High-Density MEA Reveals Distinct Sharp-Wave Ripple Network Dynamics Across Induction Methods in the Hippocampus

Learning and memory are fundamental brain functions governed by rhythmic oscillatory activity, which synchronizes neural communication and modulates network dynamics. Distinct oscillatory patterns-theta (θ), beta (β), gamma (γ), and sharp wave-ripples (SWR)-coordinate neural ensemble activity, particularly in the hippocampal CA1-CA3 regions, where they play a crucial role in learning and memory. Understanding the mechanisms underlying SWR generation is crucial, as these oscillations play a fundamental role in memory consolidation, synaptic plasticity, and cognitive function. Unlike previous small-scale studies that relied on limited electrode coverage, our approach leverages high-density microelectrode arrays (HD-MEAs) to capture SWRs across large-scale hippocampal networks. This enables a direct comparison of how different induction methods influence network-wide dynamics, rather than focusing on isolated neuronal activity. By quantitatively assessing spatiotemporal propagation, frequency distributions, and ensemble synchronization, we aim to determine whether experimentally evoked SWRs truly replicate the functional characteristics of their spontaneous counterparts or introduce distinct network properties. Our findings provide a critical foundation for interpreting SWR activity in both physiological and experimental settings, offering novel insights into large-scale neural dynamics and their implications for memory-related processes and therapeutic interventions.