Selective serotonin reuptake inhibitors (SSRI’s), commonly known as anti-depressants or anti- anxiety medication, have a wide variety of side effects. One of the most common side effects in users is sexual dysfunction, or a change in sexual behavior. The cause of sexual dysfunction by SSRI’s is unknown. However, evidence suggests that SRRI’s activate serotonin 2 receptors, and stimulates serotonin 1A, 1B, & 1C receptors (Meston and Frohlich 2000). Activation of serotonin 2 impairs sexual function, stimulation of serotonin 1A lowers the threshold for ejaculation, and receptors 1B & 1C inhibit sexual behaviors (Meston and Frohlich 2000). Fluoxetine, an SSRI, is the active ingredient in Prozac and has recently been discovered in the surface water of many streams that are the habitat to different species of fish (Foran et al. 2004). In aquatic systems, such as ponds and rivers, Fluoxetine has been found anywhere from 12 to 540 ng/L (Mennigen 2010). In a study done, on the reproduction of male gold fish a decrease in circulating testosterone levels after exposure to Fluoxetine was found (Mennigen 2010). Introduction Does Fluoxetine hydrochloride effect the sexual reproduction of male zebrafish? Question The impact of fluoxetine hydrochloride on sexual reproduction in male zebrafish (Danio rerio) Cassie Willman Department of Biology, York College MethodsConclusions 1.There is a slight trend that the fluoxetine hydrochloride treated group was less successful in breeding (30% success) than the control group (42% success). 2.However, statistically there was no significant difference in breeding occurring or not occurring in both the treated and control groups. 3.In addition, the embryos did not have any better chance of survival whether they came from the fluoxetine treated group or the control group. Male and Female zebrafish seperated and put into 4 tanks. Male zebrafish were placed into tupperware containers with (6µg/mL) or without fluoxetine for 3 hours. Male and Female zebrafish were placed into breeding tanks overnight. Male and Female were given 3 hours to breed the following morning. Embryos were collected from tanks and washed in 0.001% bleach and 10% HBSS. Data Collected: Did the fish breed? How many embryos were alive and dead? After 24 hours? Results Figure 1. Effects of fluoxetine hydrochloride on the breeding of male zebrafish (Danio rerio). Fluoxetine appeared to have little effect on whether or not breeding occurred (Fisher's exact, p=0.5204). Sample size was n=20 for fluoxetine treated group and n=21 for control. Figure 2. Percent survival rate of embryos after 24 hours from male zebrafish (Danio rerio) who were either treated with fluoxetine hydrochloride or were not. Unpaired t-test (means wtih 95% CI) was used for analysis. There was no significant difference found between the treated (n=20) and non-treated (n=21) male zebrafish offspring percentage of survival after 24 hours (p=0.1813). Future Studies This experiment could be done with a longer exposure time to fluoxetine. The longer exposure time could be accompanied by a smaller concentration closer to that found in the environment. Another component that could be examined is sperm release and testoserone levels of the male zebrafish. Literature Cited Foran, C., Weston, J., Slattery, M., Brooks, B., and Hugget, D Reproductive assesment of Japanese Medaka (Oryzias Latipes) Following a Four-Week Fluoxetine (SSRI) Exposure. Environmental Contamination and Toxicology 46: Mennigen, J., Lado, W., Zamora, J., Duarte-Guterman, P., Langlois, V., Metcalfe, C., Chang, J., Moon, T., and Trudeau, V Waterborne fluoxetine disrupts the reproductive axis in sexually mature goldfish, Carassius auratus. Aquatic Toxicology 100: Meston, C., and Frohlich, P. The Neurobiology of Sexual Function. Arch Gen Psychology Acknowlegements I would like to thank Dr. Boehmler and Dr. Haggerty for their help in the completion of this project. I would also like to thank the York College of Pennsylvania Biology Department for their support