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The Heilongjiang-Lena River Basin is a major high-latitude transboundary watershed spanning northeastern China and the Russian Far East, representing a typical cold-region system under climate change. However, long-term assessments of eco-environmental dynamics and their multi-factor driving mechanisms in such climate-sensitive basins remain limited. Using multi-source remote sensing data from 2000 to 2024, this study constructed a Remote Sensing Ecological Index (RSEI) and integrated Sen's trend analysis, the Mann-Kendall test, and an optimized Geodetector model to examine spatiotemporal patterns and driving forces of eco-environmental quality. The mean RSEI ranged from 0.522 to 0.662, indicating overall stability, with 61.37% of the area showing no significant change, 22.45% improvement, and 16.18% degradation. A persistent north-south gradient was observed, characterized by relatively better conditions in the north and comparatively lower values in the south. Temperature emerged as the dominant driver, followed by land use and vegetation cover, with pronounced nonlinear enhancement effects-particularly between temperature and land use. Policy interventions contributed to ecological restoration in parts of China, while permafrost degradation and forest fires induced environmental fluctuations in the Russian sector. Overall, the basin exhibits considerable resilience despite localized vulnerabilities. The integrated RSEI-Geodetector framework provides transferable insights for long-term monitoring and governance of high-latitude and transboundary ecosystems.

Crystalline rock massif of the Yeniseiskiy site (Krasnoyarsk region) is considered for the disposal of radioactive waste in the Russian Federation. In this study the resistance of different types of rocks located at target depths in the site of geological disposal facility (gneisses, dolerites, and carbonatized fissure filling) to dissolution by groundwater was simulated by short-term stage-by-stage treatment with 18 % HCl solution and aqua regia. The impact of dissolution on isolation properties was also investigated. A high sorption capacity to Cs(I) and Eu(III) which chemical behavior is similar to Am (III) and Pu (III) of gneiss, dolerite, and fissure filling samples was established. During the studies of sorption properties, it was found that the greatest influence on the retention of Cs by gneiss and dolerite have the specific surface area (SSA) value. This effect is most pronounced for gneiss due to the increased available surface area of mica minerals biotite and muscovite. The retention effect of the fissure filling material is mainly determined by the content of mixed-layer illite-smectite clay minerals and chlorite. It was found that the greatest influence on the retention of europium by gneiss and mineral fissure filling is the content of chlorite in the samples. The obtained results reflect the resistance of the host rock of the Yeniseiskiy site to the most aggressive acid environments, which allows assessing the stability of their isolation properties for a long-term perspective.

Migratory birds crossing large ecological barriers can exhibit significant plasticity in their circadian movement patterns, e.g., shifting from nocturnal to continuous flight over seas. But substantial plasticity in the circadian patterns of active migration has also been reported in other birds, such as most intra-Palearctic dabbling ducks, that do not face major ecological barriers en route. Yet, the factors driving such behavioural variation in these species remain poorly understood. We investigated how biotic and abiotic factors influenced circadian movement patterns and seasonal migratory schedules during pre-breeding migration of GPS-tracked Northern pintails (Anas acuta) tagged in late winter in northern Adriatic wetlands (Italy) and migrating across Eurasia towards their breeding areas. We classified behaviours from GPS data and estimated the probability of being in active migration as a function of biome, altitude of the sun above the horizon, average ground temperature, and orthodromic distance from the breeding site. While showing a consistent preference for conditions of low (and decreasing) sun altitude throughout migration (n = 22 pintails, n = 25 complete migration events), we observed a gradual shift towards diurnal flight along the movement path, with the level of diurnality varying according to the specific biome encountered and, likely, to the potential exposure to predators in forested areas, across latitudes. Stopovers were longer in the first half of migration and shorter and more frequent as pintails neared the breeding grounds (located mainly in the Russian Arctic). Although active migration segments were covered at very high speeds, the overall migration pace was consistently slow, suggesting a tendency to follow seasonal cues en route. Our study provided evidence that circadian migration patterns and seasonal migratory schedules in pintails were continuously adjusted in response to the environmental conditions encountered during migration. This variation was not solely due to the steep reduction in dark hours as individuals migrated northeast, nor to the increasing urgency to reach the breeding grounds. Rather, it likely resulted from an adaptation to ecological contexts favouring daytime migration, counteracted by the necessity of waiting for environmental conditions to become suitable for breeding.

