180 research outputs found

    Reference place conditioning procedure with cocaine: Increased sensitivity for measuring associatively motivated choice behavior in rats

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    Place conditioning is widely used to study the conditioned rewarding effects of drugs. In the standard version, one reward (cocaine) is compared to no reward (saline). A modified variant of this task, “reference-conditioning” procedure, compares two potentially rewarding stimuli (high versus low cocaine dose). There has been little research on the utility of this procedure. Experiment 1 used the standard protocol with saline administered before confinement to the reference compartment of a place-conditioning chamber. On alternating days, saline, 2.5, 5, 7.5, 10, or 20 mg/kg cocaine was administered before confinement to the opposite compartment. In Experiments 2 and 3, reference-compartment saline was replaced with 5 and 7.5 mg/kg cocaine, respectively. Relative to saline, 7.5–20 mg/kg cocaine had comparable conditioned rewarding effects (i.e., similar increase in time in paired compartment). When cocaine replaced saline, there was competition at doses lower than 7.5 mg/kg. Rats that received 7.5 versus 2.5 mg/kg spent similar time in each compartment, indicating competition. Competition was not seen with 5 versus 20 mg/kg; preference was for the 20 mg/kg compartment. Experiment 4 showed that the competition at 2.5 mg/kg was not due to reward sensitization—. The reference-conditioning procedure has increased sensitivity for measuring associatively-motivated choice behavior

    Gene expression profiling in the lungs of pigs with different susceptibilities to Glässer's disease.

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    BACKGROUND: Haemophilus parasuis is the causative agent of Glässer's disease in pigs. Currently, little is known about the molecular mechanisms that contribute to disease susceptibility. This study used a porcine oligonucleotide microarray to identify genes that were differentially expressed (DE) in the lungs of colostrum-deprived animals previously characterized as being either 'Fully Resistant' (FR) or 'Susceptible' to infection by H. parasuis in a bacterial challenge experiment. RESULTS: Gene expression profiles of 'FR' and 'Susceptible' animals were obtained by the identification of genes that were differentially expressed between each of these groups and mock-inoculated 'Control' animals. At 24 hours post-inoculation, a total of 21 and 58 DE genes were identified in 'FR' and 'Susceptible' animals respectively. At 72 hours, the numbers of genes were 20 and 347 respectively. 'FR' animals at 24 hours exhibited an increased expression of genes encoding extracellular matrix and TGF-beta signalling components, possibly indicative of tissue repair following the successful early resolution of infection. The gene expression profile of 'FR' animals at 72 hours supported the hypothesis that higher levels of antibacterial activity were responsible for the 'FR' phenotype, possibly due to an increase in natural immunoglobulin A and decrease in signalling by the immunoregulatory transcription factor peroxisome proliferator-activated receptor gamma (PPAR-gamma). The expression profile of 'Susceptible' animals at both time-points was characterized by an imbalance in signalling between pro and anti-inflammatory cytokines and an increased expression of genes involved in biological processes associated with inflammation. These include the pro-inflammatory cytokine genes resistin (RETN) and interleukin 1-beta (IL1B). At 72 hours, a reduction in the expression of genes involved in antigen presentation by both MHC class I and II molecules was observed, which could have contributed to the inability of 'Susceptible' animals to clear infection. CONCLUSIONS: This study is the first to have identified discrete sets of DE genes in pigs of differing susceptibility to H. parasuis infection. Consequently, several candidate genes and pathways for disease resistance or susceptibility phenotypes have been identified. In addition, the findings have shed light on the molecular pathology associated with Glässer's disease.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    Gene expression profiling in the lungs of pigs with different susceptibilities to Glässer's disease

