scholarly journals All-optical recording and stimulation of retinal neurons in vivo in retinal degeneration mice

PLoS ONE ◽  
2018 ◽  
Vol 13 (3) ◽  
pp. e0194947 ◽  
Author(s):  
Soon Keen Cheong ◽  
Jennifer M. Strazzeri ◽  
David R. Williams ◽  
William H. Merigan
Keyword(s):  
Retinal Degeneration ◽  
Optical Recording ◽  
Retinal Neurons ◽  
All Optical ◽  
Stimulation Of

scholarly journals Optogenetic strategies for high-efficiency all-optical interrogation using blue light-sensitive opsins

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Angelo Forli ◽  
Matteo Pisoni ◽  
Yoav Printz ◽  
Ofer Yizhar ◽  
Tommaso Fellin
Keyword(s):  
Blue Light ◽  
Large Scale ◽  
High Efficiency ◽  
Average Power ◽  
Optical Methods ◽  
Neuronal Ensembles ◽  
Two Photon ◽  
All Optical ◽  
Stimulation Of

All-optical methods for imaging and manipulating brain networks with high spatial resolution are fundamental to study how neuronal ensembles drive behavior. Stimulation of neuronal ensembles using holographic techniques requires high-sensitivity actuators to avoid photodamage and heating. Moreover, two-photon-excitable opsins should be insensitive to light at wavelengths used for imaging. To achieve this goal, we developed a novel soma-targeted variant of the large-conductance blue light-sensitive opsin CoChR (stCoChR). In the mouse cortex in vivo, we combined holographic two-photon stimulation of stCoChR with an amplified laser tuned at the opsin absorption peak and imaging of the red-shifted indicator jRCaMP1a. Compared to previously characterized blue light-sensitive soma-targeted opsins in vivo, stCoChR allowed neuronal stimulation with more than 10-fold lower average power and no spectral crosstalk. The combination of stCoChR, tuned amplified laser stimulation, and red-shifted functional indicators promises to be a powerful tool for large-scale interrogation of neural networks in the intact brain.

scholarly journals All-optical electrophysiology reveals excitation, inhibition, and neuromodulation in cortical layer 1

2019 ◽  
Author(s):  
Linlin Z. Fan ◽  
Simon Kheifets ◽  
Urs L. Böhm ◽  
Kiryl D. Piatkevich ◽  
Hao Wu ◽  
...  
Keyword(s):  
Neural Circuit ◽  
Barrel Cortex ◽  
Cortical Layer ◽  
Optical Recording ◽  
Tight Coupling ◽  
Basic Principles ◽  
All Optical ◽  
The Stability ◽  
Circuit Function

AbstractThe stability of neural dynamics arises through a tight coupling of excitatory (E) and inhibitory (I) signals. Genetically encoded voltage indicators (GEVIs) can report both spikes and subthreshold dynamics in vivo, but voltage only reveals the combined effects of E and I synaptic inputs, not their separate contributions individually. Here we combine optical recording of membrane voltage with simultaneous optogenetic manipulation to probe E and I individually in barrel cortex Layer 1 (L1) neurons in awake mice. Our studies reveal how the L1 microcircuit integrates thalamocortical excitation, lateral inhibition and top-down neuromodulatory inputs. We develop a simple computational model of the L1 microcircuit which captures the main features of our data. Together, these results suggest a model for computation in L1 interneurons consistent with their hypothesized role in attentional gating of the underlying cortex. Our results demonstrate that all-optical electrophysiology can reveal basic principles of neural circuit function in vivo.One Sentence SummaryAll-optical electrophysiology revealed the function in awake mice of an inhibitory microcircuit in barrel cortex Layer 1.

scholarly journals Electronic "photoreceptors" enable prosthetic vision with acuity matching the natural resolution in rats

2021 ◽  
Author(s):  
Bing-Yi Wang ◽  
Zhijie Charles Chen ◽  
Mohajeet Bhuckory ◽  
Tiffany W Huang ◽  
Andrew Shin ◽  
...  
Keyword(s):  
Retinal Thickness ◽  
Ex Vivo ◽  
Forward Bias ◽  
Retinal Neurons ◽  
Photovoltaic Array ◽  
High Acuity ◽  
Grating Acuity ◽  
Novel Design ◽  
Stimulation Of

