Kartiranje receptivnih polj oči navadnega obada (Tabanus bromius) z draženjem s simulacijo naravnega vidnega okolja

Atanackov, Peter (author), Belušič, Gregor (mentor)

Uvedli smo novo metodo kartiranja receptivnih polj žuželk, z uporabo slikovnih dražljajev, ki simulirajo naravno okolje in so predstavljeni z uporabo hitrega DLP projektorja. Za razliko od klasične metode, ki temelji na bliskovnih dražljajih, draženje z DLP omogoča kartiranje receptivnih polj tako svetlo kot temno adaptiranih celic in omogoča opis oblike receptivnega polja in izračun vpadnega kota fotoreceptorja po poljubni osi. Prvič smo kartirali receptivna polja tako fotoreceptorjev kot tudi velikih monopolarnih celic pri isti vrsti žuželk. Na osnovi znotrajceličnih elektrofizioloških meritev odziva na dražljaje, ki oponašajo naravno okolje, smo ugotovili, da ima navadni obad vpadni kot fotoreceptorjev, primerljiv z drugimi predstavniki hitro letečih dvokrilcev. Ločljivost vida na nivoju velikih monopolarnih celic je omejena z vpadnim kotom fozoreceptorjev in je mehanizem nevralne superpozicije ne degradira. Oblika receptivnih polj je izotropna, velikost pa neodvisna od svetlobne adaptacije. Ločljivost analiziranih celic smo preverili še z meritvijo minimalnega kota med svetlobnima dražljajema, ki ju fotoreceptorji zaznajo kot ločena objekta. Ugotovili smo, da vpadni kot na ustrezen način opiše ločljivost, ter da obadi nimajo nadločljivostnega vida.

• Language: Slovenian
• Keywords: navadni obad/vid/receptivno polje/fotoreceptorji/sestavljene oči
• Work type: Master's thesis/paper
• Organization: BF - Biotechnical Faculty
• Year: 2017
• PID: 20.500.12556/RUL-95650
• COBISS.SI-ID: 4502863
• Publication date in RUL: 21.09.2017

Secondary language

• Language: English
• Title: MAPPING OF RECEPTIVE FIELDS OF EYES IN THE BAND-EYED HORSEFLY (Tabanus bromius) WITH NATURALISTIC STIMULI

Abstract

A new method has been implemented for the mapping of receptive fields of insect compound eyes with image stimuli that simulate the natural environment and are displayed by means of a fast DLP projector. As opposed to the classic method of flash presentation, stimulation with the DLP allows for mapping of receptive fields in both light and dark adapted cells, measuring the receptive field shape and allows to calculate the acceptance angle at any axis. Receptive fields of photoreceptors and large monopolar cells have been mapped for the first time in the same insect species. On the basis of intracellular electrophysiological measurements responses to stimuli that mimick the natural scenes we concluded that the horsefly photoreceptor acceptance angle is comparable to that of other fast-flying Dipterans. Angular resolution at the level of the large monopolar cells is limited by the acceptance angle of the photoreceptor and as such isn’t degraded by the mechanism of neural superposition. The receptive fields are isotropic in shape and their size does not dependend on light adaptation. The angular resolution of analysed cells has been additionally tested by estimating the minimal interstimulus angle, at which the light sensitive cells can detect two objects separately. We found that the acceptance angle accurately describes the resolving power and that the horseflies do not possess hyperacute vision.

• Keywords: band-eyed brown horsefly/vision/receptive field/photoreceptors/compound eyes