Chemically-mediated signals and physical contact-mediated signals are utilized in wide varieties of cells of the brain to transfer information to each other. For example, chemically-mediated signals provide pivotal communication between vascular endothelial cells and perivascular cells to control local blood circulation. Also, chemically-mediated signals play essential roles in the learning, memory and cognition via mediating communication between neurons. In contrast, the existence and function of nano-scale cell-cell contacts in the brain is not fully understood. This is because, to identify nano-scale contacts between cells, three-dimensional (3D) reconstructions of high spatial resolution images rather than single two-dimensional microphotographs are required. The procedures are technically difficult and time-consuming. For these reasons, until now, there have been only a few studies in which this cumbersome task has been undertaken. In this study, to learn more about physical contact-mediated signals in the brain, we conducted high-resolution 3D reconstruction of vascular cells, perivascular cells, neurons and glia from a series of sequential electron micrograph images of the early postnatal mouse cerebellum. Here, we report that nano-scale membrane protrusions extending from the abluminal surface of capillary endothelial cells invade into perivascular astrocytic endfeet, and the closed tips terminate within the astrocytic endfeet (Fig.1). Likewise, nano-scale processes extending from neurons invade Bergmann glia and the closed tips terminate within the glial cell body. These results suggest that nanoscale connections between endothelial cells and perivascular astrocytes and between neurons and glia may provide a unique morphological platform in the developing brain for physical contact-mediated signals.