Том 55, № 3 (2024)

A review of the results of half a century of research into the visual system as a hierarchical structure is presented: a multichannel, multilayer “pyramid”, each layer of which has a different spatiotemporal resolution, but together provides an invariant description of images for their classification, decision making, organization of eye movements and target search. An analysis of the multichannel organization of the human visual system was carried out, as the most effective and most economical. The “periscope and telescopic vision” systems, unique in their morphological and functional characteristics, are identified, providing gaze translation and recognition when searching and achieving a goal. Models of the pyramidal organization of the visual system have justified their existence by having an exceptional influence on the development of engineering solutions for the design of recognition systems operating in real time and the creation of artificial neural networks.

The article presents an overview of the modern literature on the structure, distribution, biological and physiological role of xanthine oxidoreductase (XOR). XOR has been identified in all living organisms, from bacteria to humans. However, only in mammals it is presented in two forms, other species contain exclusively the XDH form. The enzyme is a homodimer with independent electron transfer in each monomer. XOR catalyzes the oxidation of hypoxanthine to xanthine and xanthine to uric acid in the final stage of purine metabolism and is widely distributed enzyme. The review highlights the forms of XOR and their role in the generation of reactive oxygen species (ROS), reactive nitrogen species (RNS) and synthesis of uric acid which are involved in many physiological processes. Uric acid shows antioxidant activity, and ROS and RNS play a role in innate immunity, in signaling, metabolism of xenobiotics, regulation of cellular redox potential and are also involved in mammogenesis and lactogenesis. Thus, in recent years significant progress has been made in understanding the biochemical and physiological nature of this enzyme system.

Autophagy is an intracellular mechanism for the isolation, transport and degradation of macromolecules and organelles. The physiological significance of autophagy lies, firstly, in maintaining the constancy of the intracellular environment through the timely disposal of proteins with a disrupted structure and damaged organelles. Secondly, due to the selective degradation of macromolecules, autophagy supplies the cell with monomers, which are then used by it to synthesize new compounds, which serves to ensure the rearrangement of cellular metabolism in the processes of cell differentiation, ontogenesis and adaptation to environmental challenges. Autophagy is an extremely important mechanism for maintaining normal functioning of postmitotic and differentiated cells, including neurons. Impaired neuronal autophagy leads to the formation of aggregated protein plaques, the accumulation of damaged cellular organelles, defects in the structure of processes and neuronal degeneration, which often accompanies to the progression of some forms of neurodegenerative diseases. In addition, the role of autophagy in synaptic plasticity and memory mechanisms has been established. Since autophagy has a significant impact on cellular metabolism, the study of the regulation and main pathways of this mechanism may be crucial in the elaboration of means and approaches to the treatment and prevention of many pathologies that progress with age. This review describes the basic concepts of the autophagy process, summarizes the key functions of autophagy in cells, and also presents current data on its role in ensuring the normal metabolism and implementation of specific functions of neurons.

Abstract – Different types of headaches, including migraine, may have a causal relationship with cold exposure, and this relationship can be either positive or negative, i.e. cold can both provoke and alleviate cephalalgia. Various representatives of the transient receptor potential ion channel superfamily, in particular TRPM8, act as molecular thermoreceptors that provide signal transduction in the response to low temperatures. These channels, which are known to mediate the normal cold sensation and play a role in both cold-induced pain and cryoanalgesia, are often considered as a promising target for the development of principally new anti-migraine drugs. This review summarizes recently obtained data on the TRPM8 structure and function, and their role in the pathogenesis of migraine, as well as discusses the intriguingly inconsistent results of studying TRPM8 agonists and antagonists in experimental headache models and clinical trials. Analyzing data from various studies allows to conclude that TRPM8 activation can be both pro- and antinociceptive; this correlates with the reported dual effect of cold exposure on the induction and resolution of headaches, leaving open the question on the vector of the TRPM8 pharmacological modulation required to produce anticephalgic effect.