INHIBITION OF TNF-ALPHA DECREASES MICROGLIA ACTIVATION IN RATS NEONATALLY TREATED WITH POLY I:C

Introduction: Current medical treatment for individuals diagnosed with schizophrenia (SCHZ) primarily relies on the inhibition of the dopamine D2 receptor that has been shown to be supersensitive in these patients. Treatment occurs through the use of antipsychotic medication which leads to a number of debilitating dose-dependent side effects, such as weight gain, agranulocytosis, and seizures. Patients diagnosed with SCHZ have also been shown to have increased inflammation in their central nervous system (CNS), particularly within specific brain regions such as the prefrontal cortex and hippocampus. This is in large part due to the interaction between a pro-inflammatory cytokine called tumor necrosis factor-alpha (TNFa) and microglia, which are resident CNS defense cells. TNFa is a cell-signaling protein, regulates a variety of immune cells, and is involved in the acute phase reaction of inflammation. Upon activation by TNFa secretion, microglial cells switch from being anti-inflammatory (M2) to pro-inflammatory (M1), thereby resulting in neuroinflammation as well as synaptic loss and neuronal death. In this project, we hypothesized oral administration through the diet of a novel TNFa modulator (PD2024) developed by P2D Biosciences, Inc. (Cincinnati, OH) would significantly reduce microglia activation in rats neonatally treated with Polyinosinic:polycytidylic acid (poly I:C). Methods and Results: To test our hypothesis, four groups (Neonatal Poly I:C/TNFa, Neonatal Poly I:C/Control, Neonatal Saline/TNFa, and Neonatal Saline/Control) were intraperitoneally injected with either poly I:C or saline during postnatal days (P)5-7. Poly I:C is an immunostimulant that mimics neonatal infection in humans, which also has been found to be a factor for the development of SCHZ later in life. Between days (P)30-(P)60, the Neonatal Poly I:C/TNFa and Neonatal Saline/TNFa groups were orally administered PD2024 through the diet. After (P)60, brain tissue was evaluated by immunohistochemistry (IHC) and confocal microscopy. Immunohistochemistry was used to label microglial cells in the prefrontal cortex and hippocampus with a green fluorescent dye attached to Iba1, a protein that specifically binds to these cells. Upon completion of IHC, tissue was evaluated using a confocal microscope and then analyzed with NIH ImageJ software. Analysis parameters included cell count, sampled cell body fluorescence, and overall image fluorescence. The results obtained showed a significant decrease in microglia activation for the Poly I:C/TNFa group when compared to the Poly I:C/Control group, as well as similarities in activation levels with the Saline/Control group. These results were demonstrated in both sampled cell body fluorescence and overall image fluorescence measurements. Conclusion: This data supports the hypothesis that PD2024 is successful in reducing microglia activation through the modulation of TNFa. Therefore, treatment with a TNFa modulator such as PD2024 alongside of current antipsychotic medication could mediate neuroinflammation and reduce the dose-dependent side effects. This approach could be a promising therapeutic treatment option for those diagnosed with schizophrenia, as well as potentially for other neurocognitive and behavioral disorders

The Effect of Two Novel Anti-Inflammatory Drugs on Sensorimotor Gating and Microglial Activation in the Poly I:C Rodent Model of Schizophrenia

