behavioral assays that model some aspects of these human disorders. of different drugs with potentials related to modeling PD or drug addiction (). The intent of the present article is to provide a pragmatic outline for establishing and optimizing behavioral assays and phenotyping batteries, ensuring that the. Nictation. C. elegans dauers can occasionally be found flailing at the top of mold An assay for this behavior has not been developed.
assays 2.4 Behavioural
The climbing ability of the flies was monitored twice, at day 6 when the flies were six days old and at day The analysis was done using a data-mining tool WizWhy [ 27 ] to identify the underlying rules that explain the dependent variable—the health condition.
Furthermore the algorithm identified, based on the extracted rules, the unexpected cases deviating from the rules and issued predictions for new cases. The rules summary is shown in Table 1. Since several couples copulated in less than 10 minutes, we normalized the 4 following measured parameters for each couple, by dividing it in the total time, emphasizing fast copulating males.
Orientation time revealed an average of Similarly, Oregon-R vibration time was Interestingly, the two groups differed in nonsexual encounters NSEs. Here we noticed the occurrence of NSE mainly prior to beginning of any sexual activity; thus we did not divide the measured values by the total time.
For further comparison, all parameters of the six traits were summed up and normalized for each group. While each parameter is sufficient to distinguish between the two groups, we find the overall difference as a ratification of the results Figure 1 b.
We monitored the climbing ability of the flies at the age of 6 days, the age of flies tested in the courtship assay. Our results did not indicate a significant difference between the two groups prior to 21 days data not shown , as was also reported previously [ 12 , 13 ].
As each male fly represented an array of numbers, describing 8 parameters with regards to the 6 sexual activities, we established a two-dimensional matrix. Choosing health condition as the dependent variable, we used WizWhy 4.
Our analysis revealed that if at least one of the seven conditions holds for a given fly, it was healthy with a probability of However, if none of the seven conditions holds, there was Thus we were able to predict the health condition of Drosophila has been used extensively as a model for human brain diseases, mainly due to the simplicity of the experiments along with the similarity to humans.
Drosophila has a central nervous system containing orders of magnitude fewer neuronal and glial cells than in vertebrate central nervous systems, yet they share the same types of neurotransmitter systems such as GABA, glutamate, dopamine, serotonin, and acetylcholine, and they are able to perform complex behavior, including sexual displays, social behavior, and learning [ 32 ].
Courtship in Drosophila was studied and described in detail [ 20 , 33 — 36 ], but to the best of our knowledge, this is the first time that it is characterized in a PD fly model. We examined five essential components of the male's courtship ritual and suggest one new activity, NSE, and its inverse, SFI. In all traits, PD male flies performed worse. Surprisingly, NSE was the most well-represented characteristics in the if-and-only-if rules, composing 4 out of the 7 derived conditions.
Further study is needed to explore the relationship between courtship and sexual focus in male PD model flies. When compared to the well-established climbing assay, thoroughly reported as a convenient behavioral measure to determine neurological damage and aging in Drosophila flies [ 12 , 13 ], courtship is a more complex behavior to assay.
In courtship, the male must follow the female closely and engage in several coordinated behaviors, which is physically more demanding than simple climbing and which engages all the senses, as described previosly. Furthermore, the courtship abnormality is apparent at a much earlier age than the climbing deficiency. While at age 5—10 days the PD male flies court maximally, it takes approximately three weeks for the appearance of severe climbing phenotype in them Figure 2.
On the other hand, the climbing assay yields a binary score, pass or fail, whereas courtship must be evaluated quantitatively. Our results immediately suggest a follow-up experiment, evaluating behavior with the courtship assay at various ages post eclosion.
On balance, this behavioral assay provides a better evaluation of PD pathology dysfunction, and may allow assessment of dopaminergic dysfunction prior to loss of dopaminergic neurons, although the exact neuronal deficits underlying this behavioral phenotype need to be determined in follow-up studies. Interestingly, in the case of Fragile X, another brain disorder modeled in Drosophila , McBride et al. This was followed by studies in the mouse model and now clinical studies in afflicted patients [ 38 , 39 ].
Therefore, behavioral deficiencies during courtship in disease model flies can be an important and relevant assay for drug screening. Indexed in Science Citation Index Expanded. Subscribe to Table of Contents Alerts.
Table of Contents Alerts. Strains and Rearing We used three strains of Drosophila: Courtship Assay Flies used for the courtship assay were kept in an opaque box. Climbing Assay Currently, the only behavioral assay of PD model flies is the climbing test. PPI is abnormal in several human disorders, such as schizophrenia and major depression.