To conduct a comparative analysis of existing approaches to determining the early stages of cognitive impairment, and based on the results, to propose a universal practical approach to their coding and develop diagnostic criteria. A comparative analysis of available literature data was performed, including Russian and international sources in the PubMed and eLibrary databases addressing the issues of determining, diagnosing, preventing, and treating the predementia stages of cognitive deficits. The article discusses various options for identifying the predementia stages of cognitive impairment. Based on the analysis, it is proposed to use the universal term-the early signs of cognitive impairment-in everyday practice to encode the stage of cognitive impairment preceding the moderate cognitive impairment (MCI). The following diagnostic criteria are proposed: the symptoms of decreased memory, attention, and general mental activity presented independently or identified during an interview; the symptoms are repeated at least once a week and are not associated with any obvious reasons and external factors; extended neuropsychological examination can reveal deviations from the reference indicators; the presence of risk factors for the development of cognitive impairment; the duration of symptoms is at least 6 months; concern about their condition due to a feeling of a worse cognitive activity in comparison with other people of the same age; no MCI criteria are met. Early objective diagnosis of the initial stages of cognitive impairment is challenging even for trained, problem-oriented specialists; therefore, it is necessary to standardize and universalize the diagnostic criteria available at all stages of medical care. A comprehensive assessment of the symptoms, the circumstances of their occurrence, and their persistence and recurrence is necessary. Objective evidence of impairment should be standardized using a universal set of neuropsychological methods. Провести сравнительный анализ существующих подходов к определению начальных стадий когнитивного снижения, на основе которого предложить универсальный практический подход к их кодированию и разработать критерии диагностики. Выполнен сравнительный анализ доступных данных литературы, включая отечественные и иностранные источники, представленные в базах данных PubMed, eLibrary, в которых отражены вопросы определения, диагностики, профилактики и лечения додементных стадий когнитивного дефицита. В статье обсуждены различные варианты определения додементных стадий когнитивных расстройств. На основе проведенного анализа для кодировки стадии когнитивных нарушений, предшествующей умеренному когнитивному расстройству (УКР), предложено в повседневной практической деятельности использовать универсальный термин «начальные признаки когнитивных нарушений». Предложены критерии диагностики: наличие жалоб на снижение памяти, внимания, умственной деятельности в целом, предъявляемые самостоятельно или при активном опросе; жалобы носят повторяющийся характер, регистрируются не реже 1 раза в неделю и не зависят от каких-либо явных причин и внешних факторов; расширенное нейропсихологическое обследование может выявить: отклонения от нормативных показателей; наличие факторов риска развития когнитивных нарушений; длительность имеющихся жалоб не менее 6 мес; обеспокоенность своим состоянием в связи с ощущением худшего состояния когнитивной деятельности в сравнении с другими людьми того же возраста; отсутствуют критерии УКР. Ранняя объективная диагностика начальных стадий когнитивных нарушений представляет собой сложную задачу даже для подготовленных и ориентирующихся в проблеме специалистов, в связи с чем необходимы стандартизация и универсализация диагностических критериев, доступных на всех этапах оказания медицинской помощи. Необходима всесторонняя оценка особенностей жалоб, обстоятельств их возникновения, стойкости, повторяемости. Объективные доказательства нарушения должны быть стандартизированы с применением универсального комплекса нейропсихологических методик.

