Brain development and repair

Question 1

Median crush injury

Answer 1

Accurate regeneration as the endoneural tube stays intact

Question 2

Median nerve cut injury

Answer 2

Inaccurate regenerations as axons can regenerate along the wrong endoneural tubes and innervate the wrong targets

Question 3

Wallerian degeneration

Answer 3

Distal fragmentation of the myelin and axon
Myelin is phagocytosed by macrophages and Schwann cells (glial)
Regeneration along endoneurial tube

Question 4

Astrocyte scar

Answer 4

After injury
Astrocytes produce CSPGs (chondroitin sulphate proteoglycans) that inhibit axon growth
Oligodendrocyte myelin has NogoA to inhibit axon growth

Question 5

Promoting repair

Answer 5

Olfactory ensheathing cells
Blocking CSPGs with Chondroitinase ABC
Graft human neutron progenitor cells
Combine electrical stimulation with training for developing plasticity of spared circuits

Question 6

LTP in Ca1 vs Ca3

Answer 6

Ca1: postsynaptic changes; replacement of NMDA with AMPA (via stargazin phosphorylation to free it)
Ca3: presynaptic changes