X-Message-Number: 30502
From: "Basie" <>
Subject:  high-resolution microscopy
Date: Tue, 19 Feb 2008 22:20:43 -0500

" Importantly, if blood flow was restored, as can occur using stroke 
treatments with clot-busting drugs, 94 per cent of all synaptic connections 
recovered from severe deformation."

Using high-resolution microscopy, scientists demonstrated that the structure 
and function of cortical synapses were severely compromised only one to 
three minutes after stroke during a massive wave of electrical discharge 
termed ischemic depolarization. Importantly, if blood flow was restored, as 
can occur using stroke treatments with clot-busting drugs, 94 per cent of 
all synaptic connections recovered from severe deformation. Further studies 
will examine the upper limits of blood flow restoration time and synaptic 
connection recovery.

The study suggests that even short duration loss of blood flow, 
(approximately one to three minutes) could lead to damaged synapses.  In 
humans, brief loss of brain blood flow can occur during medical procedures 
such as bypass surgery, which can trigger blood clots to enter the brain. 
Other conditions with brief recurrent loss of blood flow include transient 
ischemia attacks, or mini strokes.  For these situations Murphy suggests, 
"Strategies that control ischemic depolarization associated with stroke's 
effect on synapses would be fruitful avenues for future drug development."

http://www.sciencedaily.com/releases/2008/02/080218214642.htm 

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