ABSTRACT
Linking patterns of neuronal electrical activities with behavior is a major goal towards delineating neuronal circuit functions and ultimately understanding the human brain. Microelectrode-based electrophysiology has been, and largely still is, the golden standard for measuring neuronal signals at the level of single neurons while macroscopic electrical measurements such as electroencephalography (EEG) are a traditional tool in basic and clinical research at the systems level. However, both single cell-level and whole brain-level electrophysiology only provide partial insight, as many brain functions emerge from the interactions between groups of cells (neural ensembles) coupled by neural circuits, and therefore need to be understood at the level of neuronal circuits. Mechanistic understanding of neuronal networks underlying behavior and cognitive functions requires experimental approaches to measure neuronal activity patterns with spatiotemporal resolution and coverage beyond the limits of electrode-based methods (Knöpfel et al., 2006; Knöpfel, 2012).
