Real-time dopamine measurement in awake monkeys

Area of Science:

• Neuroscience
• Electrophysiology
• Primate Research

Background:

• Fast-scan cyclic voltammetry (FSCV) is crucial for real-time dopamine measurement in rodents.
• Adapting FSCV for primate research is essential for advanced behavioral studies and preclinical models.

Purpose of the Study:

• To demonstrate the feasibility of dopamine recordings in awake, behaving monkeys using FSCV.
• To adapt and integrate techniques from rodent, primate, and brain slice studies for primate FSCV.

Main Methods:

• Developed a long carbon fiber electrode for primate brains.
• Utilized a recording chamber and micromanipulator system for electrode placement.
• Employed tungsten stimulating electrodes and a custom electrical stimulation controller.
• Introduced a stimulation-based method for estimating inter-electrode distances.

Main Results:

• Successfully recorded dopamine responses in the striatum of awake monkeys (Macaca mulatta).
• Dopamine release was evoked by both local striatal and midbrain (VTA/SNc) stimulation.
• Natural rewards (juice) also elicited dopamine responses in the ventral striatum.
• Demonstrated activation of the monkey midbrain dopamine system mimicking rodent VTA stimulation.

Conclusions:

• Established the efficacy of FSCV for recording dopamine in awake, behaving primates.
• Validated a stimulation technique to activate the primate dopamine system, comparable to rodent models.
• Paved the way for advanced neuroscientific research and preclinical applications in primates using FSCV.