For many years the Tilden research lab has focused on crustacean nervous systems, specifically the neural tissue of the fiddler crab, Uca Pugilator. Most of the resarch has focused on the effects of that melatonin has on neurite growth in neurons cultured from the x-Organ/Sinus gland complex of the fiddler crab. This study was designed with the question of how we could prolong and/or promote the neurite growth in mind.
The fiddler crab was a great model organism for us in that the extraction of specific tissues from its eyestalk proved feasible in our undergraduate lab setting. Before delving into our project, Andrea briefed us on the structures we were about to examine.
Within the eyestalk sits an organ collectively known as the X-organ/ sinus gland, analogous to the hypothalamus and pituitary gland in humans. The somata comprise the x-organ portion of the complex, while the synaptic endings (axons) constitute the sinus gland. The X-organ/ sinus gland regulates and secretes a number of hormones directly into the hemolymph, where it reaches target organs marked by hormone-specific receptors. Cardioactive hormone, pigment dispersing and concentrating hormones, crustacean hyperglycemic hormone, and molt inhibiting hormone, are some of the many integral hormones under the control of the X-organ/ sinus gland.
The X-organ/ sinus gland has three lobes, but we focused primarily on the tissue directly opposite the blue sinus gland, which served as a visual landmark during dissection. We harvested only the X-organ cells because they most closely resemble human hippocampus cells, those cells most important for making synaptic connections during learning and memory,
In researching common dietary and herbal supplements used in Alzheimer's patients, we came across the antioxidant Ginkgo Biloba Extract. Ginkgo Biloba Extract has been used in Chinese medicine for centuries to treat nearly every type of ailment, and has relatively recently made it to the United States as a treatment/preventative measure for Alzheimer's and other neurodegenerative conditions. The flavonoid compounds found in the leaves of Ginkgo Biloba are antioxidants, which bind to free radicals in the cells. By binding to the free radicals, the flavonoids prevent the free radicals from "stealing" electrons from the growing neurite membranes. We hypothesized that this antioxidant property would result in enhanced neurite growth. Furthermore, Ginkgo Biloba extract contains terpenoid compounds, which are less studied, but are thought to enhance neural connections.