Long-term plasticity mediated by mGluR1 at a retinal reciprocal synapse.
The flow of information across the retina is controlled by reciprocal synapses between bipolar cell terminals and amacrine cells. However, the synaptic delays and properties of plasticity at these synapses are not known. Here we report that glutamate release from goldfish Mb-type bipolar cell terminals can trigger fast (delay of 2-3 ms) and transient GABA(A) IPSCs and a much slower and more sustained GABA(C) feedback. Synaptically released glutamate activated mGluR1 receptors on amacrine cells and, depending on the strength of presynaptic activity, potentiated subsequent feedback. This poststimulus enhancement of GABAergic feedback lasted for up to 10 min. This form of mGluR1-mediated long-term synaptic plasticity may provide retinal reciprocal synapses with adaptive capabilities.
Vigh
Jozsef
J
The Vollum Institute, Oregon Health and Science University, 3181 S.W. Sam Jackson Park Road, Portland, Oregon 97239, USA.
Li
Geng-Lin
GL
Hull
Court
C
von Gersdorff
Henrique
H
D000818:Animals; D006054:Goldfish; D009473:Neuronal Plasticity / Q000502:physiology*; D009924:Organ Culture Techniques; D018408:Patch-Clamp Techniques; D018079:Receptors, GABA / Q000378:metabolism; D018094:Receptors, Metabotropic Glutamate / Q000378:metabolism*; D012160:Retina / Q000502:physiology*; D013569:Synapses / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D018079:Receptors, GABA; D018094:Receptors, Metabotropic Glutamate; C104077:metabotropic glutamate receptor type 1; D005680:gamma-Aminobutyric Acid