JMShamberg+Assignments

 [|[1]] Yang, J. N., O. Bjorklund, et al. (2009). "Mice heterozygous for both A(1) and A(2A) adenosine receptor genes show similarities to mice given long-term caffeine." Journal of Applied Physiology 106(2): 631-639. =[Full Marks JCB]=
 * First Assignment:**

//Summary:// ~Introduction~ > Caffeine a known psychoactive drug, popular and widely consumed. Some of the known affects of caffeine are the result of knowing out the A(2A) Adenosine receptors. In this study we hypothesize that mice with a reduced number of A1 and A(2A) receptors will show feature of mice that have been subjected to long term caffeine treatments, similar to human responses. ~Materials and Methods~ > During the experiment a variety of mice were used and cared for under the regulation of "Guide for the Care and Use of Laboratory Animals". Mice were studied with either half the normal amount of A1 and A(2A) receptors or the normal quantity. There are wild type and both male and female mice in the study. A telemetry study is being preformed with the use of a computer program to monitor body temperature and locomotion activity.

> For the locomotion activity the study took place in an open field arena equipped with a photocell system allowing for recording of any major movement. The photocell system is however flawed and unable to record small movements. Also all locomotion tests were preformed during the designated morning hours for the test; since the mice were kept on a 12 hour light and 12 hour dark schedule

> The receptor densities were monitored to see what affect the dosages of caffeine and other inhibitors had on Adenosine during the course of the experiment. The reason for this was to see any detrimental affects one the receptors during the course of the experiment. Specific antagonists were used for each receptor.

> Preparation of cDNA and RT-PCR took place using dissected subject brains that were obtained and rapidly frozen. A Qiagen RNeasy kit was used to isolate RNA. This was done to assist in A2B and A3 receptor detection using real-time RT-PCR. //(This portion of the material and methods is specific to a portion of the experiment unrelated to desired subject mater)//

> //(next section talks about isolation of adipocytes and lipolysis experiments//. //I have to reread the experiment again to find what important this has on the experiment has on a whole.)//

> Statistical data was preformed using GraphPad Prism 4 or 5 ~Results~ > This first main result was the study on A1 and A(2A) receptor stability when the other is being directly affected or removed from the system. The result was that the two receptors are independent of the other.

> A Study on adaptive changes in A2B or A3 receptors, however these receptors tent to be less abundant and they study in mouse tissue was not readily available.

> The peak orally consumed caffeine does was 0.3g/l which was less than fifty percent of peak injection quantity at 15 mg/kg

> The long term affects of caffeine ingestion are divided into a few different categories. The first of which was a Heart Rate and Locomotive activity. Within these two categories there is a different set of results depending on gender of the mouse. There was also a comparison to wild type mice. In terms of Heart rate there was evidence of a lower heart rate in non wild type mice most particularly in the females. There is evidence that orally digested caffeine produces a different set of results than injected. The first of which is a noncumulative affect along wiht a less obvious difference between male and female mice.

> The Locomotive activity (LA) was studied in two period of examiniation. The first of which started after the mice had accustomed themselves to their new surroundings. The second set started after the mice had been recieving their drinking water containing or not containing caffeine. During the first set the (LA) showed increased activity between both sexes however a reduced (LA) during the second set. Suggesting a possible level of tolerance to the caffeine having built up.

> A study was then wanted to be conducted to see if the mice injected with the caffeine would also build up a tolerance to the acute effects of the drug. What was learned from this is that mice that have had their A(2A) receptors deleted due to the affects of the original caffeine treatment had a much higher baseline. On the other hand those that had their A1 receptors deleted had normal affects to the caffeine. Finally those with normal A(2a) and A1 receptors from the initial sets showed less of the acute effects during this test. ~Discussion~ > Deleting either A(2a) or A1 receptors had no affect on the opposite receptor telling us that they are independent on one another. Also no adaptive changes were noticed in the other Adenosine receptors.

> //(more reading is necessary to fully understand what shift they speak of taking place)//

> The data collected reflected the known affects caffeine can have on the human system primarily in regards to the A(2A) and A1 adenosine receptors other minor affects were not studied. It was also shown that without the A1 or A(2A) receptors no effects of caffeine are shown.

> Clear affects on the mice Heart rates and locomotive activity were noticed but no body temperature changes were documented.

> Long term caffeine treatment was seen to decrease the hear rate of female mice, since the receptors in questions have an affect on the central nervous system directly linked to the cardiac control centers

> It is seen that there are no acute affects on the heart rate unlike the long term dosages which does show such affects

> the expected increased locomotive activity was seen as they are the known the affects of caffeine.

> In this study it was noted that the Basal heart rate is higher in females than in males. This is however not believed to be due to stimulation of estrogen.

> The mice showed the ability to show the long term affects of the caffeine treatment.

> it has not been determined what causes the appearance of caffeine tolerance. One belief is that the rate in which caffeine is metabolized increases allowing for a reduction in the quantity present.

> it is noted that an increase in the density of adenosine binding sites in variant locations on the brain were found. THis is not believed to be a cause of tolerance which leads to the blief tolerance to caffeine is the result of many different mechanisms

> The experiment was a success showing some predicted responses to the treatments.


 * Second Assignment:** Look on FAQ page - completed question 15 - Topic: Real Name vs. Pseudonym
 * Third Assignment:** Located here