ATP depletion inhibits retraction of chromatophores induced by GABA in cephalopod Todarodes pacificus

作者：Kinoshita Yasunori; Kato Sanae^*; Yoshioka Takeya; Konno Kunihiko

来源：Fisheries Science, 2013, 79(4): 605-610.

DOI：10.1007/s12562-013-0630-9

• ATP
• Chromatophore
• GABA
• L-Glutamate
• Motility
• Neurotransmitter
• Squid
• Retraction

Color changes in cephalopods are generated by the expansion or retraction of chromatophores located under the dermis. The behavior of the chromatophores is regulated by neurotransmitters; l-glutamate (l-Glu) is an excitatory transmitter that causes the chromatophores to expand. To date, serotonin [5-hydroxytryptamine (5-HT)] is the only neurotransmitter known to stimulate retraction of chromatophores. We found that the chromatophores in the Japanese squid Todarodes pacificus were regulated by gamma-aminobutyric acid (GABA), an inhibitory neurotransmitter, and that GABA caused expanded chromatophores to retract. We also found that adenosine 5%26apos;-triphosphate (ATP) concentrations in skin samples remained stable at their initial values for more than 24 h after the death of each squid; therefore, the chromatophores could respond to both l-Glu and GABA during that period. Furthermore, we attempted to reduce the levels of ATP by storing skin sample in sodium azide solution. The chromatophores in sodium azide-treated skin samples were induced to expand by l-Glu, but these expanded chromatophores could not be induced to retract by GABA. Based on these observations, we conclude that ATP is essential for retraction, but not expansion, of chromatophores.

• 出版日期2013-7