[Osphradial chemosensory organ as a probable trigger of the cardiac system adaptive reaction to the effect of heavy metals in aquatic mollusks].

The responses of osphradium in the fresh-water mollusk Viviparus sp. and single osphradial neurons in the pond snail Lymnaea stagnalis to L-glutamine and L-asparagine as well as the changes in these responses under the effect of heavy metals (Cu, Cd) were recorded electrophysiologically. The functional connections of osphradium with the identified neurons of the central pattern generator of respiratory movements and cardiac activity as well as the modification of these connections under the effect of short-term application of HgCl2 solution on the snail's osphradium were investigated.

[Study of circadian activity in the crayfish Pontastacus leptodactylus during their multimonth stay in the river water flow].

By the method of non-invasive on-line recording and processing of photoplethysmograms of testaceous invertebrates, the circadian rhythm of cardiac activity was studied in the crayfish Pontastacus leptodactylus by recording for several months the heart rate (HR) and stress-index (characteristics of variational pulsometry). The crayfish were kept in the natural running water in the regime of natural illumination alteration (the first group) or at constant artificial illumination of low intensity (the second group). The circadian rhythm was more frequent and more distinct in crayfish of the first group.

The role of motivation in the performance of conditioned reflex switching of a maze skill in response to substitution of food reward quality in ants of the species Myrmica rubra.

The characteristics of learning in ants - active Myrmica rubra foragers - were studied in a maze at different levels of colony carbohydrate food need with reinforcement consisting of carbohydrate (sugar syrup) or protein (pupae of Lasius niger ants). Measures of the maze skill during learning reinforced with syrup were somewhat worse than those during learning reinforced with pupae, especially in terms of time-based measures. Ants were able to modify the acquired conditioned reflex reaction when the quality of reinforcement changed.

[The role of motivation in the performance of a conditioned switching-over of the maze habit in ants Myrmica rubra after a change in the quality of the food reinforcement].

Active foragers Myrmica rubra were trained in a maze under conditions of different levels of colony need in food with carbohydrate (sugar syrup) or protein (ants Lasius niger pupae) reinforcement. Acquisition of the maze habit was better under conditions of reinforcement with pupae, especially by its time indices. Ants were able to modify the acquired habit when the reinforcement quality was changed.