Minimum message length clustering: an explication and some applications to vegetation data

In this paper, we examine the application of a particular approach to induction, the minimum message length principle and illustrate some of the problems that can be addressed through its use. The MML principle seeks to identify an optimal model within some specified parameterised class of models and for this paper we have chosen to concentrate on a single model class, that of mixture separation or fuzzy clustering. The first section presents, in outline, an MML methodology for fuzzy clustering. We then present some applications, including the nature of the within-cluster model, examination of the univocality of results for different groups of species and the effectiveness of presence data compared to purely quantitative data. Finally, we examine some possibilities of extending MML methodology to include within-class correlation of species, the existence of dependence between observed samples and the comparison of different classes of models

Communication impairment in ultrasonic vocal repertoire during the suckling period of Cd157 knockout mice: Transient improvement by oxytocin

Communication consists of social interaction, recognition, and information transmission. Communication ability is the most affected component in children with autism spectrum disorder (ASD). Recently, we reported that the CD157/BST1 gene is associated with ASD, and that CD157 knockout (Cd157-/-) mice display severe impairments in social behavior that are improved by oxytocin (OXT) treatment. Here, we sought to determine whether Cd157-/- mice can be used as a suitable model for communication deficits by measuring ultrasonic vocalizations (USVs), especially in the early developmental stage. Call number produced in pups due to isolation from dams was higher at postnatal day (PND) 3 in knockout pups than wild-type mice, but was lower at PNDs 7 and 10. Pups of both genotypes had similarly limited voice repertoires at PND 3. Later on, at PNDs 7 and 10, while wild-type pups emitted USVs consisting of six different syllable types, knockout pups vocalized with only two types. This developmental impairment in USV emission was rescued within 30 min by intraperitoneal OXT treatment, but quickly returned to control levels after 120 min, showing a transient effect of OXT. USV impairment was partially observed in Cd157+/- heterozygous mice, but not in Cd157-/- adult male mice examined while under courtship. These results demonstrate that CD157 gene deletion results in social communication insufficiencies, and suggests that CD157 is likely involved in acoustic communication. This unique OXT-sensitive developmental delay in Cd157-/- pups may be a useful model of communicative interaction impairment in ASD. © 2017 Lopatina, Furuhara, Ishihara, Salmina and Higashida

Designing in vitro Blood-Brain Barrier Models Reproducing Alterations in Brain Aging

Blood-brain barrier (BBB) modeling in vitro is a huge area of research covering study of intercellular communications and development of BBB, establishment of specific properties that provide controlled permeability of the barrier. Current approaches in designing new BBB models include development of new (bio) scaffolds supporting barriergenesis/angiogenesis and BBB integrity; use of methods enabling modulation of BBB permeability; application of modern analytical techniques for screening the transfer of metabolites, bio-macromolecules, selected drug candidates and drug delivery systems; establishment of 3D models; application of microfluidic technologies; reconstruction of microphysiological systems with the barrier constituents. Acceptance of idea that BBB in vitro models should resemble real functional activity of the barrier in different periods of ontogenesis and in different (patho) physiological conditions leads to proposal that establishment of BBB in vitro model with alterations specific for aging brain is one of current challenges in neurosciences and bioengineering. Vascular dysfunction in the aging brain often associates with leaky BBB, alterations in perivascular microenvironment, neuroinflammation, perturbed neuronal and astroglial activity within the neurovascular unit, impairments in neurogenic niches where microvascular scaffold plays a key regulatory role. The review article is focused on aging-related alterations in BBB and current approaches to development of “aging” BBB models in vitro

Plasticity of Adipose Tissue-Derived Stem Cells and Regulation of Angiogenesis

Adipose tissue is recognized as an important organ with metabolic, regulatory, and plastic roles. Adipose tissue-derived stem cells (ASCs) with self-renewal properties localize in the stromal vascular fraction (SVF) being present in a vascular niche, thereby, contributing to local regulation of angiogenesis and vessel remodeling. In the past decades, ASCs have attracted much attention from biologists and bioengineers, particularly, because of their multilineage differentiation potential, strong proliferation, and migration abilities in vitro and high resistance to oxidative stress and senescence. Current data suggest that the SVF serves as an important source of endothelial progenitors, endothelial cells, and pericytes, thereby, contributing to vessel remodeling and growth. In addition, ASCs demonstrate intriguing metabolic and interlineage plasticity, which makes them good candidates for creating regenerative therapeutic protocols, in vitro tissue models and microphysiological systems, and tissue-on-chip devices for diagnostic and regeneration-supporting purposes. This review covers recent achievements in understanding the metabolic activity within the SVF niches (lactate and NAD+ metabolism), which is critical for maintaining the pool of ASCs, and discloses their pro-angiogenic potential, particularly, in the complex therapy of cardiovascular and cerebrovascular diseases

Аберрантный ангиогенез в ткани головного мозга при экспериментальной болезни Альцгеймера