Congenital lobar emphysema should be considered in infants with persistent respiratory symptoms unresponsive to standard therapy. Chest CT is the definitive diagnostic tool, reliably distinguishing CLE from other causes of unilateral hyperlucency. In symptomatic infants with progressive lobar hyperinflation, early surgical lobectomy yields excellent outcomes and prevents further respiratory compromise.

We investigated the involvement of NOP receptors in the response of the primary fibroblast culture to oxidative stress (OS) and in the mechanisms of the cytoprotective effect of the NALE peptide. OS led to a decrease in the number of cells in monolayers and the absence of mitotic figures, increased the proportion of p53+ cells and the area of the nucleus, and reduced the number of nucleoli. Preliminary incubation with a NOP receptor blocker J-113397 before OS showed its cytoprotective effect: the number of p53+ cells decreased, though still was significantly higher than in the control, the area of the cell nuclei corresponded to the control parameter, and the density of the cell culture increased. Preincubation with the NALE peptide also attenuated the effects of OS in the cell culture. The combined application of the NOP receptor blocker and NALE peptide had a protective effect. Changes in the nucleo-nucleolar apparatus of cells were similar to those observed after incubations with the NALE peptide: a significant increase in the area of nuclei, a decrease in the number of nucleoli, an increase in the total area of nucleoli, and a significant increase in the number of cells in monolayers were recorded. An increase in mitotic activity was found in comparison with the effects of NOP receptor blocker and OS. NOP receptor blocker exhibited a weak anabolic effect: the number of nucleoli and their total area increased. The study demonstrated preservation of the cytoprotective effect of the non-opiate analogue of leu-enkephalin against the background of NOP receptor blockade. Moreover, according to some indicators, there is a synergistic effect of the NALE peptide and the NOP receptor antagonist J-113397.

Neurodegenerative diseases are often presented with myoclonus, sudden, short-term, involuntary muscle contractions («flinching»). According to the literature, myoclonus in Alzheimer's disease (AD) can occur up to 40-50% in cases of disease with early onset and in atypical forms. Importantly, epileptic myoclonus may indicate a risk of seizures with loss of consciousness, convulsions, and epileptiform activity, which may lead to more rapid progression of cognitive deficits. Diagnosis of myoclonus is essential for timely treatment and improving the quality of life of AD patients. The paper describes the main features of myoclonus in AD, the possibility of using additional examination methods, in particular video-electroencephalographic (video-EEG) monitoring for differential diagnosis and etiology clarification, and also presents a clinical case of a patient with AD and epileptic and non-epileptic myoclonus. Нейродегенеративные заболевания нередко сопровождаются миоклонусом — внезапными кратковременными непроизвольными мышечными сокращениями («вздрагиваниями»). Согласно данным литературы, миоклонус при болезни Альцгеймера (БА) может встречаться до 40—50% в случаях заболевания с ранним дебютом и при атипичных формах. Важно, что эпилептический миоклонус может свидетельствовать о риске развития приступов с утратой сознания, судорогами у таких пациентов, а эпилептиформная активность может приводить к более быстрому прогрессированию когнитивного дефицита. Диагностика миоклонуса важна для назначения своевременного лечения и повышения качества жизни пациентов с БА. В статье освещены основные особенности миоклонуса при БА, возможности применения дополнительных методов обследования, в частности видеоэлектроэнцефалографического (видео-ЭЭГ) мониторинга с целью проведения дифференциального диагноза и уточнения его этиологии, а также представлен клинический пример пациента с БА и миоклонусом эпилептического и неэпилептического генеза.

