No abstract available.
Dendrites* ; Hippocampus* ; Interneurons*

In this study, change of optical properties and microstructure of an Ag-Pd-In alloy according to Ag content was investigated. For this purpose, specimen alloys were prepared by adding 0–100 wt.% of Ag to the 50Pd-50In (wt.%) alloy. When the content of Ag was more than 40 wt.%, the color difference with pure gold specimen was increased(p < 0.001). L* value increased as the Ag content of the specimen increased, but a* and b* value increased until the addition of 20 wt.% Ag, and then decreased with increasing Ag content(p < 0.001). Ag-free specimen was single phase in the as-cast state, but when the content of Ag was more than 20 wt.%, the phase separation occurred and two phases of matrix and dendrite or granular structure were confirmed. The dendrite or granular structure was composed of the InPd phase, and the matrix was composed of the Ag-rich phase. From these results, it can be concluded that the specimens with Ag content of 20–70 wt.% have the Ag-rich matrix which has a high L* value and low a* and b* value, and have the dendrite structure which has a low L* value and high a* and b* value. As the content of Ag increased, the color changed from light yellow to silver white due to the increase in the ratio of the matrix to the dendrite or granular structure.
Alloys ; Dendrites ; Silver

No abstract available.
Child* ; Dendrites* ; Epilepsy* ; Humans ; Interneurons*

For expressing the condolences on the passing away of Dr. Hsiang-Tung Chang, one of the distinguished members of the Chinese Academia of Sciences, the pioneer studies on cortical dendritic potentials that Dr. Chang carried out in the 1950s and the prosperous progresses since then, especially, concerning the modifications of synaptic plasticity by the dendritic back-propagating action potentials were briefly reviewed.
Action Potentials ; Dendrites ; physiology ; Humans ; Neuronal Plasticity

Sixty years elapsed since Chang (Hsiang-Tung Chang, Xiang-Tong Zhang) presented his seminal report "Cortical neurons with particular reference to the apical dendrite" at the Cold Spring Harbor Symposium. Thanks to the development of elaborated techniques through the 6 decades, our understanding of the dendrite has been pushed forward greatly: the backward and forward conductions during excitation, sodium and calcium conductances, chemical excitation by uncaging glutamate at a dimension of micrometer, and the quantitative study of chemical organization of postsynaptic density (PSD), etc. Though the progression is great, there are still tough problems in dendritic research, especially the integration through dendritic spine.
Calcium Signaling ; Dendrites ; physiology ; Glutamic Acid ; metabolism

Dendrites ; physiology ; History, 20th Century ; Neurophysiology ; history

Ultrastructural parameters related to synaptic release and their correlation with synaptic connectivity were analyzed in the low-threshold mechanoreceptive vibrissa afferent boutons in laminae III and IV of the trigeminal caudal nucleus (Vc). Rapidly adapting vibrissa afferents were intra-axonally labeled, and quantitative ultrastructural analyses with serial sections were performed on the labeled boutons and their presynaptic endings (p-endings). The volume of the labeled boutons was widely distributed from small to large ones (0.8~12.3 microm3), whereas the p-endings were small and uniform in size. The volume of the labeled boutons was positively correlated with the ultrastructural parameters such as mitochondrial volume (correlation coefficient, r=0.96), active zone area (r=0.82) and apposed surface area (r=0.79). Vesicle density (r=-0.18) showed little correlation to the volume of labeled boutons, suggesting that the total vesicle number of a bouton is proportional to its volume. In addition, the bouton volume was positively correlated with the number of p-endings (r=0.52) and with the number of dendrites postsynaptic to the labeled bouton (r=0.83). These findings suggest that low-threshold mechanoreception conveyed through vibrissa afferents is processed in a bouton size-dependent manner in the Vc, which may contribute to the sensory-motor function of laminae III/IV in Vc.
Animals ; Cats ; Dendrites ; Mitochondrial Size ; Synapses ; Trigeminal Caudal Nucleus

