Fig. 2

Morphology of the brain and spinal cord in Alligator mississippiensis. The specimens used for images A-C were sub-adult animals used in the present study. a parasagittal MRI, b photograph of a hemisected specimen, c magnified view of the myodural bridge (red arrow), d micro-CT transverse image through the cervical spinal canal of a hatchling specimen. The green lines in (a) indicate the region studied by Doppler ultrasonography in this study. The vertical purple lines indicate the surgical openings made to record CSF pressure; the marker on the skull is accurate. The actual surgical site to record spinal CSF pressure was nine vertebrae more caudal. Abbreviations: 1—olfactory tract; 2—cerebral cortex; 3—optic lobe of the midbrain; 4—cerebellum; 5—medulla oblongata; a—arachnoid mater; d — dura mater; m—myodural bridge; n—spinal nerve; o—occipital condyle; p—proatlas