Format

Send to

Choose Destination
Curr Biol. 2007 Jun 5;17(11):960-5. Epub 2007 May 24.

Coding of azimuthal directions via time-compensated combination of celestial compass cues.

Author information

1
Department of Biology, Animal Physiology, University of Marburg, 35032 Marburg, Germany.

Abstract

Many animals use the sun as a reference for spatial orientation [1-3]. In addition to sun position, the sky provides two other sources of directional information, a color gradient [4] and a polarization pattern [5]. Work on insects has predominantly focused on celestial polarization as an orientation cue [6, 7]. Relying on sky polarization alone, however, poses the following two problems: E vector orientations in the sky are not suited to distinguish between the solar and antisolar hemisphere of the sky, and the polarization pattern changes with changing solar elevation during the day [8, 9]. Here, we present neurons that overcome both problems in a locust's brain. The spiking activity of these neurons depends (1) on the E vector orientation of dorsally presented polarized light, (2) on the azimuthal, i.e., horizontal, direction, and (3) on the wavelength of an unpolarized light source. Their tuning to these stimuli matches the distribution of a UV/green chromatic contrast as well as the polarization of natural skylight and compensates for changes in solar elevation during the day. The neurons are, therefore, suited to code for solar azimuth by concurrent combination of signals from the spectral gradient, intensity gradient, and polarization pattern of the sky.

PMID:
17524646
DOI:
10.1016/j.cub.2007.04.059
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center