Effect of sensory input on the levels of enzymes involved in energy metabolism

Presentation of sensory stimuli of various modalities to rats immediately before their decapitation led to a significant increase in the level of succinate dehydrogenase in the hippocampus, the magnitude of the increase being dependent on the number of stimuli presented. In each individual case, this enzyme's activity was proportional to the amplitude of the population spike recorded in the hippocampus of the same rat. An inverse relationship was noted between the rate of plastic processes in the hippocampus upon rhythmic stimulation and succinate dehydrogenase activity. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 6, pp. 608–611, June, 1994 Presented by V. S. Rusinov, Member of the Russian Academy of Medical Sciences     

Lactate and succinate dehydrogenase activity in blood lymphocytes of aggressive and submissive male mice

The influence of social status on some immunological characteristics in experimental animals was studied (sensory contact model). Lactate dehydrogenase activity in blood lymphocytes changed similarly in aggressive and submissive mice probably due to social stress. The activity of succinate dehydrogenase changed differently and correlated with the type of social behavior. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 129, No. 1, pp. 53–55, January 2000     

EMG responses in humans during painful heterosegmentary stimulation

The amplitude-temporal parameters of the nociceptive flexor reflex evoked in the upper and lower extremities by painful heterosegmentary electrical stimulation were studied in healthy volunteers. This reflex was detected bilaterally in the muscles of the upper and lower extremities independently of the site of painful stimulation. The maximum amplitude of the reflex was observed in the case, when the segmentary muscle innervation and the application site of painful stimulation coincided. The least latency of the nociceptive flexor reflex was observed after painful stimulation of the ear lobe. It was concluded the nociceptive flexor reflex is not an elementary polysysnaptic spinal reaction, but involves also some supraspinal centers. Translated fromByulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 130, No. 11, pp. 531–535, November, 2000     

Effect of acoustic stimulation on cell composition of auditory brain structures in Krushinskii-Molodkina rats

We studied the effect of acoustic stimulation on cell composition of auditory brain structures in Krushinskii-Molodkina rats. Significant structural changes in the inferior colliculi of rats with high seizure activity were revealed 1 month after acoustic stimulation. Therefore, this brain structure plays a role in the development of audiogenic epileptic activity. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 142, No. 10, pp. 400–402, October, 2006     

Mechanisms of stimulation of granulocytopoiesis with neupogen in patients with breast cancer during chemotherapy

The mechanisms of granulocytopoiesis stimulation with granulocytic CSF (neupogen), added to chemotherapy protocol (adriablastine+taxotere) in patients with stages III–IV breast cancer, were studied. The hemostimulatory effect of granulocytic CSF preparation is based on stimulation of proliferation and differentiation of granulomonocytopoisis precursor cell in the hemopoietic tissue, due to neupogen effects on hemopoietic elements and on the hemopoiesis-inducing microenvironment cells. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 145, No. 4, pp. 449–454, April, 2008     

Effectiveness of sensory stimulation on tactile extinction

 Eleven brain-damaged patients with extinction were asked to report double tactile stimuli before, during, and after optokinetic stimulation and transcutaneous electrical stimulation of the posterior neck region. The goal of the study was to test whether tactile extinction is sensitive to these experimental manipulations in order to better understand the nature of the disorder. Both of these sensory stimulations are known to be effective in modulating only higher-order (cognitive) disorders of spatial coding, such as visual hemineglect, deficit of position sense, hemianesthesia, etc. When applied to the side contralateral to the cerebral lesion, both optokinetic and transcutaneous electrical stimulation significantly affected patients’ performances, increasing the amount of detections of contralesional double stimuli. A tendency towards worse performance was observed when sensory stimulation was applied to the ipsilesional side. The reported effectiveness in reducing tactile extinction suggests that the deficit can not be fully ascribed to a peripheral sensory disorder and that it reflects damage to a higher-order cognitive function involved in contralesional space representation or in the deployment of attention to that side of space. The nature of the close relationship between extinction and hemineglect is also discussed from the point of view of extinction as a deficit of space coding. Received: 19 September 1998 / Accepted: 19 February 1999     

Effect of acoustic stimulation on GABAergic neurons in limbic structures of Krushinskii-Molodkina rats

