Intercellular Communication in a Contact-Free Co-Culture of Neurons and Oligodendrocytes

Begin with a contact-free co-culture of neurons and oligodendrocytes.

A permeable membrane separates the neurons in the transwell insert from the oligodendrocytes at the bottom well.

Add potassium to the insert to raise extracellular potassium levels, which inhibits the efflux of intracellular potassium.

The potassium accumulation depolarizes the neurons, triggering the opening of voltage-gated calcium channels and allowing calcium influx.

The influx stimulates the release of excitatory neurotransmitters, which diffuse across the permeable membrane to reach the bottom well and activate receptors on oligodendrocytes, leading to calcium influx.

The rise in calcium activates signaling pathways that induce the inward budding of membranes in early endosomes.

The budding encloses cytoplasmic proteins and RNAs within vesicles called exosomes inside multivesicular bodies or MVBs.

The MVBs fuse with the oligodendrocyte plasma membrane, releasing exosomes into the extracellular environment.

The secreted exosomes are now ready to assess intercellular communication.