Neonatal sepsis-induced cardiovascular dysfunction includes impaired myocardial function (which may be systolic and/or diastolic) and vasoregulatory failure (which may lead to vasodilation or vasoconstriction). The haemodynamic response in neonatal sepsis may therefore be hyperdynamic or hypodynamic, and the underlying pathophysiological mechanisms are heterogenous. The assessment of the neonate with sepsis and cardiovascular dysfunction is critical for targeted pathophysiology-based management. However, this assessment is challenging; it may include clinical features, echocardiography, electrocardiography and heart rate variability monitoring, non-invasive cardiac output monitoring (NICOM), near-infrared spectroscopy (NIRS) and biomarkers. Neonatologist performed echocardiography (NPE), in particular, can aid in the evaluation of the pathophysiological mechanism of cardiovascular dysfunction specific to each patient and further guide individualised management. IMPACT: WHAT DOES THIS ARTICLE ADD TO THE EXISTING LITERATURE?: This review provides an integrative overview of current methods for assessing cardiovascular dysfunction in neonatal sepsis, combining clinical evaluation with echocardiographic, electrocardiographic, non-invasive hemodynamic (NICOM, NIRS), and biomarker-based approaches to support early recognition and management.

We demonstrate an exceptional radiation hardness of thin films of pristine fullerene C60 and its organic derivative phenyl-C61-butyric acid methyl ester (PC61BM) in lateral resistor and field-effect transistor device geometries under exposure to ultra-high doses of 60Co gamma rays approaching 5-8 MGy (5-8 MRad). The obtained results exhibit the great promise of organic semiconductors for the development of radiation-hard electronics for outer space exploration and other extreme environments.

We studied the effect of repeated immobilization stress against the background of preliminary intranasal administration of valine-containing glyproline Pro-Gly-Pro-Val (100 μg/kg) on the morphometric parameters of mast cells (mastocytes) in the connective tissue of the mucosal and muscular layers of the tongue in male Wistar rats. Repeated stress increased in the density of distribution, mean size, and degranulation index of mast cells in both layers. Preliminary administration of the peptide decreased the mean area and degranulation index of mast cells, which suggests that the peptide has a stabilizing effect on the morphological structure and activity of mast cells.

Spinocerebellar ataxias (SCAs) are a group of neurodegenerative diseases characterized by progressive cerebellar dysfunction, which leads to impaired coordination, dysarthria, oculomotor disorders, and subsequently to a marked reduction in quality of life and high disability. In addition to the main motor symptoms, patients often suffer from cerebellar cognitive-affective syndrome, depression, and sleep disturbances. Despite advances in understanding the molecular and genetic underpinnings of SCAs, there are currently no disease-modifying therapies approved by the FDA (U.S. Food and Drug Administration) or EMA (European Medicines Agency), and management remains largely symptomatic, focusing on improving quality of life and functional independence. Recent systematic reviews and clinical guidelines emphasize a combination of pharmacological, non-pharmacological, and novel gene and cell therapies that are currently under investigation, with varying levels of evidence for their efficacy. The transition to precision medicine and early intervention at the pre-ataxic stage are essential for effectively combating neurodegeneration. This review summarizes the latest data on the treatment of SCA, including existing and new treatments, their effectiveness, limitations, and future prospects.

Depression poses a major global health challenge, highlighting the urgent need for valid animal models to elucidate its pathogenesis and develop novel treatments. This review offers a comprehensive characterization and validation of an original rodent model of depression induced by chronic exposure to variable-frequency ultrasound (20-45kHz), termed the ultrasound model (US-model). We hypothesize that this model uniquely recapitulates a state of "information uncertainty", providing a highly relevant framework for studying depression amid modern urban environments. Based on extensive experimental data collected over 10 years (2013-2024), the model has been systematically evaluated using three key criteria for validity. First, the US-model demonstrates face validity, recapitulating core behavioral abnormalities such as anhedonia, behavioral despair, social withdrawal, anxiety, and cognitive deficits. Second, its construct validity is supported by the faithful reproduction of key pathophysiological mechanisms, including monoamine system dysfunction, impaired neuroplasticity, neuroinflammation, oxidative stress, and hypothalamic-pituitary-adrenal (HPA) axis hyperactivity. Finally, the model exhibits strong predictive validity, showing sensitivity to various established classes of antidepressants (e.g., fluoxetine, clomipramine), novel compounds (e.g., vindeburnol, neuropeptides), electroconvulsive therapy, and agents with antioxidant or anti-inflammatory properties. Compared to classic models, the US-model may offer several potential advantages such as a relatively high degree of standardization and an arguably more ethical profile, as it is less invasive. In conclusion, the US-model of depression represents a reliable and reproducible tool to investigate the pathogenesis of affective disorders and screen new therapeutic agents.

