title: Olfactory stimulation selectively modulates the OFF pathway in the retina of zebrafish.
abstract: Cross-modal regulation of visual performance by olfactory stimuli begins in the retina, where dopaminergic interneurons receive projections from the olfactory bulb. However, we do not understand how olfactory stimuli alter the processing of visual signals within the retina. We investigated this question by in vivo imaging activity in transgenic zebrafish expressing SyGCaMP2 in bipolar cell terminals and GCaMP3.5 in ganglion cells. The food-related amino acid methionine reduced the gain and increased sensitivity of responses to luminance and contrast transmitted through OFF bipolar cells but not ON. The effects of olfactory stimulus were blocked by inhibiting dopamine uptake and release. Activation of dopamine receptors increased the gain of synaptic transmission in vivo and potentiated synaptic calcium currents in isolated bipolar cells. These results indicate that olfactory stimuli alter the sensitivity of the retina through the dopaminergic regulation of presynaptic calcium channels that control the gain of synaptic transmission through OFF bipolar cells.
authors.affiliation: Laboratory of Molecular Biology, Medical Research Council, Cambridge CB2 0QH, UK.
authors.forename: Federico
authors.initials: F
authors.lastname: Esposti
authors.forename: Jamie
authors.initials: J
authors.lastname: Johnston
authors.forename: Juliana M
authors.initials: JM
authors.lastname: Rosa
authors.forename: Kin-Mei
authors.initials: KM
authors.lastname: Leung
authors.forename: Leon
authors.initials: L
authors.lastname: Lagnado
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D001552:Benzazepines / Q000494:pharmacology; D018491:Dopamine Agonists / Q000494:pharmacology; D018492:Dopamine Antagonists / Q000494:pharmacology; D008715:Methionine; D009812:Odorants; D009830:Olfactory Bulb / Q000187:drug effects / Q000378:metabolism*; D011954:Receptors, Dopamine / Q000378:metabolism; D012160:Retina / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D051245:Retinal Bipolar Cells / Q000187:drug effects / Q000378:metabolism*; D012903:Smell / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology; D013764:Tetrahydronaphthalenes / Q000494:pharmacology; D015027:Zebrafish / Q000378:metabolism*
chemical_list: D001552:Benzazepines; D018491:Dopamine Agonists; D018492:Dopamine Antagonists; D011954:Receptors, Dopamine; C534628:SCH 23390; D013764:Tetrahydronaphthalenes; C011639:ADTN; D008715:Methionine