice and spatial transcriptomics, we will tackle the following issues: (A) assess how impaired septal GABAergic projections affect spatial- and object-coding in the medial and lateral entorhinal cortex (MEC and LEC), (B) assess the functional consequence thereof on spatial and associative memory in the LEC (C) gauge putative cellular mechanisms, with focus on mitochondria, that render septal long-range GABAergic projections vulnerable and (D) identify genes/gene networks whose expression is involved in degeneration of septal GABAergic neuron axons. With these studies we will elucidate how septal neurons contribute to cognition, reveal common mechanisms for axonal degeneration, and ideally identify novel biomarkers and therapeutic targets for “mitochondropathies”.
Fields of science (EuroSciVoc)
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques.
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques.
You need to log in or register to use this function
Keywords
Programme(s)
- HORIZON.1.1 - European Research Council (ERC) Main Programme
Topic(s)
Funding Scheme
HORIZON-ERC - HORIZON ERC GrantsHost institution
69120 Heidelberg
Germany