The behavioral effects of α-synuclein oligomers were studied at various times after its chronic intranasal administration to 75-day-old C57BL/6J mice in comparison with the dynamics of changes in the transcriptional activity of caspases genes (Casp9, Casp8, and Casp3) in the hippocampus, frontal cortex, and cerebellum. The negative effects of α-synuclein oligomers on exploratory activity and short-term memory in the novel object recognition test were most pronounced after 90 days from the end of administration, while after 1 and 270 days, partial compensation of the studied cognitive functions was observed. Analysis of the expression of caspase genes suggests that early compensatory mechanisms are associated with suppression of the effector caspase-3 gene expression along with increased activity of the genes encoding initiator caspases-9 and -8. Late compensation processes are associated with a decrease in the activity of initiator caspases in the frontal cortex and cerebellum.

Образование нейротоксических амилоидогенных форм белка альфа-синуклеина (α-син) является ключевым молекулярным звеном патогенеза ряда нейродегенеративных заболеваний, включая болезнь Паркинсона (БП). Есть основания полагать, что развитие когнитивных нарушений на субклиническом уровне предшествует манифестации моторных симптомов БП, причем имеются весомые свидетельства сопряженности этих нарушений с дезорганизацией механизмов регуляции нейрогенеза в зрелом мозге. Однако сведения о долгосрочном влиянии амилоидогенных форм α-син на динамику когнитивной активности и молекулярные процессы в трансляционных моделях синуклеинопатий практически отсутствуют. Цель работы – изучение динамики эффектов интраназального введения олигомеров α-син молодым половозрелым животным в отношении исследовательской активности и эпизодической памяти, а также экспрессии генов S100A6 и ASCL1, регулирующих различные стадии нейрогенеза, в гиппокампе, фронтальной коре и мозжечке с одновременной оценкой структурно-функциональных связей между поведенческими и молекулярными показателями. Материалы и методы. Самцам мышей С57BL/6J 2,5-месячного возраста в течение 14 дней интраназально вводили раствор полученных in vitro олигомеров рекомбинантного α-син либо физиологический раствор с последующим тестированием поведения в модели «Распознавание нового объекта» в возрасте 3, 6 и 12 месяцев. В каждой из возрастных точек определяли экспрессию генов S100A6 и ASCL1 в гиппокампе, фронтальной коре и мозжечке методом полимеразной цепной реакции. Результаты исследования. В возрасте 3 месяцев у мышей, получавших олигомеры α-син, обнаружено снижение относительно контроля скорости передвижения в условиях повышения новизны контекста при сохранности других показателей поведения, а также возрастание экспрессии генов S100A6 и ASCL1 во фронтальной коре и снижение активности гена ASCL1 в мозжечке. В возрасте 6 месяцев у животных экспериментальной группы наблюдалось снижение исследовательской активности и эпизодической памяти при отсутствии отличий от контроля по показателям транскрипционной активности исследованных генов. В 12 месяцев в опытной группе выявлены нарушения инициации исследовательского поведения и эпизодической памяти; наблюдалось также снижение экспрессии гена ASCL1 во фронтальной коре и мозжечке. Выявленные в различных временных точках корреляционные связи молекулярных и поведенческих показателей свидетельствуют о возможной компенсаторной/протекторной роли изменений экспрессии гена ASCL1 после введения олигомеров α-син у 3-месячных животных. Заключение. Результаты проведенных исследований показывают, что динамика развития когнитивного дефицита после введения амилоидогенных форм α-син определяется не только их токсическим воздействием, но также компенсаторными процессами, включающими изменения транскрипционной активности генов, регулирующих процессы нейрогенеза в зрелом мозге. Полученные данные позволяют предположить существование специфичных для определенных возрастных периодов компенсаторных механизмов, связанных с регуляцией стадий пролиферации и дифференцировки нейрогенеза у взрослых животных. Дальнейшие исследования, направленные на выявление таких механизмов, представляются необходимыми для развития персонализированных стратегий профилактики и терапии нейродегенеративных нарушений. The formation of neurotoxic amyloidogenic forms of the protein alpha-synuclein (α-syn) is a key molecular link in the pathogenesis of a number of neurodegenerative diseases, including Parkinson’s disease (PD). There is reason to believe that the development of cognitive impairment at a subclinical level precedes the manifestation of motor symptoms of PD, and there is significant evidence that these disorders are associated with disorganization of the mechanisms regulating neurogenesis in the mature brain. However, information about the long-term influence of amyloidogenic forms of α-syn on the dynamics of cognitive activity and molecular processes in translational models of synucleinopathies are practically absent. The aim of the work is to study the dynamics of the effects of intranasal administration of α-syn oligomers to young sexually mature animals in relation to exploratory activity and episodic memory, as well as the expression of the S100A6 and ASCL1 genes, which regulate various stages of neurogenesis, in the hippocampus, prefrontal cortex and cerebellum with simultaneous assessment of the structural functional connections between behavioral and molecular indicators. Materials and methods. Male C57BL/6J mice, 2.5 months old, were intranasally injected with a solution of recombinant α-syn oligomers or saline for 14 days, followed by behavioral testing in a novel object recognition model at the ages of 3, 6, and 12 months. At each age point, the expression of the S100A6 and ASCL1 genes in the hippocampus, frontal cortex and cerebellum was determined using the polymerase chain reaction method. Results. At the age of 3 months, mice treated with α-syn oligomers showed a decrease in movement speed relative to control under conditions of increasing context novelty while maintaining other behavioral indicators, as well as an increase in the expression of S100A6 and ASCL1 genes in the cortex and a decrease in ASCL1 activity in the cerebellum. At the age of 6 months, animals in the experimental group showed a decrease in exploratory activity and episodic memory, with no differences from the control in terms of transcriptional activity of the studied genes. At 12th months in the experimental group, disturbances in the initiation of exploratory behavior were revealed while maintaining its total duration and episodic memory; there was also a decrease in gene ASCL1 expression in the prefrontal cortex and cerebellum. Correlations of molecular and behavioral parameters identified at different time points indicate a possible compensatory/protective role of changes in gene ASCL1 expression after administration of α-syn in 3-month-old animals. Conclusion. The results of the studies show that the dynamics of the development of cognitive deficit after administration of α-syn is determined not only by the toxic effects of amyloidogenic forms of the protein, but also by compensatory processes, including changes in the transcriptional activity of genes that regulate the processes of neurogenesis in the mature brain. The data obtained also suggest the existence of age-specific compensatory mechanisms associated with the regulation of the cellular proliferation/differentiation stages of neurogenesis. Further research aimed at identifying such mechanisms seems necessary for the development of personalized strategies for the prevention and treatment of neurodegenerative disorders.

