A method for simultaneous recording of electrical activities and spectrophotometric signals from brain slice preparations in vitro

1991 ◽  
Vol 419 (2) ◽  
pp. 205-208 ◽  
Author(s):  
Takanori Fujii ◽  
Ken'ichi Toita
Keyword(s):  
Brain Slice ◽  
Simultaneous Recording ◽  
Electrical Activities

Coordination of electrical activities in muscle layers of the pig colon

1987 ◽  
Vol 252 (1) ◽  
pp. G136-G142
Author(s):  
J. D. Huizinga ◽  
E. Chow ◽  
N. E. Diamant ◽  
T. Y. el-Sharkaway
Keyword(s):  
Longitudinal Muscle ◽  
Circular Muscle ◽  
Muscle Layer ◽  
Simultaneous Recording ◽  
Frequency Range ◽  
Longitudinal Muscle Layer ◽  
Circular Muscle Layer ◽  
High Level ◽  
Electrical Activities

Simultaneous recording of electrical activities from the circular and longitudinal muscle layers of the pig colon was performed in vitro to study possible coordination of activities. The electrical activity of both muscle layers consisted of electrical oscillations with superimposed spikes. The frequency range of the electrical oscillations in the circular muscle was 0.5-3.5 cycles per minute (cpm) and in the longitudinal muscle 24-42 cpm. Coordination of the activities of both muscle layers occurred consistently only after stretch or cholinergic stimulation. Then it occurred in a unique fashion. Each oscillation in the circular muscle layer occurred at the same time as the onset of a burst of oscillations in the longitudinal muscle. In addition, multiple simultaneous recordings of the electrical activities from each muscle layer were obtained showing that within the circular muscle layer electrical oscillations were phase locked in the circumferential direction and along the long axis of the colon. They appeared to propagate in either the oral or aboral direction. In tetrodotoxin (with stretch as stimulus) and also in presence of carbachol, bursts of oscillations in the longitudinal muscle layer were phase locked circumferentially (in the different taeniae) and longitudinally. This study shows that the muscle layers in the colon, which have different myogenic electrical activities, can obtain a high level of coordination.

TMOD-31. AN ORGANOTYPIC TISSUE PLATFORM TO BRIDGE IN VITRO AND IN VIVO ASSAYS FOR BRAIN CANCER TREATMENT

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi222-vi222
Author(s):  
Breanna Mann ◽  
Noah Bell ◽  
Denise Dunn ◽  
Scott Floyd ◽  
Shawn Hingtgen ◽  
...  
Keyword(s):  
Cell Lines ◽  
Brain Cancer ◽  
Brain Slice ◽  
Brain Slices ◽  
In Vitro Assays ◽  
Preclinical Model ◽  
Short Period ◽  
The Brain

Abstract Brain cancers remain one of the greatest medical challenges. The lack of experimentally tractable models that recapitulate brain structure/function represents a major impediment. Platforms that enable functional testing in high-fidelity models are urgently needed to accelerate the identification and translation of therapies to improve outcomes for patients suffering from brain cancer. In vitro assays are often too simple and artificial while in vivo studies can be time-intensive and complicated. Our live, organotypic brain slice platform can be used to seed and grow brain cancer cell lines, allowing us to bridge the existing gap in models. These tumors can rapidly establish within the brain slice microenvironment, and morphologic features of the tumor can be seen within a short period of time. The growth, migration, and treatment dynamics of tumors seen on the slices recapitulate what is observed in vivo yet is missed by in vitro models. Additionally, the brain slice platform allows for the dual seeding of different cell lines to simulate characteristics of heterogeneous tumors. Furthermore, live brain slices with embedded tumor can be generated from tumor-bearing mice. This method allows us to quantify tumor burden more effectively and allows for treatment and retreatment of the slices to understand treatment response and resistance that may occur in vivo. This brain slice platform lays the groundwork for a new clinically relevant preclinical model which provides physiologically relevant answers in a short amount of time leading to an acceleration of therapeutic translation.

