Something Completely Different

Posted by Reid at 1:11 p.m.

In my last year of my program at the University of Alberta, I have had the opportunity to participate in some pretty cool things. One of the coolest was a surgery on a rat. I'm taking this space up on the blog to explain the procedure and show some pictures.

[A note from Johnny: If you're squeamish like I am, be warned. Otherwise, enjoy the rat pictures.]

The rat was anaesthetised with a ketamine anaesthetic. For those of you up on street drugs, that's Special K which has a similar mechanism to PCP/Angel Dust (NMDA-receptor drugs). These drugs are dissociative anaeasthetics, allowing the rat to be dissociate from the pain even if it wakes up mid surgery. It's a good thing, because my rat did wake up a bit mid surgery. His head snapped up while digging around the nerves in his neck. No need for me to explain in words, I have pictures.



Rat = 500g. Note the urine escaping his bladder onto the hot water bottle. Under anaesthetic the rat will loose control of it's bladder and constantly leaks. He's on a hot water bottle and under a heat lamp because of his inability to regulate his body temperature. Well, let's cut him open.
And yes, he is still alive. I need his heart to pump to run the tests.







A nice little incision removes the epithelium. This was done with regular scissors. Nothing too spectacular here. Almost no bleeding, just a bunch of tissue. Now to find the carotid artery.











It's a bit of a dig but sure enough you find a large tube like tissue. Beneath it lies the trachea and carotid, so off we go.











Opened up, you can easily see the rat's trachea. The carotid is just in behind it, so using tweezers you pull up to front as shown in the next picture.









It's tough to tell, but there is a nerve attached to the carotid. This makes the vessel less flexible and nearly impossible to work with. It took two of use to remove the nerve from the vessel.











Use some ties to keep the artery pulled forward and accessible. But knotting tightly on the distal (left) side of the vessel, the vessel swells so we can see it with a bit more ease.










Time to cut. Take some scissors, find the vessel, cut it about half way through and hope for the best. If that clamp isn't on correctly blood goes everywhere, so you hope for the best and cut away.









Success! Now to run a tube into the artery to measure the blood pressure and heart rate. It's a lot harder to do that I would have thought. It probably took longer than the rest of the surgery.








Tie the tube down, flush with heparin to remove any clots and viola! Cannula #1 done. Next is the jugular.












So I skipped a bunch of steps and just went to the tie down of the jugular. It looks sexy, no?

This tube will carry drug directly in to the rat's heart. The experiment called for acetylcholine and atropine to determine the effects on blood pressure and heart rate. The rat lived until the end of the surgery when he was injected with euthenol. It killed the rat within 5 seconds. The other method would be to take scissors and cut its chest cavity open and toss it in the garbage.

All in all, it was a great learning experience and it showed the difficulty of in vivo experiments.

To the anonymous who loves Johnny, just tell him face to face. I am pretty sure it will drive him crazy...unless of course you are a male, in which case you can keep it your little secret.