High spatiotemporal resolution imaging of the neurovascular response to electrical stimulation of rat peripheral trigeminal nerve as revealed by in vivo temporal laser speckle contrast

In vivo glucose-induced insulin secretion was greater in preweaned preobese 17-day-old Zucker rats than in the corresponding controls. This hypersecretion of insulin was reversed to normal by acute pretreatment with atropine. A short-lived (30 s) electrical stimulation of the vagus nerve preceding a glucose load potentiated the in vivo glucose-induced insulin release in adult animals (6-9 wk) and more so in obese Zucker (fa/fa) than in lean rats. This suggested the existence of enhanced sensitivity and/or responsiveness of the B cells of obese animals to the parasympathetic system. That the parasympathetic tone was increased in adult obese Zucker (fa/fa) rats was corroborated by the observation that acute vagotomy of these animals resulted in a significant decrease in glucose-induced insulin secretion, whereas no such effect was seen in lean rats. Also, perfused pancreases from adult obese (fa/fa) rats oversecreted insulin during a stimulation by arginine when compared with controls, an oversecretion that was restored toward normal by superimposed infusion of atropine. It is concluded that a) the increased insulin secretion of preobese Zucker fa/fa rats is an early abnormality that is mediated by the vagus nerve, and b) increased secretion of insulin in adult obese fa/fa rats continues to be partly vagus-nerve mediated, although a decreased sympathetic tone and other unknown defects could conceivably play a role as well.

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Laser Speckle Contrast Imaging on in vivo Blood Flow: a Review

Chinese Journal of Lasers ◽

10.3788/cjl201845.0207006 ◽

2018 ◽

Vol 45 (2) ◽

pp. 0207006

Author(s):

李晨曦 Li Chenxi ◽

陈文亮 Chen Wenliang ◽

蒋景英 Jiang Jingying ◽

范颖 Fan Ying ◽

杨婧孜 Yang Jingzi ◽

...

Keyword(s):

Blood Flow ◽

Laser Speckle ◽

Contrast Imaging ◽

Laser Speckle Contrast Imaging ◽

Speckle Contrast

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FA05.03: EFFECT OF EPHEDRINE ON GASTRIC CONDUIT PERFUSION MEASURED BY LASER SPECKLE CONTRAST IMAGING (LSCO) AFTER ESOPHAGECTOMY: A PROSPECTIVE IN-VIVO COHORT STUDY

Diseases of the Esophagus ◽

10.1093/dote/doy089.fa05.03 ◽

2018 ◽

Vol 31 (Supplement_1) ◽

pp. 10-10

Author(s):

Sanne Jansen ◽

Daniel De Bruin ◽

Simon Strackee ◽

Mark I Van Berge Henegouwen ◽

Ton Van Leeuwen ◽

...

Keyword(s):

Anastomotic Leakage ◽

Gastric Tube ◽

Gastric Conduit ◽

Laser Speckle ◽

Contrast Imaging ◽

Laser Speckle Contrast Imaging ◽

Speckle Contrast ◽

Before And After ◽

Gastric Tube Reconstruction

Abstract Background Compromised perfusion due to ligation of arteries and veins in esophagectomy with gastric tube reconstruction often (5–20%) results in necrosis and anastomotic leakage, which relate to high morbidity and mortality (3–4%). Ephedrine is used widely in anesthesia to treat intra-operative hypotension and may improve perfusion by the increase of cardiac output (CO) and mean arterial pressure (MAP). This study tests the effect of ephedrine on perfusion of the future anastomotic site of the gastric conduit, measured by Laser Speckle Contrast Imaging (LSCI). Methods This prospective, observational, in-vivo pilot study includes 26 patients undergoing esophagectomy with gastric tube reconstruction from October 2015 to June 2016 in the Academic Medical Center (Amsterdam). Perfusion of the gastric conduit was measured with LSCI directly after reconstruction and after an increase of MAP by ephedrine 5 mg. Perfusion was quantified in flux (LSPU) in four perfusion locations, from good perfusion (base of the gastric tube) towards decreased perfusion (fundus). Intra-patient differences before and after ephedrine in terms flux were statistically tested for significance with a paired t-test. Results LSCI was feasible to image gastric microcirculation in all patients. Flux (LSPU) was significantly higher in the base of the gastric tube (791 ± 442) compared to the fundus (328 ± 187) (P < 0.001). After administration of ephedrine, flux increased significantly in the fundus (P < 0·05) measured intra-patients. Three patients developed anastomotic leakage. In these patients, the difference between measured flux in the fundus compared to the base of the gastric tube was high. Conclusion This study presents the effect of ephedrine on perfusion of the gastric tissue measured with LSCI in terms of flux (LSPU) after esophagectomy with gastric tube reconstruction. We show a small but significant difference between flux measured before and after administration of ephedrine in the future anastomotic tissue (313 ± 178 vs. 397 ± 290). We also show a significant decrease of flux towards the fundus. Disclosure All authors have declared no conflicts of interest.

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Suppression of Superficial Microglial Activation by Spinal Cord Stimulation Attenuates Neuropathic Pain Following Sciatic Nerve Injury in Rats

International Journal of Molecular Sciences ◽

10.3390/ijms21072390 ◽

2020 ◽

Vol 21 (7) ◽

pp. 2390

Author(s):

Masamichi Shinoda ◽

Satoshi Fujita ◽

Shiori Sugawara ◽

Sayaka Asano ◽

Ryo Koyama ◽

...

