Question

Differentiate between oligodendrocytes and Schwann Cells

What is the role of calcium in neurotransmitter release?

Answer 1

Answer

1) Difference between oligodendrocytes and Schwann Cells

Oligodendrocytes	Schwann Cells
They are neuroglial cells in central nervous system that produces myelin surrounding the axon.	They are neuroglial cells in peripheral nervous system that produces myelin surrounding the axon.
One oligodendrocyte can insulate about 50 axons.	One Schwann cell only insulates a single axon.
It is derived from a precursor cell called oligodendrocyte precursor cell.	It is derives from neural crest (embryonic structure that promotes development of peripheral nervous system).

2) Role of calcium in neurotransmitter release

• When an action potential arrives at the axon terminal of the neuron, voltage gated calcium channels on its membrane opens.
• Calcium ions enters the synaptic bulb of axon terminal.
• Calcium triggers activation of proteins in the synaptic vesicles.
• These activated proteins stimulates synaptic vesicles to fuse to the presynaptic membrane and perform exocytosis of neurotransmitter molecules.
• The neurotransmitter is then released into the synaptic cleft.
• Hence, calcium plays a major role in neurotransmitter release.