G. V. Portnova

Aggression and 5HTT polymorphism in females: study of synchronized swimming and control groups.

Aggression is a heterogeneous heritable psychological trait, also influenced by environmental factors. Previous studies, mostly conducted on male population, have found some associations of the aggression with the polymorphisms of genes, regulating the activity of serotonin (5-HT) in the brain. However, psychological as well as biochemical manifestations of the aggression are different in males and females. Our study aimed to investigate the association of 5-HTT gene polymorphism with different facets of aggression (BDHI) in females. Two groups: the synchronized swimming and non-athlete control, - were examined to study the possible modulation effect of sport on the association between 5-HTT gene polymorphism and aggression. It was found that in both groups the low-active 5-HTT polymorphism (SS) was associated with increased scores on Indirect Hostility scale and decreased scores on Negativism scale, compared to LL genotype. No interaction effect between sport and 5-HTT polymorphism was found. The higher percentage of LL-carriers and lower of LS-carriers in the synchronized swimming group compared to the control one was observed. This may be the sign of the importance of LL polymorphism of 5-HTT gene, previously associated with higher resistance to stress factors, for being an athlete, although this result has to be taken cautiously keeping in mind the stratification problem. Synchronized swimmers had lower scores on Assault, Negativism, Irritability and Verbal Hostility compared to age-matched control girls (in general and for each 5-HTT genotype separately), suggesting that they may have more matured emotional system (older control group has also lower scores on these scales).

Correlation of BOLD Signal with Linear and Nonlinear Patterns of EEG in Resting State EEG-Informed fMRI

Concurrent EEG and fMRI acquisitions in resting state showed a correlation between EEG power in various bands and spontaneous BOLD fluctuations. However, there is a lack of data on how changes in the complexity of brain dynamics derived from EEG reflect variations in the BOLD signal. The purpose of our study was to correlate both spectral patterns, as linear features of EEG rhythms, and nonlinear EEG dynamic complexity with neuronal activity obtained by fMRI. We examined the relationships between EEG patterns and brain activation obtained by simultaneous EEG-fMRI during the resting state condition in 25 healthy right-handed adult volunteers. Using EEG-derived regressors, we demonstrated a substantial correlation of BOLD signal changes with linear and nonlinear features of EEG. We found the most significant positive correlation of fMRI signal with delta spectral power. Beta and alpha spectral features had no reliable effect on BOLD fluctuation. However, dynamic changes of alpha peak frequency exhibited a significant association with BOLD signal increase in right-hemisphere areas. Additionally, EEG dynamic complexity as measured by the HFD of the 2–20 Hz EEG frequency range significantly correlated with the activation of cortical and subcortical limbic system areas. Our results indicate that both spectral features of EEG frequency bands and nonlinear dynamic properties of spontaneous EEG are strongly associated with fluctuations of the BOLD signal during the resting state condition.

MRI Morphometry of the Cerebral Ventricles in Patients with Attention Deficit Hyperactivity Disorder

A total of 27 right-handed patients aged 7–30 years with diagnoses of attention deficit hyperactivity disorder were studied using standard MRI scans. Of these, 14 were aged below 13 years. The volumes of the lateral ventricles were measured using T1-weighted MRI images of sagittal sections of the brain to a precision of 3 mm3. External head sizes were also measured to allow ventricle volumes to be normalized. All patients underwent complex neuropsychological investigations. Memory was assessed, along with visual, auditory, tactile, and spatial recognition functions and the motor and speech spheres. Test data were assessed in terms of the severity of impairments associated with one brain structure or another on a tenpoint scale. Assessment points were summed for each hemisphere, for the “first area” (cortical structures), and all structures for statistical analysis. Neuropsychological testing revealed functional impairments predominantly of the frontal areas of the hemispheres, the hippocampus, and the reticular formation. Neuropsychological deficits were least linked with alterations in the postcentral and parietal areas of the cortex. Statistical analysis demonstrated a significant positive correlation between the normalized left lateral ventricle volume and the degree of neuropsychological impairments (r = 0.5127 at p = 0.0063) for the whole study group. The correlation was more marked on comparison of the normalized left ventricular volume and the severity of neuropsychological impairments related to the left hemisphere (r = 0.6303 at p = 0.0004). A relationship was seen between the volume of the intraventricular space and cortical functional impairments (r = 0.5071 at p = 0.0069) in patients less than 13 years old. A relationship between ventricular volume and linear head size was confirmed (r = 0.5759 at p = 0.0017), which was more marked in subjects less than 13 years old (r = 0.6833 at p = 0.01).

Comparative Analysis of Brain Activity in Verbal and Spatial Thought in Healthy Subjects and Patients with Speech Disorders

We report here an analysis of specific brain activity measured by fMRI during solution of spatial and verbal tasks in 15 healthy subjects and nine patients with dysarthria or mild sensorimotor aphasia. In healthy subjects, activation of Brodmann area (BA) 19 and Broca’s area was more characteristic of verbal thought, while greater bilateral activation of the temporal-parietal-occipital zone, along with the left insula and visual fields 17 and 18 on the left, was specific for spatial thought. In patients with speech disorders, the distribution of areas specific to one task or another underwent significant changes, with non-activation of areas of brain activation characteristic of healthy subjects. Despite the absence of clinical signs of cognitive impairments, the mean verbal task solution time was significantly longer and the proportion of correct responses was smaller in patients than in healthy subjects.

