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keepgoing
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04/03/07 - 09:01 AM

A 35 year old man was revived after having been subemerged underwater for 15minutes. his doctors were concernd that he suffered from hypoxic damage to his brain. Which of following structure is most likely be damaged?

1. Claustrum

2.Layer 2 of cereberal cortex

3.Mammilary bodies

4. Purkinje layer of cerebellum

5.Subiculum

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shalini.ravi
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04/03/07 - 09:09 AM

purkinje cells ?

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new_n_lost
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04/03/07 - 02:14 PM

5.Subiculum ===> Part of the Hippocampal Regionm which is most effected by Hypoxia.

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keepgoing
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04/04/07 - 01:02 AM

its purkinje layer of cerebellum which is commonly affected by hypoxic injuries...!

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new_n_lost
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04/04/07 - 02:01 AM

No KG i have searched this n found out the Most MCC area in Brain in the Hypoxic Injury is the Hippocampal REgion n its associates.

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new_n_lost
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04/04/07 - 02:08 AM

I m sure u must have chked but can u plz re chk plz plz

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keepgoing
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04/04/07 - 04:55 AM

i agree with u nnl...but subiculum lies medially & inferiorly to hipocampus and its not selectively vulnerable to hypoxia,in contrast to nearly CA1 subfield of hippocampus...

Purkinje Cells of cereberal cortec,pyramidal cells in CA1 subfield of hippocampus,pyramidal cells in layer 3 and 5 of cerebral cortex are all sensitive to cerebral hypoxia or ischemia.the basis for this selectivity vulnerability may be NMDA-receptor mediated excitotoxic injury of their specific population of nerons..

ref--kaplan

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Jackofknives
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04/04/07 - 05:37 AM

Purkinje Cells of cereberal cortec,pyramidal cells in CA1 subfield of hippocampus,pyramidal cells in layer 3 and 5 of cerebral cortex are all sensitive to cerebral hypoxia or ischemia.the basis for this selectivity vulnerability may be NMDA-receptor mediated excitotoxic injury of their specific population of nerons..

totally agree with the above.

This is the mechanism for glutamate excitotoxicity - No O2 => no ATP => Na+/K+ ATPase doesnt work = cells depolarise => NMDA receptors works better, Ca2+ flows in => cell death => release glutamtic acid to extracellular space => further depolarize neighboor neurons => more Ca2+ flows in...

Therefore the sites where neurons are heavily stimulated by glumate is high vulnerable.

I think it’s a poorly thought question though. 5 min without O2 brains start to turn black, 15 min your ENTIRE brain will be severally damaged whether there is glutamate or not lol. Hypoxia is mainly concerned with stroke where you get some oxygen but not sufficient. As far as I know there is medication to reverse this vicious cycle.

However, if I really have to pick one I'd choose subiculum as well as Purkinje, both seem to be right.

To Keepgoing, are you saying subiculum does not does not contain neurons with NMDA receptors? It being the projection part of the hippocampus n all.

Edited by Jackofknives on 04/04/07 - 11:36 AM

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po
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04/05/07 - 03:23 PM

hi KG,what is the question source ,please?thanks.

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