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Synaptic transmission-dependent regulation of neurotransmitter receptor accumulation at postsynaptic sites underlies the formation, maintenance and maturation of synaptic function. Previous in vitro studies showed that glycine receptor (GlyR) clustering requires synaptic inputs. However, in vivo GlyR regulation by synaptic transmission is not fully understood. Here, we established a model system using developing zebrafish, in which GlyRs are expressed in Mauthner cells (M-cells), a pair of giant, reticulospinal, hindbrain neurons, thereby enabling analysis of GlyR clusters over time in identifiable cells. Bath application of a glycinergic blocker, strychnine, to developing zebrafish prevented postsynaptic GlyR cluster formation in the M-cells. After strychnine removal, the GlyR clusters appeared in the M-cells. At a later stage, glycinergic transmission blockade impaired maintenance of GlyR clusters. We also found that pharmacological blockade of either L-type Ca(2+) channels or calcium-/calmodulin-dependent protein kinase II (CaMKII) disturbed GlyR clustering. In addition, the M-cell-specific CaMKII inactivation using the Gal4-UAS system significantly impaired GlyR clustering in the M-cells. Thus, the formation and maintenance of GlyR clusters in the M-cells in the developing animals are regulated in a synaptic transmission-dependent manner, and CaMKII activation at the postsynapse is essential for GlyR clustering. This is the first demonstration of synaptic transmission-dependent modulation of synaptic GlyRs in vivo.

application/pdf, Article, Naunyn-Schmiedeberg's Archives of Pharmacology. 2017, 390 (3), p.261-268

For a special arrangement of multiple floating bodies, it is known that the wave drift force acting on a body surrounded by a finite number of bodies becomes zero at a certain frequency due to hydrodynamic interactions; which is related to ‘cloaking’ phenomenon. In order to study this phenomenon in more detail and its application to engineering problems, we have developed an accurate computer code and an optimization scheme using a genetic algorithm and presented some preliminary results. In the present paper, study is made on the wave pattern in the cloaking phenomenon and its relationship with the wave drift force. Specifically, we conducted the measurement of not only hydrodynamic forces but also the wave pattern around vertical circular cylinders of finite draft arranged in a cloaking configuration. Comparison is made between numerical and measured results, and it is shown that when the geometrical parameters of surrounding circular cylinders are optimized such that the total scattered-wave energy becomes minimal, the wave drift force reduces to nearly equal to zero not only on the central cylinder but also outer surrounding cylinders individually.

The purpose of this study was to investigate whether rhythmic arm swing modulates the long latency effect of transcranial magnetic stimulation (TMS) on soleus motoneuron pool excitability. Ten healthy humans rhythmically swung the left arm back and forth in a sitting position. The soleus H-reflex was evoked when the arm was in the backward swing phase. Conditioning TMS was delivered over the motor cortex 8 ms before the soleus H-reflex was evoked. The soleus H-reflex amplitude in both legs was depressed by the rhythmic arm swing. In contrast, rhythmic arm swing enhanced the facilitatory effect of conditioning TMS over the motor cortex contralateral to the arm swing side on the soleus H-reflex ipsilateral to the arm swing side. This finding indicates that rhythmic arm swing enhances some polysynaptic facilitatory pathways from the motor cortex contralateral to the arm swing side to the soleus motoneuron pool ipsilateral to the arm swing side.

We propose the concept and implementation of a graphical information hiding technique for interactive tabletops where users can view the information by simply casting real shadows. We placed three projectors (one in the rear and two in the front) in such a way that the rear one projects graphical information onto a tabletop surface, and the front ones project a complementary image, so that the combined image displayed on the surface becomes uniformly gray, thus hiding the information from the viewer. Users can view the hidden information by blocking the light from the front projector, revealing the complementary image that is being projected onto the occluder. We use the other front projector and polarization filters to make the complementary image projected onto the occluder also uniformly gray. Because the technique completely relies on optical phenomena, users can interact with the system without suffering from any false recognitions or delays.

BACKGROUND The protease activity leading to degradation of the extracellular matrix was compared between human endometrial cancer and normal uterine endometrium. METHODS Conditioned medium from tumor cells and normal endometrial cells was subjected to electrophoresis on sodium dodecyl sulfate (SDS)-polyacrylamide gel containing gelatin as a substrate. After electrophoresis, the gel was stained with Coomassie blue, and then the enzyme activity, expressed as the zone of dye clearing, was analyzed by densitometry. RESULTS Densitometric analysis showed that all the endometrial cancers expressed a very high molecular weight enzyme activity (Mr 220,000), which was not detected in medium from normal endometrial cells. The analysis also showed that in endometrial cancer the activity of a Mr 92,000 enzyme was always superior to that of a Mr 64,000 enzyme, which was in contrast to the situation for normal endometrium. CONCLUSIONS These results indicate that the expression of Mr 220,000 enzyme activity and the higher activity of the Mr 92,000 enzyme than the Mr 64,000 enzyme are involved in the malignant phenotype of native endometrial cancer.

