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https://www.readbyqxmd.com/read/28222167/emergence-and-development-of-gut-motility-in-the-chicken-embryo
#1
N R Chevalier, V Fleury, S Dufour, V Proux-Gillardeaux, A Asnacios
The gastrointestinal tract transports the food bolus by peristalsis. Gut motility starts at an early age in the developing embryo, well before it is required for nutrition of the organism. We present a comprehensive kinematic study of the emergence and physiological development of gut motility in all regions of the lower digestive tract of the chicken embryo from embryonic days E5 through E9. We characterized motility emergence time, propagation patterns, speed, frequency and amplitude of peristalsis waves...
2017: PloS One
https://www.readbyqxmd.com/read/28208796/recent%C3%A2-trends%C3%A2-in%C3%A2-marine%C3%A2-phycotoxins%C3%A2-from%C3%A2-australian%C3%A2-coastal%C3%A2-waters
#2
Penelope Ajani, D Tim Harwood, Shauna A Murray
Phycotoxins, which are produced by harmful microalgae and bioaccumulate in the  marine food web, are of growing concern for Australia. These harmful algae pose a threat to  ecosystem and human health, as well as constraining the progress of aquaculture, one of the fastest  growing food sectors in the world. With better monitoring, advanced analytical skills and an  increase in microalgal expertise, many phycotoxins have been identified in Australian coastal  waters in recent years...
February 9, 2017: Marine Drugs
https://www.readbyqxmd.com/read/28193882/neuronal-hyperexcitability-in-a-mouse-model-of-scn8a-epileptic-encephalopathy
#3
Luis F Lopez-Santiago, Yukun Yuan, Jacy L Wagnon, Jacob M Hull, Chad R Frasier, Heather A O'Malley, Miriam H Meisler, Lori L Isom
Patients with early infantile epileptic encephalopathy (EIEE) experience severe seizures and cognitive impairment and are at increased risk for sudden unexpected death in epilepsy (SUDEP). EIEE13 [Online Mendelian Inheritance in Man (OMIM) # 614558] is caused by de novo missense mutations in the voltage-gated sodium channel gene SCN8A Here, we investigated the neuronal phenotype of a mouse model expressing the gain-of-function SCN8A patient mutation, p.Asn1768Asp (Nav1.6-N1768D). Our results revealed regional and neuronal subtype specificity in the effects of the N1768D mutation...
February 13, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28192153/comparison-of-the-acute-inhibitory-effects-of-tetrodotoxin-ttx-in-rat-and-human-neuronal-networks-for-risk-assessment-purposes
#4
Emma E J Kasteel, Remco H S Westerink
Tetrodotoxin (TTX) is an extremely toxic marine neurotoxin. TTX inhibits voltage-gated sodium channels, resulting in a potentially lethal inhibition of neurotransmission. Despite numerous intoxications in Asia and Europe, limited (human) toxicological data are available for TTX. Additionally, the degree of interspecies differences for TTX is not well established, hampering the use of available (animal) data for human risk assessment and establishing regulatory limits for TTX concentrations in (shell)fish. We therefore used micro-electrode array (MEA) recordings as an integrated measure of neurotransmission to demonstrate that TTX inhibits neuronal electrical activity in both primary rat cortical cultures and human-induced pluripotent stem cell (hIPSC)-derived iCell(®) neurons in co-culture with hIPSC-derived iCell(®) astrocytes, with IC50 values of 7 and 10nM, respectively...
February 10, 2017: Toxicology Letters
https://www.readbyqxmd.com/read/28191772/human-induced-pluripotent-cell-derived-sensory-neurons-for-fate-commitment-of-bone-marrow-derived-schwann-cells-implications-for-remyelination-therapy
#5
Sa Cai, Lei Han, Qiang Ao, Ying-Shing Chan, Daisy Kwok-Yan Shum
Strategies that exploit induced pluripotent stem cells (iPSCs) to derive neurons have relied on cocktails of cytokines and growth factors to bias cell-signaling events in the course of fate choice. These are often costly and inefficient, involving multiple steps. In this study, we took an alternative approach and selected 5 small-molecule inhibitors of key signaling pathways in an 8-day program to induce differentiation of human iPSCs into sensory neurons, reaching ≥80% yield in terms of marker proteins. Continuing culture in maintenance medium resulted in neuronal networks immunopositive for synaptic vesicle markers and vesicular glutamate transporters suggestive of excitatory neurotransmission...
