Many different neuropeptides co-exist with fast-acting classical neurotransmitters in neurons of the central nervous system and play a modulatory role on brain function. In particular they are important for the modulation of learning and memory associated with changes in the internal state of the subject (arousal, stress, inflammation, reward…). In this context, our work aims at understanding the role of the opioid neuropeptidergic systems in the acquisition and consolidation of memory, with a special interest for the nociceptin/orphaninFQ system and its regulation by stress. Our hope is to identify new pharmacological targets useful to improve pathological conditions such as anxiety disorders and neurodegenerative diseases. Our ongoing projects focus more specifically on: