These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Muscarinic cholinoceptors that mediate pigment aggregation are present in the melanophores of cyprinids (Zacco spp.).
    Author: Hayashi H, Fujii R.
    Journal: Pigment Cell Res; 1993 Feb; 6(1):37-44. PubMed ID: 8502624.
    Abstract:
    Like melanophores of many teleosts, those of the dark chub, Zacco temmincki, and the common minnow, Z. platypus (Cyprinidae, Cypriniformes) responded to norepinephrine (NE) by the aggregation of pigment. It was further found that some melanophores were responsive to acetylcholine (ACh) in the same way. The response to NE was blocked by an alpha-adrenergic blocker, phentolamine, whereas the response to ACh was not. By contrast, two muscarinic cholinoceptor antagonists, namely, atropine and scopolamine, effectively blocked the action of ACh. The pigment aggregation due to the liberated sympathetic neurotransmitter was blocked by phentolamine but not by cholinergic blockers. These results suggest that, although the melanophores of these species are controlled in an orthodox manner by the sympathetic nervous system, some of them possess extra muscarinic cholinoceptors that also mediate the aggregation of pigment. The present report is the first to describe the presence of cholinoceptors on the chromatophores in species of fish other than those that belong to the order Siluriformes. The evolutionary implications of these findings are discussed.
    [Abstract] [Full Text] [Related] [New Search]