[Impairment of attention and executive functions in chronic cerebrovascular disease and Alzheimer's disease]. / Narushenie vnimaniya i upravlyayushchikh funktsii pri sosudistykh kognitivnykh narusheniyakh i bolezni Al'tsgeimera.

OBJECTIVE: To establish specific features of executive functions (EF) impairment and attention in vascular cognitive impairment (VCI) and Alzheimer's disease (AD). MATERIAL AND METHODS: Eighty people (over the age of 50) diagnosed with cerebrovascular disease (CVD) and AD, as well as 29 healthy volunteers (control group), were examined. The following neuropsychological methods were used to study the quantitative and qualitative characteristics of cognitive impairments: Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), EXIT-25, Frontal Assessment Battery (FAB), Clock Drawing Test, «12 Words¼ test, verbal associations (literal and categorical) method, Trail Making Test A and B, Symbol-Digit Modalities Test (SDMT), Stroop Test, and Benton Visual Retention Test. Mandatory inclusion criteria in the study included having a completed magnetic resonance imaging (MRI) of the brain (in T1, T2, FLAIR, DWI, SWI modes) within 1 year before enrollment in one of the groups. RESULTS: No significant differences in age, sex, and level of education were found between the groups. Groups AD and CVD were also comparable in the severity of cognitive impairment overall. Attention and working memory deficits were observed in both CVD and AD, with slightly more pronounced deficits in the AD group. Qualitative analysis of individual components of working memory revealed that both CVD and AD groups had comparable cognitive control impairment compared to the control group, while AD was characterized by a more significant decrease in intellectual flexibility compared to CVD. Sustained attention was equally impaired among patients in the CVD and AD groups, with a significant difference from the control group (p<0.05). In terms of memory, it was found that auditory-verbal memory and semantic memory were significantly more affected in AD, while visual memory was impaired in both conditions. CONCLUSION: Attention and EF impairments are not specific to the «subcortical¼ type of cognitive disorders. Already in the early stages, AD is characterized by a significant impairment of attention and EF, and such a component of EF as intellectual flexibility suffers at the onset of AD to a greater extent than in VCI. Memory impairments are not specific to AD; already at the onset of VCI, visual memory impairment comparable to AD is noted. The obtained data can be used for early neuropsychological diagnosis and differential diagnosis of dementing cerebral diseases.

Specific Aspects of Eye Movement Reactions as Markers of Cognitive Control Disorders in Patients with Obsessive-Compulsive Disorder (Review).

Multiple studies in patients with obsessive-compulsive disorder (OCD) became the basis for revealing selective attention, inhibitory control, and working memory impairments, which correlates with an imbalance in the activity of the cortico-striatal-thalamic-cortical circuit associated with maintenance of cognitive control functions. Patients with OCD often demonstrate changes in the parameters of target-oriented eye movement reactions being a consequence of a possible impairment of the cognitive control neurophysiological framework. This review summarizes and analyzes data on cognitive control disorders in OCD obtained with eye movement recording techniques. It was established that the most often used are smooth pursuit eye movements tasks, memory-guided saccades, and anti-saccadic tasks. Data on smooth pursuit eye movements tasks and memory-guided saccades are contradictory, although they partially confirm selective attention and working memory impairment. Most studies on the anti-saccadic task identified impaired inhibitory control in patients with OCD. Similar disorders in form of increased latency and higher error rate in anti-saccades were also noted in the patients' first-degree relatives, which allows considering such disorders as manifestations of the endophenotype associated with the underlying risk of OCD. Future confirmation of these results in experiments using complex anti-saccadic tasks with images of various modalities (taking into account the increased anxiety in patients with OCD as the disorder basis) might contribute to validation of the OCD-specific markers.

Anisotropic ZnS:Cr2+ crystal: material for compact and efficient mid-IR tunable lasers.

