The effects of serotonin and ecdysone on primary sensory neurons in crayfish

Robin L. Cooper, Elizabeth Ward, Recennah Braxton, Hao Li, Wendy M. Warren

Research output: Contribution to journalArticlepeer-review

16 Scopus citations


The overall behaviors and motivational states observed during social interactions and throughout the molting cycle of crayfish have been linked to the effects of humoral neuromodulators. Both serotonin (5-HT) and a molt-related hormone, 20-hydroxyecdysone (20-HE), are known to be present in the hemolymph of crustaceans. To determine if they alter the activity of a primary sensory neuron that monitors proprioceptive information, we examined their effects on the activity of the slow-adapting muscle receptor organ (MRO) of the crayfish abdomen, a model sensory system that has been extensively studied. 5-HT within the range of 100 nM to 1 μM, increases the firing frequency of the neuron during sustained stimulation. In experiments in which 20-HE was added alone, an increase in the firing frequency also occurred, although to a lesser degree than that for 5-HT at the same concentrations. When the MRO is first exposed to 20-HE, followed sequentially by 5-HT, the activity increases to about the same degree as in the reverse order of exposure. This outcome indicates that mixtures of these endogenous neuromodulators, at various levels, are more important in alternating behavior than the absolute level of any one of them introduced alone.

Original languageEnglish
Pages (from-to)336-345
Number of pages10
JournalMicroscopy Research and Technique
Issue number3
StatePublished - Feb 15 2003


  • Crustacean
  • Ecdysone
  • Neuromodulation
  • Proprioception
  • Serotonin

ASJC Scopus subject areas

  • Anatomy
  • Histology
  • Instrumentation
  • Medical Laboratory Technology


Dive into the research topics of 'The effects of serotonin and ecdysone on primary sensory neurons in crayfish'. Together they form a unique fingerprint.

Cite this