Muscularis mucosae contraction evokes colonic secretion via prostaglandin synthesis and nerve stimulation

2003 ◽  
Vol 284 (2) ◽  
pp. G213-G220 ◽  
Author(s):  
W. H. Percy ◽  
T. H. Fromm ◽  
C. E. Wangsness
Keyword(s):  
Contractile Activity ◽  
In Vitro Study ◽  
Simultaneous Recording ◽  
Prostaglandin Synthesis ◽  
Potential Difference ◽  
Muscularis Mucosae ◽  
Mucosal Secretion ◽  
Colonic Secretion ◽  
Mucosal Innervation

This in vitro study tested the hypothesis that muscularis mucosae contractile activity contributes to rabbit colonic mucosal function by mechanisms other than simple mechanical deformation of the epithelium. Experiments were performed by using a technique that allows simultaneous recording of muscle activity and transmucosal potential difference, a measure of epithelial ion transport. ATP, bradykinin, histamine, PGE2, PGF1α, and PGF2α elicited muscularis mucosae contractions that were resistant to atropine and TTX. Only ATP-induced contractions were indomethacin sensitive, and only those to dimethylphenylpiperazinium iodide (DMPP) were reduced by atropine. All agonist-evoked increases in transmucosal potential difference were atropine resistant, and, with the exception of those to PGE2, PGF2α, and VIP, they were also TTX sensitive. Mucosal responses to ATP, bradykinin, and histamine were indomethacin sensitive, whereas those to DMPP, the prostaglandins, and VIP were not. When cyclooxygenase activity or the mucosal innervation was compromised, even maximal muscularis mucosae contractions did not produce large secretory responses. It is concluded that contraction-related prostaglandin synthesis and noncholinergic secretomotor neuron stimulation represent the physiological transduction mechanism through which muscularis mucosae motor activity is translated into mucosal secretion.

scholarly journals An in-vitro study to evaluate the accuracy of dies obtained from dual arch impression trays using addition silicone impression material and tray combinations

2015 ◽  
Vol 12 (2) ◽  
pp. 111-117
Author(s):  
P K Parajuli ◽  
S George ◽  
V Shenoy
Keyword(s):  
In Vitro Study ◽  
Dimensional Accuracy ◽  
Acrylic Resin ◽  
Simultaneous Recording ◽  
T Test ◽  
Impression Material ◽  
Tooth Preparation ◽  
Made In ◽  
Plastic Trays

Background: Dual-arch impression technique allows the simultaneous recording of  tooth preparation, opposing anatomic tooth and maxillomandibular relationship. The  accuracy of reproduction of this easy and quick technique, however, has not been  studied in detail in past. Objective: To compare the accuracy of the impressions  made by using the same impression material in dual arch plastic trays, dual-arch  metal trays and acrylic resin custom trays. Methods: The dies obtained from the  addition silicone impressions made in dual-arch plastic trays, dual-arch metal trays  and full arch acrylic resin custom trays were compared for the dimensional accuracy  with the prepared typodont tooth as a control. Student’s paired t-test and unpaired  t-test were used for the data analyses using the Statistical Package for Social Studies  (SPSS) version 11.5. Results: The dies obtained from all the impression combinations  showed increased dimension (acrylic resin custom trays 9.4 mm±0.048, dual-arch  plastic trays 9.5 mm±0.035, dual-arch metal trays 9.41 mm±0.017) as compared to  the dimension of control (9.39 mm±0.007). Conclusion: All the tray-impression  material combinations showed variable accuracies. Full arch acrylic resin trays  resulted in greatest accuracy whereas dual-arch plastic trays the least accuracy.Health Renaissance 2014;12(2):  pp: 111-117

scholarly journals Chinese Veterinary Medicine B307 Promotes Cardiac Performance and Skeletal Muscle Contraction via Enhancing Intracellular Calcium Levels and Neural Electrical Activity in Animal and Cell Models

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Chia-Ying Lien ◽  
Chen-Wen Lu ◽  
Chih-Hsiang Hsu ◽  
Tai-Yuan Chuang ◽  
Li-Yu Su ◽  
...  
Keyword(s):  
Veterinary Medicine ◽  
Electrical Activity ◽  
Intracellular Calcium ◽  
Cell Model ◽  
Color Doppler ◽  
Neuroblastoma Cell ◽  
Motor Functions ◽  
Electrical Activities