Localized stimulation of the inner retinal neurons for high-acuity prosthetic vision requires small pixels and minimal cross-talk from neighboring electrodes. Local return electrodes within each pixel can limit the crosstalk, but they over-constrain the electric field, thus precluding the efficient stimulation with subretinal pixels smaller than 50 μm. Here we demonstrate a high-resolution prosthetic vision based on a novel design of a photovoltaic array, where field confinement is achieved dynamically, leveraging the adjustable conductivity of the diodes under forward bias to turn the designated pixels into transient returns. We validated computational modeling of the field confinement in such an optically-controlled circuit by ex-vivo and in-vivo measurements. Most importantly, we demonstrated that by using this strategy, the grating acuity of prosthetic vision with 20 μm pixels matches the 28 μm limit of the natural visual acuity in rats. This method will enable customized field shaping for each patient based on individual retinal thickness and distance from the implant, paving the way to prosthetic vision with acuity as high as 20/80 in atrophic macular degeneration.

Stimulation of ovarian progesterone secretion by oxytocin in vivo

1988 ◽  
Vol 117 (4_Suppl) ◽  
pp. S199-S200
Author(s):  
E. DIETRICH ◽  
K. RENTELMANN ◽  
W. WUTTKE
Keyword(s):  
Progesterone Secretion ◽  
Stimulation Of

scholarly journals GPR40 Is Necessary but Not Sufficient for Fatty Acid Stimulation of Insulin Secretion In Vivo

Diabetes ◽  
2007 ◽  
Vol 56 (4) ◽  
pp. 1087-1094 ◽  
Author(s):  
M. G. Latour ◽  
T. Alquier ◽  
E. Oseid ◽  
C. Tremblay ◽  
T. L. Jetton ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Fatty Acid ◽  
Insulin Secretion In Vivo ◽  
Stimulation Of

scholarly journals Photoelectric Dye, NK-5962, as a Potential Drug for Preventing Retinal Neurons from Apoptosis: Pharmacokinetic Studies Based on Review of the Evidence

Life ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 591
Author(s):  
Toshihiko Matsuo ◽  
Shihui Liu ◽  
Tetsuya Uchida ◽  
Satomi Onoue ◽  
Shinsaku Nakagawa ◽  
...  
Keyword(s):  
Biological Evaluation ◽  
Pharmacokinetic Studies ◽  
Retinal Neurons ◽  
Retinal Cells ◽  
Intravitreous Injection ◽  
Rcs Rats ◽  
Photoelectric Dye ◽  
Dark Conditions

NK-5962 is a key component of photoelectric dye-based retinal prosthesis (OUReP). In testing the safety and efficacy, NK-5962 was safe in all tests for the biological evaluation of medical devices (ISO 10993) and effective in preventing retinal cells from death even under dark conditions. The long-term implantation of the photoelectric dye-coupled polyethylene film in the subretinal space of hereditary retinal dystrophic (RCS) rats prevented neurons from apoptosis in the adjacent retinal tissue. The intravitreous injection of NK-5962 in the eyes of RCS rats, indeed, reduced the number of apoptotic cells in the retinal outer nuclear layer irrespective of light or dark conditions. In this study, we reviewed the in vitro and in vivo evidence of neuroprotective effect of NK-5962 and designed pharmacokinetic experiments. The in vitro IC50 of 1.7 μM, based on the protective effect on retinal cells in culture, could explain the in vivo EC50 of 3 μM that is calculated from concentrations of intravitreous injection to prevent retinal neurons from apoptosis. Pharmacokinetics of NK-5962 showed that intravenous administration, but not oral administration, led to the effective concentration in the eye of rats. NK-5962 would be a candidate drug for delaying the deterioration of retinal dystrophy, such as retinitis pigmentosa.

