Impact of manganese accumulation on Na,K-ATPase expression and function in the cerebellum and striatum of C57Bl/6 mice.

Overexposure to Mn causes a neurological disorder-manganism-with motor symptoms that overlap closely with disorders associated with haploinsufficiency in the gene encoding for α isoform of Na,K-ATPase (NKA). The present study was designed to test the hypothesis that behavioral changes in the mouse model of manganism may be associated with changes in the expression and activity of α NKA in the cerebellum (CB) and striatum (STR)-the key brain structures responsible for motor control in adult mice. C57Bl/6 mice were exposed to MnCl at 0.

Simultaneous exposure to chronic irradiation and simulated microgravity differentially alters immune cell phenotype in mouse thymus and spleen.

Deep-space missions may alter immune cell phenotype in the primary (e.g., thymus) and secondary (e.

A pharmacokinetic study of morphine-6-O-sulfate in rat plasma and brain.

Morphine-6-O-sulfate (M6S), a polar, zwitterionic sulfate ester of morphine, is a powerful and safe analgesic in several rat models of pain. A sensitive liquid chromatography-tandem mass spectrometry bioanalytical method was developed and validated for the simultaneous determination of M6S and morphine (MOR) in rat plasma and brain after M6S administration. Morphine-d was used as internal standard.

A Transgenic Mouse Model to Selectively Identify α Na,K-ATPase Expressing Cells in the Nervous System.

The α Na,K-ATPase (αNKA) is one of four known α isoforms of the mammalian transporter. A deficiency in αNKA is linked to severe movement control disorders. Understanding the pathogenesis of these disorders is limited by an incomplete knowledge of αNKA expression in the brain as well as the challenges associated with identifying living cells that express the isoform for subsequent electrophysiological studies.

Evaluation of morphine-like effects of the mixed mu/delta agonist morphine-6--sulfate in rats: Drug discrimination and physical dependence.

Morphine-6-O-sulfate (M6S) is as a mixed-action mu/delta (μ/δ) opioid receptor agonist with high potency and analgesic efficacy. These studies used assays of drug discrimination and schedule-controlled responding to assess abuse-liability, tolerance, and physical dependence as compared to morphine in rats. Attempts to train 0.

Pinprick hypo- and hyperalgesia in diabetic rats: Can diet content affect experimental outcome?

Existing literature concerning the effect of experimentally-induced diabetes on pain thresholds in rodent models remains controversial. In this work, we describe a phenotypical switch from streptozotocin-induced pinprick hypoalgesia to hyperalgesia observed in the same laboratory, in the same strain of rats, obtained from the same vendor, and measured by the same technique carried out by the investigators. This switch was observed around January 2015, at the time when there was a change in the diet of rats at the Radley North Carolina Charles River facility.

Sub-cellular Electrical Heterogeneity Revealed by Loose Patch Recording Reflects Differential Localization of Sarcolemmal Ion Channels in Intact Rat Hearts.

The cardiac action potential (AP) is commonly recoded as an integral signal from isolated myocytes or ensembles of myocytes (with intracellular microelectrodes and extracellular macroelectrodes, respectively). These signals, however, do not provide a direct measure of activity of ion channels and transporters located in two major compartments of a cardiac myocyte: surface sarcolemma and the T-tubule system, which differentially contribute to impulse propagation and excitation-contraction (EC) coupling. In the present study we investigated electrical properties of myocytes within perfused intact rat heart employing loose patch recording with narrow-tip (2 μm diameter) extracellular electrodes.

Preclinical assessment of utility of M6S for multimodal acute and chronic pain treatment in diabetic neuropathy.

Aims: Previous reports from our laboratory have established that morphine-6-O-sulfate (M6S) is a mixed μ/δ opioid receptor (OR) agonist and a potential improved alternative to morphine for treatment of chronic multimodal pain in non-diabetic rats. This study extends the antinociceptive effects of M6S and morphine in STZ-induced diabetic rats.

Materials And Methods: Effects of morphine and M6S were studied across a range of pain modalities, using hot plate threshold (HPT), pinprick sensitivity threshold (PST) and paw pressure threshold (PPT) tests.

Clock Scan Protocol for Image Analysis: ImageJ Plugins.

The clock scan protocol for image analysis is an efficient tool to quantify the average pixel intensity within, at the border, and outside (background) a closed or segmented convex-shaped region of interest, leading to the generation of an averaged integral radial pixel-intensity profile. This protocol was originally developed in 2006, as a visual basic 6 script, but as such, it had limited distribution. To address this problem and to join similar recent efforts by others, we converted the original clock scan protocol code into two Java-based plugins compatible with NIH-sponsored and freely available image analysis programs like ImageJ or Fiji ImageJ.

Evaluation of Analgesia, Tolerance, and the Mechanism of Action of Morphine-6-O-Sulfate Across Multiple Pain Modalities in Sprague-Dawley Rats.

Background: Morphine-6-O-sulfate (M6S) is a mixed μ/δ-opioid receptor (OR) agonist and potential alternative to morphine for treatment of chronic multimodal pain.

Methods: To provide more support for this hypothesis, the antinociceptive effects of M6S and morphine were compared in tests that access a range of pain modalities, including hot plate threshold (HPT), pinprick sensitivity threshold (PST) and paw pressure threshold tests.

Results: Acutely, M6S was 2- to 3-fold more potent than morphine in HPT and PST tests, specifically, derived from best-fit analysis of dose-response relationships of morphine/M6S half-effective dose (ED50) ratios (lower, upper 95% confidence interval [CI]) were 2.

