Meeting Abstract
Avians show a specialization of their lumbosacral (LS) region, which is unique amongst vertebrates. The birds’ neural canal is enlarged in the range of seven lumbosacral segments. A glycogen body sits on top of both spinal cord hemispheres, and a network of denticulate ligaments spans ventrally under the spinal cord. Accessory lobes are organized pairwise in each segment directly connected to the spinal cord hemispheres. The lumbosacral canal is relatively easily visible, due to its macroscopic dimensions in the millimeter range, but it is hard to observe its soft tissue in detail. The question of its functionality has raised a long time. Necker (1999) hypothesized a function similar to that of the inner ear and argued the ‘lumbosacral organ’ (LSO) presents another center of equilibrium. In this project, we characterize the LS region both with a combination of state of the art tools and classical dissection, towards a new, different hypothesis. Specifically, we attempt to quantify the possibility of elastic deformation of soft neural tissue, within the enlarged and fluid-filled LS cavity. Caused by external acceleration from locomotion, soft LS tissue would be excited to oscillate within the neural canal, leading to the stimulation of mechanoreceptors. To create a new 3-dimensional map of all LS soft tissues, we scanned an iodine solution treated specimen of a common quail (Coturnix coturnix). We conducted a classical dissection to describe finer structures which were otherwise not visible with micro-CT. We will present our combined dissection results, provide details from our morphometric analysis, and calculations for ligament strain of a potential elastic deformation.
