Polyydipsia Experiments

This summary is based on a video series, found on YouTube, depicting the findings of neurologist, Dr. V.S. Ramachandran. Ramachandran is noted for his use of experimental methods that rely relatively little on complex technologies such as neuroimaging. According to Ramachandran, "too much of the Victorian sense of adventure [in science] has been lost."

He studied the brain of a woman that exhibited strange behavior, memory loss, and difficulty with language before she died. While studying the brain of this woman, he found several clumps that are now called amyloid plaque and tangles of fibers that are called neurofibrillary tangles. These structures are the key to a gradual progression of a treacherous disease; that will erode a person’s ability to live independently, sustain speech, maintain healthy relationships, or memory. Neurologically, the brain is destroyed with amyloid plaque, neurofibrillary tangles, and loss of connection in the neurons of the brain. As the brain’s neurons die more damage is created and the damage to the brain becomes more widespread, resulting in shrinkage of the brain.

The experiment was conducted using adult male Sprague-Dawley rats from the Charles River Laboratories in Hollister, California. The rats were housed in cages, two rats per cage, for a 12 hour light/dark cycle. The investigation began by combining the use of lateral

This study will be comprise two experiments. The animal trials will be conducted at the Experiment Research Station and the laboratory work in the facilities of the Institute of Animal Science, University of Hohenheim. Field studies will not be included.

Male Wistar rats between 120 and 140 kg will be fed an ammonium acetate rich diet to induce them with hyperammonemia for a 5-week period. Thirty Wistar rats will undergo surgery to implant portacaval shunts. This model was created to develop a system that has a pure hyperammonemic state that is commonly found in individuals with chronic liver disease. Four groups of 10 Wistar rats, split into 2 control groups and 2 experimental groups. The four designated groups will be: the normal fed control group, the control + PMO group, the portacaval shunted group (ammonia group), and the portacaval shunted Wistar rats + PMO groups. Portacaval shunts will be performed, in order to induce alterations in nitrogen metabolism caused by changing the function of the liver. The control + PMO group and portacaval shunted Wistar rats + PMO group will be given 60 mg/L of PMO in their drinking water everyday at the same time until their deaths. In order to ensure all water will be consumed, all Wistar rats will be provided with only 10 ml of water. The Wistar rats in the control groups will be given tap water on the same drinking schedule as the two experimental groups. After 5 days of treating each experimental group, the Wistar rats willingness to explore brain function was assessed using a Y-Maze learning test everyday for 10 trials. Additionally, ammonium

Male, 5-6 wk old Wistar rats weighing 200-250 g (Charles River Breeding Laboratories, Montreal, Quebec, Canada) were housed on a 12-hour light/dark cycle at constant room temperature and fed a standard commercial rat chow (120 µmol Na+/g,) and water ad libitumFor all surgeries, rats were anesthetized with 2% isoflurane in oxygen. Effective levels of anesthesia were maintained by observing reactions to physical stimulation such as toe-pinch, as well as monitoring the pattern of respiration. For pain relief, slow release buprenorphine (1mg/kg) was injected sc 1 hour before surgery which provides adequate analgesia for 3 days. . All surgeries and experiments for the present study were approved by the University of

Researchers used twenty three year old female Sprague-Dawley rats in this experiment. The rats were kept in standard laboratory cages on a light dark cycle in a temperature-controlled room. The rats were given seven day to adjust to their new homes before beginning the experiment. When sixteen of the female rats reached thirty days of age they were administered injections of CB1 and CB2. These female rats were the WIN-F1 group. Each day injection dosage increased. The first day was a 1kg, second day 2kg, third day 4kg. The female rats were weighed daily. The control group, VEH-F1, consisted of sixteen female rats that were administered saline. At 60 days of ages the female rats were mated with colony male rats. On postnatal day 21 male offspring were housed until test began. Only one offspring per litter was used. When the male offspring became 40 or 60 days old they were tested for CPP responses to morphine or saline. Rats were tested in three chambers, which had infrared to track the rat. During preconditioning, day 1, rats were placed in the middle chamber but allowed to go to any of the three chambers. Researchers recorded the amount of time spent in each chamber during 15 minutes. Day 2 morning, the rats were weighed, given saline, and placed in chamber A for 30 minutes. Five hours later rats were administered either saline or morphine and placed in camber B for 30 minutes. Conditioning repeated for 3 days. On the fifth day rats were placed in the middle