In the cerebellum, hippocampus, and prefrontal cortex of mature male Wistar rats with trained spatial navigational skill in the Morris water maze, the transcriptional activity the NAPA gene that regulates the transport and secretion of synaptic vesicles, release of neurotransmitters, and protein degradation was determined by real-time PCR. Animals subjected to forced swimming in a time-matched regime (active control) and naïve rats were used as the comparison groups. Suppression of NAPA gene activity was found in the hippocampus and cerebellum of the active control group, while navigation skill training led to a significant increase in gene expression in all brain structures under study. The findings suggest the existence of specific mechanisms regulating NAPA gene activity during the formation of spatial memory and adaptive behavior under stress conditions.

Parameters of blood cytokine profile in male and female rats subjected to prenatal stress on the model of swimming in cold water (10°C, 5 min, days 10-16 of gestation) were studied. Prenatal stress had no significant effects on the blood levels of IL-6 and IL-10 cytokines. The blood concentration of proinflammatory cytokine TNFα in 60-day-old rats was higher than in age-matched controls. Stress led to a lower level of anti-inflammatory IL-4 in the blood of 30-day-old males compared to controls. In female rats subjected to prenatal stress, the concentration of IL-4 decreased on day 21, but increased by day 60 of postnatal ontogeny. Specific effects of prenatal stress on the blood cytokine profile in male and female animals at different periods of ontogeny were revealed. Different and even opposite changes in blood cytokine levels could be largely mediated by sex- and age-specific features of immune functions after prenatal stress.