Antipsychotic medications remain the first line of treatment for individuals diagnosed with schizophrenia (SCZ). However, antipsychotic treatment is often not compliant due to dysregulation of both the central (CNS) and autonomic (ANS) nervous systems, resulting in debilitating dose-dependent side effects. Recent work suggests a new approach for treatment of SCZ that could potentially lower treatment doses and reduce side effects. Increased neuroinflammation has been shown in patients diagnosed with SCZ, particularly within the prefrontal cortex (PFC) and hippocampal (HPC) regions of the brain. Tumor necrosis factor-alpha (TNFa) is one of the key pro-inflammatory cytokines observed to be secreted during the inflammatory response. When TNFa is chronically secreted, resident CNS microglia become pro-inflammatory and toxic to the local environment. Microglial activation alongside of dopamine dysregulation thereby results in both the behavioral and neuroinflammatory aspects of SCZ. In this study, we hypothesized dietary administration of two different novel TNFamodulators (PD2024 – Experiment 1 and PD340 – Experiment 2) developed by our collaborators from P2D Bioscience, Inc. (Cincinnati, OH) would alleviate auditory sensorimotor gating deficits and reduce microglial cell activation caused by neonatal polyinosinic:polycytidylic acid (Poly I:C) treatment in rats, which is a validated rodent model of SCZ. Four groups (Experiment 1: Poly IC/PD2024, Poly IC/Control, Saline/PD2024, Saline/Control and Experiment 2: Poly IC/PD340, Poly IC/Control, Saline/PD340, Saline/Control) were intraperitoneally administered either Poly I:C (2 mg/kg) or saline (0.9% NaCl) from postnatal days 5-7. From P30-67, animals were placed on the experimental diet containing either low (10 mg/kg) or high (30 mg/kg) doses of either PD2024 or PD340, whereas the control animals remained on a normal diet. Prepulse inhibition (PPI) was used to test for auditory sensorimotor gating (behavioral abnormalities) in both adolescence (P44-46) and in adulthood (P60-66). At P67, immunohistochemistry (IHC) and confocal microscopy were used to evaluate and examine microglial cell activation using the Iba1-GFP antibody (neuroinflammatory abnormalities) in the PFC and HPC. Results revealed auditory sensorimotor gating deficits in Poly IC/Controls were alleviated in both adolescence and adulthood with either PD2024 or PD340. It was also found that both TNFa modulators significantly reduced microglial activation in the HPC, but not the PFC. The data supports our hypothesis that dietary administration of PD2024 or PD340 alleviates behavioral deficits and decreases neuroinflammation generated from the Poly I:C rodent model of SCZ. Therefore, an approach with a TNFa modulator alongside of current antipsychotic medications could treat both the behavioral and neuroinflammatory aspects of SCZ

Outcome following valve surgery in Australia: Development of an enhanced database module

Background: Valvular heart disease, including rheumatic heart disease (RHD), is an important cause of heart disease globally. Management of advanced disease can include surgery and other interventions to repair or replace affected valves. This article summarises the methodology of a study that will incorporate enhanced data collection systems to provide additional insights into treatment choice and outcome for advanced valvular disease including that due to RHD. Methods: An enhanced data collection system will be developed linking an existing Australian cardiac surgery registry to more detailed baseline co-morbidity, medication, echocardiographic and hospital separation data to identify predictors of morbidity and mortality outcome following valve surgery. Discussion: This project aims to collect and incorporate more detailed information regarding pre and postoperative factors and subsequent morbidity. We will use this to provide additional insights into treatment choice and outcome. © 2017 The Author(s)

Rothamsted Conference RC No 2 : The culture and manuring of fodder crops

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The effects of environmental enrichment on nicotine sensitization in a rodent model of schizophrenia

Environmental enrichment, for more than fifty years, has shown to increase learning in behaviors and to alter some brain structures (Renner and Rosenzweig). Some brain changes that occur when environmental enrichment is implemented include the following: increases in cortical thickness, especially the occipital cortex, increases in size of neuronal cell bodies, number of dendrites and dendritic spines, increases in astrocyte branching, increases in the number of brain blood capillaries, and increases in mitochondria (an indication of higher metabolic activity) (Stairs and Bard). It has been shown in research studies that rats in the environmental enrichment group are less sensitive to nicotine effects, both repeated and acute, than rats in isolated situations (Green et al). This is so because enrichment changes the intensity of the acute administration of drugs of abuse. Rats are stimulated by the environment, rather than a particular stimulant

The Incentive Amplifying Effects of Nicotine Are Reduced by Selective and Non-Selective Dopamine Antagonists in Rats

