Hereby we briefly review the articles that comprise the special issue of “Lomonosov Biology Journal” (“Vestnik Moskovskogo universiteta. Seria 16. Biologia”), which commemorates the centennial anniversary of the Department of Human and Animal Physiology of Lomonosov Moscow State University, founded by prominent Russian physiologist Alexander F. Samoilov. The main stages of the Department’s history are briefly described. The published studies of the leading Russian researchers, including the scientific research group from Department of Human and Animal Physiology, are discussed within the scope of main current challenges of physiological science.

The paper focuses on the light habitat of two populations of opossum shrimps Mysis relicta (Crustacea: Mysidacea) and the molecular mechanism of their visual pigments spectral tuning. Data are presented according to which spectral tuning is based on the expression of different opsins genes, and not on the replacement of chromophore groups: retinal 1 (A1) ↔ retinal 2 (A2).

This short review focuses on cytokines, molecular mediators of immunity and many other physiological functions of the body. Research on cytokines revealed new principles of cell-tocell communications and new paradigms in intracellular signal transduction. A few recombinant cytokines and, paradoxically, some cytokine inhibitors found practical use in medicine.

The intracellular concentration of chlorine anions ([Cl^-]_i), the equilibrium potential for chlorine anions (E_Cl) and transmembrane chloride currents (I_Cl) are the factors that significantly influence the electrophysiological properties of excitable tissue, including the myocardium. Several types of chloride (anion) conductance have been identified in the heart. In recent years, a number of transmembrane proteins demonstrating chloride conductance have been identified (CFTR, ClC, TMEM16, LRRC8), and the expression of these macromolecules in cardiac tissue has been confirmed. Accumulated data allow for establishing a molecular substrate for some chloride anion currents (I_Cl,PKA, I_Cl,ir, I_Cl,vol, I_Cl,swell, I_Cl,Ca, I_to2) detected in the heart. Furthermore, the molecular mechanisms regulating [Cl^-]_i and E_Cl through chloride cotransporters (KCC, NKCC1) and chloride-bicarbonate exchangers have been established. The variety of structures determining chloride transmembrane conductivity and the complexity of molecular mechanisms regulating chloride homeostasis underlie the complex effects of activation of chloride transporters in the pacemaker, conduction system and working myocardium of the heart. This review discusses the structural, biophysical properties and molecular regulation of chloride transporter protein complexes identified in the myocardium. The review also covers the mechanisms by which chloride transmembrane transport influences the bioelectrical activity of cardiomyocytes.

Terrestrial gastropods have evolved new structures in the nervous system compared to marine and aquatic snails in order to adapt to their new habitat. The behavior of these animals is qualitatively different from the behavior of aquatic gastropods, includes not only the possibility of active interaction with other animals, but also the demonstration of interest by active approach, avoidance or escape in certain cases. The “arrow of love” used in copulation is unique to Nature. Almost all types of associative memory can be formed in these animals, consolidation and reconsolidation of memory can be demonstrated, and mechanisms of memory maintenance and modification can be analyzed. At the level of functionally identified neurons and neural clusters, it is possible to study associative processes in vitro, a 3-neural model of associative longterm changes in synaptic efficiency has been developed.

The study of prolactin function evolution provides key insights into the diverse effects of this hormone in mammals, both in health and disease, which is relevant from both theoretical and practical perspectives. This article reviews both original and literature data concerning the role of prolactin and its receptors in regulating the sexual dimorphism of freshwater adaptation in the three-spined stickleback Gasterosteus aculeatus L. It is demonstrated that mRNA expression of prolactin gene 1 (one of two prolactin paralogs) and its receptor PRLRA increases in the brains of female sticklebacks only upon transitioning to freshwater. The brain and kidneys of sticklebacks, as androgen-dependent organs, exhibit sex-dependent expression of Prlra in seawater. It is suggested that sex-dependent osmoregulatory effects of prolactin are mediated through the PRLRA receptor in these organs. The PRLRB receptor, expressed in the kidneys and brains of sticklebacks regardless of sex in seawater, shows increased sensitivity to reduced salinity, suggesting a more active role in implementing sex-independent osmoregulatory functions of prolactin. Gills and intestines, as osmoregulatory organs, express the PRLRA and PRLRB receptors independent of sex in both seawater and freshwater. With freshwater adaptation, there is a concurrent increase in the expression of Prl1 in the brains of females and the expression of Atp1a1 (α1a subunit of Na⁺/K⁺-ATPase), Nhe3 (NHE3 sodium-proton antiport gene), and Ecac (epithelial calcium channel gene) in their gills. It is presumed that these gill genes are under positive control by prolactin. Exploring the potential for prolactin’s osmoregulatory function in mammals revealed that it may manifest in conditions such as pathologies accompanied by increased expression of prolactin receptor isoforms in osmoregulatory organs. One of such pathologies is cholestasis in female rats, which was associated with an increase in Prlr isoform expression and changes in activity and ratio of Na⁺/K⁺-ATPase subunits in the kidney. Thus, it is concluded that in fish, the osmoregulatory function of prolactin is sex-dependent, while in mammals, it may manifest under conditions of disrupted water-salt exchange.

Growth of the body in early postnatal ontogenesis is associated with changes in the functioning of many organ systems, including the cardiovascular system. The circulatory system of newborns is characterized by numerous structural and functional features, which at the systemic level is manifested in a significantly lower level of blood pressure. This review describes the differences in the mechanisms of regulation of vascular smooth muscle cell contraction in early postnatal ontogenesis and in adulthood, including age-related changes in the functioning of ion channels, which activity affects membrane potential level and intracellular concentration of calcium ions, as well as changes in calcium sensitivity of the contractile apparatus. The final section of the review discusses the connection between the mechanisms regulating contraction and differentiation of vascular smooth muscle cells during maturation.

The goal of the work was to study the role of the second messenger NAADP (Nicotinic Acid Adenine Dinucleotide Phosphate), which causes the release of Ca²⁺ ions from lysosomes and endosomes, in the regulation of heart contractions. Isolated hearts of the grape snail Helix pomatia and a chicken embryo were used as models. Using the membrane-permeable acetooxymethyl ester NAADP-AM, we showed that NAADP at nanomolar concentrations increases the frequency and amplitude of spontaneous cardiac contractions in H. pomatia. The NAADP antagonist NED19, without affecting the amplitude of contractions, dose-dependently reduces their frequency, completely blocking spontaneous contractions of the mollusk heart at a concentration of 5 μM. The V-type H⁺-ATPase inhibitor bafilomycin A1 suppresses the accumulation of calcium ions in lysosomes and acidic endosomes. We have shown that bafilomycin A1 causes attenuation of spontaneous contractions and cardiac arrest in H. pomatia. Serotonin increases the amplitude of contractions of the H. pomatia heart without affecting heart rate. NED19 at saturating concentrations (10 μM) reduces the frequency of contractions when the snail heart is activated by serotonin, but only partially reduces their amplitude. In experiments with the isolated chick embryo heart, we showed that NED19 reduces the frequency of spontaneous contractions without affecting the amplitude of contractions. Based on the data obtained, a hypothesis was put forward that the release of calcium ions from lysosomes and endosomes under the influence of endogenous NAADP ensures the maintenance of spontaneous contractions of the heart.

Taste attractivity of 15 organic acids and their derivatives (ascorbic, citric, sorbic, malic, oxalic, acetic, glycolic, α- and γ-aminobutyric acids, their Na⁺- and K⁺-salts; 0,1 M) was compared for 5 species of cichlid fishes (Cichlidae) – Nile Oreochromis niloticus and Mozambique O. mossambicus tilapias, golden mbuna Melanochromis auratus, lemon cichlid Neolamprologus leleupi and tailbar cichlid Vieja hartwegi. Citric and oxalic acids, Na+-ascorbate, K⁺-sorbate and K⁺-citrate, ammonium oxalate have an attractive or indifferent taste for fish, ascorbic and sorbic acids, Na+-citrate and Na⁺-malate have an aversive or indifferent taste. Malic acid has an attractive taste for tailbar cichlid, an aversive taste for Mozambique tilapia and an indifferent taste for other cichlids. Acetic acid and isomers of aminobutyric acid have indifferent taste for all fishes. The taste attractivity of organic acids may be different compared to salts formed on their basis. The attractiveness of salts is higher than that of the corresponding acids in 10 out of 28 cases, lower in 4 cases, and the same in 14 cases. The conversion of ascorbic and sorbic acids into Na⁺ and K+ salts is accompanied by an increase in taste attractivity in most cichlids, malic acid to malate Na⁺ – in half of the species. For most fish, citric acid and its Na⁺- and K⁺-salts have similar attractiveness. Oxalic acid, compared with ammonium oxalate, has a higher attractiveness for lemon cichlid, a lower one for Mozambique tilapia and the same taste quality for the other three fish species. There are no differences between the consumption of agar pellets with isomers of aminobutyric acid and pellets with acetic and glycolic (hydroxy acetic) acids in all cichlids. The feeding behavior shown by cichlids during the orosensory testing of pellets is similar – fish perform a small number of rejections and repeated grasps of pellets, the duration of pellet retention time in the oral cavity is similar.

