Using Zebrafish as a Model to Evaluate Anxiety

My laboratory uses zebrafish as a model organism and focuses on assessment of anxiety in the fish. Zebrafish are easily maintained and have the ability to absorb substances through their gills, eliminating any stress induced by the traditional method of injections. Zebrafish, as vertebrates, have complexity that is useful for behavioral models. Their social structure and conditioned behaviors are being carefully characterized. Relevant to these studies, the Danios’ behavior in a novel dive tank has been demonstrated to correspond to their anxiety. (Anxious fish spend more time near the bottom of the tank while control fish spend more time near the surface.) Using this behavioral assay, fish were treated with chemicals or light, and their relative anxiety was measured. Caffeine was able to reduce anxiety at low concentrations, but the effect was reversed at higher doses. Treatment with blue light increased anxiety while exposure to orange light reduced anxious behaviors in the fish

Utilizing The Zebrafish species, Danio rerio, to assess the effect of acute treatment with St. John’s Wort Supplements on Anxiety as measured by the Novel Dive Tank Test

Background: The zebrafish species, Danio rerio, is a widely utilized model organism with well-characterized behaviors including anxiety-like behavior when placed into a novel environment. In addition, the fish can be treated with substances by immersion. St. John’s Wort has been suggested as a plant-based treatment for depression and anxiety because it contains compounds that inhibit the serotonin transporter (SERT) among other effects. A number of St. John’s Wort supplements are commercially available. The National Institute of Mental Health (NIMH) estimates that about 19% of US adults suffer an anxiety disorder each year and about 31% will experience an anxiety disorder in their lifetime. Clearly effective, inexpensive, and readily available treatments for anxiety represent an important area of research. Objectives: Assess the ability of acute treatment with St. John’s Wort to reduce anxiety-like behavior in zebrafish. Method: Zebrafish will be treated by immersion in a solution of St. John’s Wort supplements and assessed for anxiety in the Novel Dive Tank (NDT) Test. Results: Acute treatment with St. John’s Wort supplements increased anxiety as measured using the NDT. Conclusions: Acute treatment with the water-soluble constituents of St. John’s Wort supplements tested did not reduce apparent anxiety in the fish. Future studies will utilize a longer treatment time and more hydrophobic solvents

Graduate and Undergraduate Faculty Collaboration Utilizing Peer Observation to Enhance Educational Opportunities for Students and Faculty: A Case Example

While evidence supports the use of cadavers to facilitate the teaching and learning of human anatomy, cadaver-based teaching may not be present at the undergraduate level at many institutions due to limited laboratory access, financial constraints, and the lack of qualified faculty trained to teach in this type of setting.  The following case example outlines a unique program designed to provide cadaver-based instruction to undergraduate students, while simultaneously training undergraduate faculty to teach in this setting through peer observational methods. More specifically, the following teaching collaboration was designed with the intent to achieve the following: 1) expose undergraduate anatomy students to cadaver-based learning; 2) provide education and training to undergraduate faculty so they are better qualified to teach human anatomy in the context of a cadaver laboratory; 3) provide graduate physical therapy students additional opportunities to dissect and reinforce their anatomy knowledge; and 4) demonstrate the value of interdisciplinary collaboration.  Eighty-one undergraduate students were exposed to the cadaver laboratory for four educational sessions throughout the semester. Course evaluations revealed that 93% of the undergraduate students reported that their experiences in the cadaver laboratory served to enhance their learning, and 97% reported that the use of human cadavers should be continued in future courses. This interdisciplinary model allowed anatomy instruction to be expanded to previously unserved student groups as well as provided a mechanism for professional development of undergraduate anatomy faculty. This model may serve as a template to promote new program development to enhance faculty and student learning, while simultaneously encouraging interdisciplinary collaboration across the university. Keywords: interdisciplinary, peer observation, pedagogy, anatomy, cadave

Pharmacological effects of Crocus Sativus (Saffron) on Memory and Anxiety

The Crocus Sativus flower gives rise to the Saffron spice which contains five active ingredients known as crocin, crocetin, picrocrocin and safranal. The rich antioxidant containing components of Saffron have been shown to cross the blood brain barrier by passive transcellular diffusion, making them effective in relation to treating neurological disorders. In order to test the effects of Saffron on memory and anxiety, Zebrafish Danio Rerio were placed into two groups and put through a series of assessments including a three compartment memory tank and a dive tank. Zebrafish continue to be at the forefront of behavioral and pharmacological studies due to their ability to display real time effects of substances in the environment. Many strong similarities have been drawn between zebrafish’s neuroanatomy and physiology in comparison to mammals, making them a reliable tool in assessing environmental toxicity. Zebrafish have shown to be a great asset in drug screenings and preclinical trials due to their sensitivity to pharmacological stimulants and fast phenotypic responses. Saffron was administered to a test group via skin absorption, while the control group was transported directly from their habitat to the assessment tanks. The three compartment memory tank consisted of a middle, right, and left chamber separated by movable dividers. Subjects were initially placed in the center compartment and given a choice of swimming either towards the right or left sections. The two sides of the tank contained visual cues which included photos of shapes taped to the wall. The choice of swimming towards the correct compartment was rewarded by the subject being reunited with their tank mates; while making the incorrect decision led to adverse stimuli such as reduction of swim area. Subject memory was tested by their ability to promptly swim towards the intended side during each trial. It was hypothesized that subjects in the test group will learn to swim in the correct compartment significantly faster than the control group. The anxiety evaluation was conducted by individually placing subjects from the control and test groups into a dive tank. The dive tank utilizes vertical distribution in a novel environment to measure the behavioral response in Zebrafish. Once placed in the tank, the subjects will combat their inherent nature of seeking protection in an open environment. During each trial, subject movements, behavior, and activity were tracked and analyzed by the Nolds Ethovision software. It was hypothesized that Saffron dosed Zebrafish will show a reduction in anxiety by increasing their vertical swimming and exploration significantly faster than those in the control groups

The Effects of Delta-8-tetrahydrocannabinol on Danio rerio

Delta-8-tetrahydrocannabinol (THC), although less potent than THC, can still reduce memory cognition and anxiety. However, Delta-8 can have adverse effects at high doses, like inducing anxiety, confusion, and hallucinations. The brain of Danio rerio (zebrafish) resembles human neuroanatomical and neurochemical pathways and demonstrates robust behavioral phenotypes, making zebrafish an excellent model organism for memory and anxiety. Subjects will be fed 5mg of Delta 8-THC before entering the experimental apparatus. Fish for both memory and anxiety tests will be observed and recorded through Noldus Ethovision Software. For testing memory, five female and five male zebrafish will be individually placed in a three-compartment memory tank. One side of the memory tank will have a star shape, while the other side will have a circle shape. About .83mg of commercial fish flakes will be administered to the fish on the circle side in the first trial, then on the star side in the second trial, and will continue on either side for 20 trials. Correct responses will be scored when the fish are present on the side of the tank used to present the fish flakes. We hypothesize that there will be fewer correct responses for fish fed with Delta-8-THC than the control. For testing anxiety, ten male and female zebrafish will be fed 5mg of Delta 8-THC before entering the diving tank. Typically, zebrafish experiencing anxiety will stay at the bottom of the diving tank, but if they are relaxed, they will be at the top. We hypothesize that fish fed with Delta-8-THC will spend more time at the top of the diving tank than the control