B. Jill Venton
The Venton group is interested in the development and characterization of analytical techniques to measure neurochemical changes. Measurements in the brain are challenging because tiny quantities of neuroactive molecules must be detected in a chemically-complex sample while disturbing the tissue as little as possible. In addition, fast time resolution measurements are needed to track the fast dynamics of neurotransmitter release and uptake. Our lab develops both electrochemical and separations methods to monitor these rapid changes in neurotransmitters in model systems. The development of new analytical tools will enable a better understanding of the central nervous system and facilitate the development of new treatments for neurological disorders. Several specific projects are highlighted below:
Electrochemical Detection of Adenosine
Adenosine is a neuromodulator that has a variety of actions including regulation of cerebral blood flow, modulation of neurotransmission, and protection against neuronal injury during stroke. We are studying the regulation of adenosine release in vivo and changes in adenosine in a brain slice model of stroke using cyclic voltammetry at carbon-fiber microelectrodes. We are also developing new methods for ATP and adenosine detection.
Detection of Neurotransmitter Release in Drosophila
Drosophila melanogaster (the fruit fly) is a favorite model organism for biologists, but the central nervous system of a Drosophila larva is only 8 nL in volume! Current projects involve characterizing electrochemically-detected dopamine and serotonin release and comparing the control of neurotransmission in the fly to mammalian systems. We have developed the first method to measure real-time changes in neurotransmitter concentrations in the CNS of a single larva or adult. We also use capillary electrophoresis to measure tissue content of single brains.
Development of Carbon Nanotube-Based Electrodes
Carbon nanotubes have interesting electrical, chemical and mechanical properties and have been shown to promote electron transfer in electrochemical experiments. Our aim is to characterize carbon nanotube-based electrodes with fast-scan cyclic voltammetry. We are exploring different ways to add nanotubes to a carbon-fiber microelectrode surface as well as fabricate new electrodes our of carbon nanotubes.
Mechanisms of Drugs of Abuse using Capillary Electrophoresis
We are also developing capillary electrophoresis instrumentation for making rapid separations. We are interested in using this separations based technique to monitor both neurotransmitter and drug concentrations simultaneously. For example, the effect of amphetamine on amino acid concentrations could be studied in vivo. Different fluorescent tags will be examined to study secondary amines such as Ecstasy.
Figure: Codetection of serotonin and dopamine in the rat brain using a nanotube coated electrode.
Transient Adenosine Release Is Modulated by NMDA and GABAB Receptors. M.D. Nguyen, Y. Wang, M. Ganesana, B.J. Venton. ACS Chemical Neuroscience, 8(2):376–385 (2017).
Analytical techniques in neuroscience: Recent advances in imaging, separation, and electrochemical methods. M. Ganesana, S.T. Lee, Y. Wang, B.J. Venton. Analytical Chemistry, 89(1): 314-341 (2017).
O2 plasma etching and antistatic gun surface modifications for CNT yarn microelectrode improve sensitivity and antifouling properties. C. Yang, Y. Wang, C.B. Jacobs, I. Ivanov, B.J. Venton. Analytical Chemistry, 89:5605-5611 (2017).
Fast-scan cyclic voltammetry (FSCV) detection of endogenous octopamine in Drosophila melanogaster ventral nerve cord. P. Pyakurel, E. Privman Champaloux, B.J. Venton. ACS Chemical Neuroscience, Aug 17;7(8):1112-1119 (2016).
Quantitation of dopamine, serotonin and adenosine content in a tissue punch from a brain slice using capillary electrophoresis with fast-scan cyclic voltammetry detection. Fang H, Pajski ML, Ross AE, Venton BJ. Anal Methods. 5:2704-2711 (2013).
Kinetics of the dopamine transporter in Drosophila larva. Vickrey TL, Xiao N, Venton BJ. ACS Chem Neurosci. 4:832-7 (2013).
The mechanism of electrically stimulated adenosine release varies by brain region. Pajski ML, Venton BJ. Purinergic Signal. 9:167-74 (2013).