Glutamate and dopamine modulate synaptic plasticity in horizontal cell dendrites of fish retina.
Horizontal cell dendrites protruding into the cone pedicles in fish retina exhibit a light-dependent plasticity. In a light-adapted retina they form numerous spinules having membrane densities at their tips. These spinules disappear during dark adaptation. Experiments with light- or dark-adapted retinas which were incubated in glutamate or its agonists and antagonists, respectively, revealed that this putative cone transmitter is able to reduce the expression of spinules in a light-adapted retina. Dopamine, on the other hand, induces the formation of spinules in a dark-adapted retina and haloperidol reduces the expression in a light-adapted retina. These data suggest a control of spinules plasticity through two retinal neurotransmitter systems.
D000818:Animals; D002347:Carps / Q000502:physiology*; D003530:Cyprinidae / Q000502:physiology*; D003712:Dendrites / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D004298:Dopamine / Q000494:pharmacology*; D005971:Glutamates / Q000494:pharmacology*; D018698:Glutamic Acid; D006220:Haloperidol / Q000494:pharmacology; D066298:In Vitro Techniques; D007608:Kainic Acid / Q000494:pharmacology; D008029:Lighting; D008854:Microscopy, Electron; D009473:Neuronal Plasticity / Q000187:drug effects*; D012160:Retina / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D013569:Synapses / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure
D005971:Glutamates; D018698:Glutamic Acid; D006220:Haloperidol; D007608:Kainic Acid; D004298:Dopamine