title: Insect photoreceptor adaptations to night vision.
abstract: Night vision is ultimately about extracting information from a noisy visual input. Several species of nocturnal insects exhibit complex visually guided behaviour in conditions where most animals are practically blind. The compound eyes of nocturnal insects produce strong responses to single photons and process them into meaningful neural signals, which are amplified by specialized neuroanatomical structures. While a lot is known about the light responses and the anatomical structures that promote pooling of responses to increase sensitivity, there is still a dearth of knowledge on the physiology of night vision. Retinal photoreceptors form the first bottleneck for the transfer of visual information. In this review, we cover the basics of what is known about physiological adaptations of insect photoreceptors for low-light vision. We will also discuss major enigmas of some of the functional properties of nocturnal photoreceptors, and describe recent advances in methodologies that may help to solve them and broaden the field of insect vision research to new model animals.This article is part of the themed issue 'Vision in dim light'.
authors.affiliation: Nano and Molecular Systems Research Unit, Faculty of Science, University of Oulu, Oulu, Finland.
authors.forename: Anna
authors.initials: A
authors.lastname: Honkanen
authors.affiliation: Nano and Molecular Systems Research Unit, Faculty of Science, University of Oulu, Oulu, Finland.
authors.forename: Esa-Ville
authors.identifier: http://orcid.org/0000-0002-5576-0627
authors.initials: EV
authors.lastname: Immonen
authors.affiliation: Nano and Molecular Systems Research Unit, Faculty of Science, University of Oulu, Oulu, Finland.
authors.forename: Iikka
authors.initials: I
authors.lastname: Salmela
authors.affiliation: Nano and Molecular Systems Research Unit, Faculty of Science, University of Oulu, Oulu, Finland kyosti.heimonen@oulu.fi.
authors.forename: Kyösti
authors.identifier: http://orcid.org/0000-0001-7570-238X
authors.initials: K
authors.lastname: Heimonen
authors.affiliation: Nano and Molecular Systems Research Unit, Faculty of Science, University of Oulu, Oulu, Finland.
authors.forename: Matti
authors.initials: M
authors.lastname: Weckström
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D003624:Darkness; D007313:Insecta / Q000502:physiology*; D017956:Photoreceptor Cells, Invertebrate; D014785:Vision, Ocular
keywords: compound eye; night vision; photoreceptor; phototransduction; quantum bump