A laser-quality anisotropic ZnS:Cr2+ element was obtained using prolonged hot isostatic pressing at high temperature. Lasing centered at a wavelength of 2.45 µm was obtained with longitudinal pumping at a wavelength of 1.94 µm. The short-cavity laser slope efficiency with respect to the absorbed power was about 78%. The lasing wavelength was continuously tuned in the range of 2.35-2.52 µm by rotating the Brewster active element around the normal to its surface.

A Method for Recording the Bioelectrical Activity of Neural Axons upon Stimulation with Short Pulses of Infrared Laser Radiation.

The aim of the study was to develop a method for long-term non-invasive recording of the bioelectrical activity induced in isolated neuronal axons irradiated with short infrared (IR) pulses and to study the effect of radiation on the occurrence of action potentials in axons of a neuron culture in vitro. MATERIALS AND METHODS: Hippocampal cells of mouse embryos (E18) were cultured in microfluidic chips made of polydimethylsiloxane and containing microchannels for axonal growth at a distance of up to 800 µm. We studied the electrophysiological activity of a neuronal culture induced by pulses of focused laser radiation in the IR range (1907 and 2095 nm). The electrophysiological activity of the neuronal culture was recorded using a multichannel recording system (Multi Channel Systems, Germany). RESULTS: The developed microfluidic chip and the optical stimulation system combined with the multichannel registration system made it possible to non-invasively record the action potentials caused by pulsed IR radiation in isolated neuronal axons in vitro. The propagation of action potentials in axons was detected using extracellular microelectrodes when the cells were irradiated with a laser at a wavelength of 1907 nm with a radiation power of 0.2-0.5 W for pulses with a duration of 6 ms and 0.5 W for pulses with a duration of 10 ms. It was shown that the radiation power positively correlated with the occurrence rate of axonal response. Moreover, the probability of a response evoked by optical stimulation increased at short optical pulses. In addition, we found that more responses could be evoked by irradiating the neuronal cell culture itself rather than the axon-containing microchannels. CONCLUSION: The developed method makes it possible to isolate the axons growing from cultured neurons into a microfluidic chip, stimulate the neurons with infrared radiation, and non-invasively record the axonal spiking. The proposed approach allowed us to study the characteristics of neuronal responses in cell cultures over a long (weeks) period of time. The method can be used both in fundamental research into the brain signaling system and in the development of a non-invasive neuro-interface.

Peculiarities of Histological Structure of Pulmonary Veins in Patients with Total Anomalous Pulmonary Venous Drainage as Morphological Substrates Relating to Formation of Postoperative Pulmonary Venous Obstruction.

The histological and immunohistochemical methods were employed to examine the peculiarities of histological structure of pulmonary veins and left atrium of the heart in norm and in various types of total anomalous drainage of pulmonary veins. In contrast to normal pulmonary vein covered with external multiple muscle layers (myocardial sleeve), such sleeve is absent in veins that have no connection with the left atrium irrespective of the type of the defect. In patients with total anomalous pulmonary venous drainage, the structure of left atrium was heterogeneous featuring either the presence or absence of inner angiomural lining in this atrium. The structural peculiarities are important for insight into etiology of the development of postoperative pulmonary venous obstruction in patients with total anomalous pulmonary venous drainage.

[An fMRI Study of the Brain Activation Related to Intensive Positive Emotions During Viweing Erotic Pictures in 49-74 Old Men].

According to psychological research erotic images are evaluated in the context of positive emotions as the most intense, most associated with emotional arousal, among the variety of pleasant and unpleasant stimuli. However it is difficult to separate areas of the brain that are related to the general emotional process from the activity of the brain areas involved in neuronal representations of reward system. The purpose of this study was to determine differences in the brain activity using functional magnetic resonance imaging (fMRI) in male subjects in evaluating an intensity of pleasant images, including erotic, or unpleasant and neutral pictures. When comparing the condition with evaluation of the pleasant erotic images with conditions containing neutral or unpleasant stimuli, a significant activation was observed in the posterior cingulate cortex; the prefrontal cortex and the right globus pallidus. An increased activity of the right anterior central gyrus was observed in the conditions related to evaluation of pleasant and neutral stimuli. Thus, in the process of evaluating the intensity of emotional images of an erotic nature the active brain areas were related not only to neuronal representations of emotions, but also to motivations and control system of emotional arousal, which should be taken into account while using erotic pictures as intensive positive emotional stimuli.

