A unified model of cortico-hippocampal interactions through neural field theory

Cortico-hippocampal interactions underlie both healthy cognition and neurological disorders. Using neural field theory, we build a biophysically constrained model in which autonomous cortical and hippocampal activity emerges from distinct feedback loops: corticothalamic circuitry generates alpha rhythms and hippocampo-septal circuitry produces theta rhythms. We integrate these subsystems via topologically and topographically structured cortico-hippocampal coupling. Weak coupling reproduces spatially precise, experimentally observed correlations between cortical and hippocampal signals. Increasing coupling strength pushes the joint system toward criticality, inducing state transitions and mode mixing that enable cross-scale propagation and reorganization of both cortical and hippocampal dynamics. The same mechanism explains the disproportionate involvement of the hippocampus in seizure initiation and spread, a prediction validated using intracranial EEG from human focal-onset epilepsy. This framework links geometry, physiology, and dynamics to furnish a unified, quantitatively interpretable account of large-scale cortico-hippocampal activity and provides a physically principled foundation for studying other distributed neural systems.