In order to evaluate the changes in uterine oxytocin receptor-specific mRNA during pregnancy, receptor expression in Xenopus oocytes are examined electrophysiologically following microinjection of mRNA from human uterus. In voltage-clamped oocytes injected with term myometrial mRNA, oxytocin elicited an inward current response. The amplitude of the oxytocin-induced current increased with increasing dose of oxytocin, but no current was elicited following stimulation with vasopressin. The oxytocin-induced current was completely eliminated as a result of pretreatment with a specific oxytocin antagonist. 21 of 27 oocytes injected with term myometrial mRNA showed a large amplitude (77.0 +/- 16.1 nA) reaction to oxytocin. In comparison, only 3 of 13 oocytes injected with early gestational myometrial mRNA exhibited a small amplitude (4.6 +/- 1.4 nA) reaction to oxytocin. No oxytocin response was observed in oocytes injected with non-pregnant myometrial mRNA. These results indicate that the striking increment in oxytocin sensitivity in term uterus depends on the increase in mRNA encoding oxytocin receptors.

We investigated the biological effect of sex-steroid hormones, secreted from the corpus luteum and placenta, on the induction of mRNA encoding macrophage colony-stimulating factor (MCSF) and c-fms proto-oncogene (MCSF receptor) in the human uterine myometrium. Poly(A)+RNA was extracted from the myometrium of pregnant and non-pregnant uterine myometrium and then Northern blot analysis was performed on poly(A)+RNA. The myometrium of non-pregnant women expressed neither mRNA of macrophage colony-stimulating factor (MCSF) nor any transcript related to the c-fms proto-oncogene. On the other hand the myometrium of pregnant women expressed MCSF mRNA (4.7 kb) and two kinds of transcript related to the c-fms proto-oncogene (3.9 and 1.3 kb). The mRNAs of both MCSF and c-fms proto-oncogene were induced in the uterine myometrium of non-pregnant women under pseudopregnant therapy of mestranol and norethindrone. These results indicate that sex steroid hormone secreted from the corpus luteum of pregnancy and/or placenta may be deeply involved in the hypertrophic change of uterus during pregnancy by inducing MCSF and MCSF receptor (c-fms proto-oncogene protein product) in the myometrium.

Progestins have biological effects of regression and differentiation on human endometrial adenocarcinoma. We investigated the effects of progestin on the induction of macrophage-colony-stimulating factor (M-CSF) and its receptor messenger RNAs in the human endometrial adenocarcinoma cell line Ishikawa which has receptors for both estrogen and progesterone. Poly(A)+RNA extracted from Ishikawa cells cultured with or without synthetic progestin R5020 was subjected to Northern blot hybridization using M-CSF and c-fms cDNA probes. The expression of M-CSF mRNA in Ishikawa cells increased about 2.3 times following treatment with R5020 at 10(-7) M. Induction of M-CSF mRNA by R5020 was antagonized by anti-progestin RU486 in a dose-dependent manner. However, c-fms mRNA, coding the M-CSF receptor, was expressed constitutively in Ishikawa cells and its expression was not affected by hormonal treatment. We further examined the biological effects of M-CSF on endometrial cancer cells. Colony formation of Ishikawa cells in soft agar, which represents anchorage-independent cell growth, was inhibited by M-CSF treatment. On the other hand, accumulation of glycogen granules in cytoplasm detected by periodicacid-Schiff staining was observed in Ishikawa cells treated with M-CSF. These results indicate that M-CSF, whose gene expression was enhanced by progestin, suppressed growth and induced differentiation of endometrial adenocarcinoma cells. These effects of M-CSF on endometrial cancer cells are similar to those of progestins, so the effects of progestins on these cells are, at least in part, probably mediated by M-CSF in an autocrine or paracrine manner.

We demonstrate the existence of functional endothelin receptors in human uterine myometrium using the Xenopus oocyte expression system. Fifty nanograms of poly(A) +RNA from myometrium was injected into Xenopus laevis oocytes and incubated for 70–80 h. The membrane potential of the oocyte was clamped at −60 mV and membrane current was measured during and after endothelin stimulation. Endothelin-1 elicited a large inward membrane current in the oocytes injected with poly(A) +RNA; endothelin-2 elicited a small current; while endothelin-3 did not induce any membrane current. These results indicate the existence of messenger RNA encoding functional endothelin-1 receptors in human uterine myometrium.