[Correlation of Resting State Functional Connectivity with Behavioral and Psychological Indices].

In recent years, a large amount of data was published about resting state networks (RSN), namely, continu- ously recorded brain activity in a state of quiet wakefulness. In particular, such states are reflected in the spa- tial maps of active regions of the brain, obtained by means of functional magnetic resonance imaging (fMRI). RSNs have stable and reproducible spatial structure over time in healthy subjects, but may differ substantially in clinical pathology. One of the important parameters of the brain activity is functional connectivity (FC) of individual elements within a network or between resting state networks. This review considers results of the studies focused at correlation of behavioral indicators and FC of brain areas activated during resting state. In addition, we describe data on reproducibility of RSN over time in healthy subjects, as well as data on changes in FC-of networks, depending on the individual experience.

[Comparative Analysis of the Brain Activity during Verbal and Spatial Thinking in Healthy Subjects and Patients with Speech Disorders].

We analyzed the specific brain activity, measured by fMRI in spatial and verbal tasks, in 15 healthy sub- jects and in 9 patients with dysarthria or mild sensorimotor aphasia. In healthy participants, verbal thinking was characterized by activation in Brodmann area 19 and Broca area while specific activation for spatial thinking was observed in bilateral temporal-occipital-parietal areas, left insula, left visual fields 17 and 18. In patients with impaired speech, this distribution of networks specific to a particular type of task underwent significant changes with deactivation of the brain areas, as compared to healthy subjects. Despite the absence of clinical manifestations of cognitive impairment, the average time .to solve verbal tasks was significantly higher, and the percentage of correct answers was less in patients as compared to these values for a group of healthy subjects.

[Age differences of event-related potentials in the perception of successive and spacial components of auditory information].

The perception of spatial and successive contexts of auditory information develops during human ontogeny. We compared event-related potentials (ERPs) recorded in 5- to 6-year-old children (N = 15) and adults (N = 15) in response to a digital series with omitted digits to explore age differences in the perception of successive auditory information. In addition, ERPs in response to the sound of falling drops delivered binaurally were obtained to examine the spatial context of auditory information. The ERPs obtained from the omitted digits significantly differed in the amplitude and latency of the N200 and P300 components between adults and children, which supports the hypothesis that the perception of a successive auditory structure is less automated in children compared with adults. Although no significant differences were found in adults, the sound of falling drops presented to the left ears of children elicited ERPs with earlier latencies and higher amplitudes of P300 and N400 components in the right temporal area. Stimulation of the right ear caused increasing amplitude of the N100 component in children. Thus, the observed differences in auditory ERPs of children and adults reflect developmental changes in the perception of spatial and successive auditory information.

[Mismatch negativity and its hemodynamic equivalent (based on fMRI) in research of speech perception in healthy and in speech disorders].

The review is devoted to the use of electrophysiological index of auditory discrimination, known as "mismatch negativity" (MMN), and its hemodynamic equivalent obtained by functional magnetic resonamce imaging (fMRI) to study speech perception in normal and pathological conditions. Most attention is paid to works with using MMN as a neurophysiological index of the phonemic hearing impairment in patients with sensory aphasia. The MMN applicability for examination of speech compensation degree is substantiated. Also the perspectives of simultaneous EEG-fMRI registration in exploring speech pathologe are considered.

[Brain mapping in verbal and spatial thinking].

