Chemoreception: - Mechanisms of olfactory discrimination of binary mixtures of amino acids in fishes resemble mechanisms of olfactory discrimination in man. Catfish learn first to detect the more stimulatory component of the binary mixture, than, after additional discrimination training, they detect the minor components of the mixture. -Olfactory discrimination of multimixtures of amino acids. Catfish easily learned to discriminate mixtures of 7 amino acids from mixtures of 6 of the same amino acids; however they were unable to learn to discriminate mixtures of 12 amino acids from mixtures of 11 of the same amino acids. This indicates that catfish olfactory apparatus has limitations most probably originating in chemotopy of the olfactory bulb. -We described how chemical senses are used by fishes that live in different ecological niches such as omnivorous and predatory niches. -First description of the role of olfactory learning in maturation and use of the olfactory system in predatory fishes. -First description of olfactory discrimination of amino acids in zebrafish (Danio rerio) -Different chemotopic codes enable olfactory discrimination whereas equal chemotopic codes do not enable olfactory discrimination of amino acids in zebrafish. -Discovery of normal function of fish olfactory organs in highly purified water (R biger than 18,2 mega Ohms). We were the first to successfully record responses of silent olfactory receptor neurons to amino acid stimuli in higly purified water. -In zebrafish there is a correlations between olfactory discrimination (behavior) and chemotopy of the olfactory bulb. -We discovered significant correlation between amplitude of the electroolfactogram (EOG) and responsiveness of silent olfactory receptor neurons to sigle amino acids stimuli in catfish. -Olfactory discrimination of amino acids in catfish with regenerated olfactory rosetae is equally good as the olfactory discrimination of amino acids in catfish with intact olfactory organs. Photoreception: -Definition of time and intensity dependence of metabolic response of highly metabolically active tissue to step changes in energy requirements using fly's photoreceptor cells as a model. -Development of a method for dynamic difference reflection spectrophotometic measurements (DDRS) in combination with principal analysis based spectral deconvolution (Pfluegers Arch 2003, 447:109). The method resolves a number of issues encountered in physiological optical measurements in living systems. -A successful pilot transfer of this method to vertebrate tissue. -Definition of the time course of the elements of the respiratory chain to step changes in PO2. Our results gave us insigt into regulation of metabolism in excitable cells. In addition flies as model organisms allow, due to their morphological and functional features, experiments, which are not possible in vertebrate tissue. -Determination and clarification of the dual role of arrestin 1 in phototransduction and adaptation processes in the eyes of a fruit fly. The findings represent a world class novelty and bears important implications for all cell types with metabotropic receptors and various TRP channels as also found in practically all mammalian excitable and non-excitable cells. -Establishment of the presence of arrestin 1 in the membrane of owlfly photoreceptors (Ascalaphus macaronius; FEBS Lett. (2001) 493:112). -Identification of general principles of mechanoreception in firebug (Pyrrhocoris apterus). Our findings indicate the existence of at least three types of trichobotria, distinguished by their spontaneous activity and sensory adaptation. These results challenge many of the generally accepted models of insect mechanotransduction. Honeybee: We introduced honeybee as a model organism for research of ethanol impact on insects and other organisms.