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Evidence That Thyroid Hormone Induces Olfactory Cellular Proliferation In Salmon During A Sensitive Period For Imprinting, Sean C. Lema, Gabrielle A. Nevitt

Biological Sciences

Salmon have long been known to imprint and home to natal stream odors, yet the mechanisms driving olfactory imprinting remain obscure. The timing of imprinting is associated with elevations in plasma thyroid hormone levels, with possible effects on growth and proliferation of the peripheral olfactory system. Here, we begin to test this idea by determining whether experimentally elevated plasma levels of 3,5,3′-triiodothyronine (T₃) influence cell proliferation as detected by the 5-bromo-2′-deoxyuridine (BrdU) cell birth-dating technique in the olfactory epithelium of juvenile coho salmon (Oncorhynchus kisutch). We also explore how natural fluctuations in thyroxine (T₄) …