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    <p>Abstract</p> <p>Background</p> <p><it>Haemophilus parasuis </it>is the causative agent of Glässer's disease in pigs. Currently, little is known about the molecular mechanisms that contribute to disease susceptibility. This study used a porcine oligonucleotide microarray to identify genes that were differentially expressed (DE) in the lungs of colostrum-deprived animals previously characterized as being either 'Fully Resistant' (FR) or 'Susceptible' to infection by <it>H. parasuis </it>in a bacterial challenge experiment.</p> <p>Results</p> <p>Gene expression profiles of 'FR' and 'Susceptible' animals were obtained by the identification of genes that were differentially expressed between each of these groups and mock-inoculated 'Control' animals. At 24 hours post-inoculation, a total of 21 and 58 DE genes were identified in 'FR' and 'Susceptible' animals respectively. At 72 hours, the numbers of genes were 20 and 347 respectively. 'FR' animals at 24 hours exhibited an increased expression of genes encoding extracellular matrix and TGF-β signalling components, possibly indicative of tissue repair following the successful early resolution of infection. The gene expression profile of 'FR' animals at 72 hours supported the hypothesis that higher levels of antibacterial activity were responsible for the 'FR' phenotype, possibly due to an increase in natural immunoglobulin A and decrease in signalling by the immunoregulatory transcription factor peroxisome proliferator-activated receptor gamma (PPAR-γ). The expression profile of 'Susceptible' animals at both time-points was characterized by an imbalance in signalling between pro and anti-inflammatory cytokines and an increased expression of genes involved in biological processes associated with inflammation. These include the pro-inflammatory cytokine genes resistin (<it>RETN</it>) and interleukin 1-beta (<it>IL1B</it>). At 72 hours, a reduction in the expression of genes involved in antigen presentation by both MHC class I and II molecules was observed, which could have contributed to the inability of 'Susceptible' animals to clear infection.</p> <p>Conclusions</p> <p>This study is the first to have identified discrete sets of DE genes in pigs of differing susceptibility to <it>H. parasuis </it>infection. Consequently, several candidate genes and pathways for disease resistance or susceptibility phenotypes have been identified. In addition, the findings have shed light on the molecular pathology associated with Glässer's disease.</p

    Mecamylamine, dihydro-β-erythroidine, and dextromethorphan block conditioned responding evoked by the conditional stimulus effects of nicotine

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    Current smokers express the desire to quit. However, the majority find it difficult to remain abstinent. As such, research efforts continually seek to develop more effective treatment. One such area of research involves the interoceptive stimulus effects of nicotine as either a discriminative stimulus in an operant drug discrimination task, or more recently as a conditional stimulus (CS) in a discriminated goal-tracking task. The present work investigated the potential role nicotinic acetylcholine receptors in the CS effects of nicotine (0.4 mg/kg) using antagonists with differential selectivity for β2*, α7*, α6β2*, and α3β4* receptors. Methyllycaconitine (MLA) had no effect on nicotine-evoked conditioned responding. Mecamylamine and dihydro-β-erythroidine (DHβE) dose dependently blocked responding evoked by the nicotine CS. In a time-course assessment of mecamylamine and DHβE, each blocked conditioned responding when given 5 min before testing and still blocked conditioned responding when administered 200 min before testing. Two novel bis-picolinium analogs (N, N’-(3, 3′-(dodecan-1,12-diyl)-bis-picolinium dibromide [bPiDDB], and N, N’- (decan-1,10-diyl)-bis-picolinium diiodide [bPiDI]) did not block nicotine-evoked conditioned responding. Finally, pretreatment with low dose combinations of mecamylamine, dextromethorphan, and/or bupropion were used to target α3β4* receptors. No combination blocked conditioned responding evoked by the training dose of nicotine. However, a combination of mecamylamine and dextromethorphan partially blocked nicotine-evoked conditioned responding to a lower dose of nicotine (0.1 mg/kg). These results indicate that β2* and potentially α3β4* nicotinic acetylcholine receptors play a role in the CS effects of nicotine and are potential targets for the development of nicotine cessation aids

    Mecamylamine, dihydro-β-erythroidine, and dextromethorphan block conditioned responding evoked by the conditional stimulus effects of nicotine

