Fig. 2.

Previous use of PMP for small cranial windows in the olfactory bulb. (a) The same animal can be imaged with two-photon imaging, fUS and BOLD fMRI. (b) Two-photon (microscopic) and fUS (mesoscopic) imaging. Bottom left: schematic of the vascular network, which can be imaged at the microscopic (TPLSM, top) or mesoscopic level (fUS, right). Top: light per se dilates a pial artery labeled with Texas Red. Dilation follows calcium decrease in smooth muscle cells expressing GCaMP6f (scale bar: $30\mu \mathrm{m}$) (modified from Rungta et al.¹⁸). Bottom: reproducibility of fUS responses ($\mathrm{\Delta }\mathrm{PD}$) to odor (modified from Boido et al.¹¹). (c) Red blood cell velocity response to odor in a capillary imaged (linescan acquisition) 9 months after the implantation of the window (unpublished data). (d) Coregistration of two-photon and fUS imaging systems: a given voxel is centered on a glass bead. (e) A specific voxel, centered on the glomerulus most sensitive to ethyl tiglate (left) shows an fUS response ($\mathrm{\Delta }\mathrm{PD}/\mathrm{PD}$) that mirrors the increase of red blood cell velocity in the glomerulus capillary (modified from Aydin et al.¹⁹). Average of five responses for fUS and four responses for TPLSM ${\mathrm{Ca}}^{2+}$ imaging and red blood cell velocity.