The behavioral and functional states preceding the onset specific parkinsonian symptoms were studied at an early (pre-symptomatic) stage of hemi-parkinsonian syndrome development in rodents and monkeys. The pre-symptomatic stage of the hemi-parkinsonian syndrome was determined in rodents (mice and rats) treated by chronic administration of low doses of rotenone toxin. The consecutive steps of neuropathological traits development in rodents included the cognitive impairment at the 1st-2nd week of exposure to rotenone, minor movement disorders at the 3st-4nd week before the onset of severe motor dysfunction as well as some biochemical indicators. The latencies and amplitudes of visually guided saccades (VGS) while conditioned instrumental task performing were studied in nonhuman primates (Macaca mulatta) chronically treated with low doses of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). The elongation of VGS latencies and the decline of their accuracy were revealed with development of MPTP-induces syndrome but conditioned instrumental performance was not affected. The negative behavioral effects manifested in animals at the pre-symptomatic stage of toxins induced disease both in the rotenone model in rodents and in MPTP model in monkeys suggesting them as early markers of a hemi-parkinsonian syndrome.

The intensive development of oil and gas industries in the Arctic threatens Arctic aquatic ecosystems. The toxic and primarily lethal cardiotoxic effects of oil in living organisms are believed to be associated with polyaromatic hydrocarbons (PAHs), and previous works revealed the electrophysiological mechanisms of action of individual oil-derived PAHs. However, the physiological effects of a complex PAHs mixture in oil water-soluble fraction (WSF) have not been previously studied. This study is focused on the effects of oil WSF on electrical activity and major ionic currents in the working myocardium of navaga (Eleginus nawaga), which is one of the most important commercial fish species in the Arctic. We found that 1% and 10% solutions of oil WSF cause a marked increase in the duration of action potentials (APs) in navaga cardiomyocytes. This effect appears to be due to the suppression of rapid delayed rectifying current I_Kr (IC₅₀ about 3% in ventricular and atrial myocardium). At higher concentrations, oil WSF also suppressed calcium current I_CaL (IC₅₀ = 10.6%), which led to a decrease in the contractile activity in isolated myocardial preparations. Unlike individual tricyclic PAHs, oil WSF did not affect fast sodium current INa and AP upstroke velocity. An assessment of the content of tricyclic PAHs in 10% solution of oil WSF showed that their total concentration is relatively low and does not exceed 100 nM. Thus, oil WSF also has a powerful cardiotoxic effect in fish myocardium, but its effects differ from the previously studied effects of tricyclic PAHs and suggest the presence of yet unexplored oil compounds that have a more powerful toxic potential against ERG channels.

The work was dedicated to investigation of the influence of two endocannabinoids – arachidonoylethanolamide (AEA), also known as anandamide, and 2-arachidonoylglycerol (2-AG) on the parameters of miniature endplate potentials (MEPP) and evoked endplate potentials (EPP) of motor synapses at the early stage of regeneration during muscle reinnervation. 2-AG increased the amplitude of MEPP by 35%, and also increased the amplitude of EPP by 37%, without affecting quantal content of EPP or any other parameters of neurotransmitter secretion. This effect was prevented by vesicular acetylcholine transporter inhibitor vesamicol and by inverse agonist of CB1-type cannabinoid receptors AM251. AEA did not change the amplitude or any other parameters of MEPP, but reduced the quantal content of EPP by 27%. The inhibitory effect of AEA was prevented by AM251 and by the L-type Ca²⁺ channel blocker nitrendipine. Thus, it was established for the first time that in newly formed motor synapses AEA and 2-AG activate the same type of presynaptic cannabinoid receptors, but have different final targets, influence different parameters of quantal ACh secretion and have multidirectional effects on synaptic transmission. The presence of both facilitatory and inhibitory effects of endocannabinoids in regenerating synapses may serve to fine-tune and regulate synaptic transmission during their maturation.

Tactile imagery remains a relatively understudied phenomenon in the field of mental imagery research. However, alongside motor imagery, this technique holds promise as an effective tool for sensorimotor rehabilitation following stroke and spinal cord injuries. In this study, conducted with 22 healthy volunteers, we investigated the source localization of mu-rhythm event related desynchronization (Event-Related Desynchronization, ERD) using multi-channel electroencephalogram recordings and subsequent inverse problem solution with the sLORETA method. All participants exhibited ERD during tactile imagery task, as well as under vibrotactile stimulation. It was demonstrated that mu-rhythm ERD during vibrotactile stimulation, as well as tactile imagery, was localized in the sensorimotor areas of the contralateral hemisphere. Within the source space, ERD in the postcentral gyrus was significantly stronger compared to the precentral gyrus. These findings indicate that tactile imagery, akin to the perception of real tactile stimuli, leads to prominent activation of sensorimotor cortical areas, consistent with the general understanding of the shared neural substrate during mental imagery and perception.