February 2017: Stem Cells Translational Medicine
https://www.readbyqxmd.com/read/28188663/histamine-facilitates-gabaergic-transmission-in-the-rat-entorhinal-cortex-roles-of-h1-and-h2-receptors-na-permeable-cation-channels-and-inward-rectifier-k-channels
#6
Nicholas I Cilz, Saobo Lei
In the brain, histamine (HA) serves as a neuromodulator and a neurotransmitter released from the tuberomammillary nucleus (TMN). HA is involved in wakefulness, thermoregulation, energy homeostasis, nociception and learning and memory. The medial entorhinal cortex (MEC) receives inputs from the TMN and expresses HA receptors (H1 , H2 , and H3 ). We investigated the effects of HA on GABAergic transmission in the MEC and found that HA significantly increased the frequency of spontaneous inhibitory postsynaptic currents (sIPSCs) with an EC50 of 1...
February 11, 2017: Hippocampus
https://www.readbyqxmd.com/read/28160390/angiotensin-ii-type-ii-receptors-and-colonic-dysmotility-in-2-4-dinitrofluorobenzenesulfonic-acid-induced-colitis-in-rats
#7
M G Zizzo, M Auteri, A Amato, G Caldara, D Nuzzo, M Di Carlo, R Serio
BACKGROUND: Angiotensin II (Ang II), the main peptide of the renin-angiotensin system (RAS), has been suggested to be involved in inflammatory bowel diseases. Since RAS has emerged as gut motility regulator, and dysmotility is associated with intestinal inflammation, our objective was to investigate in rat 2,4-dinitrobenzenesulfonic acid (DNBS)-induced colitis the functionality of RAS and its contribution to colonic motor alterations. METHODS: The effects of Ang II on the longitudinal colonic muscular contractility of control and DNBS-treated rats were characterized in vitro...
February 3, 2017: Neurogastroenterology and Motility: the Official Journal of the European Gastrointestinal Motility Society
https://www.readbyqxmd.com/read/28159808/optogenetic-identification-of-hypothalamic-orexin-neuron-projections-to-paraventricular-spinally-projecting-neurons
#8
Olga Dergacheva, Akihiro Yamanaka, Alan R Schwartz, Vsevolod Y Polotsky, David Mendelowitz
Orexin neurons, and activation of orexin receptors, are generally thought to be sympathoexcitatory; however, the functional connectivity between orexin neurons and a likely sympathetic target, the hypothalamic spinally-projecting neurons (SPNs) in the paraventricular nucleus of the hypothalamus (PVN), has not been established. To test the hypothesis that orexin neurons project directly to SPNs in the PVN, channelrhodopsin-2 (ChR2) was selectively expressed in orexin neurons to enable photoactivation of ChR2-expressing fibers while examining evoked postsynaptic currents in SPNs in rat hypothalamic slices...
February 3, 2017: American Journal of Physiology. Heart and Circulatory Physiology
https://www.readbyqxmd.com/read/28148643/developmental-nicotine-exposure-alters-potassium-currents-in-hypoglossal-motoneurons-of-neonatal-rat
#9
Marina Cholanian, Jesse Wealing, Richard B Levine, Ralph F Fregosi
We previously showed that nicotine exposure in utero and after birth via breast milk [developmental nicotine exposure (DNE)] is associated with many changes in the structure and function of hypoglossal motoneurons (XIIMNs), including a reduction in the size of the dendritic arbor and an increase in cell excitability. Interestingly, the elevated excitability was associated with a reduction in the expression of glutamate receptors on the cell body. Together, these observations are consistent with a homeostatic compensation aimed at restoring cell excitability...
February 1, 2017: Journal of Neurophysiology
https://www.readbyqxmd.com/read/28145492/hypocretin-orexin-peptides-excite-rat-neuroendocrine-dopamine-neurons-through-orexin-2-receptor-mediated-activation-of-a-mixed-cation-current
#10
David J Lyons, Arash Hellysaz, Rachida Ammari, Christian Broberger
Hypocretin/Orexin (H/O) neurons of the lateral hypothalamus are compelling modulator candidates for the chronobiology of neuroendocrine output and, as a consequence, hormone release from the anterior pituitary. Here we investigate the effects of H/O peptides upon tuberoinfundibular dopamine (TIDA) neurons - cells which control, via inhibition, the pituitary secretion of prolactin. In whole cell recordings performed in male rat hypothalamic slices, application of H/O-A, as well as H/O-B, excited oscillating TIDA neurons, inducing a reversible depolarising switch from phasic to tonic discharge...
February 1, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28141971/paracrine-maturation-and-migration-of-sh-sy5y-cells-by-dental-pulp-stem-cells
#11
P Gervois, E Wolfs, Y Dillen, P Hilkens, J Ratajczak, R B Driesen, T Vangansewinkel, A Bronckaers, B Brône, T Struys, I Lambrichts
Neurological disorders are characterized by neurodegeneration and/or loss of neuronal function, which cannot be adequately repaired by the host. Therefore, there is need for novel treatment options such as cell-based therapies that aim to salvage or reconstitute the lost tissue or that stimulate host repair. The present study aimed to evaluate the paracrine effects of human dental pulp stem cells (hDPSCs) on the migration and neural maturation of human SH-SY5Y neuroblastoma cells. The hDPSC secretome had a significant chemoattractive effect on SH-SY5Y cells as shown by a transwell assay...
