[FORMATION OF VISUAL-AUDITORY ASSOCIATIONS IN RECOGNITION OF PHONEMES IN CHILDREN].

In this study, we investigated a question about a possibility to form involuntary auditory-visual associations in children (8-11 yrs) during discriminations of speech sounds (phonemes) when they presented simultaneously with visual stimuli. It was used two types of static images - geometrical figures and images of hand gestures. We judge about the formation of auditory-visual association by behavioral disturbance (reaction time, percentage of wrong reactions during discriminations of phonemes) after changes in experimental protocol viz, partial substitution of preceding pairs of stimuli which were used during training to form auditory-visual associations for the new combinations of previous images and sounds. We find that in research conditions comparatively fast formed pronounced auditory-visual association; however features of response to mismatch stimuli in comparison with adults make to suggest the relative immaturity ofneurons of social perception in children.

[Inhibition of proteolysis of nuclear histones by metal ions]. / Ingibirovanie proteoliza gistonov iader ionami metallov.

3-5 hours incubation of calf thymus nuclei at 37 degrees C leads to the proteolysis of histones H1, H3 and H2B; 1-10 mM NiCl2 and ZnSO4 inhibits the proteolysis of the histones H1, H3 and H2B.

[Effect of urea on proteolysis of histone H2A in calf thymus nuclei]. / Vliianie mocheviny na proteoliz gistona H2A iader timusa telenka.

The 1 hour incubation of calf thymus nuclei at 37 degrees C leads to a proteolysis of the histones H1, H3 and H2B. Urea does not influence the histone degradation while 1.5 and 2.0 M NaCl lead to the proteolysis of the H2A histone. On this background, 2 M urea restrains the degradation of the H2A histone. It is assumed that hydrogen bonds are very important for the activity of the proteinases and its interaction with the H2A histone.

[Inhibition of nuclear histone proteolysis by nucleotides]. / Ingibirovanie proteoliza gistonov iader nukleotidami.

Effects of nucleotides on the proteolysis of histones in nuclei incubated at 37 degrees C during 1, 3 and 20 h were studied. It has been shown that the H1 histone is removed first during proteolysis and then the H3 and H2B histones are digested. The H4 histone is not cleaved even after 20 h incubation. PMSF and ATP inhibit the H1 cleavage when its structure was not disturbed before ATP, CTP, ADP, NAD+, AMP and NADH inhibit the partial cleavage of the core histones H3 and H2B. ATP, CTP, AMP and NADH prevent the total digestion of H2B. ATP and, at lower extent, CTP prevent the H3 digestion. ATP, CTP, ADP and NAD+ inhibit the cleavage of the H2A histone in the experiments with 20 h incubation, when H4 is only resistant in the absence of nucleotides. The data obtained suggest an important role of ATP and other nucleotides in maintaining the structure of histones and chromatin.

[Characteristics of brain gastrin/cholecystokinin-binding proteins]. / Kharakteristika gastrin/kholetsistokininsviazyvaiushchikh belkov golovnogo mozga.

Gastrin/cholecystokinin-binding proteins were purified using the column affinity chromatography on immobilized pig tetragastrin and cholecystokinin. Immunoblotting analysis of different human tissue extracts with specific antisera obtained against gastrin-binding proteins was performed. It was found that high molecular weight polypeptide zones of 120 kDa and 35 kDa were characteristic of the brain only. Autoantisera of patients with type A gastric disease reacted with some gastrin/cholecystokinin-binding proteins in human brain and mucosa including human brain polypeptide of 120 kDa. It is supposed that there are neurospecific gastrin-binding proteins (possibly gastrin/cholecystokinin receptors in the brain).

[A study of membrane glycoproteins from the rat brain using D-galactose-specific lectin]. / Izuchenie membrannykh glikoproteinov mozga krysy s ispol'zovaniem D-galaktozospetsificheskogo lektina.

Immobilized D-galactose-specific lectin from Zea mais was used to purify rat brain membrane glycoproteins. The membrane glycoproteins preliminarily washed from soluble proteins were solubilized consecutively by 2% triton X-100 and 1% SDS. PAG-electrophoresis with SDS and 2-mercaptoethanol revealed 10 polypeptide bands (Mm 109, 62, 59, 54, 51, 42, 16, 14, 12.5 and 12 kDa) in the membrane fraction of glycoproteins solubilized with triton X-100. Additional solubilization with SDS revealed 3 bands (Mm 109, 62, and 54 kDa). Only 3 polypeptide bands (Mm 62, 59, 42 kDa) were identified when analogous procedure was used for purification of the rat liver glycoproteins. Horse radish peroxidase labelled D-galactose-specific lectin from Zea mais was found to bind to neuron bodies and neurites in the cerebellum. It is suggested that the identified brain-specific membrane glycoproteins may take part in the cell adhesion between neurons.