Antinociceptive effects of the 6-O-sulfate ester of morphine in normal and diabetic rats: Comparative role of mu- and delta-opioid receptors.

Unlabelled: This study determined the antinociceptive effects of morphine and morphine-6-O-sulfate (M6S) in both normal and diabetic rats, and evaluated the comparative role of mu-opioid receptors (mu-ORs) and delta-opioid receptors (delta-ORs) in the antinociceptive action of these opioids. In vitro characterization of mu-OR and delta-OR-mediated signaling by M6S and morphine in stably transfected Chinese hamster ovary (CHO-K1) cells showed that M6S exhibited a 6-fold higher affinity for delta-ORs and modulated G-protein and adenylyl cyclase activity via delta-ORs more potently than morphine. Interestingly, while morphine acted as a full agonist at delta-ORs in both functional assays examined, M6S exhibited either partial or full agonist activity for modulation of G-protein or adenylyl cyclase activity, respectively.

Defects in the COG complex and COG-related trafficking regulators affect neuronal Golgi function.

The Conserved Oligomeric Golgi (COG) complex is an evolutionarily conserved hetero-octameric protein complex that has been proposed to organize vesicle tethering at the Golgi apparatus. Defects in seven of the eight COG subunits are linked to Congenital Disorders of Glycosylation (CDG)-type II, a family of rare diseases involving misregulation of protein glycosylation, alterations in Golgi structure, variations in retrograde trafficking through the Golgi and system-wide clinical pathologies. A troublesome aspect of these diseases are the neurological pathologies such as low IQ, microcephaly, and cerebellar atrophy.

Age-dependent decline in density of human nerve and spinal ganglia neurons expressing the α3 isoform of Na/K-ATPase.

Ambulatory instability and falls are a major source of morbidity in the elderly. Age-related loss of tendon reflexes is a major contributing factor to this morbidity, and deterioration of the afferent limb of the stretch reflex is a potential contributing factor to such age-dependent loss of tendon reflexes. To evaluate this, we assessed the number and distribution of muscle spindle afferent fibers in human sacral spinal ganglia (S1) and tibial nerve samples obtained at autopsy, using immunohistochemical staining for the α3 isoform of Na(+), K(+)-ATPase (α3NKA), a marker of muscle spindle afferents.

[Effect of insulin on characteristics of contractile responses of fast and slow skeletal muscles of rats with streptozotocin-induced overt diabetes].

Comparison of amplitude-time characteristics of fast (m. EDL) muscles in rats with acute model of streptozotocin diabetes (SD) (12 and 30 days after treatment with streptozotocin) did not reveal significant changes in strength of single normalized contractile responses as compared with control. In slow (m.

Animal model of simulated microgravity: a comparative study of hindlimb unloading via tail versus pelvic suspension.

The aim of this study was to compare physiological effects of hindlimb suspension (HLS) in tail- and pelvic-HLS rat models to determine if severe stretch in the tail-HLS rats lumbosacral skeleton may contribute to the changes traditionally attributed to simulated microgravity and musculoskeletal disuse in the tail-HLS model. Adult male Sprague-Dawley rats divided into suspended and control-nonsuspended groups were subjected to two separate methods of suspension and maintained with regular food and water for 2 weeks. Body weights, food and water consumption, soleus muscle weight, tibial bone mineral density, random plasma insulin, and hindlimb pain on pressure threshold (PPT) were measured.

[Action of insulin on contraction and electrical responses of rat skeletal muscle].

The effect of insulin on contractility of directly stimulated skeletal muscles was studied in experiments in isolated preparations of rat fast, extensor digitorum longus (m. EDL), slow, soleus (m. SOL) and mixed, diaphragm muscles.

[Effect of barium and ouabain on electrogenesis in various sites of intact and detubulated skeletal muscle fibers of the frog R. temporaria].

In loose patch clamp experiments on intact sartorious muscle fibers of the frog Rana temporaria there were revealed two types of wave forms of the extracellularly recorded action potentials (AP). Responses of the first type (T1AP) consisted of the initial positive phase with subsequent phase of strong negativity. Responses of the second type (T2AP) had an additional positive phase concluding their waveform.

Two types of extracellular action potentials recorded with narrow-tipped pipettes in skeletal muscle of frog, Rana temporaria.

Two types of muscle fibre action potentials (APs) were recorded using narrow-tipped extracellular pipettes in isolated sartorius muscles of frog, Rana temporaria. The waveform of type 1 responses (T1 AP, 75% of recordings) was biphasic, 'positive–negative.' The type 2 signals were tri-phasic, 'positive–negative–positive' (T2 AP, 18%).

Pressure hyperalgesia in hind limb suspended rats.

Introduction: Spaceflight and simulated microgravity often associate with pain and prediabetes. Streptozotocin (STZ)-induced moderate insulinopenia rat models of prediabetes result in pressure hyperalgesia. The current study was designed to determine whether or not simulated microgravity induced by hind limb suspension (HLS) in rats lead to insulinopenia and pressure hyperalgesia.

Antiangiogenic and antimitotic effects of aspirin in hypoxia–reoxygenation modulation of the LOX-1-NADPH oxidase axis as a potential mechanism.

Hypoxia–reoxygenation (HR) is a primary driver of angiogenesis in both atherogenesis and tumorigenesis. The main target of hypoxia-driven proangiogenic signaling is adherens junctions responsible for contact inhibition of endothelial cells. We analyzed the effects of hypoxia (8–12 hours) followed by a brief period of reoxygenation (2 hours) (HR) on angiogenesis and integrity of adherens junction in cultured human umbilical vein endothelial cells as well as the effects of aspirin on modulation of human umbilical vein endothelial cells' response to HR.