Microfabricated multi-electrode device for detecting oligodendrocyte-regulated changes in axonal conduction velocity.

Area of Science:

• Neuroscience
• Biomedical Engineering
• Cell Biology

Background:

• Myelin disorders impair cognitive function, but the network-level impact of abnormal myelin on neural activity remains unclear.
• Simultaneous monitoring of axonal conduction and network activity is technically challenging, hindering research.
• Understanding myelination's role in neural network function is crucial for addressing cognitive deficits.

Purpose of the Study:

• To develop a specialized culture device for detecting myelination-dependent changes in axonal conduction velocity.
• To enable simultaneous monitoring of axonal conduction and network activity in a controlled co-culture system.
• To investigate the influence of oligodendrocytes on neural network signal propagation.

Main Methods:

• Fabrication of a photolithographic device with microtunnels for guiding axons.
• Integration of microelectrodes and oligodendrocyte (OL) culture compartments within microtunnels for co-culture.
• Culturing rat cortical neurons and OLs, followed by immunocytochemical analysis and electrophysiological recordings of action potential conduction velocity.

Main Results:

• Successful co-culture of neurons and OLs was maintained for up to 42 days in vitro (DIV).
• Axonal conduction velocity in unmyelinated axons was measured at 0.31 m/s.
• Despite no visible myelin sheath, co-culture with OLs halved the conduction delay by 45 DIV, indicating OL-mediated effects.

Conclusions:

• The developed culture device effectively detects oligodendrocyte-regulated changes in axonal conduction velocity.
• This technology facilitates the study of myelination's impact on neural network dynamics.
• The findings provide a foundation for investigating myelin disorders and developing therapeutic strategies.