7?-Hydroxypregnenolone, a key neuronal modulator of locomotion, stimulates upstream migration by means of the dopaminergic system in salmon.

ABSTRACT: Salmon migrate upstream against an opposing current in their natal river. However, the molecular mechanisms that stimulate upstream migratory behavior are poorly understood. Here, we show that 7?-hydroxypregnenolone (7?-OH PREG), a newly identified neuronal modulator of locomotion, acts as a key factor for upstream migration in salmon. We first identified 7?-OH PREG and cytochrome P450 7?-hydroxylase (P4507?), a steroidogenic enzyme producing 7?-OH PREG, in the salmon brain and then found that 7?-OH PREG synthesis in the brain increases during upstream migration. Subsequently, we demonstrated that 7?-OH PREG increases upstream migratory behavior of salmon. We further found that 7?-OH PREG acts on dopamine neurons in the magnocellular preoptic nucleus during upstream migration. Thus, 7?-OH PREG stimulates upstream migratory behavior through the dopaminergic system in salmon. These findings provide new insights into the molecular mechanisms of fish upstream migration.

SUBMITTER: Haraguchi S 

PROVIDER: S-EPMC4518220 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature