A 3D MRI‐based atlas of a lizard brain

Abstract

Magnetic resonance imaging (MRI) is an established technique for neuroanatomical analysis, being particularly useful in the medical sciences. However, the application of MRI to evolutionary neuroscience is still in its infancy. Few magnetic resonance brain atlases exist outside the standard model organisms in neuroscience and no magnetic resonance atlas has been produced for any reptile brain. A detailed understanding of reptilian brain anatomy is necessary to elucidate the evolutionary origin of enigmatic brain structures such as the cerebral cortex. Here, we present a magnetic resonance atlas for the brain of a representative squamate reptile, the Australian tawny dragon (Agamidae: Ctenophorus decresii), which has been the subject of numerous ecological and behavioral studies. We used a high-field 11.74T magnet, a paramagnetic contrasting-enhancing agent and minimum-deformation modeling of the brains of thirteen adult male individuals. From this, we created a high-resolution three-dimensional model of a lizard brain. The 3D-MRI model can be freely downloaded and allows a better comprehension of brain areas, nuclei, and fiber tracts, facilitating comparison with other species and setting the basis for future comparative evolution imaging studies. The MRI model and atlas of a tawny dragon brain (Ctenophorus decresii) can be viewed online and downloaded using the Wiley Biolucida Server at wiley.biolucida.net.

Embryonic development of a parthenogenetic vertebrate, the mourning gecko (Lepidodactylus lugubris)

“…Squamates are becoming increasingly used as models in evolutionary and developmental neurobiology . However, the general difficulty of gross dissection of delicate, soft tissues like the embryonic brain is challenging, especially in small species; this task is facilitated by means of nondestructive imaging methods, such as magnetic resonance imaging (MRI) or diffusible iodine‐based contrast‐enhanced computed tomography (diceCT). Among amniotes, mammals and avian reptiles exhibit a well‐developed telencephalon that possesses derived internal architectures .…”

Quantitative Classification of Cerebellar Foliation in Cartilaginous Fishes (Class: Chondrichthyes) Using Three-Dimensional Shape Analysis and Its Implications for Evolutionary Biology

“…Corfield et al, 2008a; Berquist et al, 2012; Zeigler et al, 2014]. Recent studies have demonstrated the utility of MRI for comparative brain morphology in marine mammals [Marino et al, 2001a, b; Montie et al, 2008; Oelschlager et al, 2010; Berns et al, 2015], birds [Corfield et al, 2008a, b], reptiles [Hoops et al, 2014], teleosts [Van der Linden et al, 2004; Ullmann et al, 2010a, b, c] and cartilaginous fishes [Pradel et al, 2009; Yopak et al, 2009, 2010a; Yopak and Frank, 2007], which provides invaluable data on the size and precise anatomical position of major neuroanatomical features and allows for the non-invasive assessment of specimens. The majority of comparative neuroanatomical studies in non-mammalian vertebrates that utilize MRI have acquired 3D information for the purposes of assessment of whole brain volume or the volume of major brain regions across taxa [Marino et al, 2003; Kaufman et al, 2005; Oelschlager et al, 2008; Yopak and Frank, 2009; Ullmann et al, 2010c].…”

Spatial tissue profiling by imaging-free molecular tomography

“…To demonstrate the applicability of STRP-seq for examining unconventional or rare samples we profiled brain sections from Pogona vitticeps, a non-model organism lizard endemic to semi-arid regions of Australia ( Fig. 4a,b; [33], [34]). We used STRP-seq to measure and reconstruct 8,183 annotated genes in the brain of P. vitticeps [35].…”