Immunolocalization suggests a role of the histamine‐gated chloride channel PxHCLB in spectral opponent processing in butterfly photoreceptors. Issue 4 (12th November 2018)

• Record Type: Journal Article
• Authors: Chen, Pei‐Ju; Matsushita, Atsuko; Wakakuwa, Motohiro; Arikawa, Kentaro
• Is Part Of: Journal of comparative neurology. Volume 527:Issue 4(2019)
• Page Start: 753
• Page End: 766
• Publication Date: 2018-11-12
• Subjects: compound eye -- histamine receptor -- insect -- lamina -- medulla -- photoreceptor -- RRID:AB_260435 -- RRID:AB_2737352 -- RRID:AB_2737353 -- RRID:AB_2737354 -- RRID:AB_528479; Comparative neurobiology -- Periodicals; Neurology -- Periodicals; 616
• DOI: 10.1002/cne.24558
• Languages: English
• ISSNs: 0021-9967

Abstract

Abstract: Spectrally opponent responses, that is, wavelength‐dependent inversions of response polarity, have been observed at the level of photoreceptors in butterflies. As inter‐photoreceptor connections have been found in the butterfly Papilio xuthus, and histamine is the only neurotransmitter so far identified in insect photoreceptors, we hypothesize that histaminergic sign‐inverting synapses exist in the lamina between different spectral receptors as a mechanism for spectral opponency as in the medulla of Drosophila . Here, we localized two histamine‐gated chloride channels, PxHCLA ( Drosophila Ort homolog) and PxHCLB ( Drosophila HisCl1 homolog), in the visual system of Papilio xuthus by using specific antisera. The antiPxHCLA labeling was associated with the membrane of nonphotoreceptor cells that are postsynaptic to photoreceptors, while the antiPxHCLB labeling overlapped with photoreceptor axons, indicating that PxHCLB is expressed at inter‐photoreceptor synapses: PxHCLB is likely involved in producing spectral opponency at the first visual synapses. Color processing in Papilio may appear earlier than previously hypothesized in insect visual systems. Abstract : Two histamine‐gated chloride channels, PxHCLA ( Drosophila Ort homolog) and PxHCLB (HisCl1 homolog), were localized in the spectrally‐rich visual system of a butterfly Papilio . PxHCLA was detected in nonphotoreceptor cells postsynaptic to photoreceptors. PxHCLB was detected at inter‐photoreceptor synapses, likely producing spectral opponency in photoreceptors even in the lamina.