Meeting Abstract
LBS2.5 Thursday, Jan. 3 Experimental assessment of behavioral signals in trabecular architecture of the hind limb. CARLSON, Kristian J*; LUBINSKY, Svetlana; JUDEX, Stefan; New York College of Osteopathic Medicine; Stony Brook University; Stony Brook University kcarlson@nyit.edu
Studies of vertebrate morphology implicate bone functional adaptations to behavioral repertoires when comparing mechanical milieus. With the advent of microcomputed tomography (microCT), efforts have been extended to trabecular architecture. Bone responds to in vivo loading conditions in a complex fashion, one that is superimposed upon genetics and non-mechanical factors (e.g., hormones). Furthermore, the breadth and frequency of locomotor behaviors of free-ranging vertebrates often are incompletely documented. Experimental studies of bone functional adaptations often manipulate locomotor repertoires using artificial situations (e.g., treadmills) or activity level differences (e.g., exercise effects), which can be difficult to extrapolate to free-ranging animals. Here we present results from a novel mouse model that accentuates components of naturalistic locomotor repertoires. Specifically, we assess trabecular architecture of hind limb elements at multiple volumes of interest (VOIs) in response to particular locomotor behaviors (i.e., linear locomotion and turning). Thirty day-old female (BALB/cByJ) mice (n=10 per group) were single-housed for 8 weeks in custom-designed cages that accentuated linear or turning locomotion or allowed subjects to freely roam standard cages. Hind limb skeletal elements were removed and scanned (microCT40, Scanco) at the end of the experimental protocol. Groups differed in connectivity density, trabecular bone volume fraction (BV/TV), trabecular surface (SMI), number (Tb.N), spacing (Tb.Sp), thickness (Tb.Th), and degree of anisotropy. As with a prior analysis of diaphyseal cortical bone, increased frequency of non-linear locomotion impacts trabecular bone differently than linear locomotion.
