DELINEATION OF BRAIN STRUCTURES IN THE MONODELPHIS DOMESTICA OPOSSUM BRAIN

The Monodelphis opossum became an important laboratory animal and is often used in biomedical research. However, data on the brain anatomy are scarce and there is no reliable brain anatomy reference. The aim of this study is to present neuroanatomical delineation of basic brain structures. Data which served for construction of the 3-dimensional atlas were magnetic resonance images (MRI) and stained brain sections. MRI was obtained 48 h after perfusion of the animal with 4% paraformaldehyde and gadotheridol contrast (ProHance 20:1 v:v). The second MRI was performed 30 days after perfusion of the same animal. Both MRIs were aquired using Bruker Biospin system with voxel reolution of 50 mu m super(3). For Nissl and myelin staining, coronal brain sections were cut in cryostat at 40 mu m thickness. To minimize tissue deformation, sections were transferred from the cutting blade to slides using the Tape-Transfer System. Then brain sections stained either with Nissl or for myelin were imaged with a high resolution scanner and were transformed to three-dimensional form. By superimposing all three-dimensional data, several brain structures were delineated, e.g., the olfactory bulb, cerebral cortex, hippocampus, white matter and other.