[The functional brain state of hibernators and nonhibernators at different animals temperatures].

Literature and our own data on structural and functional state of neocortex and hippocampus during both entrance in hibernation of ground squirrel (Spermophilus undulates) and Wistar rats in hypothermia were generalized. During hibernation when body temperature is about 2-4 degrees C the suppression of both bioelectrical and protein-synthesizing activity, the decrease of neuronal cell bodies and the branching of dendrites, retraction of dendritic spines, and a decrease of postsynaptic active zones of synapses were observed. Similar changes in those parameters were triggered for rats during hypoxia-hypercapnia at body temperature 17-19 degrees C. Hypoxia-hypercapnia facilitates the entrance in torpid state for hole animals. Nonhibernating animals during cooling and hypoxia-hypercapnia trigger functioning some mechanisms similar hibernators during entrance in hibernation. Similar morphological and functional changes for both hibernators and nonhibernators at low temperature state show similarity of mechanisms which induce a low level of brain activity of different animals.

[Cyclic structural changes in endoplasmic reticulum and Golgi apparatus in the hippocampal neurons of ground squirrels during hibernation].

Repetitive remodeling and renewal of the cytoplasmic structures realizing synthesis of proteins accompanies the cycling of ground squirrels between torpor and arousal states during hibernation season. Earlier we have shown partial loss of ribosomes and nucleolus inactivation in CA3 hippocampal pyramidal neurons in each bout of torpor with rapid and full recovery after warming up. Here we describe reversible structural changes in endoplasmic reticulum (ER) and Golgi complex (G) in these neurons. Transformation of ER from mainly cysternal to tubular form and from mainly granular to smooth type occurs at every entrance in torpor, while the opposite change occurs at arousal. Torpor state is also associated with G fragmentation and loss of its flattened cisternae. Appearance in torpor of the autophagosomal vacuoles containing fragments of membrane structures and ribosomes is a sign of their partial destruction. Granular ER restoration, perhaps through assembly from the multilamellar membrane structures, whorls or bags, begins as early as in the middle of the torpor bout, while G flattened cisternae reappear only at warming. ER and G completely restore their structure 2-3 hours after the provoked arousal. Thus, hibernation represents and example of nerve cell structural adaptation to alterations in functional and metabolic activity through both active destruction and renewal of ribosomes, ER, and G. Perhaps, it is the incomplete ER autophagosomal degradation at torpor provides its rapid renewal at arousal by reassembly from the preserved fragments.

[Protective effect of hypothermia on brain neurons of rats exposed to ionizing radiation].

The conditions of the protein-synthesizing system in neurons of the hippocampus (areas CA1 and C A3) and of the cortex (sensomotor region) in rats subjected to y-irradiation at a dose of 8 Gy under hypothermia (16 - 18 degrees C) and hypoxia-hypercapnia were investigated by fluorescent and electron microscopy. Under hypothermia, the protein-synthesizing system was shown to be damaged to a lesser degree and to be restored faster in comparison with similar neurons in rats irradiated at room temperature. In rats irradiated under hypothermia, the rRNA biogenesis and the protein-synthesizing activity of polyribosomes were restored in two days. The protective influence of hypothermia did not spread to changes in membrane structures (endoplasmic reticulum and Golgy apparatus); i.e., a partial loss of integrity and possible transformation of their structure caused by the irradiation and the restoration of these structures occurred at a lower rate.

[Influence of ionizing radiation on the condition of the protein-synthesizing system in ground squirrel brain neurons at different functional states].

It was shown by fluorescent and electron microscopy that the physiological state of ground squirrels subjected to ionizing radiation at different phases of the torpor-normothermia cycle plays a determining role in the alteration of the conditions of the protein-synthesizing system in neurons of hippocampus fields CA1 and CA3 and sensomotor area of the brain. In ground squirrels irradiated under normothermia, the neurons were less radioresistant and restored slower compared with torpor animal cells, the distinctions being most expressed in CA1 field neurons. The effect of irradiation was minimum during the entrance into torpor and maximum during arousal. It was supposed that the inhibition of protein synthesis in the latter case occurred at the elongation stage when heavy polyribosomes were formed in neuron cytoplasm.

[A comparative analysis of restoration of electroencephalographic and protein-synthesizing activities in neocortex and hippocampus in hibernating (ground squirrels) and nonhibernating (rats) animals during exit from hypothermia].

