Question
Asked 26 April 2017

Mouse activity recovery after MCAO surgery is too fast. how can I help with?

I'm using the doccol's 20mm silicon suture for MCAO in 20-23g of mice.
And I'm sure that I insert the suture in right place, ICA,
because the phenotype of the mouse appears right after the surgery.
However, about 2 hours after surgery, the mouse's activity is recovered.
The occlusion is not enough to study for my job.
There is anyone who can give me some tips for MCAO?

Most recent answer

Jacob Huffman
University of Missouri–St. Louis
What strain of mice are you using, and what is their average weight. I am assuming you are only using males, correct? You may be using a suture that is slightly too small, allowing some blood to pass by the silicone tip, preventing a full MCA stroke. Its hard to tell without a devise to measure CBF. Also, are you using the Longa or Koizumi MCAO model?
I would highly recommend investing in a machine that can measure CBF through the skull in mice. There are a multitude of issues that can arise during the MCAO surgery, i.e. hemorrhage, collapsed vessels, etc., that will still produce the same transient phenotype, but are clearly different on LDF measures. 
Unfortunately, I don't see how you could expand the infarct region without increasing the duration of the stroke. In my view, there should be much more damage following an 80min stroke measured 24 hrs post-op than what your images are showing. This leads me to believe that your MCAO procedure is not completely blocking the the ICA/MCA intersection. 
Here is a recent reference I recommend reading:

All Answers (4)

Jacob Huffman
University of Missouri–St. Louis
How long of an occlusion duration are you using, i.e. how long are you blocking the ICA/MCA intersection? In our lab, we regularly see full mobility within a few hours after a 30 minute occlusion. That doesn't mean the occlusion isn't working, though. There is noticeable brain damage, easily identified with TTC staining, and locomotor deficits after a 30min occlusion. However, these deficits and brain damage diminish considerably over time, and are very difficult to find after 7 days. By day 7 with TTC, you are likely to only see penumbra. Simply increasing the duration of stroke should solve your problem, assuming your experiment permits the change. However, post-op mortality rates are proportionate to the duration of stroke, so you will likely need to expand post-op care.
Also, how do you verify proper occlusion outside of the standard phenotype? Ideally, you should use a laser Doppler flowmeter to measure cerebral blood flow (CBF). Temporal CBF should be reduced by >85% to attained an adequate MCA occlusion. 
Kyungri Kim
Yonsei University
First of all, I would like to thank you for your reply and I will answer your questions.
Our lab's occlusion time is 1hour and 20 minutes. I can see the locomotor deficits after the surgery. 
1 day after the MCAO surgery, I confirmed with TTC staining whether the experiment was done correctly. I attached the picture of my experiment.
Our lab does not have Doppler flowmeter, so we just confirm with phenotype and TTC staining.
In summary, I'd like to expand the infarction area without adjusting the occlusion time.
Jacob Huffman
University of Missouri–St. Louis
What strain of mice are you using, and what is their average weight. I am assuming you are only using males, correct? You may be using a suture that is slightly too small, allowing some blood to pass by the silicone tip, preventing a full MCA stroke. Its hard to tell without a devise to measure CBF. Also, are you using the Longa or Koizumi MCAO model?
I would highly recommend investing in a machine that can measure CBF through the skull in mice. There are a multitude of issues that can arise during the MCAO surgery, i.e. hemorrhage, collapsed vessels, etc., that will still produce the same transient phenotype, but are clearly different on LDF measures. 
Unfortunately, I don't see how you could expand the infarct region without increasing the duration of the stroke. In my view, there should be much more damage following an 80min stroke measured 24 hrs post-op than what your images are showing. This leads me to believe that your MCAO procedure is not completely blocking the the ICA/MCA intersection. 
Here is a recent reference I recommend reading:

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