Our aim is to elucidate the roles of signaling molecules in regulating cognitive brain processes such as learning or attention. To achieve this goal, external manipulations， i.e., electrical stimulation or drug administration, are applied in animal models. We apply lab-developed sample extraction approaches in combination with high resolution analysis on LTQ-Orbitrap to screen and monitor the changes in signaling molecules. We also develop innovative chemical approaches and novel tools to monitor such changes both in vitro and in vivo.