A similarity in the sequence of restoration of the EEG spectrum between ground squirrels arousing from torpor and rats passing out of artificial hypothermia (17-18 degrees C) was shown. First of all, the low-frequency part of the EEG spectrum was restored. As animals warmed up, their breathing became hurried, cold shivering appeared, and the theta- and alpha-rhythms increased. During the exit from hypothermia, the activity of the protein-synthesizing system in both rats and ground squirrels was almost entirely restored when the animal body temperature achieved 21-22 degrees C. In ground squirrel, the rate of protein synthesis in the neocortex was lower than in hippocampus CA1 and CA3 areas, whereas in rats, on the contrary, it was higher in the neocortex in comparison with the CA3 area.

[Investigation of the pollen chromatin state of Hippeastrum hibridum at the early stages of development with fluorescent dye Hoechst 33342]. / Issledovanie sostoianiia khromatina pyl'tsevogo zerna Hippeastrum hibridum na nachal'nykh stadiiakh razvitiia s pomoshch'iu fluorestsentnogo krasitelia Khekhsta 33342.

The work was carried out on the pollen of Hippeastrum hibridum, whose size (ca 55 mcm) permits to follow both the pollen tube formation and development of the vegetative nucleus and generative cell within the first two hours before the growing point arising. Using fluorescent dye Hoechst 33342 chromatin state alterations accompanying changes in the pollen physiological state were investigated. The maximum fluorescent intensity was observed in 30 min of staining and reflected the maximum chromatin functional activity. Histograms of pollen distribution according to fluorescent intensity differ considerably with doses of irradiation (500, 1000, 2000, 3000 and 4000 Gy). Besides, a germinative index of fluorescence intensity was calculated. A comparative analysis of these data has shown that the lowest decrease in fluorescent intensity observed at 500, 3000 and 4000 Gy, was accompanied by different germinative indices. At 500 Gy, the index was 2.5 times lower than in the control, but at 4000 G no germination was not noted. The process of pollen grain development is supposed to be more intensive and faster at 500 Gy, than in the control. At 4000 Gy, a decrease in the functional pollen activity is accompanied by decrease or inhibition of chromatin functional activity.

[Fluorescent analysis of irradiation-induced changes in chromatin state]. / Fluorestsentnyi analiz izmeneniia sostoianiia khromatina pri obluchenii.

A fluorescent technique with Hoechst-33258 and acridine orange staining was used to assess changes in chromatin state induced by radiation. Fluorochromes with different modes of binding to DNA were chosen. In T lymphocytes chronic irradiation caused a rearrangement of binding between nonhiston proteins and lipids accompanied by conformational changes in DNA, resulting in chromatin condensation. The decrease in fluorescence probably resulted from a reduction in the number of sites accessible for dye binding. After acute irradiation, the fluorescence intensity decreases predominantly due to double-strand breaks.

[Effect of an antioxidant (ubiquinone Q-9) and chronic low-dose irradiation on rat chromatin structure and T-lymphocyte proliferation]. / Vliianie antioksidanta (ubikhinona Q-9) i khornicheskogo oblucheniia v malykh dozakh na strukturu khromatina i proliferatsiiu T-limfotsitov krys.

We have demonstrated the protective effect of natural antioxidant coenzyme Q-9 on the T-cell proliferative capacity and chromosomal DNA state under low dose chronic irradiation. The DNA-staining fluorescent dye Hoechst-33258 and acridine orange were to observed the nuclear morphology changes in T-lymphocytes. Ubiquinone diet partially restored the decreasing in immune response and the luminescence intensity of DNA-Hoechst-33258 complex in T-cells of low dose irradiated rats.

[Cytoplasmic RNA in neocortical neurons in vitro]. / Sostoianie tsitoplazmaticheskoi RNK v neironakh neokorteksa in vitro.

The investigation of the ratio of neuronal cytoplasmic RNA mono- and two-chain sections was performed in thin neocortical slices by means of fluorescent probing. Changes of the relative intensity of Acridine Orange red luminescence indicated a decrease in the quota of monochain sections in the common neuronal RNA pool. In eight hours of superfusion it was authentically less than in the control slices and in the slices which were incubated during four hours. Deep profiles of red fluorescence became plane in the process of incubation. It was suggested that the essential decrease in the red luminescence intensity of cytoplasmic RNA in vitro, observed between four and eight hours, may be conditioned by disintegration of polysomes to monosomes, and this, in its turn, may cause the decrease in ribosomal synthetic activity.