The aim was to study the molecular mechanisms of the violation of the structural and functional integrity ofthe blood-brain barrier in chronic neurodegeneration of the Alzheimer’s type associated with the development of cerebral angiopathy.Materials and methods. The transgenic model of Alzheimer’s disease is the B6SLJ-Tg line mice (APPSwFlLon,PSEN1 * M146L * L286V) 6799Vas group which includes 9 months aged males. The control group included C57BL / 6 x SJL mice, males aged 9 months.Results. The total length of the vessels in the area of the dentate gyrus is 2.5 times greater in transgenic animal models of Alzheimer’s disease than in animals of the control group (p < 0.01). The average diameter of blood vessels in all areas of the hippocampus is smaller compared with the control (p < 0.05). Transgenic modeling of neurodegeneration in the CA2 zone of the hippocampus increases the relative area of tissue with increased permeability of blood-brain barrier (BBB) (17.80 [9.15; 36.75]) compared to control (1.38 [0.04; 7.60]) at p < 0.05. A similar difference (p < 0.05) is also observed in the hippocampal area CA1. A tendency (p > 0.05) to decrease the number of CD31+ endothelial cells in the dentate gyrus of the hippocampus (21.52 [17.56; 24.50]) in animals of the experimental group compared with the control group (23.08[21.18; 29.84]) was detected. A similar situation is observed in the CA2 and CA3 areas of the hippocampus.Conclusion. Neurodegenerative changes in the hippocampus of animals with a transgenic AD model are associated with impaired microcirculation in the brain tissue as a result of a reduction in the diameter and branching of blood vessels, and damage and increased permeability of BBB.Цель – изучение молекулярных механизмов нарушения структурно-функциональной целостности гематоэнцефалического барьера (ГЭБ) при хронической нейродегенерации  альцгеймеровского типа, ассоциированной с развитием церебральной ангипопатии. Материалы и методы. Опытная группа – генетическая модель болезни Альцгеймера (БА) – мыши линии B6SLJ -Tg(APPSwFlLon,PSEN1*M146L*L286V)6799Vas, самцы в возрасте 9 мес. Контрольная группа – мыши линии C57BL/6 x SJL, самцы в возрасте 9 мес.Результаты. У животных с генетической моделью БА в зубчатой извилине гиппокампа  общая длина сосудов в 2,5 раза больше, чем у контрольной группы (p < 0,01), при этом  средний диаметр сосудов во всех областях гиппокампа меньше по сравнению с контролем (p < 0,05). Выявлено, что при генетическом моделировании  нейродегенерации в СА2 зоне гиппокампа наблюдается увеличение относительной  площади ткани с повышенной проницаемостью ГЭБ (17,80 [9,15;36,75]) по сравнению с контролем (1,38 [0,04;7,60]) при p < 0,05. Подобное различие (p < 0,05) наблюдается и в зоне СА1 гиппокампа. У животных опытной группы выявлена тенденция (p > 0,05) к снижению количества CD31+ эндотелиальных клеток в зубчатой извилине гиппокампа (21,52 [17,56; 24,50]) по сравнению с контролем (23,08 [21,18; 29,84]). Аналогичная ситуация наблюдается в зонах СА2 и СА3 гиппокампа.Заключение. Нейродегенеративные изменения в гиппокампе животных с генетической  моделью БА ассоциированы с нарушением микроциркуляции в ткани головного мозга в  результате сокращения диаметра и разветвленности сосудов, повреждения и повышения проницаемости ГЭБ

Differential Roles of Environmental Enrichment in Alzheimer’s Type of Neurodegeneration and Physiological Aging

Impairment of hippocampal adult neurogenesis in aging or degenerating brain is a well-known phenomenon caused by the shortage of brain stem cell pool, alterations in the local microenvironment within the neurogenic niches, or deregulation of stem cell development. Environmental enrichment (EE) has been proposed as a potent tool to restore brain functions, to prevent aging-associated neurodegeneration, and to cure neuronal deficits seen in neurodevelopmental and neurodegenerative disorders. Here, we report our data on the effects of environmental enrichment on hippocampal neurogenesis in vivo and neurosphere-forming capacity of hippocampal stem/progenitor cells in vitro. Two models – Alzheimer’s type of neurodegeneration and physiological brain aging – were chosen for the comparative analysis of EE effects. We found that environmental enrichment greatly affects the expression of markers specific for stem cells, progenitor cells and differentiated neurons (Pax6, Ngn2, NeuroD1, NeuN) in the hippocampus of young adult rats or rats with Alzheimer’s disease (AD) model but less efficiently in aged animals. Application of time-lag mathematical model for the analysis of impedance traces obtained in real-time monitoring of cell proliferation in vitro revealed that EE could restore neurosphere-forming capacity of hippocampal stem/progenitor cells more efficiently in young adult animals (fourfold greater in the control group comparing to the AD model group) but not in the aged rats (no positive effect of environmental enrichment at all). In accordance with the results obtained in vivo, EE was almost ineffective in the recovery of hippocampal neurogenic reserve in vitro in aged, but not in amyloid-treated or young adult, rats. Therefore, EE-based neuroprotective strategies effective in Aβ-affected brain could not be directly extrapolated to aged brain