The goal of this study was to describe the topography of the active cortical areas and subcortical structuresin verbal and spatial thinking. The method of functional magnetic resonance imaging (fMRI) was used. 18 right-handed subjects participated in the study. Four types of tasks were presented: two experimental tasks--verbal (anagram) and spatial (search for a piece to complement a square), and two types of control tasks (written words and a spatial task, where all the pieces are identical). In solving verbal tasks the greater volume of activation was observed in the left hemisphere involving Broca's area, while the right middle frontal gyrus was activated in solving the spatial tasks. For occipital region an activation of the visual field 18 was more explicitin solving spatial problems, while the solution of anagrams caused an activation of the field 19 associated with higher levels of visual processing. The cerebellum was active bilaterally in both tasks with predominance in the second. The obtained fMRI data indicate that the verbal and spatial types of thinking are provided by an activation of narrow specific sets of brain structures, while the previous electrophysiological studies indicate the distributed nature of the brain processes in thinking. Combining these two approaches, it can be concluded that cognitive functions are supported by the systemic brain processes with a distinct location of the particular salient structures.

[FMRI-study of speech perception impairment in post-stroke patients with sensory aphasia].

The aim of the study was to find neurophysiological correlates of the primary stage impairment of speech perception, namely phonemic discrimination, in patients with sensory aphasia after acute ischemic stroke in the left hemisphere by noninvasive method of fMRI. For this purpose we registered the fMRI-equivalent of mismatch negativity (MMN) in response to the speech phonemes--syllables "ba" and "pa" in odd-ball paradigm in 20 healthy subjects and 23 patients with post-stroke sensory aphasia. In healthy subjects active brain areas depending from the MMN contrast were observed in the superior temporal and inferior frontal gyri in the right and left hemispheres. In the group of patients there was a significant activation of the auditory cortex in the right hemisphere only, and this activation was less in a volume and intensity than in healthy subjects and correlated to the degree of preservation of speech. Thus, the method of recording fMRI equivalent of MMN is sensitive to study the speech perception impairment.

[Changes in indexes of cardiovascular system in different mental tasks].

The influence of different types of mental activity on the cardiovascular system was analyzed by following indexes: the heart rate (HR), the variation magnitude (VM), the amplitude of systolic wave (SWA) and the pulse wave transit time (PWTT). A registration of these indexes was conducted when the subjects solved verbal-logical and spatial mental tasks. HR was significantly greater in the spatial tasks than in the verbal-logical tasks, while SWA had an inverse relationship. The time for solving of tasks of the both types did not differ significantly. Therefore, the observed changes in autonomic indexes were not related to a difficulty of the mental tasks, but depended on the specific cognitive processes involved in the mental tasks of different types. Thus, the observed change in HR and the decrease in SWA correlating with the blood pressure rise reflect an influence of the sympathetic nervous system on the heart work during mental tasks of the verbal-logic type. The obtained results suggest that the indexes of HR and a blood pressure may also serve as supporting criteria in a development of new technologies for a determination of different types of mental operations in addition to the rhythms of the brain electrical activity.

[Effect of water soluble non-membrane proteins on the phospholipid structure]. / Vliianie vodorastvorimykh nemembrannykh belkov na strukturnuiu organizatsiiu fosfolipidov.

The interaction of water-soluble nonmembraneous proteins (trypsin and the basic pancreatic trypsin inhibitor (BPTI)) with soybean phospholipids was studied using multilamellar vesicles. Multilamellar vesicles were obtained from soybean lipid extracts and mixtures of individual phospholipids based on phosphatidylcholine. These mixtures contain different phospholipids: "bilayer", "nonbilayer", and negatively charged. It was shown that the content of both proteins in the complex depends on pH and the presence of negatively charged components. On the basis of this finding, the conclusion about the electrostatic nature of lipid-protein interaction was made. The structural organization of soybean phospholipids in multilamellar vesicles was studied in the presence and absence of the proteins using broad-line 31P-NMR spectroscopy. It was found that, in mixtures of phospholipids of complex composition, different types of phases coexist, and phospholipids of different classes can compensate the effects of each other. Trypsin and BPTI affect the structure of phospholipids in a similar way, inducing considerable structural changes in multilamellar vesicles of preparations containing negatively charged components in whose structure there coexisted primordially the bilayer and isotropic phases.

