Valerie Flores

Major and Classification

Gerontology and Minor in Natural Science

Faculty Mentor

  • Albert Herrera, Ph.D.


  • Biological Sciences

McNair Project

Taking a Closer Look: Developing an Effective Method for Fluorescent Staining of the Neuromuscular Junction

Upon birth, mammals contain numerous synaptic connections throughout the nervous system. These synaptic connections are used to carry a multitude of signals and information to different areas of the body. During development, some of the synaptic connections are lost via synapse elimination. Synapse elimination is a programmed process that removes excess synapses in the nervous system in an effort to refine neural circuitry. Synapse elimination is believed to occur in the early stages of development. However, in order to determine when synapse elimination occurs, it is first necessary to develop a proper staining method that can be used to visualize the synaptic connections of neurons. The aim of this study was to develop a new staining method that could be utilized in the study of synapse elimination at the neuromuscular junction. It was discovered that 1,1″-dioctadecyl-3,3′,3′-tetramethylindocarbocyanine perchlorate (DiI) application to nerves was an effective staining method. More specifically, application of a crystal form of lipophillic DiI proved to have the best results. This new technique allowed the dye to diffuse down the length of a nerve until it reached the neuromuscular axon terminal. The time frame for sufficient staining of the neuromuscular junction was three weeks. Once staining was complete, it was possible to visualize the axon terminals of the neuromuscular junctions under a fluorescent microscope, which in turn allowed for the study of synapse elimination at the neuromuscular junction.