In vivo dialysis setup with a loop injection valve facilitates retrodialysis studies
K V Thrivikraman1, Becky Kinkead1, Karen E Murray1
1Department of Psychiatry & Behavioral Sciences, Emory University School of Medicine, Atlanta, GA 30322, USA.
Journal of Pharmacological and Toxicological Methods
|July 9, 2013
Summary
A new medium pressure injection valve simplifies in vivo retrodialysis, enabling neuroactive agent delivery and cellular activity monitoring without interrupting flow. This technique enhances neuropharmacological research capabilities.
Area of Science:
- Neuroscience
- Pharmacology
Background:
- Retrodialysis is crucial for in vivo neuroactive agent delivery and monitoring effects on cellular activity.
- Traditional methods involve complex setups like liquid-switches or tubing exchanges, often interrupting the experiment.
- These limitations necessitate simpler, more efficient retrodialysis techniques.
Purpose of the Study:
- To introduce and evaluate a novel medium pressure injection valve for retrodialysis.
- To overcome the limitations of existing retrodialysis methods, such as multiple pumps or flow interruptions.
- To demonstrate the valve's efficacy in delivering neuroactive agents and monitoring neurochemical changes.
Main Methods:
- A medium pressure injection valve was configured with a 20μL loop for solution delivery.
- Artificial cerebrospinal fluid (CSF) flow was established through the valve to a microdialysis probe in the ventral hippocampus of anesthetized mice.
- Escitalopram was delivered via retrodialysis (0.3μM at 1μL/min) and microdialysis (2mg/kg BW subcutaneously), with dialysate collected for serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) analysis.
Main Results:
- The in-line valve assembly successfully facilitated retrodialysis and microdialysis sampling without compromising data integrity.
- Escitalopram administration via the valve produced comparable 5-HT and 5-HIAA response patterns to previously reported studies.
- The valve setup proved easy and simple to manipulate for retrodialysis procedures.
Conclusions:
- The developed in-line injection valve is a valuable and promising adaptation for retrodialysis studies.
- This valve system can be readily integrated as standard instrumentation for in vivo dialysis research.
- The simplified approach enhances the efficiency and practicality of neuropharmacological investigations.
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