January 1, 2017: Journal of Dental Research
https://www.readbyqxmd.com/read/28138042/control-of-neurotransmission-by-nav1-7-in-human-guinea-pig-and-mouse-airway-parasympathetic-nerves
#12
Michaela Kocmalova, Marian Kollarik, Brendan J Canning, Fei Ru, Robert A Herbstromer, Sonya Meeker, Silvia Fonquerna, Monica Aparici, Montserrat Miralpeix, Xian Chi, Baolin Li, Ben Wilenkin, Jeff McDermott, Eric Nisenbaum, Jeff Krajewski, Bradley J Undem
Little is known about the voltage-gated sodium channels (NaVs) that control neurotransmission in the parasympathetic nervous system. We evaluated the expression of the α subunits of each of the nine NaVs in human, guinea pig, and mouse airway parasympathetic ganglia. We combined this information with a pharmacological analysis of selective NaV blockers on parasympathetic contractions of isolated airway smooth muscle. As would be expected from previous studies, tetrodotoxin potently blocked the parasympathetic responses in the airways of each species...
January 30, 2017: Journal of Pharmacology and Experimental Therapeutics
https://www.readbyqxmd.com/read/28119091/functional-interaction-between-bdnf-and-mglur-ii-in-vitro-bdnf-down-regulated-mglur-ii-gene-expression-and-an-mglur-ii-agonist-enhanced-bdnf-induced-bdnf-gene-expression-in-rat-cerebral-cortical-neurons
#13
Shingo Suzuki, Hisatsugu Koshimizu, Naoki Adachi, Hidetada Matsuoka, Satoko Fushimi, Junichiro Ono, Ken-Ichi Ohta, Takanori Miki
Accumulating evidence suggests functional interaction between brain-derived neurotrophic factor (BDNF) and metabotropic glutamate receptor (mGluR) signaling pathways in the central nervous system (CNS). To date, eight subtypes of mGluRs, mGluR1-8, have been identified, and a previous study suggested that BDNF leads to down-regulation of GluR2 mRNA in rat cerebral cortical cultures. However, precise transcriptomic effects of BDNF on other mGluRs and their cellular significance on the BDNF signaling pathway remain largely unknown...
January 21, 2017: Peptides
https://www.readbyqxmd.com/read/28116849/a-pharmacological-approach-to-understanding-the-control-of-insulin-secretion-in-human-islets
#14
Jean-Claude Henquin, Denis Dufrane, Valery Gmyr, Julie Kerr-Conte, Myriam Nenquin
AIMS: To understand better the control of insulin secretion (IS) by human β-cells and identify similarities and differences with rodent models. METHODS: Dynamic IS was measured in perifused human islets treated with pharmacological agents of known modes of action. RESULTS: Glucokinase activation (Ro28-1675) lowered the glucose threshold for stimulation of IS to 1 mmol/l (G1), augmented the response to G3-G5 but not to G8-G15 whereas tolbutamide remained active in G20, which indicates that not all KATP -channels were closed by high glucose...
January 24, 2017: Diabetes, Obesity & Metabolism
https://www.readbyqxmd.com/read/28115552/xenin-augments-duodenal-anion-secretion-via-activation-of-afferent-neural-pathways
#15
Izumi Kaji, Yasutada Akiba, Ikuo Kato, Koji Maruta, Atsukazu Kuwahara, Jonathan D Kaunitz
Xenin-25, a neurotensin (NT)-related anorexigenic gut hormone generated mostly in the duodenal mucosa, is believed to increase the rate of duodenal ion secretion, since xenin-induced diarrhea is not present after Roux-en-Y gastric bypass surgery. Since the local effects of xenin on duodenal ion secretion have remained uninvestigated, we thus examined the neural pathways underlying xenin-induced duodenal anion secretion. Intravenous infusion of xenin-8, a bioactive C-terminal fragment of xenin-25, dose-dependently increased the rate of duodenal HCO3- secretion in perfused duodenal loops of anesthetized rats...
