Gustatory receptor responses in marbled rockfish Sebastiscus marmoratus |
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| Authors: | JUN KOHBARA KAZUHIRO OOHARA TOMOYUKI MATSUDA IWAO HIDAKA KENJI TAKII HIDEMI KUMAI |
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| Institution: | ;Faculty of Bioresources, Mie University, Kamihama, Tsu, Mie 514-8507 and ;Fisheries Laboratory, Kinki University, Nachikatsuura, Wakayama 649-5145, Japan |
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| Abstract: | Gustatory response of marbled rockfish Sebastiscus marmoratus was recorded from the facial nerve supplying the anterior palate. In amino acids, the lowest threshold was for L -proline at 10?6–10?5 M; in ATP-related substances, the value for inosine was approximately 10?5 M and in organic acids, the value for L -lactic acid was approximately 10?6 M. An almost complete self-adaptation was observed for stimulants after 5 s application. While a weak solution of L -lactic acid as adapting stimulus depressed the response to it completely, it did not appreciably affect the response to 10-times or more concentrated L -lactic acid solution. In contrast to a weak solution, a moderate solution caused a severe depression of the response to stronger solutions, resulting in a shift of the dose–response curve towards a high concentration range. Time for recovery from adaptation differed depending on chemicals and stimulus duration: for 10?4 M L -lactic acid, it took about 2.3 and 4.5 s for 1/2 recovery of response magnitude under unadapted condition from the adaptation after 1 s- and 5 s-stimulation, respectively. L -Lactic acid and L -alanine strongly depressed the response to each other, yielding a rightward shift of the dose–response curve. A similar profound cross-adaptation was also observed between inosine and 5'-inosinic acid. The possible role of gustation is discussed. |
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| Keywords: | adaptation gustatory response inosine lactic acid marbled rockfish Sebastiscus marmoratus |
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