Retrosplenial PV and SST interneurons shape egocentric spatial precision and stability

Accurate navigation requires egocentric representations of environmental geometry to be continuously updated by self-motion while remaining stable over time. The retrosplenial cortex (RSC) is central to this process, yet how local inhibitory circuits support this balance remains unclear. We show that parvalbumin (PV) and somatostatin (SST) interneurons regulate distinct components of egocentric spatial coding in RSC. PV interneurons are strongly modulated by self-motion and exhibit bearing-aligned synchrony that precedes SST activation, linking movement to egocentric coding precision. In contrast, SST interneurons display weak self-motion modulation but robust boundary-anchored activity with