“Bats exhibit an outstanding diversity of cranial morphologies and diets. However, comparative studies of jaw muscle architecture have been difficult due the small size of most bats. This study used diceCT to provide, for the first time, a detailed characterization of the gross and internal anatomy of the jaw muscles across an ecologically diverse sample of bats. DiceCT allowed me to evaluate interspecific differences in muscle attachments, compartments, and scaling in the context of dietary specialization, and to provide novel anatomical descriptions within the feeding apparatus of bats. By doing so, this study revealed unexplored anatomical diversity that can inform future work in functional and evolutionary morphology.”
“Manual dissection is both inherently destructive to specimens, and reliant upon the use of sampling sites to assess muscle fascicle properties and their distribution. We present the results of a digital technique using diceCT to identify and map whole-muscle fascicle distributions within the jaw-adductor musculature of a primate specimen. Comparing these data to dissection results of the contralateral muscles, we demonstrate an ability to determine architectural variables non-invasively through the use of diceCT. Though muscle complexity may impact the convergence between traditional and digital methods, we conclude that this technique offers great potential for future work of whole-muscle mapping, whilst circumventing specimen loss.”
“Is iodine perfusable?”
This is one of the most frequently asked questions by the diceCT community, and the Witmer Lab at Ohio University has answered: “Absolutely!”
SpiceCT (selectively perfusable iodine-based contrast-enhanced CT) is particularly good at staining large specimens very rapidly. Iodine is perfused through the arterial system and across capillary beds, staining soft tissues nearly instantaneously and allowing for targeting regions of interest based on blood supply.
The Witmer lab recently presented their new protocol at the Society for Integrative and Comparative Biology meeting in San Francisco on 4 January 2018 and are now sharing that poster widely on FigShare. Download the poster, and add a new tool to your arsenal!
“Does dramatic functional change depend on dramatic morphological change? Kaji et al. used contrast-enhanced micro-CT and confocal imaging, high-speed video, and kinematic experiments with select 3D-printed models, to reconstruct the evolutionary changes in form and function that yielded spectacular snapping claws from simple pinching claws in two shrimp families. They discovered that two novel claw-joint types — a slip joint and a torque-reversal joint — preceded the evolution of snapping. They also found that the evolutionary transitions slip joint ➔ torque-reversal joint ➔ snapping occurred in both shrimp families studied. These results show how subtle changes in joint-form yielded dramatic changes in claw function (e.g., closing speed) during the evolution of snapping claws.”
– Lead author, Tomonari Kaji (@)