Different receptors mediate the electrophysiological and growth cone responses of an identified neuron to applied dopamine

Neuroscience. 2006 Sep 15;141(4):1801-10. doi: 10.1016/j.neuroscience.2006.05.029. Epub 2006 Jun 27.

Abstract

Neurotransmitters are among the many cues that may guide developing axons toward appropriate targets in the developing nervous system. We have previously shown in the mollusk Lymnaea stagnalis that dopamine, released from an identified pre-synaptic cell, differentially affects growth cone behavior of its target and non-target cells in vitro. Here, we describe a group of non-target cells that also produce an inhibitory electrophysiological response to applied dopamine. We first determined, using pharmacological blockers, which receptors mediate this physiological response. We demonstrated that the dopaminergic electrophysiological responses of non-target cells were sensitive to a D2 receptor antagonist, as are known target cell responses. However, the non-target cell receptors were linked to different G-proteins and intracellular signaling pathways than the target cell receptors. Despite the presence of a D2-like receptor at the soma, the growth cone collapse of these non-target cells was mediated by D1-like receptors. This study shows that different dopamine receptor sub-types mediated the inhibitory physiological and growth cone responses of an identified cell type. We therefore not only provide further evidence that D2- and D1-like receptors can be present on the same neuron in invertebrates, but also show that these receptors are likely involved in very different cellular functions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials / drug effects
  • Action Potentials / physiology
  • Action Potentials / radiation effects
  • Analysis of Variance
  • Animals
  • Benzazepines / pharmacology
  • Dopamine / pharmacology*
  • Dopamine Antagonists / pharmacology
  • Drug Interactions
  • Electrophysiology / methods*
  • Enzyme Inhibitors / pharmacology
  • Estrenes / pharmacology
  • GABA Antagonists / pharmacology
  • Ganglia, Invertebrate / cytology
  • Growth Cones / drug effects*
  • Growth Cones / physiology*
  • Guanosine Diphosphate / analogs & derivatives
  • Guanosine Diphosphate / pharmacology
  • Lymnaea
  • Neurons / classification
  • Neurons / cytology
  • Neurons / drug effects*
  • Picrotoxin / pharmacology
  • Pyrrolidinones / pharmacology
  • Receptors, Neurotransmitter / classification
  • Receptors, Neurotransmitter / physiology*
  • Sulpiride / pharmacology
  • Thionucleotides / pharmacology

Substances

  • Benzazepines
  • Dopamine Antagonists
  • Enzyme Inhibitors
  • Estrenes
  • GABA Antagonists
  • Pyrrolidinones
  • Receptors, Neurotransmitter
  • Thionucleotides
  • 1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione
  • Picrotoxin
  • Guanosine Diphosphate
  • guanosine 5'-O-(2-thiodiphosphate)
  • Sulpiride
  • Dopamine