Effects of SSRI exposures early in life on juvenile and adult behavior in three-spine stickleback (Gasterosteus aculeatus) and possible effects in the Baltic Sea
Various drugs have been found in effluents from sewage treatment plants (STP). Swedish studies have demonstrated a wide spectrum of drugs with relative occurrence that to a high degree reflects their amounts of use in medical care. Aquatic organisms living downstream STPs are exposed chronically throughout their lifetime and possibly during several generations. As pharmaceutical drugs are designed to have biological effects there is an increasing concern about serious effects on behaviour and physiology in fish. In a recent study 66 pharmaceuticals were detected in effluents from Swedish STPs. Fifteen of the compounds were in the concentration range that with high probability can have pharmacological effects in fish. Three of these were selective-serotonin re-uptake-inhibitors (SSRIs), which are used in treatment of depressions by inhibition of the re-uptake of synaptic serotonin (5-HT) in the brain. Citalopram showed the highest concentrations among the detected SSRIs in effluents from Swedish STPs (up to 480 ng l-1) and was found in surface water. However, there are few studies addressing citalopram's possible effects on fish behavior. Recently we have observed behavioral effects of citalopram on adult three-spine stickleback (Gasterosteus aculeatus) females. We found anxiolytic effects in novel environments, increased boldness (taking more risks), decreased feeding and changes in behavior in shoaling tests. The fish were more "relaxed". The citalopram concentrations were in the range 0.07 – 7.8 µg l-1.The aim of the present study is to investigate if citalopram exposures of three-spine sticklebacks early in life result in behavior effects when they are older. Our hypothesis is that brief exposure to citalopram during early development affect stress related behaviors when they are adult. The effects may even be transmitted to the following generation (epigenetic effects). Advanced analyses of the brain will show if SSRI and stress will change expression of genes connected to the stress axis (HPI-axis) and neural differentiation that can be transmitted to the next generation. We will also investigate if stress connected behaviors of three-spine sticklebacks from STP contaminated locations in the Baltic Sea are affected in the same way as we have observed in the laboratory.