Serotonin modulates the voltage dependence of delayed rectifier and Shaker potassium channels in Drosophila photoreceptors

Neuron. 1995 Apr;14(4):845-56. doi: 10.1016/0896-6273(95)90228-7.


We describe the in situ modulation of potassium channels in a semi-intact preparation of the Drosophila retina. In whole-cell recordings of photoreceptors, rapidly inactivating Shaker channels are characterized by a conspicuously negative voltage operating range; together with a delayed rectifier, these channels are specifically modulated by the putative efferent neurotransmitter serotonin. Contrary to most potassium channel modulations, serotonin induced a reversible positive shift in the voltage operating range, of +30 mV for the Shaker channels and +10-14 mV for the delayed rectifier. The maximal current amplitudes were unaffected. Modulation was not affected by the subunit-specific Shaker mutations ShE62 and T(1;Y)W32 or a null mutation of the putative modulatory subunit eag. The modulation of both channels was mimicked by intracellularly applied GTP gamma S.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Drosophila melanogaster / physiology*
  • Electric Conductivity
  • Guanosine 5'-O-(3-Thiotriphosphate) / pharmacology
  • Mutation
  • Photoreceptor Cells, Invertebrate / physiology*
  • Potassium Channels / drug effects
  • Potassium Channels / genetics
  • Potassium Channels / physiology*
  • Retina / chemistry
  • Serotonin / pharmacology*


  • Potassium Channels
  • Serotonin
  • Guanosine 5'-O-(3-Thiotriphosphate)