Haloperidol suppresses light-induced spinule formation and biphasic responses of horizontal cells in fish (roach) retina

Neurosci Lett. 1989 Dec 15;107(1-3):200-4. doi: 10.1016/0304-3940(89)90817-3.


In retinae of lower vertebrates, negative feed-back interactions between horizontal cells (second-order neurones), and cone photoreceptors lead to generation of spectrally multi-phasic light-evoked responses (S-potentials) in horizontal cells. Spinules (finger-like extensions of horizontal cell dendrites) have been suggested to mediate these interactions in retinae of teleost fish. We have studied whether prevention of light-dependent spinule formation would indeed affect an S-potential component (the red-sensitive depolarization in H2 horizontal cells), known to depend on such negative feed-back. Haloperidol was used as a dopamine antagonist to suppress light-induced formation of spinules in retinae of the cyprinid fish, the roach. In normal (untreated) retinae, biphasic S-potentials were strongly depolarizing and horizontal cell dendrites possessed abundant spinules. However, following application of haloperidol to the vitreous prior to light adaptation, spinule formation was suppressed, and concomitantly, red-sensitive depolarizing S-potentials remained significantly under-developed. The results are consistent, therefore, with the idea that spinules mediate the negative feed-back interaction between horizontal cells and cones.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cyprinidae / physiology*
  • Dopamine / metabolism
  • Dopamine / physiology*
  • Dopamine Antagonists
  • Haloperidol / pharmacology*
  • Membrane Potentials / drug effects
  • Photic Stimulation
  • Retina / drug effects
  • Retina / physiology*


  • Dopamine Antagonists
  • Haloperidol
  • Dopamine