This study examined the interaction of acetylcholine (ACh) and oxytocin (OXT) at slow and fast timescales during various brain states. They used simultaneous fiber-photometric measurements of ACh and OXT variations in the hippocampus using G-protein-coupled receptor activation-based Ach and OXT sensors. These optical measurements were compared with sleep-wake changes and characteristic brain-state-dependent fine timescale changes of neuronal activity, including theta, gamma oscillations, SPW-Rs, sleep spindles, and population spike synchrony. Consecutively, they investigated the direction of neuromodulation-network pattern relationships by optogenetic control of ACh and OXT neurons. The data indicate how cooperative actions of these neuromodulators allow target circuits to perform specific functions.