A simultaneous optical and electrical in-vitro neuronal recording system to evaluate microelectrode performance

We have tested a new fiber-optic pressure recording system, Samba, with a thin fiber [outer diameter (OD) = 0.25 mm] and a pressure sensor (length and OD = 0.42 mm) attached to the end. The accuracy of the system tested in vitro was good, with a coefficient of variation of 2.54% at 100 mmHg. The drift was <0.45 mmHg/h, and the temperature sensitivity was ∼0.07 mmHg/1°C between 22 and 37°C. The frequency response characteristics were similar to a 1.4-Fr Millar catheter (0–200 Hz). Introduction of the Samba sensor from the right carotid artery into the left ventricle in six mice caused no drop in mean aortic pressure, whereas introduction of a 1.4-Fr Millar catheter (OD = 0.47 mm; n = 6) caused a pressure drop from 91.6 ± 9.2 to 65.1 ± 6.2 mmHg; P < 0.05. Thus the Samba sensor system may represent a new alternative to assess hemodynamic variables in the murine cardiovascular system.

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Developmental kinetics of in vitro produced bovine embryos: the effect of sex, glucose and exposure to time-lapse environment

Zygote ◽

10.1017/s0967199401001113 ◽

2001 ◽

Vol 9 (2) ◽

pp. 105-113 ◽

Cited By ~ 46

Author(s):

J. Peippo ◽

M. Kurkilahti ◽

P. Bredbacka

Keyword(s):

Sex Determination ◽

Video Recording ◽

Time Lapse ◽

Recording System ◽

Bovine Embryos ◽

Cell Stage ◽

Developmental Potential ◽

Kinetics Of ◽

Time Lapse Video

In this study, a simple time-lapse video recording system was used to compare developmental kinetics of female and male bovine embryos produced in vitro. Following embryo sex determination, the timing of each cleavage up to the 4-cell stage was compared between the sexes from the videotapes after culture in the presence and absence of glucose. In the second experiment, the consequences of exposure to a time-lapse video recording (TL) environment were studied by culturing embryos further until day 7 in an incubator, followed by collection and sex determination of morulae and blastocysts. In the absence of glucose, female embryos cleaved earlier than male ones. In the presence of glucose, however, male embryos cleaved earlier than female ones. There was no difference in the number of morulae/blastocysts in the absence of glucose, but in the presence of glucose more male than female embryos reached the morula and blastocyst stage. Exposure to the TL environment itself also had a sex-related effect, being more detrimental to male than female embryos. The difference in the number of functional X chromosomes between the sexes during early preimplantation development could explain these findings. In females, an increased capacity for oxygen radical detoxification through the pentose phosphate pathway could result in a reduced cleavage rate. Furthermore, glucose may influence the expression of enzymes located on the X chromosome. According to these results, a simple time-lapse video recording system is suitable for investigating embryo developmental kinetics and perhaps for the selection of embryos with the greatest developmental potential.

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Compact 256-channel multi-well microelectrode array system for in vitro neuropharmacology test

Lab on a Chip ◽

10.1039/d0lc00384k ◽

2020 ◽

Vol 20 (18) ◽

pp. 3410-3422

Author(s):

Daejeong Kim ◽

Hongki Kang ◽

Yoonkey Nam

Keyword(s):

High Throughput ◽

Drug Response ◽

Microelectrode Array ◽

Recording System

In this study, we developed a compact multi-well MEA with commercial ASIC based in vitro high-throughput recording system to investigate electrophysiological drug response.

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THE EFFECT OF NEUROHYPOPHYSIAL HORMONES ON THE AMPHIBIAN OVIDUCT IN VITRO, WITH SOME REMARKS ON THE HISTOLOGY OF THIS ORGAN

Journal of Endocrinology ◽

10.1677/joe.0.0470495 ◽

1970 ◽

Vol 47 (4) ◽

pp. 495-509 ◽

Cited By ~ 24

Author(s):

H. HELLER ◽

ELENA FERRERI ◽

D. H. G. LEATHERS

Keyword(s):

Recording System ◽

Muscle Fibres ◽

Seasonal Differences ◽

Contractile Responses ◽

Neurohypophysial Hormones ◽

Isotonic Contractions

SUMMARY The effect of neurohypophysial hormones has been tested in vitro on oviducts of four species of urodele and three species of anuran Amphibia. Contractile responses were obtained with all the hormones used but 8-arginine oxytocin (vasotocin) was usually most potent. The sensitivity of the oviducts varied widely from species to species; there were also pronounced seasonal differences within a species. Histological investigations yielded some information on the abundance and arrangement of muscle fibres in amphibian oviducts. A simple and sensitive (magnification up to × 1000) recording system for isotonic contractions is described.

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Effects of Gas Production Recording System and Pig Fecal Inoculum Volume on Kinetics and Variation of In Vitro Fermentation using Corn Distiller’s Dried Grains with Solubles and Soybean Hulls

Animals ◽

10.3390/ani9100773 ◽

2019 ◽

Vol 9 (10) ◽

pp. 773

Author(s):

Jae-Cheol Jang ◽

Zhikai Zeng ◽

Gerald C. Shurson ◽

Pedro E. Urriola

Keyword(s):

Exponential Model ◽

Gas Production ◽

Recording System ◽

Soybean Hulls ◽

In Vitro Fermentation ◽

Fractional Rate ◽

Manual Recording ◽

Inoculum Volume ◽

Corn Distillers

An experiment was conducted to investigate the effect of inoculum volume (IV), substrate quantity, and the use of a manual or automated gas production (GP) recording system for in vitro determinations of fermentation of corn distillers dried grains with solubles (cDDGS) and soybean hulls (SBH). A 2 × 2 × 2 factorial arrangement of treatments was used and included the factors of (1) ingredients (cDDGS or SBH), (2) inoculum volume and substrate quantity (IV30 = 0.2 g substrate + 30 mL inoculum or IV75 = 0.5 g substrate + 75 mL inoculum), and (3) GP recording system (MRS = manual recording system or ARS = automated recording system). Feed ingredient samples were pre-treated with pepsin and pancreatin, and the hydrolyzed residues were subsequently incubated with fresh pig feces in a buffered mineral solution. The GP recording was monitored for 72 h, and the kinetics were estimated by fitting data using an exponential model. Compared with SBH, cDDGS yielded less (p < 0.01) maximal gas production (Gf), required more time (p < 0.02) to achieve half gas accumulation (T/2), and had less (p < 0.01) fractional rate of degradation (µ) and in vitro fermentability of dry matter (IVDMF). Using the ARS resulted in less IVDMF (p < 0.01) compared with MRS (79.0% vs. 81.2%, respectively). Interactions were observed between GP recording system and inoculum volume and substrate quantity for Gf (p < 0.04), µ (p < 0.01), and T/2 (p < 0.04) which implies that increasing inoculum volume and substrate quantity resulted in decreased Gf (332 mL/g from IV30 vs. 256 mL/g from IV75), µ (0.05 from IV30 vs. 0.04 from IV75), and T/2 (34 h for IV30 vs. 25 h for IV75) when recorded with ARS but not MRS. However, the recorded cumulative GP at 72 h was not influenced by the inoculum volume nor recording system. The precision of Gf (as measured by the coefficient of variation of Gf) tended to increase for IV30 compared with IV75 (p < 0.10), indicating that using larger inoculum volume and substrate quantity (IV75) reduced within batch variation in GP kinetics. Consequently, both systems showed comparable results in GP kinetics, but considering convenience and achievement of consistency, 75 mL of inoculum volume with 0.5 g substrate is recommended for ARS.

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