We studied the effects of chronic intranasal administration of amyloidogenic fibrils of the proinflammatory protein S100A9 alone or in combination with glutamate antibodies on the expression of the neuregulin-1 gene (NRG1), a regulator of various physiological processes, in particular, regulation of neurogenesis and apoptosis, in the hippocampus, prefrontal cortex, and cerebellum of aging C57BL/6 mice under conditions of long-term memory disturbances. Under conditions of amnesia induced by S100A9 fibrils, pronounced (>90%) blockade of the expression of the NRG1 gene was found in all cerebral structures. Glutamate antibodies prevented/corrected disturbances in the cerebral expression of the NRG1 gene, thereby maintaining the activity of the NRG1/ErbB molecular signaling system, probably associated with the formation of spatial memory.

Abstract —Parkinson’s disease is a widespread, progressive, age-related neurodegenerative disease. The neurochemical basis of motor and non-motor disorder in Parkinson’s disease is the dysfunction of many neurotransmitter systems of the brain and, first of all, the functional deficit and imbalance of monoaminergic systems, which result from the degradation and death of certain populations of nerve cells caused by misfolding of the α-synuclein protein and the action of its amyloidogenic neurotoxic conformations. Analysis of age-related changes in monoaminergic systems and the development of motor and non-motor disorders at the preclinical and clinical stages of the disease are of particular interest. We studied the effect of α-synuclein oligomers administered intranasally for 14 days on locomotor activity, emotional state, short- and long-term memory, and the content and metabolism of dopamine, serotonin, and norepinephrine in the hippocampus, frontal cortex, and cerebellum of male C57Bl/6 mice at the age of 3 months. In behavioral experiments, the following tests were used: “open field,” “novel object recognition,” “passive avoidance,” and “elevated plus maze.” The content of monoamines and their metabolites in the brain tissue of animals was determined by high performance liquid chromatography with electromagnetic detection. It was found that mice treated with α-synuclein oligomers showed manifestations of affective-like behavior with signs of apathy. The animals showed no disorders in motor activity, short-term and long-term memory, and no changes in anxiety level. Oligomers of α-synuclein caused a significant decrease in the content of dopamine and its metabolites DOPAC and HVA in the frontal cortex, as well as a decrease in the concentration of the dopamine metabolite, 3-MT, and opposite directed changes in serotonin and dopamine metabolism in the hippocampus. However, a significant increase in the content of 3-MT in the cerebellum was recorded. We performed comparative analysis of the data obtained in this work and the results of our previous study of the neurochemical and behavioral effects of α-synuclein oligomers in 6-month-old mice. The results indicate that oligomers of α‑synuclein, when administered chronically intranasally, induce non-motor disorders and neurochemical changes in mice of 3 months of age, which are also observed at the preclinical stage of PD.

Abstract—We studied the effects of intranasal administration of native α-synuclein, whose hyperproduction and misfolding are the key link in the pathogenesis of Parkinson’s disease and other age-related neurodegenerative diseases, on hippocampal neurogenesis, the number of dopaminergic neurons in the substantia nigra, locomotor activity, learning, memory, and anxiety level in ageing animals. The experiments were performed with 12-month-old C57BL/6 male mice which were treated for 14 days with a solution of recombinant native α-synuclein or physiological saline once every 24 hours. To evaluate behavioral indices, the following tests were used: open field, novel object recognition, conditioned passive avoidance response, and elevated plus maze. Proliferating cells, immature neurons, and dopaminergic nerve cells were immunohistochemically detected using antibodies against bromodeoxyuridine, doublecortin, and tyrosine hydroxylase. It was demonstrated that α-synuclein causes a considerable increase in the number of proliferating cells and a decrease in the number of immature neurons in the dentate gyrus the hippocampus, as well as a decrease in the density of dopaminergic neurons in the substantia nigra pars compacta. Mice that received native α-synuclein demonstrated lower locomotion speed, impairments in long-term associative memory, and changes in anxiety-like behavior. We compared the obtained data with the previous results on the effects of α-synuclein oligomers and fibrils under similar experimental protocols. The data are viewed as experimental evidence of the impairment of postnatal neurogenesis during the development of synucleinopathies and support the notion that different α-synuclein conformations cause the development of different neurodegenerative diseases.

