The circadian system aligns organisms’ physiology in 24-h rhythms, anticipating recurring environmental changes – mainly light/dark cycles. In mammals, the suprachiasmatic nucleus of the hypothalamus (SCN) orchestrates these rhythms, acting as a master clock. The 20,000 cells composing the mouse SCN are topologically organised in the ventral core responding directly to light and the dorsal shell organizing the rhythmic output. Almost all SCN neurons produce and receive GABA, together with more than 100 neuropeptides involved in paracrine signaling. Recent evidence has shown that SCN astrocytes play essential roles as timekeepers, alongside neurons. While the functional heterogeneity of SCN neurons is well established and linked to their regional distribution, whether SCN astrocytes exhibit similar specialization remains unclear. In my project, I investigate whether neurons and astrocytes within the SCN share a common clonal origin and spatial organization, aiming to describe how those two cell types relate functionally in the circadian network assembly.