Localization and release of 5-hydroxytryptamine in the crayfish eyestalk

The content and regional distribution of 5-hydroxytryptamine (5-HT) in the crayfish eyestalk was determined by high-performance liquid chromatography. Levels of the 5-HT precursors l-tryptophan (L-TRP) and 5-hydroxytryptophan (5-OH-TRP), and of three metabolites, 5-hydroxytryptophol (5-HTPH), N-acetylserotonin (NA-5-HT) and 5-hydroxy-indole-3-acetic acid (5-HIAA), were also determined. The total content of 5-HT in the eyestalk was 95.4+/-49.3 pg mg-1 wet mass (mean +/- s.d., N=55) while the specific content was 9.6+/-4.9 fmol microg-1 protein (mean +/- s.d. N=5). 5-HT was present in all four ganglia of the eyestalk. The highest proportion was found in the medulla terminalis (40.2 %) and the lowest in the retina lamina ganglionaris (9.9 %), which also had the lowest specific content. Conversely, the highest specific content of L-TRP was in the retina lamina ganglionaris. 5-HT biosynthesis and metabolism were explored in isolated eyestalks. The monoamine oxidase blocker pargyline, at concentrations between 0.8 and 10 mmol l-1, elicited a dose-dependent increase in 5-HT content. The biosynthesis of 5-HT in the crayfish eyestalk is suggested by the presence of its immediate precursor (5-OH-TRP) and by the suppression of 5-HT synthesis induced by m-hydroxybenzyl-hydrazine (m-HBH), a blocker of 5-OH-TRP decarboxylase. The presence of immunopositive cell bodies and axons was demonstrated using an anti-5-HT antiserum. 5-HT-like immunopositivity was detected in various regions of the eyestalk. Efferent immunopositive axons were also identified in the optic nerve, and these may have originated in the protocerebral lobe of the supraoesophageal ganglion. The branchings of these axons were profusely distributed in the neuropile of the medulla terminalis. A basal level release of 5-HT was detected in isolated eyestalks. The amount recovered was increased two-to threefold after blocking 5-HT uptake with fluoxetine (1 micromol l-1). Incubation of eyestalks in solutions containing a high K+ concentration (80 mmol l-1) released 5-HT. Electrical stimulation of the optic nerve released 5-HT as a function of the intensity of stimulation. Both the basal and evoked release were suppressed by lowering the Ca2+ concentration in the medium. These observations support a role for 5-HT as a neurotransmitter or neuromodulator in the crayfish eyestalk.

Download Full-text

Hair cell changes after cationic stimulation of corti's organ

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100155967 ◽

1989 ◽

Vol 47 ◽

pp. 798-799

Author(s):

Cesar D. Fermin ◽

Hans-Peter Zenner

Keyword(s):

Organ Of Corti ◽

Cross Sectional ◽

Surface Areas ◽

High K ◽

Anatomical Arrangement ◽

Cell Cytosol ◽

High Concentrations ◽

K Concentration ◽

Cell Changes

Contraction of outer and inner hair cells (OHC&IHC) in the Organ of Corti (OC) of the inner ear is necessary for sound transduction. Getting at HC in vivo preparations is difficult. Thus, isolated HCs have been used to study OHC properties. Even though viability has been shown in isolated (iOHC) preparations by good responses to current and cationic stimulation, the contribution of adjoining cells can not be explained with iOHC preparations. This study was undertaken to examine changes in the OHC after expossure of the OHC to high concentrations of potassium (K) and sodium (Na), by carefully immersing the OC in either artifical endolymph or perilymph. After K and Na exposure, OCs were fixed with 3% glutaraldehyde, post-fixed in osmium, separated into base, middle and apex and embedded in Araldite™. One μm thick sections were prepared for analysis with the light and E.M. Cross sectional areas were measured with Bioquant™ software.Potassium and sodium both cause isolated guinea pig OHC to contract. In vivo high K concentration may cause uncontrolled and sustained contractions that could contribute to Meniere's disease. The behavior of OHC in the vivo setting might be very different from that of iOHC. We show here changes of the cell cytosol and cisterns caused by K and Na to OHC in situs. The table below shows results from cross sectional area measurements of OHC from OC that were exposed to either K or Na. As one would expect, from the anatomical arrangement of the OC, OHC#l that are supported by rigid tissue would probably be displaced (move) less than those OHC located away from the pillar. Surprisingly, cells in the middle turn of the cochlea changed their surface areas more than those at either end of the cochlea. Moreover, changes in surface area do not seem to differ between K and Na treated OCs.

Download Full-text

Sub-20nm Device Voltage-Sensitive SRAM Characterization and Failure Analysis

10.31399/asm.cp.istfa2018p0300 ◽

2018 ◽

Author(s):

Seng Nguon Ting ◽

Hsien-Ching Lo ◽

Donald Nedeau ◽

Aaron Sinnott ◽

Felix Beaudoin

Keyword(s):

Failure Analysis ◽

High Performance ◽

Yield Loss ◽

Technology Development ◽

High Density ◽

High K ◽

Yield Learning ◽

Oxide Deposition ◽

Edge Profile ◽

High K Dielectric

Abstract With rapid scaling of semiconductor devices, new and more complicated challenges emerge as technology development progresses. In SRAM yield learning vehicles, it is becoming increasingly difficult to differentiate the voltage-sensitive SRAM yield loss from the expected hard bit-cells failures. It can only be accomplished by extensively leveraging yield, layout analysis and fault localization in sub-micron devices. In this paper, we describe the successful debugging of the yield gap observed between the High Density and the High Performance bit-cells. The SRAM yield loss is observed to be strongly modulated by different active sizing between two pull up (PU) bit-cells. Failure analysis focused at the weak point vicinity successfully identified abnormal poly edge profile with systematic High k Dielectric shorts. Tight active space on High Density cells led to limitation of complete trench gap-fill creating void filled with gate material. Thanks to this knowledge, the process was optimized with “Skip Active Atomic Level Oxide Deposition” step improving trench gap-fill margin.