In humans, the major stimulus for cutaneous pigmentation is ultraviolet radiation. Little is known about the mechanism underlying this response, in part, because of the complexity of the interactions involving the whole epidermis. The present stucy was undertake to evaluate the effects of a single exposure of UVB on cultured normal melanocytes. Melanocytes were exposed to UVB from 5.1 mJ/cm to 203 mJ/cm. The results were as follows : 1. The main morphologic changes in UVB-exposed groups w re larger sized cells, more blunted dendrites, and shorter dendrites than in the control group. These cells increased sized according to the increased doses of VVB, but above 101.5 mJ/cm, the melanocytes shrunk and were destroyed. 2. From 20.3 mJ/cm of UVB, the proliferation of melanocyte was decreased, Especially, there was statistical!y significant difference above 50.8 mJ/cm (p<0.05, p<0.01). 3. The antiproliferativo effect increased with the passage of tirie after UVB exposure. So, cell count could not be done in 101.5 mJ/cm and 203 mJ/cm on the third day, and in 50.8 mJ/cm, 101.5 m J/cm and 203 mJ/cm on the seventh day. 4. Statistically the melanin content per well was significantl dicreased to 11-28% of each control group with dose above 50.8 mJ/cm (p<0.05, p<0.01). The melanin content per cell was increased to 107-128% of each control group when doses were below 20.3 mJ/cm and decreased to 49-79% of each control group when above 0.8 mJ/cm on the third day, but there was no statistically significant difference. In summary, when melarocytes were exposed to UVB, morphclogic changes progressed to cell differentiation. The results also suggested that a low or dose of UVB has an antiproliferative arid mild melanogenic effect, and a higher dose of UVB has a direct cytotoxic effect.
Cell Count ; Cell Differentiation ; Dendrites ; Epidermis ; Humans ; Melanins ; Melanocytes* ; Pigmentation

PURPOSE: Excitotoxic injury of the dendrites of inhibitory interneurons could lead to decrease in their synaptic activation, and explain subsequent local circuit hyperexcitability and epilepsy. A hallmark of dendrotoxicity at least in principal neurons of the hippocampus and cortex are focal or varicose swellings of dendritic abors. This research was designed to study morphologic changes of interneuron dendrite in kainate-treated hippocampal slice culture overtime. METHODS: Cultures aged to 15-16 Equivalent Postnatal Day (EPD) were exposed to 10microM kainic acid (KA), and were analyzed at 0, 8, 24, 48, 72 hours after transient (1 hour) KA exposure. Neuronal injury was determined by morphologic changes of parvalbumin (PV) positive interneuron dendrites in area CA1 of PV-immunohistochemically stained sections. RESULTS: 1) Transient (1 hour) exposure of hippocampal explant cultures to KA produced marked focal swellings of the dendrites of PV-immunoreactive interneurons in a highly reproducible manner. 2) The presence of focal swellings was reversible with kainate washout. The dendrites of KA treated explants were no longer beaded at 8, 24, 48, 72hours after KA exposure.3) The number of cells in PV-immunoreactive interneuron was decreased at 0, 8, 24 hours after exposure. But there was no significant difference among 48hr and 72hr recovery group compare with control group.4) The total length of dendrites was decreased between 0 and 8hours after exposure. But there was no significant difference among 24, 48, and 72hr recovery group compare with control group.5) The branches of dendrites were decreased just after exposure. But there was no significant difference among 8hr, 24hr, 48hr, and 72hr recovery group compare with control group. CONCLUSION: The presence of focal swellings was reversible with kainate washout, and was not accompanied by interneuronal cell death.
Cell Death ; Dendrites* ; Epilepsy ; Hippocampus ; Interneurons* ; Kainic Acid ; Neurons

We investigated whether diclofenac could influence the development of antigen-presenting cells in an oxygenated cholesterol-rich environment by determining its effects on the 27-hydroxycholesterol (27OHChol)-induced differentiation of monocytic cells into mature dendritic cells (mDCs). Treatment of human THP-1 monocytic cells with diclofenac antagonized the effects of 27OHChol by attenuating dendrite formation and cell attachment and promoting endocytic function. Diclofenac inhibited the transcription and surface expression of the mDC markers of CD80, CD83, and CD88, and reduced the 27OHChol-induced elevation of surface levels of MHC class I and II molecules to the basal levels in a dose-dependent manner. It also reduced the expression of CD197, a molecule involved in DC homing and migration. These results indicate that diclofenac inhibits the differentiation of monocytic cells into mDCs, thereby potentially modulating adaptive immune responses in a milieu rich in cholesterol oxidation products.
Antigen-Presenting Cells ; Cholesterol ; Dendrites ; Dendritic Cells* ; Diclofenac* ; Humans ; Oxygen