City College: S. Cowin, S. Fritton, S. Weinbaum
Hospital Partners: M. Schaffler, Mount Sinai
D. Spray, Albert Einstein; S. Doty, Special Surgery

Since 1991 research conducted by our group has pioneered the development of sophisticated ultrastructural models for mechanosensation in bone tissue. Mechanosensation is the term used to describe the sensing by the syncytium of bone cells of the mechanical loading applied to the whole bone. Understanding bone mechanosensation is a key to the understanding of bone loss in long term space flight, implant stability, osteoporosis and skeletal evolution. The models of bone fluid flow developed have provided an explanation not only for mechanosensation, but also for higher frequency intracellular communication and the transport of nutrients to bone cells. We are presently at work on a model that shows how blood pressure may drive bone fluid flow and, in certain situations, provide a mechanosensory stimulus.

We are also conducting experimental investigations to determine the contents of the space between the osteocytic cell process and the canalicular wall. Parts of the work received the European Society of Biomechanics Research Award. This work is currently supported by NSF and NIH (NIAMS).