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ZFIN ID: ZDB-PUB-040706-1
Muscarinic acetylcholine receptors in the brain of the zebrafish (Danio rerio) measured by radioligand binding techniques
Williams, F.E., and Messer, W.S. Jr.
Date: 2004
Source: Comparative biochemistry and physiology. Toxicology & pharmacology : CBP 137(4): 349-353 (Journal)
Registered Authors: Williams, Fred
Keywords: none
MeSH Terms:
  • Animals
  • Brain/metabolism*
  • Kinetics
  • Muscarinic Agonists/metabolism
  • Muscarinic Agonists/pharmacology
  • Muscarinic Antagonists/metabolism
  • Muscarinic Antagonists/pharmacology
  • Radioligand Assay
  • Receptors, Muscarinic/metabolism*
  • Zebrafish/metabolism*
PubMed: 15228953 Full text @ Comp. Biochem. Physiol. C Toxicol. Pharmacol.
Muscarinic acetylcholine receptors (mAChRs) play a role in learning, memory and behavior in vertebrate animals. We measured the muscarinic cholinergic receptor levels in extracts from zebrafish (Danio rerio) brain by radioligand binding techniques. Saturation binding experiments with the radioligand [3H]-quinuclidinyl benzilate (QNB) were used to determine receptor number and relative affinity for several agonists and antagonists. Affinity at zebrafish brain receptors was relatively high with a K(d) of 40 +/- 5 pM. The number of receptors, represented by Bmax, was 63 +/- 16 fmol/mg protein. Oxotremorine and carbachol, agonists at muscarinic acetylcholine receptors, bound with displacement curves indicating multiple binding sites. In addition, oxotremorine bound with a higher affinity than did carbachol. The antagonist potency profile at zebrafish receptors in brain was determined to be atropine>>pirenzipine>p-fluoro-hexahydro-sila-difenidol>>otenzepad. The results obtained with zebrafish brain compare favorably to those found in insect, fish and mammalian species. Taken together, the binding results and favorable comparisons to mammalian systems indicate that zebrafish may provide a useful model organism for evaluating the role of cholinergic systems in learning, memory and behavior.