Publication Date


Document Type


Committee Members

David R. Ladle, Ph.D. (Advisor); Patrick M. Sonner, Ph.D. (Committee Member); Mark M. Rich, M.D., Ph.D. (Committee Member); Barry Milligan, Ph.D. (Committee Member)

Degree Name

Master of Science (MS)


Proprioceptive sensory neurons encode critical mechanosensory information that helps determine how the body interacts with the outside world and monitors the proper execution of motor movements. Housed in skeletal muscles lie specialized mechanoreceptors that are critical to this feedback loop: muscle spindles supplied by group Ia & group II afferents, and Golgi tendon organs supplied by group Ib afferents relay information regarding changes in muscle force, length, and tension. All three afferent subtypes originate in the muscle and travel to the dorsal root ganglia, relaying information to the central nervous system. GTO and MS proprioceptive afferent subtypes have been identified, traced, and labeled by restrictive RNA and DNA sequencing techniques that eliminate the potential for in vivo and ex vivo analysis. To confirm the identity of different proprioceptive afferent subtypes in the dorsal root ganglia of mice, the present study developed a method of fluorescence tracing using a dextran dye to trace afferents and their origins. By injecting tetramethylrhodamine dextran dye directly into the quadriceps muscle, the muscle spindle proprioceptive afferents selectively transport the dye to the cell body in the DRG demonstrating its origin and classification. Being able to selectively label and trace muscle spindle afferents allows us to accurately collect data on the cells in the DRGs.

Page Count


Department or Program

Department of Neuroscience, Cell Biology, and Physiology

Year Degree Awarded