Keyword(s):

Spinal Cord ◽

Neuropathic Pain ◽

Electrical Stimulation ◽

Dorsal Horn ◽

Nerve Injury ◽

Spinal Cord Stimulation ◽

Microglial Activation ◽

In Vivo Optical Imaging ◽

Stimulation Of

We evaluated the mechanisms underlying the spinal cord stimulation (SCS)-induced analgesic effect on neuropathic pain following spared nerve injury (SNI). On day 3 after SNI, SCS was performed for 6 h by using electrodes paraspinally placed on the L4-S1 spinal cord. The effects of SCS and intraperitoneal minocycline administration on plantar mechanical sensitivity, microglial activation, and neuronal excitability in the L4 dorsal horn were assessed on day 3 after SNI. The somatosensory cortical responses to electrical stimulation of the hind paw on day 3 following SNI were examined by using in vivo optical imaging with a voltage-sensitive dye. On day 3 after SNI, plantar mechanical hypersensitivity and enhanced microglial activation were suppressed by minocycline or SCS, and L4 dorsal horn nociceptive neuronal hyperexcitability was suppressed by SCS. In vivo optical imaging also revealed that electrical stimulation of the hind paw-activated areas in the somatosensory cortex was decreased by SCS. The present findings suggest that SCS could suppress plantar SNI-induced neuropathic pain via inhibition of microglial activation in the L4 dorsal horn, which is involved in spinal neuronal hyperexcitability. SCS is likely to be a potential alternative and complementary medicine therapy to alleviate neuropathic pain following nerve injury.

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A Tissue Engineering Chamber for Continuous Pulsatile Electrical Stimulation of Vascularized Cardiac Tissues In Vivo

Bioelectricity ◽

10.1089/bioe.2020.0035 ◽

2020 ◽

Vol 2 (4) ◽

pp. 391-398

Author(s):

Damián Hernández ◽

Rodney Millard ◽

Anne M. Kong ◽

Owen Burns ◽

Priyadharshini Sivakumaran ◽

...

Keyword(s):

Tissue Engineering ◽

Electrical Stimulation ◽

Cardiac Tissues ◽

Stimulation Of

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Characterization of Prejunctional Muscarinic Receptors: Effects on the Release of VIP and Functional Responses and Receptor Expression in the Ovine Submandibular Gland

Advances in Pharmacological Sciences ◽

10.1155/2009/787586 ◽

2009 ◽

Vol 2009 ◽

pp. 1-6

Author(s):

Anders T. Ryberg ◽

Ondrej Soukup ◽

Gunnar Tobin

Keyword(s):

Electrical Stimulation ◽

Submandibular Gland ◽

Muscarinic Receptor ◽

Muscarinic Receptors ◽

Receptor Expression ◽

Receptor Subtypes ◽

Chorda Tympani Nerve ◽

Functional Responses ◽

Stimulation Of

In the in vivo experiments on anaesthetized sheep, it was presently examined whether muscarinic receptor antagonists with diverse selectivity affect the release of VIP in response to electrical stimulation of the parasympathetic chorda tympanic nerve differently, and if the changes in the release could be associated to altered secretory and vasodilator responses. The location of the muscarinic receptor subtypes was examined also. In the experiments, blood was collected out of the submandibular venous drainage before and during electrical stimulation of chorda tympani nerve in the absence and presence either of pirenzepine or methoctramine. While metchoctramine increased the output of protein, pirenzepine inhibited flow of saliva and increased protein output, vasodilatation, and VIP output. In morphological examinations, the inhibitory muscarinic M4 receptor occurred interacinarily in the gland. It is concluded that prejunctional muscarinic receptors, most likely of the M4 subtype, exert inhibitory modulation of the parasympathetic release of VIP in the ovine submandibular gland.

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A Robust Method for Adjustment of Laser Speckle Contrast Imaging during Transcranial Mouse Brain Visualization

Photonics ◽

10.3390/photonics6030080 ◽

2019 ◽

Vol 6 (3) ◽

pp. 80 ◽

Cited By ~ 5

Author(s):

Vyacheslav Kalchenko ◽

Anton Sdobnov ◽

Igor Meglinski ◽

Yuri Kuznetsov ◽

Guillaume Molodij ◽

...

Keyword(s):

Biological Tissues ◽

Laser Speckle ◽

Robust Method ◽

Scattering Media ◽

Contrast Imaging ◽

Speckle Contrast ◽

Non Invasive ◽

Sagittal Sinus ◽

Brain Vasculature

Laser speckle imaging (LSI) is a well-known and useful approach for the non-invasive visualization of flows and microcirculation localized in turbid scattering media, including biological tissues (such as brain vasculature, skin capillaries etc.). Despite an extensive use of LSI for brain imaging, the LSI technique has several critical limitations. One of them is associated with inability to resolve a functionality of vessels. This limitation also leads to the systematic error in the quantitative interpretation of values of speckle contrast obtained for different vessel types, such as sagittal sinus, arteries, and veins. Here, utilizing a combined use of LSI and fluorescent intravital microscopy (FIM), we present a simple and robust method to overcome the limitations mentioned above for the LSI approach. The proposed technique provides more relevant, abundant, and valuable information regarding perfusion rate ration between different types of vessels that makes this method highly useful for in vivo brain surgical operations.

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