High-resolution 3D Microstructure Imaging of Reptile Brains

High-resolution 3D CT-scans of P. vitticeps and B. fuliginosus heads were performed at the University of Helsinki imaging facility using Skyscan 1272 (Brucker, Belgium). Prior to micro-CT scanning, to allow reptile brain tissue visualization, samples were treated with 1% iodine solution as previously described (Metscher, 2009 (link); Macrì et al., 2019 (link)). The following scan parameters were used: filter: Al 0.25 mm; source voltage: 60 kV; source current: 166 μA; voxel size: 12 μm; rotation steps: 0,2°; frame averaging: 8. Scans were reconstructed using NRecon 1.7.0.4 software (Bruker) and 3D volume rendering as well as segmentation were performed using the software Amira 5.5.0 (Thermo Fisher Scientific, United States). Both the whole-brain and isolated cerebellum were segmented, thus allowing assessment of volumetric measurements of these structures. The accuracy of all generated 3D models was carefully controlled along the three anatomical planes, as described (Macrì et al., 2019 (link)).