However, direct demonstrations that coordinated theta-gamma coupling improves entorhinal-hippocampal operations are lacking. Thus, it may be the case that memory-related changes in theta-gamma coupling simply mirror memory-related increases in gamma power and phase synchrony [41]. Novel approaches (e.g., optogenetics) should allow researchers to disturb the relationship between gamma power and theta phase without affecting theta or gamma power. Such a manipulation would enable researchers to directly determine how coupling between theta and gamma affects neuronal signaling and memory operations in the entorhinal-hippocampal network.
