It is believed that sleep plays an important role in memory consolidation. In rodents, hippocampal neurons (place cells) selectively discharge when the animal is in a specific location in space. During subsequent sleep, they are reactivated in the same order at 200Hz network oscillations known as ripples. This timescale is optimal for synaptic plasticity underlying memory. The host team (Rouach) has recently shown that connexin 30 (Cx30), a main gap-junction subunit in astrocytes, regulates excitatory synaptic transmission and is upregulated in mice raised in enriched environments known to enhance learning and memory. In addition, the lack of Cx30 impairs behaviour and responsiveness to novelty implying an important role for Cx30 in behavioral, cognitive processes, and physiological network activity. However, the mechanisms involved in this role are still unclear since Cx functions extend beyond intercellular communication and include hemichannel-mediated and channel-independent functions. This project aims to investigate the role of astroglial Cx30 in ripples activity and the physiological and molecular mechanisms involved. The researcher (Cheung) has ~8 years of experience and success in research on both neurons and glia from labs in Germany and UK. After a career break, she is determined to resume her research career by leading this project in France at the host team, which is internationally recognised in the field of neuroglial and Cx physiology. In collaboration with a team of experts in electrophysiology in freely behaving animals (Zugaro), a unique multidisciplinary approach combining in vivo and in vitro electrophysiology, pharmacology and molecular biology will be taken. The Marie Curie Intra-European Fellowships for Career Development will provide an ideal platform and a prestigious opportunity for Cheung to continue developing her research career into becoming an independent researcher in Europe specialising in glial contributions to neuronal functions.