Stroke remains a leading cause of disability worldwide. Cognitive impairment is a major consequence, with post-stroke aphasia developing in approximately 30% of patients after a first stroke. Speech impairments substantially reduce quality of life, complicate rehabilitation, and hinder reintegration into daily activities. Patients with aphasia exhibit greater cognitive deficits and an increased risk of vascular dementia, regardless of stroke type. Speech therapy is a primary treatment modality. Neuroplasticity is central to post-stroke recovery, and agents that stimulate neuroplasticity represent a promising therapeutic direction. Cerebrolysin, a pleiotropic drug composed of peptides with neurotrophic properties and free amino acids, can activate neuroplasticity. Recent findings from the Efficacy and Safety of Cerebrolysin in the Treatment of Aphasia After Acute Ischemic Stroke study (ESCAS) demonstrate that combined speech therapy and Cerebrolysin use accelerates recovery of speech functions, suggesting its value as an adjunct in stroke rehabilitation. Инсульт остается одной из ведущих причин инвалидности в современном мире. Нарушения когнитивных функций являются одним из значимых симптомов после инсульта. Постинсультная афазия развивается примерно у 30% пациентов, перенесших первый инсульт. Нарушения речи представляют собой значимые инвалидизирующие расстройства у постинсультных пациентов, которые в значительной степени снижают качество жизни, затрудняют проведение реабилитационных мероприятий и возможность возвращения пациента к прежней жизни. У пациентов с афазией отмечается бо́льшая степень когнитивного снижения, повышается риск развития сосудистой деменции, независимо от типа инсульта. Одним из важнейших направлений лечения является логопедическая терапия. Ключевым процессом, обеспечивающим восстановление после инсульта, является нейропластичность. Использование средств, стимулирующих активацию процессов нейропластичности, рассматривается как одно из перспективных направлений. Церебролизин представляет собой плейотропный препарат, содержащий смесь пептидов с нейротрофическими свойствами и свободных аминокислот и обладающий способностью активировать процессы нейропластичности. Недавно были опубликованы результаты совместного применения логопедической терапии в сочетании с лечением Церебролизином в восстановлении пациентов с экспрессивной афазией после ишемического инсульта (ESCAS). Результаты этого исследования свидетельствуют о том, что Церебролизин ускоряет восстановление речевых функций, что потенциально делает его ценным дополнительным средством в реабилитации после инсульта.

Meiotic transcription is a highly regulated process involving stage-specific chromatin remodeling and dynamic RNA polymerase II (RNAPII) activity. Nevertheless, our current understanding is largely based on classical model organisms, while many nonmodel mammals remain unexplored. This study investigates the transcriptional dynamics and chromatin features during meiotic prophase I in Nannospalax xanthodon, a subterranean blind mole rat species with extensive intraspecific karyotype variation. Using immunofluorescence, we analyzed synapsis and transcriptional activity in spermatocyte nuclei of two geographically distant N. xanthodon males, detecting SYCP3, CREST, γH2AFX, and phosphorylated RNAPII (Ser5, Ser2). Telomere-associated proteins RAP1 and TERT were also examined to assess transcriptional activity at chromosomal ends. Transcriptional activity was detected at all substages of prophase I. Unlike classical models, N. xanthodon exhibited no sharp pachytene-specific transcriptional reactivation; instead, RNAPII-Ser2 and Ser5 signals increased gradually from leptotene to pachytene. Notably, RNAPII-Ser5, but not Ser2, was consistently localized at telomeric regions of autosomes and sex chromosomes. These RNAPII-Ser5 foci coincided with RAP1-positive telomeres, suggesting a poised but transcriptionally inactive polymerase state at chromosome ends. The variability of RNAPII signals around the XY bivalent may also suggest a dynamic regulation of sex chromosome silencing. This is the first analysis of meiotic transcription in mole rats. The gradual transcriptional enhancement in the chromatin of prophase I nuclei and the RNAPII-Ser5 enrichment at telomeres reflect species-specific regulatory features. These findings highlight the importance of investigating nonmodel organisms to uncover novel mechanisms of meiotic regulation and suggest that transcriptional control during meiosis may be more evolutionarily diverse than previously recognized.

