Question

What are the functions of nogo and MAG and why are these proteins an obstacle to regeneration of neuron in the spinal cord?

Answer 1

Nogo is a negative regulator of neuronal growth. It's stabilize the CNS neuronal wiring by carrying the cost of extensive plastic reconfiguration and regeneration after injury.

MAG is the myelin associated glycoprotein. It control the myelin formation and inhibits axonal regeneration. It also control myelin axonal spacing.

From this we can understand that nogo prevents neuronal growth and MAG prevents axonal formation by controlling the formation of myelin. After a apical cord injury MAG synergize with nogo to prevent neuronal formation. They are proteins that prevent neuronal growth in normal conditions to maintain the neuronal wiring in CNS. But even after the injury the function of these proteins remains the same. So they remain as an obstacle in the formation of neurones after injury in spinal cord.