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Serotonin-induced brain glycogenolysis in rainbow trout (Oncorhynchus mykiss)

“…It is known that different brain areas are targets of stress and stress hormones (McEwen, 2007), causing changes in levels of brain glycogen (Cruz and Diniel, 2002;Herzog et al, 2008). Because different types of stress lead to changes in the serotonergic activity in both mammals (Morgan and Rudeen, 1976;Joseph and Kennett, 1981;Singh et al, 1994;Filipenko et al, 2002;Khanbabian et al, 2002) and fish (Winberg and Nilsson, 1993;Winberg and Lepage, 1998), the results allow us to hypothesize that in rainbow trout this neurotransmitter may be involved in the mobilization of brain glycogen deposits during situations of stress.…”

“…However, no studies have addressed the possible role of 5-HT in controlling the brain glycogen content in fish. Nonetheless, there is some indirect evidence that indicates a possible link between 5-HT and brain glycogen: (i) in fish, different types of stress can modify brain serotonergic activity (Winberg and Nilsson, 1993;Winberg and Lepage, 1998;Gesto et al, 2008) in a manner similar to that observed in mammals (Joseph and Kennet, 1981;Singh et al, 1994;Filipenko et al, 2002;Khanbabian et al, 2002), in which changes in 5-HT activity are consistent with changes in brain glycogen content (Cruz and Diniel, 2002;Herzog et al, 2008) and (ii) in a previous study (Tubío et al, 2010) we demonstrated that peripheral 5-HT is involved in the modulation of hepatic glycogenolysis in rainbow trout.…”