Difference in dynamic properties of photoreceptors in a butterfly, Papilio xuthus: possible segregation of motion and color processing
- 402 Downloads
The eyes of the Japanese yellow swallowtail butterfly, Papilio xuthus, contain six spectral classes of photoreceptors, each sensitive either in the ultraviolet, violet, blue, green, red or broadband wavelength regions. The green-sensitive receptors can be divided into two subtypes, distal and proximal. Previous behavioral and anatomical studies have indicated that the distal subtype appears to be involved in motion vision, while the proximal subtype is important for color vision. Here, we studied the dynamic properties of Papilio photoreceptors using light stimulation with randomly modulated intensity and light pulses. Frequency response (gain) of all photoreceptor classes shared a general profile—a broad peak around 10 Hz with a declining slope towards higher frequency range. At 100 Hz, the mean relative gain of the distal green receptors was significantly larger than any other receptor classes, indicating that they are the fastest. Photoreceptor activities under dim light were higher in the ultraviolet and violet receptors, suggesting higher transduction sensitivities. Responses to pulse stimuli also distinguished the green receptors from others by their shorter response latencies. We thus concluded that the distal green receptors carry high frequency information in the visual system of Papilio xuthus.
KeywordsButterfly vision Motion vision Color vision Photoreceptor dynamics
This work was supported by the SOKENDAI visiting professorship to MKa, the JSPS (Japanese Society for Promotion of Science) Grants-in-Aid for Scientific Research C to MKi (24570084) and A to KA (26251036), JSPS open partnership joint research project (Finland) to KA, the NARO (National Agriculture and Food Research Organization) grant for SIP (Strategic Innovation Promotion) Program “Technologies for creating next-generation agriculture, forestry and fisheries” to KA, and the research grant from the Academy of Finland (269332) to MW.
- Bendat JS, Piersol AG (1971) Random data: analysis and measurement procedures. John Wiley and Sons Inc, New YorkGoogle Scholar
- Kaiser W (1975) The relationship between visual movement detection and colour vision in insects. In: Horridge GA (ed) The compound eye and vision in insects. Clarendon Press, Oxford, pp 359–377Google Scholar
- Kaiser PK, Boynton RM (ed) (1995) Human colour vision, 2nd edn. In. Optical Society of America, Washington DC, p 652Google Scholar
- Koch C (1998) Biophysics of computation: information processing in single neurons. Oxford University Press, Oxford, New York etcGoogle Scholar
- Kv Frisch (1914) Der Farbensinn und Formensinn der Biene. Zool Jb Physiol 37:1–238Google Scholar