[Proteins and saponins in the lipid preparation obtained by extraction of soybean flour]. / Belki i saponiny v lipidnom preparate, poluchennom pri ékstraktsii soevoi muki.

A complex lipid preparation was obtained by extraction of soybean flour with organic solvents. This preparation was shown to include not only phospholipids (major components), but also up to 30% saponins. These compounds were identified by TLC, HPLC, and 1H-NMR spectroscopy. Minor components of the lipid extract were represented by polypeptides associated with phospholipids via electrostatic or hydrophobic forces.

Speech sounds learned by sleeping newborns.

It is not yet clear whether humans are able to learn while they are sleeping. Here we show that full-term human newborns can be taught to discriminate between similar vowel sounds when they are fast asleep. It is possible that such sleep training soon after birth could find application in clinical or educational situations.

Mismatch negativity and late discriminative negativity in investigating speech perception and learning in children and infants.

For decades, behavioral methods, such as the head-turning or sucking paradigms, have been the primary tools to investigate speech perception and learning of a language in infancy. Recently, however, new methods provided by event-related potentials have emerged. These are called mismatch negativity (MMN) and late discriminative negativity (LDN). MMN, the brain's automatic change-detection response in audition, has been intensively used in adults in both basic and clinical studies for longer than 20 years. LDN, on the other hand, was only recently discovered. There seem to be many differences between these two responses. MMN is developmentally quite stable and can be obtained even from preterm infants. LDN, however, can be obtained most reliably from young children, and its amplitude decreases as a function of age. New data suggest that both of these responses have a special role in language processing, although both of them can also be elicited by nonspeech stimuli.

[Effect of modified SHF and acoustic stimulation on spectral characteristics of the electroencephalograms of the cat brain]. / Vliianie modulirovannoi SVCh i akusticheskoi stimuliatsii na spektral'nye kharakteristiki élektroéntsefalogrammy mozga koshki.

The effect of modulated electromagnetic fields on the spectral parameters of bioelectric brain activity in awake cats was studied by registering the electroencephalogram from the skin surface in the vertex area using carbon electrodes. In the normal electroencephalogram, spectral components in the range above 20 Hz predominated. It was shown that, upon irradiation with electromagnetic field (basic frequency 980 MHz, power density 30-50 microW/cm2), spectral components in the range of 12-18 Hz begin to prevail. A similarity in the redistribution of the power of spectral components upon both acoustic and modulated electromagnetic influences was revealed. The results suggest that there is a a common neurophysiological mechanism by which modulated electromagnetic radiation and acoustic stimulation affect the electrical activity of the brain. This ia consistent with the assumption that the effect of the electromagnetic field on the central nervous system is mediated through the acoustic sensory system.

Interaction of trypsin with multilamellar vesicles of soybean lipids.

The pH dependence of complex formation of trypsin with multilamellar vesicles (MLV) of soybean lipids has been investigated. The lipids were characterized by the same phospholipid composition, but the content of other lipids differed. Decrease of pH or introduction of negatively charged components into the lipid samples increased trypsin content in the protein-lipid complexes. This suggests electrostatic interaction between the protein and soybean lipids. The dependence of trypsin activity in the complexes with MLV on their concentration and on the presence of an ionic detergent was studied. Trypsin-MLV interaction did not result in complete inactivation of the protein molecules. Moreover, the effects of dilution and addition of ionic detergent on trypsin activity were additive. Using a fluorescence technique, complex formation with MLV was found to stabilize trypsin molecules, preventing their autolysis.