Download Full-text

Foodstuffs. Determination of aflatoxin B1, and the total content of aflatoxins B1, B2, G1 and G2 in cereals, nuts and derived products. High-performance liquid chromatographic method

10.3403/30235996u ◽

2015 ◽

Cited By ~ 1

Keyword(s):

Aflatoxin B1 ◽

High Performance ◽

Chromatographic Method ◽

Total Content ◽

High Performance Liquid Chromatographic ◽

Liquid Chromatographic Method ◽

Liquid Chromatographic

Download Full-text

Interfacial polarization-induced high-k polymer dielectric film for high-performance triboelectric devices

Nano Energy ◽

10.1016/j.nanoen.2020.105697 ◽

2021 ◽

Vol 82 ◽

pp. 105697

Author(s):

Minsoo P. Kim ◽

Chang Won Ahn ◽

Youngsu Lee ◽

Kyoungho Kim ◽

Jonghwa Park ◽

...

Keyword(s):

High Performance ◽

Dielectric Film ◽

Interfacial Polarization ◽

Polymer Dielectric ◽

High K

Download Full-text

Physiologically Active Compounds in Four Species of Phellinus

Natural Product Communications ◽

10.1177/1934578x1701200313 ◽

2017 ◽

Vol 12 (3) ◽

pp. 1934578X1701200 ◽

Cited By ~ 14

Author(s):

Katarzyna Sułkowska-Ziaja ◽

Anna Maślanka ◽

Agnieszka Szewczyk ◽

Bożena Muszyńska

Keyword(s):

Phenolic Acids ◽

High Performance ◽

Total Content ◽

Dry Weight ◽

Hplc Method ◽

Indole Compounds ◽

Methanolic Extracts ◽

Free Phenolic Acids ◽

Layer Chromatography ◽

Physiologically Active Compounds

The content of two groups of compounds with biological activity (non-hallucinogenic indole compounds and free phenolic acids) were analyzed in extracts of fruiting bodies of four species of Phellinus: P. igniarius, P. pini, P. pomaceus and P. robustus. The presence of indole compounds in methanolic extracts was analyzed by high-performance liquid chromatography and thin-layer chromatography coupled with densitometric detection. Three metabolites (serotonin, tryptamine, and L-tryptophan) were identified. The contents of individual indole compounds ranged from 1.70 (tryptamine in P. robustus) to 8.32 mg x 100 g1 dry weight (L-tryptophan in P. robustus). Four free phenolic acids were detected in methanolic extracts by the HPLC method. The total content ranged from 9.9 mg x 100 g1 DW (P. igniarius) to 32.5 mg x 100 g1 DW (P. robustus).

Download Full-text

32nm gate-first high-k/metal-gate technology for high performance low power applications

2008 IEEE International Electron Devices Meeting ◽

10.1109/iedm.2008.4796770 ◽

2008 ◽

Cited By ~ 12

Author(s):

C. H. Diaz ◽

K. Goto ◽

H.T. Huang ◽

Yuri Yasuda ◽

C.P. Tsao ◽

...

Keyword(s):

Low Power ◽

High Performance ◽

Metal Gate ◽

High K

Download Full-text

Development of high k/III-V (InGaAs, InAs, InSb) structures for future low power, high speed device applications

MRS Proceedings ◽

10.1557/opl.2013.585 ◽

2013 ◽

Vol 1538 ◽

pp. 291-302

Author(s):

Edward Yi Chang ◽

Hai-Dang Trinh ◽

Yueh-Chin Lin ◽

Hiroshi Iwai ◽

Yen-Ku Lin

Keyword(s):

Low Power ◽

Leakage Current ◽

High Speed ◽

High Performance ◽

Gate Oxide ◽

Chemical Cleaning ◽

Low Leakage ◽

Low Leakage Current ◽

High K ◽

Cleaning Methods

ABSTRACTIII-V compounds such as InGaAs, InAs, InSb have great potential for future low power high speed devices (such as MOSFETs, QWFETs, TFETs and NWFETs) application due to their high carrier mobility and drift velocity. The development of good quality high k gate oxide as well as high k/III-V interfaces is prerequisite to realize high performance working devices. Besides, the downscaling of the gate oxide into sub-nanometer while maintaining appropriate low gate leakage current is also needed. The lack of high quality III-V native oxides has obstructed the development of implementing III-V based devices on Si template. In this presentation, we will discuss our efforts to improve high k/III-V interfaces as well as high k oxide quality by using chemical cleaning methods including chemical solutions, precursors and high temperature gas treatments. The electrical properties of high k/InSb, InGaAs, InSb structures and their dependence on the thermal processes are also discussed. Finally, we will present the downscaling of the gate oxide into sub-nanometer scale while maintaining low leakage current and a good high k/III-V interface quality.

Download Full-text