Proinflammatory S100A9 protein is a promoter of inflammation-linked neurodegeneration and the Tnfrsf1A gene encodes the TNF receptor 1A that binds TNFα to function as a regulator of inflammation. We studied the effects of chronic intranasal administration of in vitro prepared S100A9 fibrils alone or in combination with anti-glutamate antibodies on the expression of the Tnfrsf1A gene in the hippocampus, prefrontal cortex, and cerebellum of aging C57BL/6 mice under conditions of impaired spatial memory. A differential cerebral pattern of Tnfrsf1A gene activity and its modification by S100A9 fibrillar structures were observed: inhibition of Tnfrsf1A gene expression in the hippocampus and cerebellum and its activation in the prefrontal cortex. Anti-glutamate antibodies normalized the expression of the Tnfrsf1A gene in the prefrontal cortex by affecting the TNF signaling pathway and preventing the development of inflammation.

Целью данного исследования явилось сравнительное изучение особенностей одновременной экспрессии генов апоптоза Вах, Dffb и Casp-3, Casp-8, Caps-9 в гиппокампе, префронтальной коре и мозжечке в условиях контрольного принудительного плавания и при обучении пространственному навыку в водном лабиринте Морриса у взрослых крыс Вистар. Методы. Для выработки долговременной пространственной памяти в работе использовали поведенческую модель водного лабиринта Морриса. Генетические исследования проведены на релевантных структурах мозга - гиппокампе, префронтальной коре и мозжечке крыс со сформированной пространственной памятью. Изучали экспрессию генов Вах, Dffb и Casp-3, Casp-8 и Casp-9 методом ПЦР в режиме реального времени в данных церебральных структурах животных. Результаты исследования. Обнаружено, что физическая нагрузка и стресс подавляют активность генов-регуляторов апоптоза в гиппокампе (по сравнению с интактными животными). В двух других структурах мозга (в префронтальной коре и мозжечке) отмечается активация гена Casp-3, что может скорее указывать на участие фермента Casp-3 в нейропластических клеточных перестройках, чем в апоптотических реакциях, при подавлении экспрессии других изучаемых генов - Вах, Dffb, Casp-8 и Casp-9. У животных, обученных навигационному навыку при формировании гиппокамп-зависимой пространственной памяти, отмечается активация генов Casp-9, Casp-3 и Вах в гиппокампе (по сравнению с активным контролем - «пассивное плавание»). В префронтальной коре мозга у обученных животных отмечается выраженное увеличение экспрессии всех изучаемых генов-регуляторов апоптоза. Мозжечок у крыс с формированной пространственной памятью манифестировал значительную активацию генов Casp-9, Вах и Dffb. Заключение. Полученные данные свидетельствуют о кооперативных эффектах экспрессии генов-регуляторов апоптоза в мозге животных, у которых сформировалась гипокамп-зависимая пространственная память в водном лабиринте Морриса. The aim of this study was to compare features of simultaneous expression of apoptosis genes, Bax, Dffb, and Casp-3, Casp-8, and Caps-9, in the hippocampus, prefrontal cortex, and cerebellum under the conditions of forced swimming (control) and during Morris water maze training for spatial skills in adult Wistar rats. Methods. To develop long-term spatial memory, the behavioral model of Morris water maze was used. Genetic studies were performed on the relevant brain structures, the hippocampus, prefrontal cortex, and cerebellum, of rats with formed spatial memory. The expression of Bax, Dffb and Casp-3, Casp-8, and Casp-9 genes was measured with real-time PCR in these cerebral structures. Results. Physical activity and stress were found to exert a suppressive effect on the apoptosis-regulating genes in the hippocampus as compared to control animals. In the prefrontal cortex and cerebellum, the Casp-3 gene was activated, which may indicate participation of the Casp-3 enzyme in neuroplasticity of cell rearrangements rather than in apoptotic reactions upon suppressed expression of the other studied genes, Bax, Dffb, Casp-8, and Casp-9. In animals trained for the navigation skill, the formation of hippocampus-dependent spatial memory was associated with activation of the Casp-9, Casp-3, and Bax genes in the hippocampus compared to the “passive swimming” control. In the prefrontal cortex of trained animals, a pronounced increase in the expression of all apoptosis-regulating genes was noted. The cerebellum of rats with formed spatial memory showed a significant activation of the Casp-9, Bax, and Dffb genes. Conclusion. The study showed cooperative effects of the expression of apoptosis-regulating genes in the brain of animals with the hippocampus-dependent spatial memory formed in the Morris water maze.