Preeclampsia (PE) is a pregnancy-specific hypertensive disorder that typically arises after 20 weeks of gestation. The role of alternative polyadenylation (APA) in the development of PE remains largely unexplored. In this study, we analyzed 3' UTR APA and its regulation in PE using bioinformatics pipelines. 3' UTR APA events were identified by DaPars suite based on integrated short-read and long-read RNA sequencing data generated in our laboratory. APAFlow and DAPAFlow pipelines were developed to identify miRNA binding motifs and construct miRNA-APA regulatory networks. Functional enrichment and correlation analyses were performed to assess the roles of APA events in PE pathogenesis. 1553 PE-specific APA events are detected, with 67.5% preferentially utilizing the distal PAS, associated with the immune system. 510 differential 3' UTR APA events are identified between PE and control group, 64.3% of which favored the proximal PAS and associated with the blood-brain barrier. Results from APAFlow and DAPAFlow indicated that a large number of miRNA binding motifs are enriched in 3' UTRs during PE development. The functional analyses indicated that these specific miRNAs participate in regulation of APA events and collaborate with targeted APA genes to contribute to PE pathogenesis, particularly through mechanisms involving the blood-brain barrier and immune function. We conducted RNA sequencing and integrative bioinformatic analyses of placental tissues from PE cases, revealing widespread 3' UTR APA events associated with disease pathogenesis. Through a miRNA-centered framework, we further delineated the regulatory mechanisms underlying APA in PE. Collectively, these findings provide novel mechanistic insights into PE and underscore APA as an additional layer of post-transcriptional regulation contributing to its etiology.

The reactivity of the orthometalated [(N^C)AuCl2] complex (N^C-pyridyl-benzothiophene) toward a series of terminal alkynes has been investigated. The reactions afford products containing a C-coordinated benzo[4,5]thieno[2,3-a]quinolizin-5-ium aromatic fragment bound to an Au(I) center. The obtained aromatic systems can be isolated in the free state through reaction of the Au(I) complexes with a protonated phosphonium cation. The studied reaction sequence may be considered a novel strategy for expansion of condensed aromatic systems via 1,4-addition of alkynes to an orthometalated N^C ligand bound to an Au(III) center. The mechanism of this transformation in the gold coordination sphere was investigated theoretically by application of the Double Anharmonic Downward Distortion Following methodology, revealing the details of the coordinated ligands transformations and confirming the key role of the solvent in determining the reaction pathway. Isolation and characterization of the Au(I) complex shed light on the mechanism of related catalytic reactions. The results obtained are of a general nature and pave the way for further development of this chemistry with the wider range of N^C and alkyne ligands, enabling the directed synthesis of new condensed aromatic systems.