An fMRI Study of the Emotional Perception of Erotic Images in Men Aged 49–74 Years

Psychological studies have indicated that erotic images are evaluated in the context of positive emotions as the most intense, associated with the greatest degree of emotional arousal, among the whole gamut of pleasant and unpleasant stimuli. It is difficult to discriminate the cortical zones directly associated with emotional arousal from the activity of structures responsible for assessing emotional stimuli in the inducement/reward system. The aim of the present work was to identify differences in cerebral activity using functional MRI scans (fMRI) in men during assessment of the intensity of pleasant images, including erotic images, or unpleasant and neutral images. Comparison of tasks involving the assessment of pleasant images of the erotic type with tasks containing neutral or unpleasant stimuli revealed significantly more marked activation in the posterior cingulate cortex, the prefrontal cortex, and the globus pallidus on the right side. Comparison of tasks with pleasant and neural stimuli revealed an increase in the activity of the right anterior central gyrus. Thus, the process of assessment of the intensity of emotional images of erotic type was related to activation of brain areas belonging not only to the neural representation of the emotions, but also to the cognitive system controlling emotional arousal and the motivational domain, which needs to be considered when using erotic images as powerful positive emotional stimuli.

Neural correlates of brain state in chronic ischemia and stroke: combined resting state electroencephalogram and transcranial Doppler ultrasonographic study.

Clinical neurology is constantly searching for reliable indices of ischemic brain damage to prevent a possible development of stroke. We suggest that resting state electroencephalogram (rsEEG) with respect to other clinical data may provide important information about the severity of ischemia. We carried out correlation analysis of rsEEG, data of transcranial Doppler ultrasonography of head vessels, and clinical assessment scores collected from healthy volunteers and four groups of patients with mild chronic microvascular ischemia (CMI-1), moderate CMI (CMI-2), severe atrophy of the cerebral hemisphere, ischemic stroke in the left middle cerebral artery stroke, and ischemic stroke in the right middle cerebral artery stroke. Using independent component analysis and k-mean clustering of EEG data, we observed prominent changes in rsEEG reflected in specific distributions of spectral peaks in all groups of patients. We found a significant correlation of EEG spectral distribution and the blood flow velocity in coronal arteries, which was also affected by the severity of ischemia and the localization of stroke. Moreover, EEG spectral distribution was more indicative of early stages of ischemia than the blood flow velocity. Our data support the hypothesis that rsEEG may reflect altered neural activity caused by ischemic brain damage.

P313 Changes in EEG complexity of brain dynamics associated with bold fluctuations during resting state

Objectives Concurrent EEG and fMRI acquisitions in resting state showed a correlation between EEG power in various bands and spontaneous BOLD fluctuations. However, there is a lack of data how the EEG complexity of brain dynamic, such as instability or entropy of EEG rhythmic structure, may reflect variations in the BOLD signal. Methods We aimed to find the relationships between EEG dynamics and brain activation obtained by simultaneous EEG-fMRI during resting state condition in 25 healthy right-handed adult voluntaries. We applied nonlinear analysis in order to obtain chaotic features of EEG, which we used as regressors in GLM relating to changes in the BOLD signal. Results Fluctuations in beta rhythm were associated with the BOLD signal increase in basal ganglia and thalamic structures ( p 0.05 , FDR-corrected). Moreover, our data showed that Higuchi fractal dimension correlated with activation of cortical areas and limbic system regions. Offset of alpha-peak frequency and envelope frequency coincided with activation of thalamus, insula, hippocampus and temporal cortex predominantly in the right hemisphere. Conclusions Previously, nonlinear EEG analysis in clinical neurophysiology pointed that decreased complexity of brain dynamics might implicate increased neuronal interaction. Our results indicate that dynamic properties of spontaneous EEG have a significant association with resting state BOLD fluctuations reflecting possible sources of rhythmic neuronal activity. In particular, the observed increase in the BOLD signal significantly correlated with deviation of beta rhythm power that supports the hypothesis of basal-thalamic origin of beta rhythm. The study was supported by a grant of the Russian Science Foundation 116-15-00300.

Brain Mapping in Verbal and Spatial Thinking

The aim of the present work was to describe the topography of active cortical zones and subcortical formations during verbal and spatial thought using functional magnetic resonance imaging (fMRI). A total of 18 right-handed subjects took part. Four types of task were presented – two study tasks, verbal (anagrams) and spatial (seeking figures to complement a square), as well as two types of control task (words and spatial tasks where all the figures are identical). Solution of verbal tasks was associated with a greater volume of activation of the left hemisphere, with involvement of Brocas area, while solution of spatial tasks was linked with activation of the middle frontal gyrus on the right. In the occipital area, solution of spatial tasks was associated with greater activation of visual field 18, while solution of anagrams was linked with greater activation of field 19, which is associated with a higher level of visual information processing. The cerebellum was activated in both tasks, to a greater extent on solution of spatial tasks. These fMRI data provide evidence that the verbal and spatial types of thought are supported by the activity of a narrowly specific set of brain structures, while previous electrophysiological studies indicated distributed cerebral processes during thought. Combining these two approaches leads to the conclusion that cognitive functions are supported by systems-type cerebral processes with certain key structures.