Nicotine is a psychomotor stimulant with ‘reinforcement enhancing’ effects — the actions of nicotine in the brain increase responding for non-nicotine rewards. We hypothesized that this latter effect of nicotine depends on increased incentive properties of anticipatory cues; consistent with this hypothesis, multiple laboratories have reported that nicotine increases sign tracking, i.e. approach to a conditioned stimulus (CS), in Pavlovian conditioned-approach tasks. Incentive motivation and sign tracking are mediated by mesolimbic dopamine (DA) transmission and nicotine facilitates mesolimbic DA release. Therefore, we hypothesized that the incentive-promoting effects of nicotine would be impaired by DA antagonists. To test this hypothesis, separate groups of rats were injected with nicotine (0.4 mg/kg base) or saline prior to Pavlovian conditioning sessions in which a CS (30 s illumination of a light or presentation of a lever) was immediately followed by a sweet reward delivered in an adjacent location. Both saline and nicotine pretreated rats exhibited similar levels of conditioned approach to the reward location (goal tracking), but nicotine pretreatment significantly increased approach to the CS (sign tracking), regardless of type (lever or light). The DAD1 antagonist SCH-23390 and the DAD2/3antagonist eticlopride reduced conditioned approach in all rats, but specifically reduced goal tracking in the saline pretreated rats and sign tracking in the nicotine pretreated rats. The non-selective DA antagonist flupenthixol reduced sign-tracking in nicotine rats at all doses tested; however, only the highest dose of flupenthixol reduced goal tracking in both nicotine and saline groups. The reductions in conditioned approach behavior, especially those by SCH-23390, were dissociated from simple motor suppressant effects of the antagonists. These experiments are the first to investigate the effects of dopaminergic drugs on the facilitation of sign-tracking engendered by nicotine and they implicate dopaminergic systems both in conditioned approach as well as the incentive-promoting effects of nicotine

Investigation of the Adenosine A(2A) Receptor on the Enhanced Rewarding Effects of Nicotine and Dopamine D2 Receptor Signaling in a Novel Heritable Model of Drug Abuse Vulnerability

Investigation of the adenosine A(2A) receptor on the enhanced rewarding effects of nicotine and dopamine D2 receptor signaling in a novel heritable model of drug abuse vulnerability Seth E. Turney, Loren D. Peeters, Olivia A. Jennings, Liza J. Wills, Russell W. Brown Many years ago, our laboratory along with a collaborator established that neonatal treatment of the dopamine (DA)D2-like receptor agonist quinpirole (NQ) to rats induces an increase in DAD2 receptor sensitivity throughout the animal’s lifetime, which has validity to schizophrenia (SZ) and a number of clinical conditions. These clinical conditions, which include SZ but also bipolar disorder, obsessive-compulsive disorder, panic disorder, and major depression all demonstrate increased drug abuse vulnerability, especially to cigarette smoking. Based on this permanent change in DAD2 sensitivity, we bred NQ-treated male and female rats with their NQ-treated or neonatal saline (NS)-treated counterparts. This F1 generation also demonstrated increases in DAD2 signaling, both behaviorally as well as through DAD2 signaling mechanisms. We have shown both d enhanced behavioral responding to nicotine on the conditioned place preference (CPP) and behavioral sensitization paradigms. These F1 offspring of NQ-treated rats also demonstrated increases of G-protein dependent and G-protein independent DAD2 signaling. Interestingly, the adenosine A(2A) receptor forms a mutual inhibitory heteromer with the DAD2 receptor. Adenosine is a known neuromodulator that can increase or decrease synaptic transmission in the brain, and there exists a hypothesis that adenosine dysfunction is the primary system which is disrupted in SZ which leads to changes in the dopamine and other neurotransmitter systems. The drug CGS 21680, an A(2A) agonist which stimulates the A(2A) receptor, is known to decrease DAD2 signaling and has been shown to block nicotine behavioral sensitization. A major focus in this project is on the adenosine A(2A) receptor as a novel pharmacological treatment target, since it is known that antipsychotic drugs which are often used to treat SZ and these other clinical conditions which have increased DAD2 signaling produce deleterious side effects, and novel medications are needed. Results here revealed that a 0.09 mg/kg dose of CGS 21680 was effective to block enhanced nicotine CPP and changes in DAD2 G-protein independent signaling in F1 generation rats. Interestingly, CGS 21680 did not affect G-protein dependent signaling in F1 generation animals, suggesting that the mechanism through which it is working may not be through the traditional DAD2 signaling mechanism. Future work is designed to analyze underlying mechanisms of this effect