Влияние инсулинорезистентности на нарушение метаболизма глюкозы в миндалине головного мозга при экспериментальной болезни Альцгеймера

Purpose. Glucose metabolism is tightly regulated in the brain. Aberrant glucose metabolism is an important feature of neurodegenerative diseases, as inAlzheimer’s disease. The transport of glucose to the cell membrane is realized through the activity of insulin-regulated aminopeptidase (IRAP) which controls transfer of glucose transporter to the plasma membrane. IRAP is considered as one of the key markers of insulin resistance in Alzheimer’s disease. However, the question of the mechanism of the action of the IRAP remains open. The aim of the study was to study the effect of IRAP expression on cells of the neuronal and glial lineage, glucose transporter (GLUT4) expression in the brain amygdala on emotional memory in animals with experimental Alzheimer’s disease.Materials and methods. The study was performed with two experimental models of Alzheimer’s disease in mice. The experimental group was mice of the CD1 line, males aged 4 months (Alzheimer’s disease model with the intra-hippocampal administration of beta-amyloid 1-42 (1 µl) bilaterally in the CA1 area). The control group was mice of the CD1 line, males aged 4 months (sham-operated animals with the intrahippocampal administration of Phosphate buffered salin (1 µl) bilaterally in the CA1). The genetic model of Alzheimer’s disease is the B6SLJ-Tg line mice (APPSwFlLon, PSEN1*M146L*L286V) 6799Vas, males aged 4 months. The control group consisted of C57BL/6xSJL mice, males aged 4 months. Evaluation of emotional memory was carried out using “Fear conditioning” protocol. Expression of molecule-markers of insulin-resistance in the amygdala was studied by immunohistochemistry followed by confocal microscopy.Results. Aberrant associative learning and emotional memory was revealed in animals with an experimental model of Alzheimer’s disease. A decrease (p ≤ 0,05) of IRAP expression on cells of neuronal and glial nature, associated with GLUT4 down-regulation was detected in amygdala of brain in animals with experimental Alzheimer’s disease.Conclusion. Decreased number of IRAP-immunopositive neuronal and astroglial cells, as well as IRAP+/ GLUT4+ in cells of amygdala in animals with an experimental model of Alzheimer’s disease, indicates the development of insulin resistance in amygdala of brain, which was in correlation with the hippocampus in performing cognitive functions and memorizing associated with emotionally colored events. Цель. В головном мозге метаболизм глюкозы четко регулируется, поэтому его нарушение является важной особенностью нейродегенеративных заболеваний, в частности болезни Альцгеймера. Транспорт глюкозы в мембрану клетки реализуется за счет активности инсулин-регулируемой аминопептидазы (IRAP), которая влияет на память и обучение, и рассматривается как один из ключевых маркеров инсулинорезистентности при болезни Альцгеймера. Однако вопрос о механизме действия IRAP остается открытым. Цель исследования – изучение влияния экспрессии IRAP на клетках нейрональной и глиальной природы, а также совместно с инсулинзависимым глюкозным транспортером (GLUT4) в миндалине головного мозга на эмоциональную память у животных с экспериментальной болезнью Альцгеймера.Материал и методы. Исследование проводили на животных с использованием двух экспериментальных моделей болезни Альцгеймера – инъекционной и генетической. Опытная группа – мыши линии CD1, самцы в возрасте 4 мес, которым билатерально вводили бета-амилоид 1-42 в зону гиппокампа CA1 (сornu аmmonis)по 1 мкл. Контрольная группа – мыши линии CD1, самцы в возрасте 4 мес, которым билатерально вводили растворитель для бета-амилоида – фосфатно-солевой буфер в зону CA1 по 1 мкл.Генетическая модель болезни Альцгеймера – мыши линии B6SLJ –Tg(APPSwFlLon,PSEN1*M146L*L286 V)6799Vas, самцы в возрасте 4 мес. Контрольная группа – мыши линии C57BL/6xSJL, самцы в возрасте 4 мес. Оценку эмоциональной памяти проводили с использованием нейроповеденческого тестирования Fear conditioning. Экспрессию молекул-маркеров инсулинорезистентности в миндалине изучали методом иммуногистохимии с последующей конфокальной микроскопией.Результаты. У животных с экспериментальной моделью болезни Альцгеймера выявлено нарушение ассоциативного обучения и эмоциональной памяти. Выявлено снижение (р ≤ 0,05) экспрессии IRAP на клетках нейрональной и глиальной природы, а также (совместно с GLUT4) в миндалине головного мозга у животных с экспериментальной болезнью Альцгеймера.Заключение. Уменьшение числа IRAP-иммунопозитивных нейрональных и астроглиальных клеток, а также экспрессии IRAP/GLUT4 в клетках миндалины у животных с экспериментальной моделью болезни Альцгеймера указывает на развитие инсулинорезистентности в миндалине головного мозга, находящейся во взаимосвязи с гиппокампом при осуществлении когнитивных функций и запоминания, сопряженных с эмоционально окрашенными событиями.