Publication Date


Document Type

Honors Project

Degree Name

Bachelor of Arts




David Bickar


Parkinson's disease, Dopamine, Neuroscience, Biochemistry, Pre-clinical Parkinson's, Hyposialorrhia, Parkinson's-Etiology, Parkinson's disease-Etiology, Salivary glands, Hypoptyalism


Salivary dopamine concentration is hypothesized to be depressed in individuals with Parkinson's disease and pre-clinical PD; it is theorized that dopaminergic neurons in the peripheral nervous system are affected prior to widespread destruction of such neurons in the central nervous system. If so, the loss of dopamine and the respective pathways in peripheral systems could be a measure for early detection of PD. Currently, PD is not diagnosable until clinical symptoms appear, at which point 80% of the dopaminergic neurons in the substantia nigra have been destroyed. The Bickar lab has developed a method of determining salivary dopamine concentrations, which has been used to determine the salivary dopamine levels for healthy adults. We now need to utilize this technique with PD patients and age-matched controls to determine whether our hypothesis, that salivary dopamine concentration is depressed in PD patients, is correct. A potentially confounding factor is that hyposialhorria often occurs with PD, which may increase total solute concentration due to the decrease in basal salivary flow. Further, multiple changes in salivary composition have been documented in PD: elevated levels of certain electrolytes (sodium, chloride and amylase) and increased total protein concentration. This necessitates determination not only of the change in absolute dopamine concentration, but also the change relative to other constituents of saliva. We thus propose to measure the dopamine, total protein, total solute, and total electrolyte concentrations in saliva, to determine mean values and ranges of variation among PD patients and healthy controls.




112 pages : color illustrations. Thesis (B.A.)--Smith College, 2017. Includes bibliographical references (pages 84-89)