In Vivo Optical Detection of Membrane Potentials in the : of

2022 ◽  
pp. 229-244
Author(s):  
Kanae Hiyoshi ◽  
Narumi Fukuda ◽  
Asuka Shiraishi ◽  
Sachiko Tsuda
Keyword(s):  
Optical Detection ◽  
Membrane Potentials

scholarly journals Signal-to-noise ratio in the membrane potential of the owl's auditory coincidence detectors

2012 ◽  
Vol 108 (10) ◽  
pp. 2837-2845 ◽  
Author(s):  
Go Ashida ◽  
Kazuo Funabiki ◽  
Paula T. Kuokkanen ◽  
Richard Kempter ◽  
Catherine E. Carr
Keyword(s):  
Neural Circuit ◽  
Signal To Noise Ratio ◽  
Phase Locking ◽  
Low Frequency ◽  
Membrane Potentials ◽  
Signal To Noise ◽  
Theoretical Predictions ◽  
Noise Ratio ◽  
Band Limited

Owls use interaural time differences (ITDs) to locate a sound source. They compute ITD in a specialized neural circuit that consists of axonal delay lines from the cochlear nucleus magnocellularis (NM) and coincidence detectors in the nucleus laminaris (NL). Recent physiological recordings have shown that tonal stimuli induce oscillatory membrane potentials in NL neurons (Funabiki K, Ashida G, Konishi M. J Neurosci 31: 15245–15256, 2011). The amplitude of these oscillations varies with ITD and is strongly correlated to the firing rate. The oscillation, termed the sound analog potential, has the same frequency as the stimulus tone and is presumed to originate from phase-locked synaptic inputs from NM fibers. To investigate how these oscillatory membrane potentials are generated, we applied recently developed signal-to-noise ratio (SNR) analysis techniques (Kuokkanen PT, Wagner H, Ashida G, Carr CE, Kempter R. J Neurophysiol 104: 2274–2290, 2010) to the intracellular waveforms obtained in vivo. Our theoretical prediction of the band-limited SNRs agreed with experimental data for mid- to high-frequency (>2 kHz) NL neurons. For low-frequency (≤2 kHz) NL neurons, however, measured SNRs were lower than theoretical predictions. These results suggest that the number of independent NM fibers converging onto each NL neuron and/or the population-averaged degree of phase-locking of the NM fibers could be significantly smaller in the low-frequency NL region than estimated for higher best-frequency NL.

scholarly journals Fluorescence modeling of in vivo optical detection of Mycobacterium tuberculosis

2019 ◽  
Vol 10 (10) ◽  
pp. 5445 ◽  
Author(s):  
Madeleine S. Durkee ◽  
Jeffrey D. Cirillo ◽  
Kristen C. Maitland
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Optical Detection

In-vivo label-free optical detection of neural activities in retina (Conference Presentation)

2018 ◽  
Author(s):  
Subrata Batabyal ◽  
Sivakumar Gajjeraman ◽  
Weldon Wright ◽  
Samarendra K. Mohanty
Keyword(s):  
Optical Detection ◽  
Label Free ◽  
Neural Activities

scholarly journals Advances in Optical Detection of Human-Associated Pathogenic Bacteria

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5256
Author(s):  
Andrea Locke ◽  
Sean Fitzgerald ◽  
Anita Mahadevan-Jansen
Keyword(s):  
Pathogenic Bacteria ◽  
Optical Detection ◽  
Diagnostic Techniques ◽  
Laser Speckle ◽  
Resistant Bacteria ◽  
In Vivo Detection ◽  
Drug Resistant Bacteria ◽  
Detection And Identification ◽  
Free Environment

Bacterial infection is a global burden that results in numerous hospital visits and deaths annually. The rise of multi-drug resistant bacteria has dramatically increased this burden. Therefore, there is a clinical need to detect and identify bacteria rapidly and accurately in their native state or a culture-free environment. Current diagnostic techniques lack speed and effectiveness in detecting bacteria that are culture-negative, as well as options for in vivo detection. The optical detection of bacteria offers the potential to overcome these obstacles by providing various platforms that can detect bacteria rapidly, with minimum sample preparation, and, in some cases, culture-free directly from patient fluids or even in vivo. These modalities include infrared, Raman, and fluorescence spectroscopy, along with optical coherence tomography, interference, polarization, and laser speckle. However, these techniques are not without their own set of limitations. This review summarizes the strengths and weaknesses of utilizing each of these optical tools for rapid bacteria detection and identification.

Ultrasensitive optical detection of anions by quantum dots

2016 ◽  
Vol 1 (2) ◽  
pp. 125-134 ◽  
Author(s):  
Yongbing Lou ◽  
Yixin Zhao ◽  
Jun-Jie Zhu
Keyword(s):  
Aqueous Solution ◽  
Quantum Dots ◽  
Optical Detection

A review about ultrasensitive optical detection of anions by quantum dots in aqueous solution or in vivo.

