CSB332H1 Lecture Notes - Lecture 16: Nimodipine, Excitotoxicity, Hemiparesis
14 May 2018
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Lecture 16(a): Neural Stem Cell Transformation
Stroke Consequences:
• Stroke is the interrupted blood flow due to a hemorrhage, aggregates of platelets/blood cells
(thrombi) that is capable of leading to local tissue destruction in the brain in a few hours
o Prognosis and recovery is dependent on the location and extent of the stroke lesion
• Different types of lesions will have variable effects – motor areas are known to being infected:
o Paretic lesion – leads to slight weakness and impairments
§ If the stroke experienced was severe it can lead to complete paralysis
o Blood supply to the brain is separated into left and right lobes, often a lesion only
occurs on one side:
§ Hemiparesis – slight weakness and/or impairments of one side of the body
§ Hemiplegia – paralysis on one side of the body
• Recovery after strokes is variable depending on the extent:
o Large-sized strokes have minimal recovery
o Small-sized strokes, most have good prognosis which can allow for extensive or full-
scale recovery of lost functions
Glutamate Excitotoxicity:
• Interrupted blood flow will cause the affected regions to have impaired Na+/K+ ATPase
pumps leading to their depolarization and excess activation through the release of glutamate
o Excess glutamate release to post-synaptic neurons will cause apoptosis due to the
excess influx of Ca2+ and Zn which negatively affect the mitochondria
• Therapeutic approaches have been investigated to prevent glutamate excitotoxicity at different
stages, however none were successful in humans
o Nimodipine is a drug that functions as a Ca2+ channel blocker
§ Ca2+ channels are involved in several areas in the brain – blood vessels & brain
(if Nimodipine is given peripherally it will have affect an all of those areas)
ð Therefore, the use of Nimodipine must be only introduced to affected regions of the brain
Document Summary
If the stroke experienced was severe it can lead to complete paralysis: blood supply to the brain is separated into left and right lobes, often a lesion only occurs on one side: Hemiparesis slight weakness and/or impairments of one side of the body. Ca2+ channels are involved in several areas in the brain blood vessels & brain (if nimodipine is given peripherally it will have affect an all of those areas) Therefore, the use of nimodipine must be only introduced to affected regions of the brain. Function to depolarize the postsynaptic neuron and increase intracellular. Ca2+ levels within the cell body (soma: increase ca2+ in the cell body will activate protease activated receptors (par4) which is a g-protein coupled receptor. Caspase3 which carves up" the nucleus; destroys dna. Par4 can be activated via increase in ros or metabolic consequence (lack of glucose: if the apoptotic pathway is prevented we are capable of stopping the apoptotic loss found associated with stroke.
