Real-Time In Vivo Monitoring of Cholinergic Neurotransmission in the Mouse Brain Using a Microelectrochemical Choline...

Area of Science:

• Neuroscience
• Biomedical Engineering

Background:

• Choline measurement is vital for understanding central nervous system (CNS) pathologies.
• Continuous, real-time monitoring of cholinergic neurotransmission in specific mouse brain regions is challenging and underdeveloped.

Purpose of the Study:

• To refine and validate a choline oxidase (ChOx) microelectrochemical biosensor for chronic, in vivo recordings in freely moving mice.
• To enable long-term, real-time detection of cholinergic neurotransmission in selective brain regions.

Main Methods:

• Utilized a 75-μm diameter polymer-ChOx composite disc electrode for microelectrochemical biosensing.
• Performed in vivo recordings in freely moving mice, including local infusions and systemic drug administrations.
• Validated biosensor response against pharmacological manipulations and selective neuronal lesions.

Main Results:

• Achieved stable and reproducible chronic real-time monitoring of choline-induced amperometric currents in vivo.
• Observed increased biosensor currents in the hippocampus upon local choline and acetylcholine infusions.
• Demonstrated that systemic donepezil decreased currents, while scopolamine and amphetamine increased them, consistent with cholinergic activity.
• Detected diurnal oscillations in biosensor recordings, reflecting natural neurotransmission patterns.

Conclusions:

• The refined ChOx biosensor is effective for long-term, in vivo monitoring of cholinergic neurotransmission in mouse brain regions.
• This technology provides a valuable tool for studying CNS pathologies and the dynamics of cholinergic systems.
• The biosensor successfully captured endogenous changes in neurotransmission, including diurnal variations.