Based on the paper briefly describe the authors hypothesis a

Based on the paper, briefly describe the author\'s hypothesis about the origin of myelinated neurons. Include time of origin, what animal group did it originate in and the possible cell type(s) involved in the origin of myelin. The link for the paper is located below.

Here is the correct link:

http://www.sciencedirect.com/science/article/pii/S0006899315007027

Solution

Myelinated neurons originated some 415 million years ago.The animal group that it originated from is placoderms that are the first vertebrates to develop hinge jaws.The evolution of myelinated neurons is believed to have taken simultaneously in the peripheral as well as central nervous system.They are believed to have originated from glial cells of the invertebrates.In the paper, it is further hypotheised thet first myelin forming cell was more of a Schwann cell type found in PNS that was linked to axons via a major myelin protein known as P0 and this was found in teleost.This Schwann cell of PNS underwent further transition to form oligodendrocyte in CNS and finally forming myelinated cells of vertebrates.