Using In Vivo Voltammetry to Demonstrate Drug Action: A Student Laboratory Experience in Neurochemistry

Providing undergraduate neuroscience students an appropriate laboratory experience that demonstrates principles of neurotransmission and drug action is a difficult task. In the following activity, fast-scan cyclic voltammetry was utilized to measure dopamine levels using carbon-fiber microelectrodes in rats in vivo. Recordings were made before and after administration of several drugs to assess their ability to alter extracellular dopamine. The following drugs were chosen due to their well established actions: haloperidol, methylphenidate, and alpha-methyl-para-tyrosine. Each demonstrated markedly altered extracellular dopamine dynamics and some basic kinetic analysis enabled students to attribute the alterations to differing modes of action. Dopamine tissue content was also assessed to compare the differences between acute drug action and overall neurotransmitter content. Any neuroscience laboratory course that desired to demonstrate principles involved in neurotransmission would be well served by the activities involved. This laboratory experience provided: 1) basic principles in experimental design, 2) small animal surgical experiences, 3) exposure to common instrumentation used in collecting neurochemical data, 4) data analysis procedures, and 5) experience in presenting their findings.