A microperfusion chamber for brain slice pharmacology.

Area of Science:

• Neuroscience
• Pharmacology
• Biomedical Engineering

Background:

• Extracellular recording is crucial for understanding neural circuit function.
• Investigating drug effects on central nervous system (CNS) tissue requires precise control over the microenvironment.
• Limited availability and high cost of certain drugs necessitate efficient experimental systems.

Purpose of the Study:

• To describe the construction and operation of a novel chamber for extracellular recording from submerged CNS tissue.
• To demonstrate the system's utility with hippocampal slices from rat brains.
• To highlight the system's advantages for pharmacological studies, especially with scarce or expensive drugs.

Main Methods:

• Construction of a specialized chamber for submerged tissue recording.
• Utilizing hippocampal slices from rat brains for system validation.
• Implementing a continuous stirring mechanism with a 95% O2-5% CO2 gas jet for tissue viability.
• Developing rapid drug solution distribution and replacement protocols.

Main Results:

• The chamber operates effectively with minimal perfusing medium (less than 0.4 ml).
• Uniform drug distribution is achieved in under 1 minute.
• Rapid exchange of perfusate allows for dynamic pharmacological interventions.
• Submerged slices remain viable for extended periods (many hours).

Conclusions:

• The described chamber provides a highly efficient and controlled environment for extracellular recordings from CNS tissue.
• This system significantly benefits synaptic pharmacology research, particularly when dealing with limited or costly compounds.
• The technology facilitates detailed investigation into drug actions on neural tissues with minimal sample requirements.