20.500.12556/RUL-145221 Vpliv nevromodulatorjev na oponentne sinapse v mrežnici metuljev Influence of neuromodulators on opponent synapses in the butterfly retina Barvni vid metuljev je ključen za ustrezno prepoznavo cvetja za prehranjevanje, za uspešno prepoznavo partnerjev ter plenilcev in na koncu primernih odlagališč jajčec. Predpostavili smo, da je delovanje fotoreceptorjev plastično in nastavljivo z intrinzičnim sproščanjem nevromodulatorjev. Z uporabo elektrofizioloških znotrajceličnih meritev smo najprej določili nabor fotoreceptorjev, ki sestavljajo mozaik v mrežnici trikromatskih in tetrakromatskih vrst metuljev. Na barvni vid smo poizkusili vplivati preko aplikacije agonistov in antagonistov oktopaminergičnega in histaminergičnega sistema. Vpliv oktopamina in njegovega antagonista epinastina na receptorski signal smo vrednotili preko sprememb v stopnji neposredne sinaptične oponence med fotoreceptorji. Ta je posledica delovanja inhibitornih interfotoreceptornih povezav v lamini in meduli metuljev. Med tem ko oktopamin na spektralno občutljivost ni imel vpliva, so imele celice, tretirane z epinastinom povišano inhibicijo oponentne enote. Še večji vpliv na oponenco je imela aplikacija blokatorjev histaminergičnih kloridnih kanalov. Z uspešno aplikacijo antagonistov oktopamina smo pokazali, da je barvni vid metuljev na najzgodnejši stopnji uravnan z nevromodulatorji, z uspešno blokado histaminergičnih kanalov pa smo razvili metodo za analitično preučevanje barvne oponence med fotoreceptorji. The colour vision of butterflies is crucial for the proper identification of foraging flowers, for the successful identification of mates and predators, and ultimately for the suitable oviposition sites. We hypothesized that photoreceptor activity is plastic and adjustable by intrinsic neuromodulator release. Using electrophysiological intracellular measurements, we first determined the set of photoreceptors that make up the mosaic in the retina of trichromatic and tetrachromatic butterfly species. We attempted to influence colour vision through the application of agonists and antagonists of the octopaminergic and histaminergic systems. The effect of octopamine and its antagonist epinastine on the receptor signal was evaluated through changes in the degree of direct synaptic opponency between photoreceptors. This is due to the action of inhibitory interphotoreceptor connections in the lamina and medulla of butterflies. While octopamine had no effect on spectral sensitivity, epinastine-treated cells had increased inhibition of the opponent unit. The effect on opponency was even greater when histaminergic chloride channel blockers were applied. By successful application of octopamine antagonists, we have shown that colour vision in butterflies is regulated by neuromodulators at the earliest stage, and by successful blockade of histaminergic channels, we have developed a method for analytically studying colour opponency between photoreceptors. Metulji barvni vid nevromodulacija fotoreceptor oponenca Butterflies colour vision neuromodulation photoreceptors opponency true false false [D. Lazar] Slovenski jezik Angleški jezik Magistrsko delo/naloga 2023-04-13 11:42:43 2023-04-13 11:42:46 2023-04-18 12:33:10 0000-00-00 00:00:00 2023 0 0 0000-00-00 NiDoloceno Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 592/599 217658 149561603 MAG_Lazar_Domen_2023.pdf MAG_Lazar_Domen_2023.pdf 1 1E30AADD196CB97056CC92A368AB1FF9 8d7e73b45fe26ac4178c9fac879b7b1b792a60a224e86e964bf7433aa310e644 6516b76a-d9df-11ed-a314-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=167937 Biotehniška fakulteta 0 0 0