The relation between connectivity gradients and spatial representations in human entorhinal cortex

Poster Session E - Monday, April 15, 2024, 2:30 – 4:30 pm EDT, Sheraton Hall ABC

Rebekka M. Tenderra¹ (tenderra@cbs.mpg.de), Christian F. Doeller^1,2,3,4, Stephanie Theves¹; ¹Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, ²Kavli Institute for Systems Neuroscience, Center for Neural Computation, The Egil and Pauline Braathen and Fred Kavli Center for Cortical Microcircuits, Jebsen Center for Alzheimer’s Disease, Norwegian University of Science and Technology, Trondheim, Norway, ³Wilhelm Wundt Institute of Psychology, Leipzig University, Leipzig, Germany, ⁴Department of Psychology, Technical University Dresden, Dresden, Germany

The entorhinal cortex (EC) is the key interface between neocortex and hippocampus in which spatial and non-spatial relations between experiences are organized in cognitive maps. Computational work suggests that the hippocampal-entorhinal system may support generalization by factorizing the representation of experiences into their structure in medial EC (MEC) and specifics in lateral EC (LEC), allowing their flexible recombination. Interestingly, a functional distinction between MEC and LEC is congruent with the abundance of spatially-tuned cells in MEC as well as with their distinct whole-brain connectivity profiles. Here we investigate the anatomical relation between spatial representations and cortical connectivity along EC to gain insights into the involvement of entorhinal representations in brain-wide cognitive processes. To this end, we assess the regional specificity of spatial representations in EC during task-based fMRI and identify a human equivalent of rodent MEC and LEC based on their distinct whole-brain functional connectivity profiles. We determine individual connectopic maps reflecting the dominant change in connectivity patterns along EC based on task- and resting-state fMRI. This analysis reveals an anterior-posterior gradient that separates EC into two distinct subregions. Based on this, we probe how individual connectopic maps relate to the distribution of spatial task representations observed in EC, and further examine implications of interindividual differences in entorhinal information processing for behavioral performance. A better understanding of the relationship between representational mechanisms in EC and its brain-wide connectivity can inform investigations on its wider role in cognition and further contribute to bridging the gap between rodent and human research.

Topic Area: LONG-TERM MEMORY: Other