The Circe Principle: Are Pollinators Waylaid by Attractive Habitats?

model to the higher image velocities: the smaller the time constant, the higher the velocity the model is tuned to (Figure 1B,C). Both flight and octopamine agonist substantially reduced its value, consistent with the observed shifts in the H1 cell’s velocity tuning [8]. An exciting parallel development is that the circuitry believed to generate the motion inputs corresponding to the Reichardt detector are, for the first time, becoming accessible to detailed studies, thanks to developments in genetics in the fruitfly, Drosophila [20]. Future studies will now be able to build on Jung et al.’s results to identify the mechanisms involved in detail. Already we know from intracellular recordings that locomotion alters the properties of the lobula plate tangential cells themselves, as well as the properties of their motion inputs [1,2]. It is certain that more signalling pathways than those using octopamine are involved, but how and where remains a mystery. Tying down the functional motivation for state-dependent vision in any model organism remains a big challenge, but based on current progress, work on the fly looks likely to succeed. References 1. Maimon, G., Straw, A.D., and Dickinson, M.H. (2010). Active flight increases the gain of visual motion processing in Drosophila. Nat. Neurosci. 13, 393–399. 2. Rosner, R., Egelhaaf, M., and Warzecha, A.K. (2010). Behavioural state affects motion-sensitive neurones in the fly visual system. J. Exp. Biol. 213, 331–338. 3. Chiappe, E.M., Seelig, J.D., Reiser, M.B., and Jayaraman, V. (2010). Walking modulates speed sensitivity in Drosophila motion vision. Curr. Biol. 20, 1470–1475. 4. Haag, J., Wertz, A., and Borst, A. (2010). Central gating of fly optomotor response. Proc. Natl. Acad. Sci. USA. 107, 20104–20109. 5. Rind, F.C., Santer, R.D., andWright, G.A. (2008). Arousal facilitates collision avoidance mediated by a looming sensitive visual neuron in a flying locust. J. Neurophysiol. 100, 670–680. 6. Niell, C.M., and Stryker, M.P. (2010). Modulation of visual responses bybehavioral state inmouse visual cortex. Neuron 65, 472–479. 7. Szuts, T.A., Fadeyev, V., Kachiguine, S., Sher, A., Grivich, M.V., Agrochão, M., Hottowy, P., Dabrowski, W., Lubenov, E.V., Siapas, A.G., et al. (2011). Nat. Neurosci. 14, 263–269. 8. Jung, S.N., Borst, A., and Haag, J. (2011). Flight activity alters velocity tuning of fly motion-sensitive neurons. J. Neurosci. 31, 9231–9237. 9. Laughlin, S.B. (1981). A simple coding procedure enhances a neuron’s information capacity. Z. Naturforsch. C 36, 910–912. 10. Laughlin, S.B. (2001). Energy as a constraint on the coding and processing of sensory information. Curr. Opin. Neurobiol. 11, 475–480. 11. Rowell, C.H.F. (1971). Variable responsiveness of a visual interneurone in the free-moving locust and its relation to behaviour and arousal. J. Exp. Biol. 55, 727–747. 12. Seelig, J.D., Chiappe, M.E., Lott, G.K., Dutta, A., Osborne, J.E., Reiser, M.B., and Jayaraman, V. (2010). Two-photon calcium imaging from head-fixed Drosophila during optomotor walking behavior. Nat. Methods 7, 535–540. 13. Naumann, E.A., Kampff, A.R., Prober, D.A., Schier, A.F., and Engert, F. (2010). Monitoring neural activity with bioluminescence during natural behavior. Nat. Neurosci. 13, 513–520. 14. Krapp, H.G., and Wicklein, M. (2008). Central processing of visual information in insects. In The Senses: A Comprehensive Reference, A.I. Basbaum, A. Kaneko, G.M. Shepherd, and G. Westheimer, eds. (San Diego: Academic Press), pp. 131–204. 15. Land, M.F. (2006). Eye movements and the control of actions in everyday life. Prog. Retin. Eye Res. 25, 296–324. 16. Bacon, J.P., Thompson, K.S., and Stern, M. (1995). Identified octopaminergic neurons provide an arousal mechanism in the locust brain. J. Neurophysiol. 74, 2739–2743. 17. Longden, K.D., and Krapp, H.G. (2009). State-dependent performance of optic-flow processing interneurons. J. Neurophysiol. 102, 3606–3618. 18. Longden, K.D., and Krapp, H.G. (2010). Octopaminergic modulation of temporal frequency coding in an identified optic flow-processing interneuron. Front. Syst. Neurosci. 4, 153. 19. Hassenstein, B., and Reichardt, W. (1953). Der Schluss von Reiz-Reaktions-Funktionen auf System-Strukturen. Z.Naturforsch. B. 8, 518–524. 20. Joesch, M., Schnell, B., Raghu, S.V., Reiff, D.F., and Borst, A. (2010). ON and OFF pathways in Drosophila motion vision. Nature 468, 300–304.