Interaction between the main components of the vertebrate retinal rod phototransduction system in solutions of detergent n-nonyl-β-D-glucoside

cGMP-Specific phosphodiesterase (PDE6) is the key enzyme of the phototransduction system of vertebrate retinal rod outer segments (ROS). The properties of PDE in extracts prepared by solubilization of bovine ROS in a high concentration (0.5% w/v) of detergent n-nonyl-β-D-glucoside (NG) and following centrifugation (ROS-NG) have been studied. Basal PDE activity of the preparations was low, but it greatly (>50-fold) increased (up to ∼20 μmol cGMP hydrolyzed/min per mg rhodopsin (R)) in the presence of trypsin. In bleached GTPγS-containing preparations the specific PDE activity was dependent on ROS-NG concentration and was half-maximal at about 0.8 μM of ROS G protein transducin (Gt). In dark-adapted GTPγS-containing ROS-NG preparations bleaching of 0.2% of the rhodopsin resulted in half-maximal PDE activation. The same result was obtained when PDE in dark-adapted ROS-NG preparations was activated by addition of a highly purified bleached rhodopsin solubilized by 0.5% solution of NG. The results demonstrate that the presence of NG has no significant influence either on the properties of the main ROS phototrans-duction system elements (R, Gt and PDE) or on the interaction between photoactivated R and Gt and suggest that the detergent NG can be used for crystallization of the rhodopsin-transducin complex.     

Specific features of distribution,ecology, and dynamics of catches of blotched snailfish Crystallichthys mirabilis (Liparidae) in Pacific waters off the northern Kuril Islands and southeastern Kamchatka

Based on materials of 1992–2002, data on the spatial-bathymetric distribution and size-age composition of blotched snailfish Crystallichthys mirabilis and species accompanying it in catches in Pacific waters off the northern Kuril Islands and southeastern Kamchatka are presented. This relatively large representative of the family Liparidae (maximum length in catches 50 cm, body weight 2150 g) is found throughout the examined area in the depth interval of 76–755 m at near-bottom temperature of ?1.2 to +4.2°C. Maximum catches (over 200–500 individuals or 180–280 kg per hour trawling) year round are recorded off the southeastern extremity of Kamchatka, from the oceanic side of the Shumshu and Paramushir islands and on the beam of the Fourth Kuril Strait in the bathymetric range of 151–350 m. The magnitude of its catches in the examined area is subjected to interannual, seasonal, and diurnal dynamics.     

A new surface gliding species of Chironomidae: An independent invasion of marine environments and its evolutionary implications

Insects have invaded marine habitats only rarely and secondarily. Recently, we discovered a flightless dipteran species skating rapidly on the surface of seawater ponds at the Pacific coast of eastern China. Morphological analyses initially suggested an isolated position of the non‐biting midge, suggesting the erection of a new genus within Chironomini (Diptera: Chironomidae). However, an analysis of molecular data revealed that the marine species is in fact nested within the species‐rich genus Dicrotendipes. The apparent conflict between molecular and morphological data can be easily explained. It is likely that the new species has evolved a series of autapomorphic adaptations. These traits clearly distinguish the taxon from other species of the genus but do not justify the erection of a new supraspecific taxon, which would render Dicrotendipes paraphyletic. The switch to marine environments was likely a trigger for various morphological modifications resulting from increased selective pressure. Molecular data suggest that the potential speciation event occurred around 19–29 Ma, linked with a migration from freshwater to seawater ponds along the Pacific Ocean. Considering the results of our analysis, we place the flightless marine skater in the genus Dicrotendipes. All life stages of Dicrotendipes sinicus Qi & Lin sp. n. are described and illustrated, associated with larvae obtained by rearing or confirmed through association with DNA barcodes. The biology and ecology of the species are outlined based on collection data and in situ observations. Evolutionary patterns linked with repeated invasions of marine habitats are discussed.     

3-Dimensional microscopy as a method for volume measurement in cells undergoing apoptosis

Different patterns of cell volume perturbations are commonly used for modes of cell death: necrosis (cell swelling) and apoptosis (cell shrinkage). In this study we employed recently developed three dimensional microscopy for the measurement of the volume of attached vascular smooth muscle cells transfected with E1A-adenoviral protein. These cells undergo rapid apoptosis in the absence of growth factors or in the presence of staurosporine. In 30–60 min of serum deprivation the volume of these cells is increased by ～40% that corresponds to the time point of maximal activation of caspase 3 and chromatin cleavage. In 10–15 min swollen cells exhibit morphological collapse indicated by formation of apoptotic bodies. In contrast to serum-deprived cells, staurosporine leads to attenuation of cell volume by 30%. In this case, apoptotic bodies are detected in ～2.5 h after maximal shrinkage. Thus, our results show that cell shrinkage can not be considered as universal hallmark of apoptosis. The role of stimulus-specific cell volume perturbation in the triggering of the cell death machinery should be examined further.     

