Insect Pol-neurons

POL-neurons are visual neurons that respond to the e-vector orientation (oscillation plane) of plane-polarized light, i.e. their activity is a function of e-vector orientation.

We have characterized extensively the physiology and morphology of some POL-neurons in crickets. The presence of POL-neurons could also be demonstrated in Cataglyphis ants but their physiology remains only incompletely described

Cricket POL-neurons
Cataglyphis POL-neurons

Sensory input to POL-neurons in the optic lobe

POL-neurons in the peripheral visual system receive input from a group of specialized ommatidia situated at the dorsal rim of the compound eye termed "dorsal rim area" or "POL-area". The dorsal rim ommatidia are characterized by a number of properties that makes them especially suitable as sensors for polarized light. The photoreceptors are strongly polarization-sensitive and in many species have large acceptance angles. In addition, each ommatidium contains two populations of photoreceptors that are tuned to mutually orthogonal e-vector orientations, subserving polarization-opponency. Fig. 1 shows the fine structure and the arrangement of ommatidia in the POL-area of a cricket. The polarization-sensitive photoreceptors in the POL-area are homochromatic, i.e. UV-sensitive in honey bees, ants, flies and monarch butterflies, but blue-sensitive in locusts and crickets.

For more information see references: