Summer Research

These days I am almost feeling normal; I go to work for 8 hours in the lab, come home to grill something on the back patio surrounded by pots of blooming flowers, devour the vampire books Erinna has begged me to read for over a year, and hang out with my family, usually with a stress free smile on my face. On the weekends, I sleep in, run, go hiking, swim, you know, all those things that "normal" people do with their time off. How am I handling it? I love it.

But of course I will never be really "normal" again, not since I have cut into the flesh of a cadaver last August, and now that I am working in a neurosurgical research lab, there is definitely no going back to normal for me. So what do I do with my days in the lab? Lots, and the more I learn, the more I want to know....I feel like a four year old again - Why? Why? Why? Wondering about nerves, the brain, and how it all works so harmoniously.

Although I was a bit hesitant at first in terms of working with rats in the lab, I have become more comfortable, both with the actual physical requirements of the work, as well as the moral implications. When my husband asked me how I could "kill" these rats, I asked how he could eat the chicken on his plate. Both are grown for a specific reason - one to further the understanding of science, and the other, to nourish our bodies. Is there a difference? I do talk to the rats, call them my little buddies, and I also silently thank them for the lives they gave up in the name of science, without their permission of course.

Like I experienced in the cadaver lab back in the first class of medical school, I have become a bit desensitized, and find it easier to do the work in the lab, especially as my fascination with the rat's body, vasculature, and brain take completely over. Maybe I am just rationalizing what I am doing, in the same way I rationalize eating meat....if there is a all-judging God waiting at the pearly gates, I guess my day will come. In the meantime I am immersed in the work, and it has opened up my eyes to many things I had not previously thought of.

First of all, the incredible amount of detailed and at times, tedious, work that is involved in research. One of the research assistants here states that the only way to continue doing this work day in and day out is to have patience, while my mentor states that you have to have a bad memory. Either way, both patience and forgetting the "failed" experiments, is what drives researchers forward every day, to repeat experiments over and over and over. But enough philosophizing; do you want to know what I am actually doing every day?

I start with getting a rat out of its cage, and give it an intraperitoneal injection (in the abdomen, but not in the bowels) of a drug, pentobarbital. I leave the rat under a heat lamp, and wait 10 minutes to make sure the drug will take effect. I set up the experiment in the meantime, getting the necessary equipment, drugs, saline, surgical supplies etc...all ready. I return to the rat and pinch its tail near the end to make sure that there is no response. If the rat jumps, or moves, then we have to decide whether to add an additional amount of drug, wait again, or get a different rat altogether. Giving the first rat an additional injection may cause problems later in the experiment, as the second bolus of drug may be released from the rat's tissues and cause the rat to go way too deep, or even die.

The first essential in setting up these experiments is to make sure that the rat is in a steady state of anesthesia. This, I imagine, is what anesthesiologists do during human surgeries; find the right amount of drug to make sure the patient is under and not conscious or waking up during the surgery, and also not deliver too much drug that would depress respiration, and cause the patient to stop breathing. In the same way, we watch the rat during the whole experiment, making sure that it's not too deep or too light. This is easier said than done.

If the rat is in a good state of anesthesia, then I do some surgery using the microscope as my eye. I make an incision in the rat's throat area (remember it's "sleeping"), and search for the jugular vein. Once found, I isolate the vessel, tie off one end, make a small slit in the vessel, and then thread a catheter (hollow tube for the delivery of drug) into the vein. I push the catheter in as far as possible, ensuring that the drug will be directly delivered to the right atrium of the heart, and hence, pumped to the whole body. Once the catheter is in, I place the rat on our experimental apparatus; he lays on a water warmed heat pad (so he won't get too cold from not moving), and put his head into a frame that holds his head stably in one place. Since we are looking for cells in the brain stem, it is imperative that the head is completely still. During this time we check to make sure he's in the right anesthetic state, by pinching his tail to check for a response, and we hook up his catheter to a drug delivery system that will continuously push drug into his blood.

Next we do cranial surgery, which involves revealing the skull bone, rubbing off the periosteum (covering over the bone), and with a very small drill, I carefully make a small hole through the cranial bone, just enough to break through, but not so much that I injure the brain tissue underneath. This is becoming easier for me, as I learn the nuances of the drill, and what it feels like to thin out the skull bone. I have to be very careful to not break any blood vessels in the area as well, since they will bleed profusely and make it very difficult to place the electrodes in the correct location. Depending on what experiment we are doing that day (it can change day to day) we may thin out another portion of the skull in order to measure cerebral blood flow with a laser Doppler instrument, and we also may drill a very very tiny hole to drop in a drug that will give the rat a "migraine".

All of this surgery requires the use of a microscope, and very fine hand dexterity. I find that I really love this part, and hope to God that I don't fall in love with surgery and decide to become a surgeon. After the surgery is complete, we wait to make sure the rat is stable, and we measure its response to facial stimulation, as well as to paw stimulation. We use these really cool mechanical stimulatory devices, call Von Frey's, and each one has a different thickness. We push the Von Frey "thread" into the face or paw, in order to find the minimal and maximal threshold. How do we know if the Von Frey is activating any nerves? We have electrodes recording activity in the brain!!!

The electrode part is way cool. We lower electrodes down into certain portions of the brain or brain stem (the location of which have previously been determined by decades of research on rat brains), and while hooked up to equipment as well as the computer, we search for active nerves cells by moving micrometers at a time (that's .000001 m, very small). The research assistant that I work with is very skilled at this part, and while I can handle the surgical aspects, I still have a huge learning curve in placing the electrodes and finding the correct kind of nerve cell to monitor for the length of that experiment.

The most frustrating parts of these experiments (and the parts that require both patience, and a bad memory) is that so many things can go wrong - the rat can die, have a cold, go too deep or too light, the electrodes may not be working well, or there is too much background electrical noise in the room to make any good recordings, the drug could be leaking and not getting into the rat's circulation, or the worse a mere half hour prior to finishing the experiment (we record results for 2-3 hours after the initial migraine is given to the rat) we loose the cell. Gone. Forever. And it's in the early afternoon, and you don't have the 5 or 6 hours required to do the whole experiment over again with a new rat. Not until the next day anyway.

Even though so much can go wrong, I love what I am experiencing. This research allows me to see a side of medicine that I never knew about before - the countless days, years, lifetimes, that are spent, by rats and humans, in trying to understand the complexity of the human body. You may be wondering at this point what a rat brain has to do with the human body, but that's a posting for another day. Cheers!