Neuronal activity of the monkey striatum points at the integration of successive actions into functional blocks

In order to study the role of the striatum in generation of multistage behavior, the spike activity of 148 cells was recorded in the monkey brain putamen. Two kinds of neuron responses were observed. Phasic response involved activity during only one stage of the behavior program, and tonic response involved activity during more than one sequential stage. The tonic responses were recorded in 132 neurons out of 148, 11 neurons responding only as tonic. Other 121 cells show under different conditions both tonic and phasic responses. Beginnings and ends of "tonic" responses as a rule corresponded to the start and completion of the nearest behavioral aim. The obtained data suggest that the neuron activity of striatum is related not only to the control of individual movements but also to the whole structure of behavior.     

Spectrum and coherent characteristics of bioelectric activity of the brain in women with normal and complicated pregnancy

Spectrum and coherent EEG analysis was performed in 86 pregnant women on the 35-36th week of gestation. It was shown that functional interhemispheric brain asymmetry is a sensitive index of normal and complicated gestation. It was found out that activation prevailing in the central and temporal brain areas contralateral to the side of placenta localization in the uterus was characteristic of the normal pregnancy. The development of gestation complications was accompanied by the inversion of interhemispheric asymmetry of EEG activation. It was suggested that correlative properties of bioelectric brain activity in women with normal gestation are an indicator of the left-hemispheric dominance of brain centers in the integration process.     

Ontogenetic features of psychophysiological mechanisms of perception of speech emotional component in musically gifted children

Cerebral mechanisms of musical abilities were explored in musically gifted children. For this purpose, psychophysiological characteristics of perception of emotional speech information were experimentally studied in samples of gifted and ordinary children. Forty six schoolchildren and forty eight musicians of three age groups (7-10, 11-13 and 14-17 years old) participated in the study. In experimental session, a test sentence was presented to a subject through headphones with two emotional intonations (joy and anger) and without emotional expression. A subject had to recognize the type of emotion. His/her answers were recorded. The analysis of variance revealed age- and gender-related features of emotional recognition: boys musicians led the schoolchildren of the same age by 4-6 years in the development of mechanisms of emotional recognition, whereas girls musicians were 1-3 years ahead. Musical education in girls induced the shift of predominant activities for emotional perception in the left hemisphere; in boys, on the contrary, initial distinct dominance of the left hemisphere was not retained in the process of further education.     

Apoptosis in serum-deprived vascular smooth muscle cells: Evidence for cell volume-independent mechanism

Shrinkage is the earliest hallmark of cells undergoing apoptosis. This study examines the role of this phenomenon in the onset of vascular smooth muscle cell (VSMC) apoptosis triggered by growth factor withdrawal. In hyperosmotic media, VSMC showed the same amplitude of shrinkage but were more resistant to apoptosis than endothelial, epithelial and immune system cells. As with growth factor withdrawal, apoptosis in hyperosmotically-shrunken VSMC was sharply potentiated by transfection with E1A-adenoviral protein and was suppressed by activation of cAMP signaling as well as by the pan-caspase inhibitor z-VAD.fmk. Both cell shrinkage and apoptosis in VSMC-E1A treated with hyperosmotic medium were potentiated under sustained Na+, K+ pump inhibition with ouabain that was in contrast to inhibition of apoptosis documented in ouabain-treated, serum-deprived cells. After 1-hr incubation in serum-deprived medium, VSMC-E1A volume declined by approximately 15%. Transfer from hypotonic to control medium decreased VSMC-E1A volume by approximately 25% without any induction of apoptosis. Neither swelling in hyposmotic medium nor dissipation of the transmembrane gradient of K+ and major organic osmolytes protected serum-deprived VSMC-E1A from apoptosis. Thus, our results show that similarly to immune system, endothelial and epithelial cells, extensive VSMC shrinkage in hyperosmotic medium leads to the development of apoptosis. In contrast to hyperosmotic medium, the modest cell volume decrease occurring in serum-deprived VSMC does not contribute to triggering of the apoptotic machinery.     

Na/K pump and intracellular monovalent cations: novel mechanism of excitation-transcription coupling involved in inhibition of apoptosis

The Na/K pump plays a key role in the regulation of the intracellular concentrations of monovalent cations and related cell function leading to electrogenesis and excitation-contraction coupling. We focus this review on the analysis of recent data showing that (i) inhibition of the Na/K pump triggers a signaling cascade independently of modulation of the intracellular [Na+]i/[K+]i ratio; (ii) elevation of [Na+]i under sustained inhibition of the Na/K pump leads to expression of a set of genes by [Ca2+]i-dependent and independent pathways; (iii) [Na+]i-sensitive genes are involved in the inhibition of programmed cell death (apoptosis) in vascular smooth muscle cells.