The study mainly investigated the effects of Chinese veterinary medicine B307 in cardiac and motor functions in animal models of pigeons and mice. Related cellular mechanisms were also studied in the neuroblastoma cell model of SH-SY5Y. Cardiac functions of pigeons and mice were examined by using moorFLPI Laser color Doppler imager and M-mode echocardiography, and motor functions were examined by using muscle electrical stimulation and force recording in the isolated breast muscle. Intracellular calcium levels and electrical activity of SH-SY5Y cells were examined by using Fura 2-AM fluorescence and MED64 system separately. Our results in vivo found that those pigeons under oral B307 treatment obviously enhanced subcutaneous microcirculation and contractile force and prolonged fatigue time in their breast muscles. Those mice under oral B307 treatment obviously elevated ejection fraction and cardiac output in their hearts. Our results in vitro showed that those SH-SY5Y cells under B307 treatment obviously increased intracellular calcium mobilization and electrical activities. These results revealed that improvement of cardiac and motor functions under B307 treatments may be caused by increasing electrical activities and intracellular calcium levels in neuromuscular cells and a similar mechanism may also occur in muscle cells. Thus, we suggested that B307 can be a functional Chinese veterinary medicine for flying pigeons.

scholarly journals Opportunities and dilemmas of in vitro nano neural electrodes

RSC Advances ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 187-200
Author(s):  
Yu Wu ◽  
Haowen Chen ◽  
Liang Guo
Keyword(s):  
Neural Electrodes ◽  
Brain Circuitry ◽  
Machine Interface ◽  
Electrical Activities

Developing electrophysiological platforms to capture electrical activities of neurons and exert modulatory stimuli lays the foundation for many neuroscience-related disciplines, including the neuron–machine interface, neuroprosthesis, and mapping of brain circuitry.

Acute hypoxia induces elevation of ornithine decarboxylase activity in neonatal rat brain slices

1995 ◽  
Vol 7 (3) ◽  
pp. 385 ◽  
Author(s):  
LD Longo ◽  
S Packianathan
Keyword(s):  
Rat Brain ◽  
Ornithine Decarboxylase ◽  
Bovine Serum ◽  
Brain Slice ◽  
Brain Slices ◽  
Neonatal Rat ◽  
Newborn Rat ◽  
Rat Brain Slice

Recent studies in vivo have demonstrated that ornithine decarboxylase (ODC) activity in the fetal rat brain is elevated 4-5-fold by acute maternal hypoxia. This hypoxic-associated increase is seen in the rat brain in both the newborn and the adult. Because of the intimate involvement of ODC in transcription and translation, as well as in growth and development, it is imperative that the manner in which hypoxia affects the regulation of this enzyme be better understood. In order to achieve this, a brain preparation in vitro was required to eliminate the confounding effects of the dam on the fetal and newborn brain ODC activity in vivo. Therefore, brain slices from 3-4-day-old (P-3) newborn rats were utilized to test the hypothesis that ODC activity increases in response to hypoxia in vitro. Cerebral slices from the P-3 rat pups were allowed to equilibrate and recover in artificial cerebrospinal fluid (ACSF) continuously bubbled with a mixture of 95% O2 and 5% CO2 for 1 h before beginning hypoxic exposures. Higher basal ODC activities were obtained by treating the slices with 0.03% fetal bovine serum (FBS) and 0.003% bovine serum albumin (BSA), rather than with ACSF alone. Hypoxia was induced in the slices by replacing the gas with 40%, 21%, 10%, or 5% O2, all with 5% CO2 and balance N2. With FBS and BSA treatment, ODC activity was maintained at about 0.15-0.11 nM CO2 mg-1 protein h-1 throughout the experiment, which was 2-3-fold higher than that without FBS and BSA. ODC activity increased significantly and peaked between 1 h and 2 h after initiation of hypoxia. For instance, with 21% O2, ODC activity increased approximately 1.5-fold at 1 h and approximately 2-fold at 2 h. These studies demonstrate that: (1) the hypoxic-induced increases observed in vivo in the fetal and newborn rat brain ODC activity can be approximated in a newborn rat brain slice preparation in vitro; (2) newborn rat brain slice preparations may provide an alternative to methods in vivo or cell culture methods for studying the regulation of acute hypoxic-induced enzymes; and (3) high, stable baseline ODC activities in brain slices suggest that the cells in the slice are capable of active metabolism if FBS and BSA are available to mimic conditions in vivo.

Neuronal Aggregate Formation Underlies Spatiotemporal Dynamics of Nonsynaptic Seizure Initiation

2003 ◽  
Vol 89 (4) ◽  
pp. 2330-2333 ◽  
Author(s):  
Marom Bikson ◽  
John E. Fox ◽  
John G. R. Jefferys
Keyword(s):  
Synaptic Transmission ◽  
Gap Junctions ◽  
High Frequency ◽  
Formation Rate ◽  
Simultaneous Recording ◽  
Aggregate Formation ◽  
Seizure Onset ◽  
Electrographic Seizures ◽  
High Frequency Activity

High-frequency activity often precedes seizure onset. We found that electrographic seizures, induced in vitro using the low-Ca2+ model, start with high-frequency (>150 Hz) activity that then decreases in frequency while increasing in amplitude. Multichannel and unit recordings showed that the mechanism of this transition was the progressive formation of larger neuronal aggregates. Thus the apparenthigh-frequency activity, at seizure onset, can reflect the simultaneous recording of several slower firing aggregates. Aggregate formation rate can be accelerated by reducing osmolarity. Because synaptic transmission is blocked when extracellular Ca2+ is reduced, nonsynaptic mechanisms (gap junctions, field effects) must be sufficient for aggregate formation and recruitment.

Relaxation oscillator and core conductor models are needed for understanding of GI electrical activities

1994 ◽  
Vol 266 (3) ◽  
pp. G339-G349 ◽  
Author(s):  
E. E. Daniel ◽  
B. L. Bardakjian ◽  
J. D. Huizinga ◽  
N. E. Diamant
Keyword(s):  
Relaxation Oscillator ◽  
Pacesetter Potentials ◽  
In Vitro Systems ◽  
Cells Of Cajal ◽  
Electrical Activities ◽  
Core Conductor ◽  
Oscillator Models

This review examines the applicability of modeling of intestinal electrical activities (slow waves or pacesetter potentials) by coupled relaxation oscillator models, in comparison to a “multidimensional model” based on core conductor theory. We briefly review the relaxation oscillator model and correct some misunderstandings. We point out that new insights about the role of networks of interstitial cells of Cajal in intestinal pacemaking require reconsideration of the mechanisms producing oscillations, the coupling between oscillators, and how the oscillator network is coupled to the driven cells. Recent advances in relaxation oscillator models allow the production of pacemaking pacemaking activity, which can be selectively varied as to waveform, frequency, and occurrence of silent periods. Core conductor models do not produce pacemaking activity or permit this flexibility. We point out that many of the criticisms leveled against relaxation oscillator models relate to studies made in simplified in vitro systems constrained by extensive dissection. Such systems do not adequately reflect the in vivo systems. We conclude that a full understanding of control of electrical (and mechanical) events in the gastrointestinal tract requires that better understanding of relaxation oscillator models growing out of recent research be combined with improved applications of core conductor theory to multidimensional models.

Simulation of In Vitro-Like Electrical Activities in Urinary Bladder Smooth Muscle Cells

2017 ◽  
Vol 33 ◽  
pp. 45-51
Author(s):  
Chitaranjan Mahapatra ◽  
Rohit Manchanda
Keyword(s):  
Smooth Muscle ◽  
Urinary Bladder ◽  
Neurotransmitter Release ◽  
Compartment Model ◽  
Bladder Smooth Muscle ◽  
Parasympathetic Nerve ◽  
Stochastic Nature ◽  
Urinary Bladder Smooth Muscle ◽  
Electrical Activities

Urinary bladder smooth muscle (UBSM) generates spontaneous electrical activities due to stochastic nature of purinergic neurotransmitter release from the parasympathetic nerve. The stochastic nature of the purinergic neurotransmitter release was represented by a simplified ‘point-conductance’ model to mimic in vitro-like electrical activities in UBSM cell. The point-conductance was represented by the independent synaptic conductance described by the stochastic random-walk processes and injected into a single-compartment model of mouse UBSM cell. This model successfully evoked irregular spontaneous depolarizations (SDs) and spontaneous action potential (sAP) as the properties of in vitro-like electrical activities in UBSM cells. The model mimics the T- and L-type Ca2+ ion channel blocker by setting their respective conductance to zero. We also found that the point-conductance model modulates the sAP properties by adding background activity.

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