Lecture 28 - Stroke

Question 1

Types of stroke?

Answer 1

ischemic or haemmorrhagic; mostly focal (in one area) but can be global

Question 2

Risk factors?

Answer 2

diabetes, hypertension, atherosclerosis, genetic polymorphisms

Question 3

Penumbra?

Answer 3

central core of infarct has cells rapidly necrosis, surrounding area - or penumbra - die via apoptosis and take longer, which is the therapeutic target as necrosis too fast to reverse

Question 4

Mechanisms of apoptosis?

Answer 4

glutamate excessive, influx of Ca, free radicals, macrophage activation

Question 5

Excitotoxicity theory?

Answer 5

excessive glutamate saturates transporters and overexcited glutamate systems contribute to cell death

Question 6

AMPA receptor subunits?

Answer 6

GluR2 pass sodium not calcium, GluR3 vice versa - in stroke down regulation of GluR2 causes abnormal Ca2+ flux

Question 7

Kainate subunits?

Answer 7

GluR5-7

Question 8

PCP function?

Answer 8

non-competative antagonist (blocker) of NMDA channel

Question 9

mGluR subunits?

Answer 9

Group 1: 1 and 5 - Gq (DAG & PKC); Group 2: 2, 3 - Gi

Question 10

Stroke to necrosis and apoptosis pathway?

Answer 10

increased NMDA activity increases Ca2+ heaps, leading to apoptosis; increased AMPA activity increased sodium and chlorine intake, leading to necrosis

Question 11

Treatments?

Answer 11

tissue plasminogen activator (TGA), hypothermia, free-radical scavengers, anti-inflammatory