There has been a spike in recent news regarding motorized scooter injuries due to the expansion of scooter sharing companies. Given the paucity of literature on this topic, the purpose of our study was to describe and quantify emergency department encounters associated with motorized scooter related injuries.The National Electronic Injury Surveillance System (NEISS) was queried for motorized scooter related injuries from 2013 to 2017. Patient demographics, diagnosis, injury location, narrative description of incident, and disposition data were collected from emergency department encounters.There were an estimated 32,400 motorized scooter injuries from 2013 to 2017. The estimated incidence did not change significantly over time with 1.9 cases per 100,000 in 2013 and 2.6 cases per 100,000 in 2017. A 77.0% increase in scooter injuries was noted for millennials from 2016 to 2017. Head injuries were the most common body area injured (27.6%). Fractures or dislocations (25.9%) were the most common diagnosis. The most common site of fracture was the wrist and lower arm (35.4%). There were no deaths. Major orthopaedic injury and concussion were the strongest independent predictors of hospital admission.Head injuries were the most commonly injured body part, while fractures or dislocations were the most common diagnosis. These results highlight the importance of using protective equipment while riding motorized scooters, and lay a foundation for future policies requiring helmet use.

Hyperproduction and disturbance of the protein conformation of α-synuclein that are associated with the formation of aggregated forms, which have a neurotoxic effect, are the key link in the mechanisms of the pathogenesis of synucleinopathies, which are chronic progressive neurodegenerative diseases. We studied the effects of chronic intranasal administration of fibrillar forms of α-synuclein on the processes of neurogenesis in the hippocampus, the content of dopaminergic neurons in the substantia nigra, motor and exploratory activity, short- and long-term memory, and anxiety in ageing animals. The experiments were performed with 12-month-old male C57Bl/6 mice, which were administered intranasally once a day with a solution of α-synuclein fibrils or physiological solution for 14 days. Behavioral experiments included the Open field, novel object recognition, passive avoidance, and elevated plus maze tests. We used antibodies against bromodeoxyuridine, doublecortin, and tyrosine hydroxylase to stain proliferating cells, immature neurons, and dopaminergic nerve cells. We found that α-synuclein fibrils do not cause significant changes in indices of neurogenesis, the number of proliferating cells and immature neurons in the hippocampal dentate gyrus; nor do they have a significant effect on exploratory behavior, short- and long-term memory, and anxiety in mice. However, animals that were treated with fibrils of α-synuclein had a significant increase in the number of dopaminergic neurons in the substantia nigra pars compacta and an increase in some indices of general motor activity. We compared the data on the effects of α-synuclein fibrils and the results of a previous study of the action of α-synuclein oligomers under the conditions of a similar experimental protocol. We discuss possible mechanism of the revealed effect of α-synuclein fibrils on dopaminergic neurons of the substantia nigra of ageing mice.

