Barnes Maze The Barnes Maze is used in behavior testing to study mental and psychological states and behaviors of animals, largely learning and memory in rodents. The maze consists of a circular platform approximately 100 cm in diameter that is elevated 40 cm from the ground with 18 escape holes along the perimeter at 30 cm intervals. A removable enclosed Plexiglas goal box is located on the underside of the platform and is placed in the same cardinal position across all experimental trials. The animal uses visual cues in the study area to remember and learn where the goal box is located. To avoid box location cues from the maze itself, the table is rotated after a set of trials and the goal box is placed in the original cardinal position. This set up relies on the premise that rodents do not prefer open spaces and will search for the dark box to enter in order to relieve the anxiety of being exposed.Prior to each trial, the animal is placed inside the goal box for 60 seconds, and then under an enclosed container at the center of the circular platform for 30 seconds. Once the container is removed, the video recording for scoring purposes begins. The rodent is then free to wander around the maze in search of the goal box for the trial for four minutes. If the animal finds the box, the trial is over and the video recording stops. If the animal does not find the goal box in the allotted trial time, it is placed back in the goal box for 60 seconds and back into its home cage between trials. All animals are analyzed for escape latency by manual methods; the time it takes for the animal to crawl into the goal box is recorded by the experimenter during the trials. The video recordings are used in automated scoring systems to score for goal box latency, primary goal box distance (the total distance the animal travels before entering the goal box) and error duration (the total amount of time the animal spends exploring the non-goal box holes). The overall distance and pattern the animal traveled during the trial is also recorded to generate data pertaining to motor activity and memory of box location. This is beneficial if an animal was given a drug or any treatment because they can be compared to the motor pattern of control animals. |
Beam Walk Test The Beam Walk Test is a behavioral test that measures the animal’s motor control, coordination, and balance. It consists of a long, elevated beam that is wider at one end and gradually becomes more narrow at the other end. At the more narrow end, there is an enclosed black box that the animals are inclined to go towards. The animals automatically go towards the box because they have the natural instinct to stay away from open areas and go towards closed off areas that are safer. Along both sides of the beam, there are touch sensitive strips that count each time the animal slips off the beam and places its paw on the side strips. To prevent the animals from injury, a nylon hammock is stretched below the beam to catch the animals if they fall. To encourage the animals to walk across the beam, a bright light is shined at the starting point as an aversive stimulus.During testing, the animals are placed on the wider end. Their performance is measured by the number of times they slip off the beam and the time it takes for them to make it to the box. A healthy animal can usually traverse the beam with little difficulty, even if it gets as narrow as half an inch on the narrow end. However, animals with motor deficits have a more difficult time with this task and often slip off the beam more than healthy animals. The Beam Walk Test is an excellent way to measure more subtle deficits in motor control because of its simplicity and accuracy of measurements. This method is often used on animals in studies involving traumatic brain injury, Alzheimer’s Disease, Parkinson’s disease, and other neurobiological diseases that are known to affect motor control. |
Novel Object Recognition The Novel Object Recognition (NOR) test assesses cognitive functioning in animal models, usually rodents, by analyzing the amount of time spent investigating a novel object. This behavioral assay consists of two trials; The first trial, also known as familiarization, involves placing the animal in an enclosed space with two identical objects placed in opposite corners. The rodent is free to roam for a period of 5 minutes, before being returned to its cage and re-entering the arena for a second trial after approximately 45-90 minutes. During the experimental trial, one of the two objects is replaced by a novel object. The animal may explore the space and inspect the novel object for a period of 3 minutes. The entirety of the test is recorded and tracked by an overhead camera to allow for data analysis. |
 Novel Object Recognition tests are reliable measures of short and long-term memory, as well as object recognition memory. Unimpaired rodents are expected to frequently explore the novel object at the start of the experimental trial, although performance is dependent on the amount of time spent between the familiarization and experimental trials. The animal’s tendency to approach the novel object indicates retention of the familiar objects. When neural damage is induced, test performance is impaired. Animals with cortical or hippocampal lesions aid in understanding the role of specific brain structures in memory. This knowledge can be applied to the field of neuropharmacology for the development of drugs to combat neurodegeneration. |
Elevated Plus Maze The elevated plus maze (EPM) is a behavioral assay generally used to assess anxiety-related behaviors in rodents. As can be seen in the image below, the EPM, consist of a center platform with four arms extending from the platform. Two of the arms have walls on both sides, these arms are referred to as the closed arms while the other two arms are the open arms. All four arms are ___cm long and ___cm wide.The EPM takes advantage of well-studied rodent behaviors such as the approach-avoidance conflict and preference for enclosed spaces. The approach-avoidance conflict is the internal struggle rodents have when presented with something novel. Naturally rodents want to investigate a novel environment which in this case is the EPM, however, rodents prefer not to be in open spaces as they are associated with danger. Rodents that are higher risk takers are more likely to spend more time in the open arms than rodents with higher anxiety indices. Common parameters that are looked at are latency to first open arm entry, number of total line crosses, frequency to entry of open arms, frequency to entry of close arms and duration in open arms. Latency to first open arm entry is an important measure because rats that higher risk taker will have a latency that is much lower than that of their anxious counterparts. An arm entry is counted when the animal is one full body length in. |
Conditioned Place Preference Test Description |
Rota Rode Description |
Grip Strength Description |