Characterization of neuronal viability and network activity under microfluidic flow.

Area of Science:

• Neuroscience
• Biotechnology
• Microfluidics

Background:

• Microfluidics offers precise control over solute concentration for studying neural volume transmission.
• Understanding microfluidic flow effects on neuronal viability and network activity is crucial for its application.

Purpose of the Study:

• To investigate the impact of microfluidic flow rates on cultured hippocampal neuron viability and network activity.
• To establish experimental conditions for real-time neural network activity measurement during rapid solution exchange.

Main Methods:

• Designed a tape-based pressurized microfluidic flow system compatible with microelectrode arrays.
• Incorporated a porous polycarbonate membrane to mitigate shear forces while allowing solute diffusion.
• Assessed neuronal viability and spiking patterns under varying flow conditions.

Main Results:

• Neuronal viability and network activity decreased proportionally with increased flow rate.
• Shear reduction measures did not enhance neuronal survival or activity.
• Media conditioning and culture age were identified as critical factors for network stability.
• Diffusion simulations suggested solute dilution as the cause of flow-induced detrimental effects.

Conclusions:

• Established experimental conditions for real-time neural network activity measurement during rapid solution exchange.
• Demonstrated that microfluidic systems, with proper media conditioning, allow sub-second drug delivery without compromising neuronal viability or network function.
• Validated the system for in vitro reproduction of neural volume transmission mechanisms.