Thrombopoietin-Induced Stimulation of Megakaryocyte- Enriched Bone Marrow Cultures

1979 ◽  
Author(s):  
K. L. Kellar ◽  
B. L. Evatt ◽  
C. R. McGrath ◽  
R. B. Ramsey
Keyword(s):  
Bone Marrow ◽  
Dna Synthesis ◽  
Bone Marrow Cells ◽  
Rabbit Plasma ◽  
Bone Marrow Cultures ◽  
Plasma Fractions ◽  
Marrow Cultures ◽  
Stimulation Of

Liquid cultures of bone marrow cells enriched for megakaryocytes were assayed for incorporation of 3H-thymidine (3H-TdR) into acid-precipitable cell digests to determine the effect of thrombopoietin on DNA synthesis. As previously described, thrombopoietin was prepared by ammonium sulfate fractionation of pooled plasma obtained from thrombocytopenic rabbits. A control fraction was prepared from normal rabbit plasma. The thrombopoietic activity of these fractions was determined in vivo with normal rabbits as assay animals and the rate of incorporation of 75Se-selenomethionine into newly formed platelets as an index of thrombopoietic activity of the infused material. Guinea pig megakaryocytes were purified using bovine serum albumin gradients. Bone marrow cultures containing 1.5-3.0x104 cells and 31%-71% megakaryocytes were incubated 18 h in modified Dulbecco’s MEM containing 10% of the concentrated plasma fractions from either thrombocytopenic or normal rabbits. In other control cultures, 0.9% NaCl was substituted for the plasma fractions. 3H-TdR incorporation was measured after cells were incubated for 3 h with 1 μCi/ml. The protein fraction containing thrombopoietin-stimulating activity caused a 25%-31% increase in 3H-TdR incorporation over that in cultures which were incubated with the similar fraction from normal plasma and a 29% increase over the activity in control cultures to which 0.9% NaCl had been added. These data suggest that thrombopoietin stimulates DNA synthesis in megakaryocytes and that this tecnique may be useful in assaying thrombopoietin in vitro.

scholarly journals Contamination of erythropoietin by endotoxin: in vivo and in vitro effects on murine erythropoiesis

Blood ◽  
1979 ◽  
Vol 54 (1) ◽  
pp. 146-158 ◽  
Author(s):  
KS Zuckerman ◽  
PJ Quesenberry ◽  
J Levin ◽  
R Sullivan
Keyword(s):  
Significant Inhibition ◽  
Erythropoietic Activity ◽  
Limulus Amebocyte Lysate ◽  
Endogenous Erythropoietin ◽  
Significant Change ◽  
In Vitro Effects ◽  
Stimulation Of

Abstract Endotoxin was detected in all erythropoietin preparations tested and was removed from four lots, without loss of erythropoietic activity, by adsorption with limulus amebocyte lysate. Comparison of adsorbed (endotoxin-depleted) and nonadsorbed (endotoxin-containing) erythropoietin preparations demonstrated significant inhibition of CFU- e and BFU-e in vitro by nonadsorbed erythropoietin at concentrations higher than 0.25 U/ml and 2.0 U/ml, respectively. CFU-e and BFU-e were inhibited significantly by readdition in vitro of 10(-5)-10(-3) mug of endotoxin per unit of limulus-adsorbed erythropoietin. Administration of saline or 6 U of nonadsorbed or adsorbed erythropoietin twice a day for 4 days of CF1 mice resulted in reticulocyte counts of 2.1%, 9.9%, and 15.9%, respectively. Nonadsorbed erythropoietin resulted in a 29% decrease in erythropoiesis, a 42% decrease in CFU-e, and a 16% increase in granulopoiesis in the marrow, whereas adsorbed erythropoietin caused a 28% increase in erythropoiesis, no significant change in CFU-e and a 19% decrease in granulopoiesis in the marrow. Both preparations resulted in marked increases in splenic erythropoiesis and granulopoiesis. The effects of adsorbed erythropoietin are similar to those produced following stimulation of hematopoiesis by endogenous erythropoietin. Hemopoietic changes induced by nonadsorbed erythropoietin in vivo and in vitro are affected substantially by contamination of the erythropoietin preparations with endotoxin.

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