In Vivo Neurochemical Monitoring Techniques

In vivo neurochemical monitoring encompasses a range of methods designed to quantify the dynamic concentrations of small molecules and ions within living brain tissue. Central to these approaches is the ability to sample or sense extracellular fluid in real time, delivering insights into neurotransmitter release, metabolic turnover and ionic fluxes underlying neuronal communication. Traditional microdialysis exploits a semipermeable membrane to collect dialysate for downstream analysis, offering broad applicability but limited temporal resolution. Complementary strategies employ electrochemical microsensors, which transduce target analyte flux directly into electrical signals, achieving subsecond measurements of redox‐active neurotransmitters. Advances in microfabrication and microfluidics have led to integrated probe platforms that digitize chemical signals into discrete droplets for transport and high-throughput analysis, while coupling with spectrometric or optical detection has expanded molecular coverage beyond classical electrochemical targets. Emerging paradigms exploit electroosmotic perfusion or novel biosensing modalities to minimise tissue perturbation and extend monitoring to neuropeptides and neuromodulators. Together, these techniques provide a versatile toolkit for dissecting neurochemical networks in health and disease, informing drug development, neuromodulation strategies and precision neurotherapeutics.

Research from Nature Portfolio

A droplet-based sampling mechanism integrated at the tip of a microfabricated neural probe has been validated in vivo, enabling discrete collection of extracellular fluid with temporal resolution on the order of seconds. The device employs on-chip droplet generation and a bespoke target plate compatible with surface-based detection, allowing time-resolved analysis of elemental and molecular neurochemical composition by laser ablation inductively coupled plasma mass spectrometry. This work demonstrates the capacity to monitor dynamic changes in trace elements implicated in neurodegenerative processes with minimal sample dispersion and high spatial fidelity.

In Vivo Neurochemical Monitoring Techniques publication trend

The graph below shows the total number of articles in in vivo neurochemical monitoring techniques across all publications each year (not limited to Nature Index journals).

Technical terms

Microdialysis: A sampling technique using a semipermeable membrane probe to collect extracellular fluid for offline or online analysis of small molecules.

Electrochemical microsensor: A miniature electrode device that converts the oxidation or reduction of target analytes into measurable electrical currents with high temporal resolution.

Droplet microfluidics: A method that partitions continuous fluid streams into discrete, nanoliter-scale droplets for transport, storage and compartmentalised analysis.

Mass spectrometry: An analytical technique that ionises chemical species and sorts the ions based on their mass-to-charge ratio to identify and quantify molecular components.

Extracellular fluid (ECF): The interstitial fluid surrounding cells in tissue, containing neurotransmitters, ions and metabolites accessible to sampling probes.

References

1. In vivo neurochemical measurements in cerebral tissues using a droplet-based monitoring system. Nature Communications (2017).
2. Microdialysis coupled with droplet microfluidics and mass spectrometry for determination of neurotransmitters in vivo with high temporal resolution. Analyst (2024).
3. Establishing In-vivo brain microdialysis for comparing concentrations of a variety of cortical neurotransmitters in the awake rhesus macaque between different cognitive states. Journal of Neuroscience Methods (2025).
4. Integrated sampling-and-sensing using microdialysis and biosensing by particle motion for continuous cortisol monitoring. Sensors & Diagnostics (2023).
5. Electroosmotic Perfusion, External Microdialysis: Simulation and Experiment. ACS Chemical Neuroscience (2023).