Effect of aging on learning in Drosophila melanogaster

My passion for fruit fly pushes me to look for a peer review journal on flies that I want to share with you. We all know that as people age, they tend to have memory dysfunctions and their learning ability decrease. To study the effect of age on learning, a researcher, Eric Le Bourg, did some experiment on fruit- fly Drosophila melanogaster to see the relationship between age and learning. He chose flies because they have a short life span and they can study many generations and also they have a well-known genetics. This journal article studies the effects of aging on learned suppression of photopositive tendencies in Drosophila melanogaster. To begin his experiment, the researcher makes the hypothesis that as flies age, the ability to learn decreases. To test his hypothesis, he proceeded to three different experiments. He used light as a conditioned stimulus associated an aversive unconditioned stimulus, the taste of quinine, and the darkened arm which was not associated with an aversive stimulus. It turned out that flies run away from light to avoid the quinine. He pointed out that quinine does not induce sensitization and has been used for many decades in learning studies using D. melanogaster because of its bitter taste.

The first experiment tested whether flies of different ages can avoid lighted vial associated with an aversive stimulus. The second tested if they can avoid the lighted vial associated with a strong (quinine) or weak (distilled water) aversive stimulus. Before both experiment, half of the flies were subjected to training with the aversive stimulus that will be used in the experiment. In the third experiment, one half of the flies was subjected to training with a lighted vial containing a paper wetted with quinine and the other half was subjected to 16 trials with a lighted vial containing a dry paper and after that, the same group of flies to 16 training trials with another lighted vial containing a paper wetted with quinine on each trial.

These experiments have shown flies of all age learn to avoid the light when it is associated with quinine or water. Quinine has a bitter taste that flies do not like and the water prevent them from flying that is why they avoid these two stimuli. However, the learning score in the older age flies decrease little bit compared to the first week age flies. Therefore, it can be concluded that age had different effects on locomotor activity and learning. Old flies walk slower but the locomotion had a slight effect on learning.

After reading this, my question is, does this conclusion also apply to human? As we grow old, do we really get stupid or we know everything but we just don’t want to talk?

                                  Drosophila melanogaster

Click here to read this article

Citation:
Eric Le Bourg, Effects of aging on learned suppression of photopositive tendencies in Drosophila melanogaster, Neurobiology of Aging, Volume 25, Issue 9, October 2004,
Pages 1241-1252, ISBN 0197-4580, 10.1016/j.neurobiolaging.2003.12.004.
(http://www.sciencedirect.com/science/article/pii/S0197458004000326)

Fruit flies and learning

This week I met with Jon Hayashi, a temp faculty member in the Biosciences Department at PC who is a good resource for the type research field that I am interesting in. We discussed about school, work and the kind of research that I want to do. After discussion, I told him that I would like to do something that has to do with genes in drosophila. So, he showed me a bunch of experiments on drosophila to look at and have an idea of what I want to do. He also gave me an article on Genetic approaches to learning in fruit flies and some videos of experiments. After looking through all these experiments, I decided to focus on fruit flies and learning.

In this area, Dr. Josh Dubnau of Cold Spring Harbor Laboratory did the T-Maze experiment to test the memories in fruit flies. After the experiment, it turned out that flies can learn. They can form a short term memory and also a long term memory if they are trained for a long period of time. To conclude his experiment, Dr Josh Dubnau stated that, “We're beginning to uncover the fact that many of the genes that are important for memory in flies are probably also important for memory in distantly related animals, even humans”.

For me, this experiment is amazing and I probably be doing something similar for my internship to learn more about fruit flies and their brain.

Here is the video of the experiment

Last Tuesday I met with Amanda Chapman, the director of the S STEM Grant. We talked little bit about school and work and how to manage both in order to be successful. She also shared with me some of her personal experiences about doing internships and how it can open your mind and guide you toward the type of career that makes happy versus the career that you choose to be in.

The next day I met with the lab staff for a 20 minutes interview.  It went really well but I was little bit surprised by the first question which was “if you could get rid of any one of the US States, which one would you get rid of and why?” Overall, I really like it because this was an opportunity for me to challenge my interview skills and to see how well I can do. I am looking forward to starting my research project and collaborate with the lab staff in order to run a very successful experiment.

I also spent 7 hours this week working in the STEM Program and helping students with their biology, math and chemistry homework. We are almost at the end the semester and everybody is overloaded with assignments and are looking for help everywhere to have them done. It is a pleasure for me to be able to help my peers and have their needs met.

Another exciting thing that happened my life this week was that I was nominated by managers as employee of the month at the Food Services department of Saint Joseph’s Hospital. I was very happy about this award because first it tells me how much they appreciate the hard work that I am doing in the food service team and for my record, this will look good on my resume. Below is the picture of the certificate that I received.

Hello,
My name is Kodjo Welbeck. I am currently working on my Associate in Sciences here at Phoenix College. I will be transferring to ASU in fall 2013 to pursue my Bachelor's Degree in Biological Sciences (Cell, Genetics and developmental Biology) and then apply for medical school.