Cellular basis of the cortical head-direction representation

• Applicant: Dr. Patricia Preston Ferrer
• Subject Area: Cognitive, Systems and Behavioural Neurobiology ; Molecular Biology and Physiology of Neurons and Glial Cells
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 499288682

The observation that neurons in the rat dorsal presubiculum (PreS) are tuned to the direction the animal is facing, represents a milestone discovery for the neural representation of direction. These head-direction (HD) neurons are thought to provide the mammalian brain with an internal compass, which is necessary for navigation. HD signals are generated subcortically, and relayed to the cortex (in primis, the PreS) where they are thought to be further processed and integrated with other visuo-spatial signals. Despite decades of modelling work, it is currently unknown whether and how HD activity and computations map onto the underlying cortical microcircuit structure.In the present proposal, we aim at filling this gap. By combing innovative in-vivo single-cell recording and optogenetic methods, quantitative neuroanatomy and behavioral techniques, we aim at dissecting the microcircuit organization of HD activity in the mouse PreS. Our ongoing work indicates that cortical modularity strongly constrains connectivity and organizes functional properties in the mouse PreS. Based on this work, we hypothesize the existence of cell-type-specific microcircuits, which process HD information and integrate it with visual landmark inputs – a computation that ensures that stability of the internal compass. Our emerging ‘microcircuit model’ offers biologically-realistic hypotheses for signal integration, that we will systematically test in the present proposal.Altogether, the proposed project is aimed at resolving the cellular basis of the cortical HD representation, and will thus provide new insights into fundamental mechanisms of neural coding and computation in the mammalian cortex.

• DFG Programme: Research Grants