Andrew Dittman Fishery Biologist Northwest Fisheries Science Center National Marine Fisheries Service 2725 Montlake Blvd. East Seattle, WA 98112 Phone: 206-860-3392 Fax: 206-860-3467 Email:andy.dittman@noaa.gov   Ph.D. 1994, University of Washington, School of Fisheries & the Department of Pharmacology RESEARCH INTERESTS: Salmon Homing & Impringting RESEARCH SUMMARY: Pacific salmon are well known for their ability to learn (or imprint) to odors associated with their natal stream as juveniles and then later use these retained odor memories to guide the final phases of their home-stream migration. The imprinting process is critical for successful completion of the spawning migration and salmon that do not experience their natal water during appropriate juvenile stages are more likely to stray to non-natal sites. Reintroduction of captively-reared fish into the wild at inappropriate developmental periods or insufficient periods of exposure to appropriate olfactory cues may result in elevated levels of straying. To determine the critical period(s) for imprinting, juvenile salmon are being exposed to known odorants at key developmental stages and are subsequently tested for development of long-term memories of these odorants using molecular, electrophysiological, and behavioral assays. Results from these studies will help develop captive broodstock reintroduction and hatchery release strategies that will minimize straying.   REPRESENTATIVE PUBLICATIONS: Dittman A. 2005 Chemical cues for sea lamprey migration. Nat Chem Biol. 1(6):316-7. Hendry, A.P., Dittman, A.H. and R.W. Hardy. 2000. Proximate composition, reproductive development, and a test for trade-offs in captive sockeye salmon. Transactions of the American Fisheries Society. 129:1082-1095. Kumar, R.S., Ijiri, S., Kight, K., Swanson, P., Dittman, A.H., Alok, D., Zohar, Y. and J.M. Trant. 2000. Cloning and functional expression of a thyrotropin receptor from the gonads of a vertebrate (bony fish): potential thyroid-independent role for thyrotropin in reproduction. Molecular and Cellular Endocrinology, 167:1-9. Speca, D. J., Lin, D. M., Sorensen, P. W., Isacoff, E. I., Ngai, J. and A. H. Dittman. 1999. Functional identification of a goldfish odorant receptor. Neuron 23:487-498. Nevitt, G. A, and A. H. Dittman 1998. A new model for olfactory imprinting in salmon. Integrative Biology. 1:215-223. Dittman, A. H., Quinn, T. P. and E. C. Volk 1998. Is the distribution, growth and survival of juvenile salmonids sex-biased? Negative results for coho salmon in an experimental stream channel. Journal of Fish Biology. 53:1360-1364. Dittman, A. H., Brown, G. S. and C. J. Foote. 1998. The role of chemoreception in salmon-egg predation by coastrange (Cottus aleuticus) and slimy (C. cognatus) sculpins in Iliamna Lake, Alaska. Canadian Journal of Zoology. 76:406-413 Dittman, A. H., Quinn, T. P., Nevitt, G.A., Hacker, B. and D. R. Storm. 1997. Sensitization of olfactory guanylyl cyclase to a specific odorant in coho salmon. Neuron 19:381-389. Swanson, P. and Dittman, A. 1997. Pituitary gonadotropins and their receptors in fish. In, "Advances in Comparative Endocrinology", S. Kawashima and S. Kikuyama, eds., Monduzzi Editore, Bologna, Italy. pp. 841-846. Dittman, A. H., Quinn, T. P. and G. A. Nevitt. 1996. Timing of imprinting to natural and artificial odors by coho salmon (Oncorhynchus kisutch). Canadian Journal of Fisheries and Aquatic Sciences. 53:434-442. Dittman, A. H. and T. P. Quinn. 1996. Pacific salmon homing: mechanisms and ecological basis. Journal of Experimental Biology. 199:83-91. Nevitt, G. A., Dittman, A. H., Quinn, T. P. and W. Moody. 1994. Evidence for a peripheral olfactory memory in imprinted salmon. Proceedings of the National Academy of Sciences, USA. 91:4288-4292. Dittman, A. H., Quinn, T. P., Dickhoff, W. W. and D. A. Larsen. 1994. Interactions between novel water, thyroxine and olfactory imprinting in underyearling coho salmon, Oncorhynchus kisutch (Walbaum). Aquaculture and Fisheries Management. 25:157-169. Dittman, A. H., and T. P. Quinn. 1994. Avoidance of a putative pheromone, 17a,20b-dihydroxy-4-pregnen-3-one, by precociously maturing male chinook salmon, Oncorhynchus tshawytscha. Canadian Journal of Zoology. 72:215-219. Dittman, A. H., Weber, J. P., Hinds, T. R., Choi, E.-J., Migeon, J. C., Nathanson, N. M. and D. R. Storm. 1994. A novel mechanism for coupling of m4 muscarinic acetylcholine receptors to calmodulin-sensitive adenylyl cyclases: cross-over from G protein-coupled inhibition to stimulation. Biochemistry. 33:943-951. Duhe, R. J., Nielson, M. D., Dittman, A. H., Villacres, E. C., Choi, E.-J. and D. R. Storm. 1994. Oxidation of critical cysteine residues of type I adenylyl cyclase by o-iodosobenzoate or nitric oxide reversibly inhibits stimulation by calcium and calmodulin. Journal of Biological Chemistry. 269: 7290-7296.