[Differences in the ribosome state of nerve cells detectable by acridine orange fluorochrome staining]. / Razlichiia v sostoianii ribosom nervnykh kletok, vyiavliaemye pri fluorokhromirovanii akridinovym oranzhevym.

Acridine orange (AO) binding with ribosomal RNA in the cytoplasm of nerve cells depends on the animal functional state to differ in active and hibernating ground squirrels. These differences are expressed as changes in the ratio of red and green AO luminescence intensities. The transition of squirrels from the activity to hibernation provokes a five-fold fall in the red luminescence, while the green one shifts no more than by 10%, thus indicating the change in AO interaction with one-helical regions of rRNA only. The red luminescence decreases simultaneously with the rise of monoribosomes portion and dissociation of polysomes, but does not depend on RNA concentration in the cytoplasm. The dependence of AO binding on protein-RNA interaction in the one-helical regions and its relation to the capacity of ribosomes of protein synthesis are discussed.

[Functional similarity of the P-2 form of primary sleep and hypobiosis in the frog Rana temporaria (based on data from luminescent microspectral analysis of the cytoplasm of neurosecretory neurons)]. / Funktsional'noe skhodstvo formy P-2 pervichnogo sna i gipobioza u liagushki Rana temporaria (po dannym liuminestsentnogo mikrospektral'nogo analiza tsitoplazmy neirosekretornykh neironov).

Using luminescent microspectral analysis of preparations stained by acridine orange, studies have been made on the ratio between single- and double-stranded parts in ribosomal RNA from the cytoplasm of neurosecretory neurones of the preoptic nucleus of the frog Rana temporaria. The animals were investigated in active period, during P-2 form of the primary sleep, in hypobiosis, and after injection of the active factor (peptide fraction with a molecular mass 1-10,000 Da) extracted from the small intestine of the ground squirrel Citellus undulatus during winter hibernation. It was shown that unlike actively awake frogs, animals from other experimental series exhibited similar changes, i.e. the decrease in the affinity of acridine orange to single- and double-stranded parts of rRNA and the decrease in the value of alpha which reflects the ratio of single- and double-stranded parts. It was also demonstrated that injection of the active factor from hibernating ground squirrels to frogs results in a condition which is rather similar to a natural resting form (P-2) of the primary sleep in cold-blooded vertebrates.

[Arrest of BHK-21 cell culture growth and its stabilization in a resting state as affected by serum fractions]. / Ostanovka rosta kul'tur kletok BHK-21 i ikh stabilizatsiia v sostoianii pokoia pod deistviem syvorotochnykh fraktsii.

By cytofluorometry the distribution of cells was studied according to the amount of DNA in a population of BHK-21 cells placed in the media containing a serum fraction that either does not stimulate cell proliferation, or stimulates it until reaching 60% of the limiting density observed in the control. The analysis of cell distribution shown that after the arrest of cell growth cells are accumulated in the G1 phase of the cell cycle to change into the quiescent state. As a control, cytofluorometric analysis of populations of BHK-21 cells cultured under normal conditions in the presence of the 10% whole serum was performed.

[Luminescence analysis of the peripheral blood in certain types of allergy]. / Liuminestsentnyi amaliz perifericheskoi krovi pri nekotorykh vidakh allergii.

Fluorescent spectral analysis of acridine-orange-stained fixed blood smears from patients taken in the period of allergic reaction revealed the presence in the blood of free granules presumably containing the major proteins given fluorescence in the green part of the spectrum. The number of these granules increases in the first phase of the allergic reaction and declines as the patient recovers.

[Ultrastructure of a mechanoreceptor neuron with acceleration of its adptation to an adequate stimulus]. / Ul'trastruktura mekhanoretseptornogo neirona pri uskorenii ego adaptatsii k adekvatnomu razdrazheniiu.

Ultrastructural changes were followed in the isolated mechanoreceptor neurons of the crayfish during post-excitational short-term trace processes (i.e. acceleration of the adaptional state), after repeated adaquate excitations. Fibrillar rearrangements of the mitochondrial cristae in the axonal mitochondria took place at the moderate excitation, no visible changes being seen in the somatic mitochondria and other organelles. However, the swelling of periaxonal areas and the rupture between strands of microtubules and electrogenic membrane occurred at the end of the fatique stimulation. In addition, the swelling of somatic mitochondria in the perinuclear zone and of the reticulum was noticed. Besides, the survival time of the excited isolated neurons strongly depended on the functional state of the surrounding glial cells. It is suggested that energetic processes are strongly involved in the postexcitational short-term traces.