January 23, 2017: Journal of Pharmacology and Experimental Therapeutics
https://www.readbyqxmd.com/read/28110076/facilitation-of-distinct-inhibitory-synaptic-inputs-by-chemical-anoxia-in-neurons-in-the-oculomotor-facial-and-hypoglossal-motor-nuclei-of-the-rat
#16
Satoshi Takagi, Yu Kono, Masashi Nagase, Soichiro Mochio, Fusao Kato
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by the selective loss of motor neurons in the brainstem and spinal cord. Clinical studies have indicated that there is a distinct region-dependent difference in the vulnerability of motor neurons. For example, the motor neurons in the facial and hypoglossal nuclei are more susceptible to neuronal death than those in the oculomotor nucleus. To understand the mechanism underlying the differential susceptibility to cell death of the neurons in different motor nuclei, we compared the effects of chemical anoxia on the membrane currents and postsynaptic currents in different motor nuclei...
January 19, 2017: Experimental Neurology
https://www.readbyqxmd.com/read/28106083/the-association-of-bacterial-c9-based-ttx-like-compounds-with-prorocentrum-minimum-opens-new-uncertainties-about-shellfish-seafood-safety
#17
Inés Rodríguez, Amparo Alfonso, Eva Alonso, Juan A Rubiolo, María Roel, Aristidis Vlamis, Panagiota Katikou, Stephen A Jackson, Margassery Lekha Menon, Alan Dobson, Luis M Botana
In 2012, Tetrodotoxin (TTX) was identified in mussels and linked to the presence of Prorocentrum minimum (P. minimum) in Greece. The connexion between TTX and P. minimum was further studied in this paper. First, the presence of TTX-producer bacteria, Vibrio and Pseudomonas spp, was confirmed in Greek mussels. In addition these samples showed high activity as inhibitors of sodium currents (INa). P. minimum was before associated with neurotoxic symptoms, however, the nature and structure of toxins produced by this dinoflagellate remains unknown...
January 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28101642/late-sodium-current-and-intracellular-ionic-homeostasis-in-acute-ischemia
#18
Carlotta Ronchi, Eleonora Torre, Riccardo Rizzetto, Joyce Bernardi, Marcella Rocchetti, Antonio Zaza
Blockade of the late Na(+) current (I NaL) protects from ischemia/reperfusion damage; nevertheless, information on changes in I NaL during acute ischemia and their effect on intracellular milieu is missing. I NaL, cytosolic Na(+) and Ca(2+) activities (Nacyt, Cacyt) were measured in isolated rat ventricular myocytes during 7 min of simulated ischemia (ISC); in all the conditions tested, effects consistently exerted by ranolazine (RAN) and tetrodotoxin (TTX) were interpreted as due to I NaL blockade. The results indicate that I NaL was enhanced during ISC in spite of changes in action potential (AP) contour; I NaL significantly contributed to Nacyt rise, but only marginally to Cacyt rise...
March 2017: Basic Research in Cardiology
https://www.readbyqxmd.com/read/28098344/inhibition-of-oxytocin-and-vasopressin-neuron-activity-in-rat-hypothalamic-paraventricular-nucleus-by-relaxin-3-rxfp3-signalling
#19
Alan Kania, Anna Czerw, Agnieszka Grabowiecka, Camila de Ávila, Tomasz Blasiak, Zenon Rajfur, Marian H Lewandowski, Grzegorz Hess, Elena Timofeeva, Andrew L Gundlach, Anna Blasiak
KEY-POINTS: Relaxin-3 is a stress-responsive neuropeptide that acts at its cognate receptor, RXFP3, to alter behaviours including feeding. In this study, we have demonstrated a direct, RXFP3-dependent, inhibitory action of relaxin-3 on oxytocin and vasopressin PVN neuron electrical activity, a putative cellular mechanism of orexinergic actions of relaxin-3. We observed a Gαi/o -protein-dependent inhibitory influence of selective RXFP3 activation on PVN neuronal activity in vitro and demonstrated a direct action of RXFP3 activation on oxytocin and vasopressin PVN neurons, confirmed by their abundant expression of RXFP3 mRNA...
January 18, 2017: Journal of Physiology
https://www.readbyqxmd.com/read/28089920/g-protein-coupled-estrogen-receptor-mediated-non-genomic-facilitatory-effect-of-estrogen-on-cooling-induced-reduction-of-skin-blood-flow-in-mice
#20
Izumi Serizawa, Nozomi Iwasaki, Hirotake Ishida, Shin-Ya Saito, Tomohisa Ishikawa
An enhanced vasoconstrictor activity of cutaneous arteries participates in the reduction of skin blood flow induced by cooling stimulation. Raynaud's phenomenon, which is characterized by intense cooling-induced constriction of cutaneous arteries, is more common in women during the period from menarche to menopause. We thus investigated the effect of 17β-estradiol (E2) on cooling-induced reduction of plantar skin blood flow (PSBF) in mouse in vivo. Ovariectomized female ddY mice, anaesthetized with pentobarbital, were treated with tetrodotoxin for eliminating the sympathetic nerve tone and artificially ventilated...
January 13, 2017: European Journal of Pharmacology
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