Laser-engineered superhydrophobic carbon fiber fabrics (CFFs) were developed as multifunctional surfaces for passive anti-icing and active electrothermal de-icing. Two laser-based texturing strategies─direct laser ablation of carbon fibers and laser-induced transfer of aluminum micro/nanoparticles─were employed to generate hierarchical surface roughness, followed by fluorosilane chemisorption. Both approaches produced stable Cassie-Baxter wetting states with water contact angles exceeding 160° while retaining superhydrophobicity after abrasive wear, with contact angles remaining above 154° and 157° for the two coatings, respectively. Superhydrophobic CFFs exhibited pronounced anti-icing behavior, delaying ice nucleation and preserving supercooled water droplets for tens of hours at moderate subzero temperatures. Under weak electrothermal heating, anti-icing performance was maintained down to -40 °C, where small droplets frequently evaporated before freezing. Compared to hydrophilic and hydrophobic fabrics, superhydrophobic CFFs enabled ice removal predominantly via interfacial sliding rather than melting, leading to substantial reductions in de-icing energy consumption and time. In particular, one optimized coating reduced ice removal time by more than a factor of 4 and total energy consumption by more than a factor of 3 relative to the untreated fabric. A clear distinction was observed between the two texturing strategies. Aluminum-textured CFFs exhibited lower electrical resistance and more efficient heat delivery to the ice-fabric interface, minimizing the total energy required to initiate ice sliding, whereas laser-textured CFFs showed higher electrical resistance and faster surface temperature rise, resulting in shorter de-icing times. These results demonstrate a decoupling of energy efficiency and temporal response in electrothermal de-icing, enabled by laser-induced surface texturing. Overall, this work establishes superhydrophobic CFFs as durable, low-power platforms for combined passive anti-icing and active electrothermal de-icing in severe cold environments.

This article examines the relationship between cognitive impairment and neurodegeneration in patients with Alzheimer's disease, with particular attention to the presence or absence of bilingualism. The concepts of cognitive and cerebral reserve are explored, along with findings from studies evaluating the effects of bilingualism on cognitive reserve and on the preservation of brain function during neurodegeneration. Bilingualism is identified as a multifaceted phenomenon encompassing various components of language experience, such as proficiency level, functional language use, language of education, age of second-language acquisition, societal status of languages, and language switching. These factors complicate research on how bilingualism influences the progression of cognitive impairment in neurodegenerative settings. The article discusses the methodological challenges inherent in bilingualism research and considers the potential influence of learning additional languages on the development of cerebral structures and neuronal connections, as shaped by language experience. The review details findings from studies investigating the impact of bilingualism on the onset and progression of Alzheimer's disease. Overall, the evidence suggests that the relationship between bilingualism and Alzheimer's disease is complex and multifactorial. Current data indicate that bilingualism is likely a significant contributor to cognitive reserve, although interpretation of research findings is frequently complicated by methodological limitations. В настоящей статье обсуждены взаимосвязь развития когнитивных нарушений и нейродегенеративного процесса у пациентов с болезнью Альцгеймера в зависимости от наличия или отсутствия билингвизма. Подробно обсуждена концепция когнитивного и церебрального резерва, приведены результаты исследований, посвященных оценке влияния билингвизма на когнитивный резерв и поддержание функций мозга в условиях развития нейродегенерации. Отдельно подчеркнуто, что билингвизм — сложное явление, состоящее из компонентов языкового опыта: уровень владения языками, функциональное использование языка, язык образовательной среды, возраст освоения второго языка, статус языков в обществе, языковое переключение, что значительно усложняет проведение исследований влияния билингвизма на скорость прогрессии когнитивных нарушений при нейродегенерациях. Обсуждены проблемы изучения билингвизма и предположительное влияние изучения второго и далее языков на формирование церебральных структур и нейрональных связей в зависимости от компонентов языкового опыта. Отдельно подробно обсуждены результаты исследований, посвященных оценке влияния билингвизма на развитие и дальнейшее прогрессирование болезни Альцгеймера. Проведенный анализ позволяет заключить, что исследование взаимосвязи билингвизма и болезни Альцгеймера представляет собой сложную и многогранную научную проблему: так, согласно имеющимся данным, билингвизм наиболее вероятно является значимым фактором когнитивного резерва; вместе с этим часто интерпретация результатов исследования сопряжена с существенными методологическими трудностями.