[Comparative studies of neurotrophic drugs based on brain hydrolysates]. / O sravnitel'nykh éksperimental'nykh issledovaniiakh neirotroficheskikh preparatov na osnove gidrolizatov golovnogo mozga.

The results of the analysis of comparative studies of neurotrophic drugs based on brain hydrolysates (BH) are presented. The most comprehensive comparative study of the BH drugs carried out by Zhang, et al. 2019 investigated the effects of four drugs (cognistar, cerebrolysate, cortexin, cerebrolysin) on a model of ischemic stroke in rats. The study showed that a significant improvement in the neurological outcome compared with placebo was observed only with cerebrolysin. Higher standardization in elemental composition, higher antioxidant activity, and presence of active peptide fragments of neuropeptides of nerve growth factor, enkephalins, orexin and galanin in cerebrolysin explains neurotrophic and neuroprotective effects of the drug.

[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.