Quantitative study of GABAergic and main cells in the hippocampus and piriform cortex of Krushinskii-Molodkina rats was performed 1 month after the incidence of seizure activity evoked by acoustic stimulation. The number of neurons significantly decreased in both regions and, particularly, in the hippocampus and central area of the piriform cortex. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 145, No. 4, pp. 375–377, April, 2008     

Parameters of phosphene-inducing electric stimulation of the cat visual cortex via implanted surface and intracortical electrodes

Parameters of phosphene-evoking electrical stimulation of cat striatal cortex via electrodes of different types (surface and intracortical) were studied. Similar actions (paw raising) in response to the light pattern and to phosphene-inducing electric stimulation of the striatal cortex were demonstrated. It seems that the animals associated phosphene sensations with light patterns. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 145, No. 1, pp. 8–11, January, 2008     

Effect of stimulation of subthalamic nucleus on grooming movements and their rhythmicity in pups and mature rats

The effect of rhythmic stimulation of subthalamic nucleus on grooming movements and their rhythmicity was studied on mature rats and on 13- and 14-day rat pups. Unilateral monopolar stimulation of subthalamic nucleus was performed on unrestrained animals via implanted electrodes. This stimulation activated virtually all grooming movements (scratching, hair-plucking, licking, and body-shaking); the effect was most pronounced in pups. Acceleration of the rhythm of grooming movements was observed only in rat pups for hair-plucking and scratching on the contralateral side relatively to the stimulated nucleus. In mature rats stimulation of the subthalamic nucleus prolonged grooming movements in most cases, but did not increase their number and rhythm. Translated fromByulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 138, No. 9, pp. 244–246, September, 2004     

Vagal stimulation modifies parameters of heterochromatin in the nuclei of vagosolitary complex neurons of medulla oblongata in rats

New data were obtained on modification of heterochromatin parameters in the nuclei of medulla oblongata neurons in Wistar rats after stimulation of the vagus nerve: decrease in the area of heterochromatin regions and redistribution of chromocenters within the neuronal nuclear system. It was concluded that realization of the viscero-visceral reflex is associated with rearrangement of chromatin in neurons involved in transmission of the corresponding information. Translated fromByulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 138, No. 8, pp. 132–134, August, 2004     

Effect of sodium succinate on histomorphological changes of autodermic grafts in rats

Sodium succinate was found to increase the viability of epithelial cells in autodermic transplants. It stimulated the proliferation of epidermal cells of the basal layer, enhanced the activity of succinate dehydrogenase, lactate dehydrogenase and adenosine triphosphatase, intensified the formation of keratin, and activated the ingrowth of blood vessels through the generation of functioning endothelial cells. Translated fromByulleten' Experimental'noi Biologii i Meditsiny, Vol. 126, No. 11, pp. 555–560, November, 1998     

Metabolic transition in the development of Hymenolepis diminuta (Cestoda)

Cysticercoids as well as 6-, 10-, and 14-day Hymenolepis diminuta were evaluated in terms of enzymatic activities related to phosphoenolpyruvate (PEP) utilization and mitochondrial succinate accumulation. The data obtained support a transition toward anaerobic electron-transport-dependent succinate accumulation, characteristic of adult H. diminuta, with development from cysticercoid to adult. This transition was reflected most prominently in the increasing activities of PEP carboxykinase (PEPCK), malate dehydrogenase, NADPH → NAD⁺ transhydrogenase, and fumarate reductase. Developmental increases in PEPCK/pyruvate kinase (PK), fumarate reductase (FR)/NADH oxidase (NO), and FR/succinate dehydrogenase (SDH) activity ratios were also apparent. Evaluations of “egg-free” immature, mature, and pregravid-gravid segments of adult H. diminuta revealed that in general the greater levels of activity were associated with the immature and mature segments. Whereas FR/NO and FR/SDH ratios remained relatively constant in segment comparisons, the greatest PEPCK/PK ratio was associated with the pregravid-gravid segment. Received: 2 December 1997 / Accepted: 5 June 1998     

Epinephrine potentiates the analgesic and antidepressant effects of polyvinylpyrrolidone and cholecystokinin due to stimulation of afferents in the gastric mucosa

