Zhurnal evoliutsionnoi biokhimii i fiziologii最新文献

To study the influence of onium atom nature on anticholinesterase efficiency of elementorganic derivatives of tetramethylenbisonium compounds as reversible inhibitors of cholinesterase (ChE) - acetyl-ChE from human erythrocytes, butyryl-ChE from horse serum, ChE from the brain of frog Rana temporaria and ChEs from visual ganglia of Pacific squid Todarodes pacificus and individuals of Comman- der squid Berryteuthis magister from different habitats in the northwestern Pacific Ocean were investigated. Bisphosphonium inhibitors were significantly more potent effectors than bisammonium ones, but this may be associated with a significantly increased size and hydrophobicity of onium groups of the former. Bisammonium organosilicon compound and its monoammonium analogue were equally active reversible ChE inhibitors in mammals. First studied bis(phenyliodonium) derivative, which is characterized by a significant increase in the degree of hydrophobicity due to introduction of fluorine atoms in the interonium tetramethylene chain, also had marked anticholinesterase effects on mammalian ChE.

In this study we investigated the effect of 5-HT on the spontaneous and miniature synaptic activity in lumbar motoneurons from isolated frog spinal cord using intracellular recording. 5-HT increased the frequency of the spontaneous and miniature postsynaptic potentials (mPSPs). The effect of 5-HT on different subpopulations of mPSPs was multidirectional: it increased the frequency of glutamatergic excitatoty mPSP by 18 % and decreased the frequency of glycinergic inhibitory mPSP by 28 %, but had no effect on the frequency of GABAergic inhibitory mPSP. The amplitude and kinetic parameters of any subpopulation of mPSPs did not change. The data obtained show that 5-HT regulates the probability of glutamate and glycine release from presynaptic terminals ending at the frog spinal motoneurons. 5-HT shifts the ba- lance between synaptic excitation and inhibition in the spinal neural network toward excitation. Thus, 5-HT participates in control of motor output and provides its facilitation.

Topographic anatomy of ascending (AN) and descending (DN) neurons of the supraesophageal and thoracic ganglia in the nervous system of winged insects (Pterygota) - representatives of infraclasses Plaeoptera (Odonata, Aeschna grandis, dragonfly) and Neoptera (Blattoptera, Periplaneta americana, cockroach) was studied. These insects are different in ecological niches, lifestyles, sets of behavioral complexes, levels of locomotor system development, evolutionary age and systematic position. Neuronal bodies and processes of ANs and DNs were stained with nickel chloride (NiC2), their topography was studied on total prerapations of the supraesophageal and thoracic ganglia. Unlike cockroaches, in dragon- fly protocerebrum DNs sending their processes to ocelli were found. Dragonfly DN processes show a spe- cific type of arborization in thoracic ganglia, with collaterals directed both ipsi- and contralaterally. In cockroaches collaterals of DN processes are arranged ipsilaterally. AN bodies in meso- and metathoracic ganglia of dragonfly lie both ipsi- and contralaterally in respect to the ascending process whereas in cock- roaches AN bodies in the same ganglia are predominantly localized contralaterally. Substantial differences in allocation of DNs and ANs in insects dissimilar in locomotor manner reflect a different extent of supraesophageal ganglion control over activity of segmental centers. It seems related to neither the evolu- tionary age of insects, nor the antiquity of origin, nor their systematic position. Probably, a different de- gree of locomotion control depends on the way of getting food - catching prey in air by <> dragonflies unlike <> maneuverable walking or running across a solid substrate by <> cockroaches.

During direct stimulation of m. Soleus by trains of 5, 10 and 50 stimuli with a frequency of 20 Hz in control experiments (n = 16) a biphasic change was observed in the amplitude of the last contractile responses (LCRN) depending on N, where N is the number of individual contractile responses within the te- tanus. Thus, an initial decrease of LCRN amplitude (up to 54 ± 8 % for LCR₅) was replaced by their subsequent growth (up 218 ± 14 % for LCR5o) associated with a significant shortening of their half-relaxation time relative to the initial response (to 44 ± 8 % for LCR₅₀). Caffeine at concentrations of 5 mM (n = 6) and 10 mM (n = 4), at the background of developing characteristic stationary contracture respon- ses, increased LCR5 depression during the initial inhibitory phase (31 ± 8 % and 15 ± 4 %, respectively). The subsequent growth of LCRN amplitude was significantly lower than in the control (114 ± 18 % and 46 ± 9 % for LCR₅₀ at 5 and 10 mM caffeine, respectively). LCR₅₀ half-relaxation time during the action of both caffeine concentrations remained still considerably shorter than the individual responses recorded both in the presence of caffeine and in control. In contrast to the control and caffeine effects, LCR5 and ₁₀ (to 143 ± 14 %) than was observed in the control muscle. Additionally, dantrolene enhanced muscle relaxation at rest. Caffeine (10 mM), at the background of dantrolene, restored the dynamics of changes of amplitude time characteristics of the last contractile responses to values close to the control. The time-amplitude characteristics of the extracellular AP recorded in individual muscle fibers in m. Soleus did not change significantly during tetanic stimulation under protocol similar to that used for mechanografical experiments. These data can be interpreted to support the previously suggested theory about the participation of <> as an additional mechanism of excitation-contraction coupling in skeletal muscle under conditions of tetanic stimulation [1, 2].

