5 - stroke recovery and rehabilitation

Question 1

what leads to excitotoxicity?

Answer 1

NMDAR activation

Question 2

what produce inflammatory mediators in the brain which contribute to local brain damage?

Answer 2

astrocytes, microglia and neurones

Question 3

what infiltrates the BBB?

Answer 3

neutrophils (mainly), T and B cells

Question 4

how are neutrophils triggered to enter the brain?

Answer 4

• cells in the brain produce chemokines which act on the liver
• liver then produces acute phase proteins, chemokines and then cytokines which activate the bone marrow to produce neutrophils

Question 5

what is the master regulator of inflammation?

Answer 5

Il-1

Question 6

what are the functions of neural repair?

Answer 6

• re-establish neural connections
• repopulate brain with neurones

Question 7

where does neurogenesis in the adult brain take place?

Answer 7

• subgranular zone (SGZ) of dentate gyrus in hippocampus
• subventricular zone (SVZ) of lateral ventricle

Question 8

describe neurogenesis in the subgranular zone

Answer 8

• newly formed cells migrate from the outer subgranular zone to inner granule layer in the hippocampal dentate gyrus

Question 9

describe neurogenesis in the subventricular zone in uninsured vs injured

Answer 9

• uninjured : neural progenitors migrate from SVZ to olfactory bulb via Rostral Migratory System (RMS)
• injured : neural progenitors from SVZ leave RMS and migrate laterally towards the damaged area

Question 10

what is angiogenesis?

Answer 10

• a biological process involved in the growth of new blood vessels from pre-existing vessels
• generally involved in wound-healing to restore the blood supply to an injured tissue/tumour development

Question 11

what factors are involved in angiogenesis after brain injury?

Answer 11

• cytokines
• chemokines
• interaction between integrins and ECM of vessel
• growth factors

Question 12

what is the main trigger factor for angiogenesis?

Answer 12

vascular endothelial growth factor (VEGF)

Question 13

what are the mediators of angiogenesis

Answer 13

Question 14

describe the stages of angiogenesis from a normal blood vessel

Answer 14

1. normal blood vessel
2. injury, BBB leakage
3. VEGF, Ang-1, endothelial activation and proliferation
   4.ECM deposition, EC proliferation to new vessels, involvement of integrins
4. vessel stabilisation, pericyte and astrocyte attachment

Question 15

what is a glial scar?

Answer 15

• response of brain to stroke/injury
• glial scar forms around lesion
• mainly formed by astrocytes
• helps protect health tissue from damaged tissue

Question 16

M1 vs M2 microglia

Answer 16

M1 = neurotoxic, inflammatory
M2 = phagocytic

Question 17

what do M1 and M2 microglia do after a CNS injury?

Answer 17