Cocaine-Induced Changes in Tonic Dopamine Concentrations Measured Using Multiple-Cyclic Square Wave Voltammetry in
Jason Yuen1,2, Abhinav Goyal1,3, Aaron E Rusheen1,3
1Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, United States.
Frontiers in Pharmacology
|July 23, 2021
Summary
A new electrochemical method, multiple-cyclic square wave voltammetry (M-CSWV), measures dopamine dynamics with high spatiotemporal resolution. This technique offers superior insight into brain dopamine signaling compared to traditional microdialysis for addiction research.
Area of Science:
- Neuroscience
- Analytical Chemistry
- Pharmacology
Background:
- Microdialysis has been used for decades to study dopamine levels in drug addiction.
- Limitations of microdialysis include probe size and sampling rate, affecting accuracy in microneural environments.
- A novel electrochemical method, multiple-cyclic square wave voltammetry (M-CSWV), offers improved spatiotemporal resolution for dopamine measurement.
Purpose of the Study:
- To utilize M-CSWV and fast-scan cyclic voltammetry (FSCV) to measure tonic and phasic dopamine release in the rat nucleus accumbens core (NAcc).
- To assess the effects of acute cocaine administration on dopamine dynamics using these techniques.
Main Methods:
- Implantation of carbon-fiber microelectrodes (CFM) and stimulating electrodes into the NAcc and medial forebrain bundle (MFB) of anesthetized rats.
- Optimization of electrode depth using FSCV to measure MFB electrical stimulation-evoked phasic dopamine release.
- Measurement of changes in phasic dopamine using FSCV and tonic dopamine using M-CSWV after intravenous saline or cocaine administration.
Main Results:
- Cocaine administration significantly augmented both phasic (approx. 2.4-fold) and tonic (approx. 1.9-fold) dopamine responses in the NAcc compared to saline.
- M-CSWV measured baseline tonic dopamine levels 10-fold higher than conventional microdialysis, potentially due to minimal tissue disruption by CFM.
- M-CSWV successfully recorded rapid changes in tonic dopamine levels, a capability not offered by other voltammetric techniques.
Conclusions:
- M-CSWV provides superior spatiotemporal resolution for measuring dopamine dynamics in vivo, surpassing microdialysis.
- The technique demonstrated phasic dopamine release changes in the NAcc following acute cocaine administration.
- M-CSWV holds significant potential for advancing our understanding of dopamine signaling in neurological and psychiatric conditions.
Keywords:
addictioncocainemental disordersneurosciencenucleus accumbenspsychiatrytonic dopaminevoltammetry
