Insect responses to linearly polarized reflections: Orphan behaviors without neural circuits
- 1Biology, Freie Universität Berlin, Germany
The e-vector orientation of linearly polarized light represents an important visual stimulus for many insects. Especially the detection of polarized skylight by a growing number of many navigating insect species is known to improve their orientation skills. While great progress has been made towards describing both the anatomy and function of neural circuit elements mediating behaviors related to navigation, relatively little is known about how insects perceive non-celestial polarized light stimuli, like reflections off water, leaves, or shiny body surfaces. Work on different species suggests that these behaviors are not mediated by the ‘Dorsal Rim Area’, a specialized region in the dorsal periphery of the adult compound eye, where ommatidia contain highly polarization-sensitive photoreceptor cells whose receptive fields point towards the sky. So far, only few cases of polarization-sensitive photoreceptors have been described in the ventral periphery of the insect retina. Furthermore, both the structure and function of those neural circuits connecting to these photoreceptor inputs remain largely uncharacterized. Here we review the known data on non-celestial polarization vision from different insect species (dragonflies, butterflies, beetles, bugs, and flies) and present three well-characterized examples for functionally specialized non-DRA detectors from different insects that seem perfectly suited for mediating such behaviors. Finally, using recent advances from circuit dissection in Drosophila melanogaster, we discuss what types of potential candidate neurons could be involved in forming the underlying neural circuitry mediating non-celestial polarization vision.
Keywords: insect vision, polarized light, Behavior, Orientation, water detection, Neuroethology, Visual ecology, neural circuits, Neuroanatomy
Received: 19 Nov 2017;
Accepted: 15 Feb 2018.
Edited by:Vilaiwan M. Fernandes, New York University, United States
Reviewed by:Abderrahman Khila, UMR5203 Institut de génomique fonctionnelle (IGF), France
Gregor Belusic, University of Ljubljana, Slovenia
Copyright: © 2018 Heinloth, Uhlhorn and Wernet. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Prof. Mathias F. Wernet, Freie Universität Berlin, Biology, Fachbereich Biologie, Chemie & Pharmazie, Koenigin-Luise Strasse 1-3, Berlin, 14195, Berlin, Germany, firstname.lastname@example.org