Treatment with epinephrine, polyvinylpyrrolidone, and cholecystokinin in the minimum effective doses produced maximum analgesic and antidepressant effects and caused bradycardia in rats. Administration of epinephrine in combination with polyvinylpyrrolidone or cholecystokinin in threshold doses (1/10–1/25 of the minimum effective dose) produced maximum analgesic and antidepressant effects, but did not cause bradycardia. The potentiating effect of epinephrine is related to stimulation of afferents in the gastric mucosa. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 143, No. 3, pp. 321–323, March, 2007     

Metabolic and phenotypic characteristics of human skeletal muscle fibers as predictors of glycogen utilization during electrical stimulation

Characteristics of skeletal muscle such as fiber type composition and activities of key metabolic enzymes have been purported to affect glycogen utilization. However, the relative importance individual factors may have in predicting glycogen utilization of individual muscle fibers has not been addressed. Thus, we sought to determine the relative importance that metabolic characteristics and phenotypic expression of individual fibers have in predicting fiber specific glycogen utilization during neuromuscular electrical stimulation (NMES) exercise. Biopsies were taken from the m, vastus lateralis (VL) of eight recreationally active males before and immediately after 30 min of non-fatiguing NMES and analyzed for type (I, IIa and IIx), succinate dehydrogenase activity (SDH), glycerol-phosphate dehydrogenase activity (GPDH), quantitative-actomyosin adenosine triphosphatase activity (qATPase), and glycogen content. Our results demonstrate that a ratio of enzyme activities representing pathways for energy supply and energy demand (SDH: qATPase) accounted for more of the variance in glycogen utilization (y=0.2091 e^−0.0329x , R ²=0.622, P≤ 0.0001) than SDH (R ²=0.321) or qATPase (R ²=0.365) alone. Fiber phenotype was also a significant predictor of glycogen utilization, but to a lesser extent than the other variables studied (R ²=0.201). A ratio of the activities of enzymes representing pathways of energy supply and energy demand, represented by SDH:qATPase, is a better predictor of glycogen utilization than either of its components independently while fiber phenotype, although a statistically significant predictor of glycogen utilization, may not be the most appropriate determinate of the functional characteristics of an individual fiber.     

Effects of antisense oligonucleotides to mRNA for the early gene zif268 on the mechanisms of synapse-specific plasticity

Acquisition of nociceptive sensitization in common snails was accompanied by long-term facilitation of the responses of defensive behavior command neuron LPl1 to sensory stimulation of chemoreceptors on the head and mechanoreceptors on the head and foot. Acquisition of sensitization during intracellular administration of antisense oligonucleotides to mRNA encoding the early gene zif268 showed suppression of synaptic facilitation in the responses of neuron LPl1 to tactile and chemical stimulation of the snail’s head. Synaptic facilitation in the responses to tactile stimulation of the foot developed as in neurons of control sensitized animals. These results suggest that the early gene zif268 is selectively involved in the mechanisms of the specific regulation of the synaptic inputs of neuron LPl1 from sensory receptors on the snail’s head. __________ Translated from Zhurnal Vysshei Nervnoi Deyatel’nosti imeni I. P. Pavlova, Vol. 56, No. 4, pp. 499–505, July–August, 2006.     

Spectral parameters of phrenic nerve activity in mature rats during electrical stimulation of retrotrapezoid nucleus

In mature rats, electrical stimulation of the retrotrapezoid nucleus increased the amplitude and frequency of the high-frequency peak in the firing spectrum of the phrenic nerve, while the amplitude of medium-frequency peak and the amplitude ratio of medium- to high-frequency peaks decreased. These changes in spectral parameters were associated with accelerated increase in central inspiratory activity, decreased amplitude of phrenic nerve firing, and increased frequency of respiratory rhythm. It is hypothesized that being a relay structure of central chemosensitive mechanism, the retrotrapezoid nucleus regulates parameters of medium-and high-frequency spectral peaks of efferent electrical activity in the respiratory center together with the dorsal and ventral respiratory groups. Translated fromByulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 138, No. 8, pp. 139–143, August, 2004     