Одним из важнейших патогенетических звеньев развития синуклеинопатий - группы хронических нейродегенеративных заболеваний, таких как болезнь Паркинсона, деменции с тельцами Леви и других является гиперпродукция белка α-синуклеина с последующей его агрегацией и образованием различающихся по размеру и структуре амилоидогенных форм белка, которые инициируют гибель нервных или глиальных клеток. В настоящее время для более полного понимания происходящих in vivo патологических процессов актуально изучение на моделях животных поведенческих эффектов как нативного белка α-синуклеина, так и его отдельных амилоидогенных структур (олигомеров и фибрилл), полученных и охарактеризованных in vitro, а также композиционных смесей данных белковых конформаций. Целью данной работы явилось изучение влияния композиционной смеси нативного белка α-синуклеина и олигомеров α-синуклеина при хроническом интраназальном введении на двигательную активность, кратковременную и долговременную память, а также тревожность стареющих мышей. Методы. Опыты проводили на 12- месячных самцах мышей C57Bl/6, которым на протяжении 14 дней один раз в сутки вводили отдельно в каждую ноздрю раствор α-синуклеина и его олигомеров, либо физиологический раствор. В тестах «Открытое поле», «Распознавание нового объекта», «Условная реакция пассивного избегания» и «Приподнятый крестообразный лабиринт» оценивали двигательную активность, кратко- и долговременную память, и тревожность животных. Результаты. Показано, что исследованная композиционная смесь конформаций α-синуклеина не вызывает статистически значимых изменений регистрируемых поведенческих показателей у стареющих мышей. Вместе с тем, ранее нами было документировано, что в условиях аналогичного экспериментального протокола нативный α-синуклеин инициирует снижение двигательной активности, а олигомеры α-синуклеина - угнетение двигательной активности, нарушение долговременной памяти и тревожности животных. Заключение. Полученные результаты свидетельствуют о менее выраженных поведенческих эффектах композиционной смеси нативной и олигомерной форм α-синуклеина, по сравнению с отдельными ее компонентами. Рассматриваются возможные механизмы выявленных особенностей влияния исследованной композиционной смеси конформаций α-синуклеина на поведенческом уровне. One of the most important steps in the pathogenesis of synucleinopathies, a group of chronic neurodegenerative diseases, such as Parkinson’s disease, dementia with Lewy bodies and others, is overproduction of α-synuclein protein, followed by its aggregation and formation of amyloidogenic protein species, which differ in their size and structure and initiate death of nerve or glial cells. At present, better understanding of in vivo pathological processes requires studying behavioral effects of both the native α-synuclein protein and its individual amyloidogenic structures (oligomers and fibrils) obtained and characterized in vitro on animal models, as well as composite mixtures of these protein conformations. The aim of this work was to study effects of chronic nasal application of a composite mixture of native α-synuclein protein and α-synuclein oligomers on motor activity, short-term and long-term memory, and anxiety of aging mice. Methods. Experiments were carried out on 12-month old male C57Bl/6 mice, which received a solution of α-synuclein and its oligomers or a saline solution separately into each nostril for 14 days daily. Motor activity, short- and long-term memory and anxiety of animals were evaluated in Open Field, Novel Object Recognition, Conditioned Passive Avoidance, and Elevated Plus Maze tests. Results. The studied composite mixture of α-synuclein conformations did not induce statistically significant changes in behavioral indices of aging mice. At the same time, we have previously documented that in a similar experimental protocol, native α-synuclein initiates a decrease in motor activity, and α-synuclein oligomers - inhibition of motor activity and disorders of long-term memory and anxiety. Conclusion. The results indicated less pronounced behavioral effects of the composite mixture of native and oligomeric forms of α-synuclein compared with its individual components. The authors discussed possible mechanisms of the behavioral effects of the studied composite mixture of α-synuclein confirmations.

The expression of Notch2, Numb, and Cas8 genes, whose protein products are involved in regulation of neurogenesis/neuroapoptosis processes, was studied in the relevant cerebral structures of male Wistar rats trained in a spatial habit. The formation of long-term spatial memory was found to be associated with the formation of a specific pattern of transcription activity of the studied genes in different brain structures. The maximum expression of Notch2 gene was found in the hippocampus and cerebellum, the maximum expression of Numb was detected in the prefrontal cortex and cerebellum, and the maximum expression of Cas8 was revealed in the prefrontal cortex of trained animals.