Meeting Abstract
83.5 Sunday, Jan. 6 Methodological Refinements to Using Lugol’s Iodine as a Contrast Agent in X-ray Micro-CT Imaging GIGNAC, P/M*; KLEY, N/J; Stony Brook University; Stony Brook University paul.gignac@stonybrook.edu
Visualization methods vastly enhance our ability to appreciate and harness complex anatomical relationships for understanding the nature of morphological change. Most notably, the widespread use of non-destructive X-ray computed tomography (CT) and micro-CT (µCT) has greatly augmented our ability to comprehensively detail and quantify the internal hard-tissue anatomy of vertebrates. However, the utility of X-ray imaging for gaining similar paradigm-altering insights into vertebrate soft tissues has yet to be fully realized due to the naturally low X-ray absorption of non-mineralized tissues. In this study we detail how the soft-tissue anatomy of the head and neck—including differences between white and grey matter of the brain, individual fascicles of the cranial musculature, dural venous sinuses, glands, fat deposits, and the complete pathways of cranial nerves—can for the first time be fully visualized in post-embryonic vertebrates (Alligator mississippiensis and Dromaius novaehollandiae) using iodine-enhanced (i-e) µCT methodologies. To date, methods using Lugol’s iodine (I2KI) have been employed to study invertebrates, vertebrate embryos, and parts of adult rodents, rabbits, and a yearling alligator—in all cases yielding promising results. However, anatomical visualizations among the larger, post-embryonic specimens have remained incomplete. Our research builds on these previous studies by systematically testing for optimal staining using differences in contrast levels of resulting i-e µCT images from intact archosaur heads prepared under differing treatments of Lugol’s iodine. We further demonstrate the utility of this method using computer rendering software to describe and quantify the 3-D anatomy of the brain, cranial musculature, and cranial nerves in A. mississippiensis and D. novaehollandiae.
