Since the first week of my lab I knew that I was running a maze to analyze mice behavior. I am working for a graduate student in my lab named Colin who is doing research on how Traumatic Brain Injury (TBI) affects the hippocampus region of the brain. At first I thought Colin was really scary because he was so serious all the time and seemed sort of aloof but he is actually really nice and he answered a lot of my questions at the beginning of my research. During the first week he gave me a paper to read about a contraption called a T- maze. A T- maze is a maze that is used to test rat/ mice behavior and memory. I'm going to try to explain how the T-maze words but it is hard to explain without demonstrating on the actual maze. There are two types of T-mazes, elevated T-mazes and flat T-mazes. They both test the same things but mice it takes mice longer to be comfortable in elevated T-mazes. Below is a picture of the maze my lab uses. You can see in the picture that there are three sections of the maze. It is shaped like a "T". Start off at the bottom of the maze and then are forced to go either left or right (a door closes behind them). If they are forced to go left, on the next run, that mouse must go right. This is called alternation. Alternation tests mouse intelligence, memory, and behavior. At the end of each side of the maze there are peanut butter chips! The first time the mouse is forced to go either left or right, he eats the peanut butter chips for 5 seconds and then I pick him up and put him in the front of the maze again! If he choses the alternate side of the mazes he is allowed to eat the peanut butter chips. If he choses the same side again I pick him up and put him back in his cage before he eats the peanut butter chips. I am basically conditioning them to expect peanut butter chips at the end of the maze and am training them so that they know they can only eat the peanut butter chips if they chose the alternate side of the maze. My PI, Dr. Cohen, ordered 6 mice for me to do this experiment and I do 10 trials for 6 mice every day. This is a continuation of Colin's research. My group of mice is called F group and he has had 5 groups of mice (A, B, C, D, and E) before my group. He sent me a google document of all of the T-maze behavior archives and mice weights. I have to weigh and feed the mice everyday. The animal lab facilities usually feed the mice but my lab is feeding them less than normal so that they are motivated to run the maze. My research is pretty repetitive because each T-maze test lasts 10 days. My second week, the mice came in and Colin showed me how to handle them and pick them. They are bred specifically for labs and are not aggressive mice. They had never been held by a human before we handled them. Although they are not aggressive mice, they were very anxious. Mice get anxious easily when introduced to new environments. Once they were used to me holding them, we introduced them to the T-maze. They HATED the T-maze because elevated closed-in environments stress them out. We piled on the peanut butter chips onto each side of the maze so they would learn that the maze=food. We would put them in for 5 minutes at a time/ until they ate at least one peanut butter chip. We wanted them to get used to the idea of eating a peanut butter chip at the end of the maze. By Monday of week 3, the mice were ready to actually start the maze without any delays. The research I am doing involves time delays. The first 10 days of the t-maze there will be no delay between us forcing them to go one way and them choosing to go the opposite way in the T-maze. At first the mice were not very accurate and did not alternate correctly between maze runs. If a mouse did not choose right after I made him go l have to take him out of the maze before he eats the peanut butter chips. I record the yields of each trial and add them to the T-maze google document after I finish all 10 trials for the 6 mice. I have been doing the same thing every day for all of week 3 because the trials are time consuming. My average day looks like this:
6:45- wake uo
7:20- leave house for train station
7:59- make train
7-8:55- make another train and walk to CHOP/UPenn Hospital
9:00- arrive at research center, badge in to an elevator, walk through this cool, top secret, spy-like, matrix-y A Level floor that is all white (woah), swipe into another door, swipe onto that elevator, swipe to press level C (mice level facilities, swipe to get scrubs, swipe to change into scrubs, and then enter super-cool 400 hallway where I do the T-maze!
I guess it was hard for my PI to get the security at CHOP to activate my ID in this building because it is very protected. Security is off the wall and it is impossible to get access to this building if you don't have access on your CHOP ID. CHOP spends a lot of money on scrubs and security equipment to keep the mice research facilities sterile and protected. I have my own locker in the changing room and there is a changing room because, as mentioned above, we have to wear scrubs! Every time we enter the room we have to wear this:
I have been enjoying my research so far and although it is slightly repetitive, I enjoy working with animals and really like studying behavior and memory! My lab does research in two different buildings. I am the only person working in the animal facilities so I do not see my PI or Colin unless I walk across the street to that building for a question that I want to ask in person. I've been having a really good time working with the mice (because they are so cute) and working in such a high-tech research center.
Lab research
My lab has lab meetings every Friday but we have not had a lab meeting the last two weeks because not everyone was here. I wish we did have lab meetings because the meeting the first week helped me understand what my lab does as a whole more than i had understood before coming to the lab. Throughout my first three weeks here I have gathered that they study naive (uninjured) and injured mice with TBI. They use a pressure machine to give mice TBI. (This machine is in the room with the T-maze in the animal research building.) I am working with naive mice and am recording their memory and behavior via the T-maze. I am fairly certain that someone in my lab will injure their brains eventually and study the difference in behavior/ memory to compare the two states of mind. Then, my lab adjusts their diet and feeds them a type of GABA transmitter that is supposed to help fix TBI! After they are finished studying the live animal they dissect the brain and study the live slices underneath a 3D microscope that can stimulate the brain slices with electrodes.
This is the room with the T-maze!
These are the mice cages!
No comments:
Post a Comment