Coevolution - the interaction of different species of animals that are closely related biologically but do not exchange genetic information. The article discusses the problem of coevolution of physiological systems within an organism as the interrelated development of structure, function and systems of their re- gulation during the formation of living systems. We consider the coevolution of osmoregulation and type of metabolism of nitrogen compounds, systemic and individual strategy of coevolution of cell volume re- gulation in poikiloosmotic and homoioosmotic animals, coevolution of effectory organs and endocrine factors in the development of water-salt homeostasis, interrelationship of nonapeptides of neurohypophysis and glucagon-like peptide 1 in regulation of renal function for stabilization of physicochemical para- meters of fluids of the internal environment.

Motion aftereffect can be regarded as a consequence of self-motion illusions and lag effect of the sensory performance. Numerous experimental facts provide evidence of common mechanisms of motion aftereffect in various modalities based on conception of motion detectors. At present here are serious rea- sons to suppose that motion aftereffect is a characteristic feature of all sensory systems involved in spatial orientation, adaptation to motion in one sensory system results in a change of performance of another one and that such adaptation has an important adjusting significance for orientation of a moving organism. This review deals with argumentation of these conceptions.

Distribution of GABA and glycine immunoreactivity was studied in synapses on primary afferent axons of the spinal cord in the lamprey Lampetrafluviatilis by double labeling technique. Approximately 25 % of synapses on afferent axons revealed immunoreactivity to GABA and more than 70 % were im- munoreactive to both neurotransmitters. As in other vertebrates, axo-axonal contacts represented three-component synaptic complexes, the so-called triades, where the immunoreactive terminal was in sy- naptic contact both with the afferent axon and the dendrite contacting with this afferent. Contact zones with membrane specializations of gap junction type were found between adjacent afferents that suggests the presence of electrotonic interaction between afferents which serves, evidently, for synchronization of afferent flow and presents a structural base for a mechanism of fast interneuronal communication of func- tionally uniform neurons which is an important element in organization of coordinated locomotor acts. Besides, our studies provide evidence that afferent-afferent interaction may be mediated not only electro- tonically but also with the aid of chemical synapses. This fact gives grounds to suppose that depolariza- tion of primary afferents, produced by glutamate, occurs not only through autoreception mechanism but also by its direct action on the membrane of an afferent axon.

The effect of maternal experience on the maturing of early behavior reactions and species-specific defensive behavior (dark preference reaction) in the offspring of Wistar rats was investigated. We found differences between maternal behavior of primiparous females and the same females after second parturi- tion. The behavior of experienced female is characterized by maintenaning a more comfortable state in the nest, and more care for the offspring. The study of the dynamic of behavior in the offspring of primiparous females revealed the disappearance of the correlation between the timing of opening the eyes and the appearance of the first offspring behavioral responses, which is a negative factor for the formation of adaptive behavior in ontogenesis. A violation of the development of a species-specific defensive behavior (dark preference reaction) was found in the offspring of naive females. The results indicate a positive in- fluence of motherhood experience on the formation of functions of their offspring.

The caudal ventrolateral medullary reticular formation is the first supraspinal level processing visce- ral nociceptive signals. In experiments on rats reactions of neurons of this zone to nociceptive stimulation of large intestine were examined and effects of selective blockade of 5-HT3-receptors on these reactions were assessed. According to the character or responses to nociceptive colorectal stimulation (CRS) the re- corded medullary cells were divided into three groups - excitated, inhibited and indifferent. Intravenous injection of 5-HT3-antagonist granisetron (1 and 2 mg/kg) as well as local application of the substance on medulla surface (1.25 and 2.5 nmole) suppressed dose-dependently background and evoked discharges of the reticular neurons excited by CRS but did not exert so much expressed influence on the cells inhibited by visceral nociceptive stimulation. Spike activity of the group of neurons indifferent to CRS under simi- lar conditions was of 5-HT3-independent character. The results obtained provide evidence that 5-HT3-re- ceptors mediate the facilitating effect of serotonin on the supraspinal transmission of abdominal nocicep- tive stimulus which, partly at least, is realized through selective activation of visceral nociceptive neurons of the medulla. The blocking of this mechanism may underlie the analgesic effect of 5-HT3-antagonists in a abdominal pain syndromes.