ASR and PPI test methods and responses are nearly identical in humans and rodents, offering homologous comparisons across species. We typically test animals using indirect dopaminergic agonists, specific dopamine D1 and D2 agonists and antagonists, cholinergic-muscarinic antagonists and glutamatergic-NMDA receptor antagonists. We also have experience using a variety of other agents for this test. This uses a labyrinthine maze with ten T-shaped cul-de-sacs branching from a central and circuitous channel leading from the start to the goal.
We record latency to find the escape and errors of commission entry into blind alleys. Recent studies we have conducted on this test demonstrate that it depends on neostriatal dopamine but not prefrontal cortex dopamine.
The test also is affected by dopamine in the nucleus accumbens but these are accompanied by changes in swimming performance in addition to learning per se and appear to arise from an interaction of motivation and associative factors.
The elevated zero EZP maze is used to test anxiety-like behavior. The maze has two open and two closed arms or quadrants closed sections have high, black acrylic walls.
Animals are tested for five minutes, and the time spent in the open areas provides the principal index of anxiety. The tests are video tracked and computer scored using AnyMaze software from Stoelting Instruments.
It also serves as a test of depression the Persolt test of swimming despair. The Persolt test evaluates swimming immobility after a training session in which the animal is placed in a cylinder half-filled with water. Passive avoidance uses the two-sided Gemini apparatus from San Diego Instruments. For this test, one side is lighted and the other side dark with a door in between. The animal is placed in the lighted side for a period of time, then the door is opened, and the animal is timed for how long it takes them to cross to the dark side.
Once they cross to the dark side, the door is closed and they are given a moderate, short, fixed-duration foot shock. They are then removed and tested for retention at different intervals after the first trial to see how long it takes them the second time to reenter the dark compartment. In some procedures trials are repeated until they learn to remain on the lighted side for 3 min whereas in 1-trial passive avoidance they are given only one training trail and retention is tested at some predetermined interval later to see how well they made the dark-shock association.
This test will show deficits in animals with hippocampal lesions if the lesion is of sufficient severity. This test evaluates the time it takes the test animal to move from light to dark areas in a divided test chamber, and dwell time between the two chambers. The test uses our photocell-equipped locomotor activity test chambers. This is the most widely used test for measuring spatial navigation and reference memory.
The test animal is placed in an open, circular pool in which there is a submerged platform. A series of tests can measure a variety of memory and navigation tasks, as the test animal swims to the platform from various locations, or tries to find the platform after it has been removed.
The animal is familiarized with two or more objects, and then is placed in a test space with one of the familiar objects changed to a novel object. We measure time spent exploring the novel object, that if sufficiently preferred by the animal is a reflection of intact memory for the original objects. This test places a grid of foreign objects marbles in a standard cage filled with bedding measured to a standard depth.
Animals are tested for 30 minutes, and the number of objects buried is recorded. This is a test of defensive anxiety. The test measures immobility in the animal by suspending it by the tail using an acrylic plate with a hole for the tail to pass through.
Once the animal determines that escape is impossible, it stops struggling. This test can show the effect of antidepressants and sedatives on the animal, and is often used to provide converging evidence for results from Forced Swim Testing FST. Animals are suspended for single trials of no more than six minutes, and the time spent immobile is manually recorded.
This test is available only for use with mice. Available Assays Show All. If the animal crosses to the opposite side from where they start, they avoid the shock; if they wait until the warning period is over, the shock is activated and they must escape to the opposite side. Two-way active avoidance is a classically conditioned response where the signal is the conditioned stimulus CS , the shock is the unconditioned stimulus US , escape is similar to an unconditioned response UR , and avoidance is a conditioned response CR.
Activity with Pharmacological Challenge Show. Cincinnati Water Maze Show. This test uses cued conditioning to evaluate amygdala function and contextual conditioning to evaluate hippocampal function Animals are first conditioned by pairing a neutral stimulus a tone to an aversive stimulus mild footshock in a specific environment.
Animal Behavior Core
Courtship, a stereotyped, ritualized behavior of Drosophila, involves . Courtship Assay. Flies used for the courtship assay were kept in an. Understand and describe common behavioral assays used in rodents, .. gait abnormalities and ataxia—abnormal muscle coordination (Figure ). Dipping. standardized behavioural assays in describing boldness, where each of the as- . Behavioural metrics as predictors of boldness axes.