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    Current smokers express the desire to quit. However, the majority find it difficult to remain abstinent. As such, research efforts continually seek to develop more effective treatment. One such area of research involves the interoceptive stimulus effects of nicotine as either a discriminative stimulus in an operant drug discrimination task, or more recently as a conditional stimulus (CS) in a discriminated goal-tracking task. The present work investigated the potential role nicotinic acetylcholine receptors in the CS effects of nicotine (0.4 mg/kg) using antagonists with differential selectivity for β2*, α7*, α6β2*, and α3β4* receptors. Methyllycaconitine (MLA) had no effect on nicotine-evoked conditioned responding. Mecamylamine and dihydro-β-erythroidine (DHβE) dose dependently blocked responding evoked by the nicotine CS. In a time-course assessment of mecamylamine and DHβE, each blocked conditioned responding when given 5 min before testing and still blocked conditioned responding when administered 200 min before testing. Two novel bis-picolinium analogs (N, N’-(3, 3′-(dodecan-1,12-diyl)-bis-picolinium dibromide [bPiDDB], and N, N’- (decan-1,10-diyl)-bis-picolinium diiodide [bPiDI]) did not block nicotine-evoked conditioned responding. Finally, pretreatment with low dose combinations of mecamylamine, dextromethorphan, and/or bupropion were used to target α3β4* receptors. No combination blocked conditioned responding evoked by the training dose of nicotine. However, a combination of mecamylamine and dextromethorphan partially blocked nicotine-evoked conditioned responding to a lower dose of nicotine (0.1 mg/kg). These results indicate that β2* and potentially α3β4* nicotinic acetylcholine receptors play a role in the CS effects of nicotine and are potential targets for the development of nicotine cessation aids

    Response to comment on 'Amphibian fungal panzootic causes catastrophic and ongoing loss of biodiversity'

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    Lambert et al. question our retrospective and holistic epidemiological assessment of the role of chytridiomycosis in amphibian declines. Their alternative assessment is narrow and provides an incomplete evaluation of evidence. Adopting this approach limits understanding of infectious disease impacts and hampers conservation efforts. We reaffirm that our study provides unambiguous evidence that chytridiomycosis has affected at least 501 amphibian species

    Achieving consensus on psychosocial and physical rehabilitation management for people living with kidney disease

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    From Crossref journal articles via Jisc Publications RouterHistory: epub 2023-05-19, issued 2023-05-19Article version: AMPublication status: PublishedPelagia Koufaki - ORCID: 0000-0002-1406-3729 https://orcid.org/0000-0002-1406-3729Background People living with chronic kidney disease (CKD) need to be able to live well with their condition. The provision of psychosocial interventions (psychological, psychiatric, and social care) and physical rehabilitation management is variable across England, as well as the rest of the United Kingdom. There is a need for clear recommendations for standards of psychosocial and physical rehabilitation care for people living with CKD, and guidance for the commissioning and measurement of these services. The NHS England Renal Services Transformation Programme (RSTP) supported a programme of work and modified Delphi process to address the management of psychosocial and physical rehabilitation care as part of a larger body of work to formulate a comprehensive commissioning toolkit for renal care services across England. We sought to achieve expert consensus regarding the psychosocial and physical rehabilitation management of people living with CKD in England and the rest of the UK. Method A Delphi consensus method was used to gather and refine expert opinions of senior members of the kidney multi-disciplinary team (MDT) and other key stakeholders in the UK. An agreement was sought on 16 statements reflecting aspects of psychosocial and physical rehabilitation management for people living with CKD. Results Twenty-six expert practitioners and other key stakeholders, including lived experience representatives, participated in the process. The consensus (&amp;gt;80% affirmative votes) amongst the respondents for all 16 statements was high. Nine recommendation statements were discussed and refined further to be included in the final iteration of the ‘Systems’ section of the NHS England RSTP commissioning toolkit. These priority recommendations reflect pragmatic solutions that can be implemented in renal care and include recommendations for a holistic well-being assessment for all people living with CKD who are approaching dialysis, or who are at listing for kidney transplantation, which includes the use of validated measurement tools to assess the need for further intervention in psychosocial and physical rehabilitation management. It is recommended that the scores from these measurement tools be included in the NHS England Renal Data Dashboard. There was also a recommendation for referral as appropriate to NHS Talking therapies, psychology, counselling or psychotherapy, social work or liaison psychiatry for those with identified psychosocial needs. The use of digital resources was recommended to be used in addition to face-to-face care to provide physical rehabilitation, and all healthcare professionals should be educated to recognise psychosocial and physical rehabilitation needs and refer/sign-post people with CKD to appropriate services. Conclusion There was high consensus amongst senior members of the kidney MDT and other key stakeholders, including those with lived experience, in the UK on all aspects of the psychosocial and physical rehabilitation management of people living with CKD. The results of this process will be used by NHS England to inform the ‘Systems’ section of the commissioning toolkit and data dashboard and to inform the National Standards of Care for people living with CKD.inpressinpres
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