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Updated: Jul 17, 2025

Determination of Photoreceptor Cell Spectral Sensitivity in an Insect Model from In Vivo Intracellular Recordings
Published on: February 26, 2016
Photobehaviours guided by simple photoreceptor systems
Emelie Brodrick1, Gáspár Jékely2,3
1Living Systems Institute, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK. E.Brodrick@exeter.ac.uk.
Abstract:
Light provides a widely abundant energy source and valuable sensory cue in nature. Most animals exposed to light have photoreceptor cells and in addition to eyes, there are many extraocular strategies for light sensing. Here, we review how these simpler forms of detecting light can mediate rapid behavioural responses in animals. Examples of these behaviours include photophobic (light avoidance) or scotophobic (shadow) responses, photokinesis, phototaxis and wavelength discrimination. We review the cells and response mechanisms in these forms of elementary light detection, focusing on aquatic invertebrates with some protist and terrestrial examples to illustrate the general principles. Light cues can be used very efficiently by these simple photosensitive systems to effectively guide animal behaviours without investment in complex and energetically expensive visual structures.
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