Lymphotropic effect of dimephosphon,mexidol, and ketorolac is realized via activation of the lymphangion and stimulation of lymph formation

Single parenteral administration of dimephosphon, mexidol, and ketorolac produces a lymphotropic effect. Dimephosphon directly affects the lymph system by increasing the number of functioning lymph capillaries and contractile activity of the walls and valves of small intestinal mesenteric lymphangions in rats, which leads to stimulation of lymph circulation. Mexidol and ketorolac increased only lymph flow rate in the thoracic lymph duct, which attested to their indirect effect of the lymph system (presumably associated with stimulation of lymph formation). Despite these differences in the mechanisms of lymphotropic effect, all these drugs activate lymph drainage and, hence, transporting function of the lymph system. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 143, No. 4, pp. 423–426, April, 2007     

Epinephrine potentiates the analgesic and antidepressant effects of amitriptyline as a result of stimulation of the gastric mucosal afferents

Intramuscular amitriptyline in the minimum effective dose causes maximum analgesic and antidepressant effect and significant sedation in rats. Combined injection of amitriptyline with epinephrine in the threshold doses (ineffective if used alone), 1/10 and 1/30 minimum effective doses, respectively, leads to the development of the maximum analgesic and antidepressant effect, but causes no sedative side effect. This potentiation is mediated by stimulation of afferents in the gastric mucosa with epinephrine. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 144, No. 11, pp. 535–537, November, 2007     

Release of cardiac troponin I from viable cardiomyocytes is mediated by integrin stimulation

Elevated cardiac troponin-I (cTnI) levels have been demonstrated in serum of patients without acute coronary syndromes, potentially via a stretch-related process. We hypothesize that this cTnI release from viable cardiomyocytes is mediated by stimulation of stretch-responsive integrins. Cultured cardiomyocytes were treated with (1) Gly–Arg–Gly–Asp–Ser (GRGDS, n = 22) to stimulate integrins, (2) Ser–Asp–Gly–Arg–Gly (SDGRG, n = 8) that does not stimulate integrins, or (3) phosphate-buffered saline (control, n = 38). Cells and media were analyzed for intact cTnI, cTnI degradation products, and matrix metalloproteinase (MMP)-2. Cell viability was examined by assay of lactate dehydrogenase (LDH) activity and by nuclear staining with propidium iodide. GRGDS-induced integrin stimulation caused increased release of intact cTnI (9.6 ± 3.0%) as compared to SDGRG-treated cardiomyocytes (4.5 ± 0.8%, p < 0.001) and control (3.0 ± 3.4%, p < 0.001). LDH release from GRGDS-treated cardiomyocytes (15.9 ± 3.8%) equalled that from controls (15.2 ± 2.3%, p = n.s.), indicating that the GRGDS-induced release of cTnI is not due to cell necrosis. This result was confirmed by nuclear staining with propidium iodide. Integrin stimulation increased the intracellular and extracellular MMP2 activity as compared to controls (both p < 0.05). However, despite the ability of active MMP2 to degrade cTnI in vitro, integrin stimulation in cardiomyocytes was not associated with cTnI degradation. The present study demonstrates that intact cTnI can be released from viable cardiomyocytes by stimulation of stretch-responsive integrins.     

Neuromuscular stimulation selectivity of multiple-contact nerve cuff electrode arrays

The feasibility of an electrical stimulation method selectively for activating skeletal muscles innervated by a common peripheral nerve trunk has been investigated. The method utilises ‘snugly’ fitting nerve cuffs that incorporate an array of 12 electrodes. These electrodes have been tested as four longitudinally aligned tripoles (located 90° apart on the cuff inner surface). In acute experiments on rabbit sciatic nerves, we have found that tripolar stimulation with this implant system is in general highly selective. ‘Field steering’, wherein a subthreshold transverse current is used in combination with a longitudinal tripolar current, tends to increase the selectivity of stimulation. On a rabbit sciatic nerve, a combination of adjacent longitudinal tripoles of the 12 electrode array generally yields a stimulation performance similar to that which would be expected if a 24 electrode array is used. This system may find a use in functional neuromuscular stimulation applications which require highly selective control over multiple muscles.