The results showed that rats raised in cooler temperatures developed a greater body and coat mass that those of warm-reared mats. This significant difference indicates that the environment plays an important role in the hair coat insulation. The rats reared in the cooler temperature had maintained a relatively heavier hair coat with darker fur while those that were raised in the warmer temperatures had relatively lighter hair in lighter color. The heavier hair coat plays a greater role in the maintenance of body temperatures of the Rattus Norvegicus due to high surface to volume ratio, which decreases with size and age. This notion supports the conclusions of the previous study where rats that were reared in the colder temperatures were smaller. It was essential for them to be smaller so that they their longer hair would have a higher surface to volume ratio. The differences found in the development of the coat mass relative to body mass as a result of thermal environment suggest that the Rattus Norvegicus adjust their hair coat insulation at the juvenile age of day 22 to reduce the energetic costs of thermoregulation in their housing

The animal experiment was approved by the University of Calgary Animal Care Committee (#AC12–0033). 32 male Sprague Dawley rats were ordered when they were 10 days old (Charles River, Montreal, QC, Canada) and randomized into treatment groups after a two-week adaptation interval. The four treatment groups were as follows (n=8): 1. Control (CON, animals fed ad libitum diet) 2. 75% restriction group (75%, animals fed 75% of the diet consumed by the control animals) 3. 50% restriction group (50%, animals fed 50% of the diet consumed by the control animals) 4. 50% restriction group and then switched to ad libitum diet after two weeks (50% +CON). The rats weighted ~80g when housed individually in metabolic cages of the Comprehensive Lab Animal Monitoring

Although it is not any major finding, it is something that leads us one step closer to understanding Alzheimer’s disease and how it

Through my time studying and researching, I have gained avid experience in animal husbandry and administering treatment in the animal facilities of Indiana University of Pennsylvania under the supervision of Dr. Christina Ruby. Moreover, while working under a circadian rhythm researcher, I acquired knowledge of the crucial importance to maintain constant conditions. Because I am well aware of how influential environmental cues are in the experiments, I know the importance of performing according to the regulations and guidelines of the facility by which I am employed. Furthermore, in my previous experience, I held the responsibility of maintaining an animal room independently; this obligation ascertained my ability to maintain records of the care activities revolving around the mice in my charge, as well as reporting to my supervisor if anything was disarray in the lab. Also, this position was intended for research purposes, so organizing and analyzing data were essential skills to hone.

Sprague-Dawley rats will be operated for immunohistochemistry, in vivo extracellular recordings, and behavioral practices. Guinea pigs will be operated for in vivo intracellular recordings.

Albino Wister rats of either sex weighing between 150 to 200gms were divided into Six groups of 6 animals each.

At the beginning of the experiment, all rats will be restricted to a condition of no exercise for 4 days, where their baseline reactions and levels of stress hormones will be recorded. After that initial period, rats will be subject to their specific levels of daily exercise and the results of tests performed will be compared to the baseline that was recorded previously for that specific rat. This will help account for individual differences in each rat, as some may have naturally higher or lower levels of stress. A select group of rats will also continue to have no exercise, just like at the start of the experiment. This will help give an idea as to what level of change observed is just caused by time spent in the lab and the controlled environmental conditions that all rats will be subject to. All rats, regardless of their experimental condition will individually be housed in the same type of cage, and receive the same type and amount of food and water. Again, this is to help control for any confounding variables that may affect the stress levels of the

Doctors are already able to look at the difference between a brain that is affected by the disease and a healthy one, but they were never able to determine whether or not the disease would onset early.