Serotonin and nitric oxide interaction in the control of bioluminescence in northern krill, Meganyctiphanes norvegica (M. Sars)

• Published in: Journal of Experimental Biology
• Main Authors: Kronstrom, Jenny, Dupont, Samuel, Mallefet, Jérôme, Thorndyke, Michael, Holmgren, Susanne
• Other Authors: UCL - AGRO/BAPA - Département de biologie appliquée et des productions agricoles
• Format: Article in Journal/Newspaper
• Language: English
• Published: Company Of Biologists Ltd 2007
• Subjects: bioluminescence; 5-HT; Meganyctiphanes norvegica; nitric oxide; nitric oxide synthase; krill; BRC; ELIB; QH301; Northern krill
• Online Access: http://hdl.handle.net/2078.1/37334; https://doi.org/10.1242/jeb.002394

The role of nitric oxide ( NO) in the control of bioluminescence ( light production) in the crustacean Meganyctiphanes norvegica ( krill) was investigated using pharmacological and immunohistochemical methods. All nitrergic drugs tested failed to induce bioluminescence per se but modulated light production stimulated by 5-hydroxytryptamine (5-HT). NO donors [ sodium nitroprusside ( SNP) and S-nitroso-N-acetylpenicillamine ( SNAP)] injected in live specimens significantly reduced light production stimulated by 5-HT, whereas inhibition of the enzyme NO synthase ( NOS) with L-NAME (N-G-nitro-L-arginine methyl ester) resulted in an enhancement of the 5-HT response. The effects of NO do not seem to be mediated via production of cGMP as injections of a cGMP analogue (8-Bromoguanosine 3',5'-cyclic monophosphate) gave inconclusive effects on the 5-HT-stimulated light response. Inhibition of cGMP production with ODQ (1H-[1,2,4] oxadiazolo[4,3-a] quinoxalin-1-one) did not affect the light response. Moreover, a few individuals showed a considerably higher response to 5-HT in April and June compared with specimens collected in the autumn and winter. Furthermore, both NOS-like and 5-HT-like materials were detected by immunohistochemistry inside the light organs. NOS-like immunoreactivity was primarily observed in structures associated with vessels inside the light organs, whereas 5-HT-like material was abundant in nerve fibres throughout the whole light organ. The results suggest that NO has a modulatory role at several levels in the control of light production in M. norvegica and that NO and 5-HT interact in this regulation.