In-vivo optical detection of brain tumor and tumor margin: a combined auto-fluorescence and diffuse reflectance spectroscopic study

2007 ◽  
Author(s):  
Shovan K. Majumder ◽  
Steven Gebhart ◽  
Reid Thompson ◽  
Kyle D. Weaver ◽  
Mahlon D. Johnson ◽  
...  
Keyword(s):  
Brain Tumor ◽  
Spectroscopic Study ◽  
Diffuse Reflectance ◽  
Optical Detection ◽  
Tumor Margin ◽  
Auto Fluorescence

In vivo membrane potentials of smooth muscle cells in the caudal artery of the rat

1985 ◽  
Vol 249 (1) ◽  
pp. C78-C83 ◽  
Author(s):  
H. J. Bryant ◽  
D. R. Harder ◽  
M. B. Pamnani ◽  
F. J. Haddy
Keyword(s):  
Smooth Muscle ◽  
Membrane Potential ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Membrane Potentials ◽  
Resting Membrane Potential ◽  
Humoral Factors ◽  
Caudal Artery ◽  
Blood Pressures

Membrane potentials measured in vivo may differ significantly from those measured in vitro in part due to humoral factors, innervation, and wall tension. These studies were initiated to determine whether it is feasible to record membrane potentials from vascular smooth muscle cells in vivo in the caudal artery of the pentobarbital-anesthetized male Wistar rat. Membrane potentials were measured using glass microelectrodes and correlated with systolic, diastolic, and mean blood pressures. For systolic blood pressures between 100 and 140 mmHg the average resting membrane potential was -38.4 +/- 0.48 mV. There was good correlation of systolic, diastolic, and mean blood pressures with membrane potential between 100 and 140 mmHg (r = 0.89, 0.75, and 0.89, respectively). Below 80 mmHg the arterial muscle cells became more depolarized than would be expected if the membrane potential were determined solely by transmural pressure. The depolarized membrane potential at low arterial pressures may be due to enhanced neural input. Spontaneous electrical activity was observed in some of the in vivo cells. When action potentials were present, they were generated at rates between 1-2/s and 6-7/min. These studies indicate that it is feasible to measure membrane potentials from arterial smooth muscle cells in vivo in the caudal artery of the rat.

Applications of 99mTC-Sestamibi in Oncology

1996 ◽  
Vol 82 (1) ◽  
pp. 12-21 ◽  
Author(s):  
Lorenzo Maffioli ◽  
Jeroen Steens ◽  
Ernest Pauwels ◽  
Emilio Bombardieri
Keyword(s):  
Plasma Membrane ◽  
Bone Cyst ◽  
Potential Gradient ◽  
Membrane Potentials ◽  
Cytotoxic Agents ◽  
Malignant Tumours ◽  
Uptake Mechanism ◽  
Translocation Mechanism ◽  
Tracer Imaging

Hexakis (2-methoxyisobutylisonitrile) technetium-99m (99mTc-SestaMIBI) is a radiopharmaceutical used in nuclear medicine for myocardial perfusion imaging. In the literature different non-cardiac applications of 99mTc-SestaMIBI have been reported. Clinical studies have been performed also in non-oncologic diseases (such as thyroid adenoma, diabetic foot, osteomyelitis, pulmonary actinomycosis, aneurysmal bone cyst, Sudeck's atrophy). Several models for the uptake mechanism of this radiopharmaceutical have been proposed such as binding to an 8-10 kDa cytosolic protein, simple lipid partitioning, or a membrane translocation mechanism involving diffusion and passive transmembrane distribution. Most evidence points in the direction of the third hypothesis. Many studies have indicated that uptake of hexakis (alkylisonitrile) technetium complexes is dependent on mitochondrial and plasma membrane potentials like other lipophilic cations. This explains the initial biodistribution of 99mTc-SestaMIBI to tissues with negative plasma membrane potentials and with a relatively high mitochondrial content (like heart, liver, kidney and skeletal muscle tissue). Malignant tumours also possess these properties in order to maintain their increased metabolism. This behaviour encouraged the study of 99mTc-SestaMIBI as an interesting tracer imaging various tumour types: osteosarcoma, brain, lung, breast, nasopharyngeal, parathyroid, and thyroid cancer. Recent research on cell cellular physiology has further revealed an active transport of 99mTc-SestaMIBI out of the tumour cells, against the potential gradient. The same mechanism is also responsible for resistance to a structurally and functionally different group of cytotoxic agents, such as vinca alkaloids, epipodophyllotoxins, anthracyclins and actinomycin D. This peculiar type of resistance is due to amplification of the mammalian MDR1 gene, located on chromosome 7. For this reason the 99mTc- SestaMIBI uptake in vivo could permit the prediction of the response to the chemotherapy, when the decreased accumulation of 99mTc-SestaMlBI implies the presence of P-gp enriched tissues. In the next future a particular attention should be dedicated to this matter since one of the most important goals of the clinical trials is the demonstration of the usefulness of 99mTc-SestaMIBI for in vivo assessment of multidrug resistance.

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