Hippocampus and two way active avoidance conditioning: contrasting effects of cytotoxic lesion and temporary inactivation

Hippocampal lesions tend to facilitate two way active avoidance (2WAA) conditioning, where rats learn to cross to the opposite side of a conditioning chamber to avoid a tone-signaled footshock. This classical finding has been suggested to reflect that hippocampus-dependent place/context memory inhibits 2WAA (a crossing response to the opposite side is inhibited by the memory that this is the place where a shock was received on the previous trial). However, more recent research suggests other aspects of hippocampal function that may support 2WAA learning. More specifically, the ventral hippocampus has been shown to contribute to behavioral responses to aversive stimuli and to positively modulate the meso-accumbens dopamine system, whose activation has been implicated in 2WAA learning. Permanent hippocampal lesions may not reveal these contributions because, following complete and permanent loss of hippocampal output, other brain regions may mediate these processes or because deficits could be masked by lesion-induced extra-hippocampal changes, including an upregulation of accumbal dopamine transmission. Here, we re-examined the hippocampal role in 2WAA learning in Wistar rats, using permanent NMDA-induced neurotoxic lesions and temporary functional inhibition by muscimol or tetrodotoxin (TTX) infusion. Complete hippocampal lesions tended to facilitate 2WAA learning, whereas ventral or dorsal hippocampal lesions had no effect. In contrast, ventral or dorsal hippocampal muscimol or TTX infusions impaired 2WAA learning. Ventral infusions caused an immediate impairment, whereas after dorsal infusions rats showed intact 2WAA learning for 40-50 min, before a marked deficit emerged. These data show that functional inhibition of ventral hippocampus disrupts 2WAA learning, while the delayed impairment following dorsal infusions may reflect the time required for drug diffusion to ventral hippocampus. Overall, using temporary functional inhibition, our study shows that the ventral hippocampus contributes to 2WAA learning. Permanent lesions may not reveal these contributions due to functional compensation and extra-hippocampal lesion effects

Which plants used in ethnomedicine are characterized? Phylogenetic patterns in traditional use related to research effort

Plants are important resources in healthcare and for producing pharmaceutical drugs. Pharmacological and phytochemical characterization contributes to both the safe use of herbal medicines and the identification of leads for drug development. However, there is no recent assessment of the proportion of plants used in ethnomedicine that are characterized in this way. Further, although it is increasingly apparent that plants used in ethnomedicine belong to preferred phylogenetic lineages, it is not known how this relates to the focusing of research effort. Here we identify species and lineages rich in ethnomedicinal use and develop methods to describe how well they are known pharmacologically and/or phytochemically. We find 50% of plant species of the family Leguminosae used in ethnomedicine in Brazil, a geographical area where plants are an important part of healthcare, have been the focus of either phytochemical screening or testing for biological activity. Plant species which have more use reports are studied significantly more often (p<0.05). Considering the taxonomic distribution of use, 70% of genera that include species with ethnomedicinal use have been studied, compared to 19% of genera with no reported use. Using a novel phylogenetic framework, we show that lineages with significantly greater numbers of ethnomedicinal species are phylogenetically over-dispersed within the family, highlighting the diversity of species used. “Hotnode clades” contain 16% of species but 46% of ethnomedicinally-used species. The ethnomedicinal species in hotnode clades have more use reports per species (p<0.05), suggesting they are more frequently used. They are also more likely to be characterized pharmacologically and/or phytochemically. Research focus has followed traditional use by these measures, at least for these Brazilian plants, yet ethnomedicinal species yielding candidate drugs, raising public health concerns and more intensively studied lie outside of the hotnode clades

Deletion of Running-Induced Hippocampal Neurogenesis by Irradiation Prevents Development of an Anxious Phenotype in Mice

Recent evidence postulates a role of hippocampal neurogenesis in anxiety behavior. Here we report that elevated levels of neurogenesis elicit increased anxiety in rodents. Mice performing voluntary wheel running displayed both highly elevated levels of neurogenesis and increased anxiety in three different anxiety-like paradigms: the open field, elevated O-maze, and dark-light box. Reducing neurogenesis by focalized irradiation of the hippocampus abolished this exercise-induced increase of anxiety, suggesting a direct implication of hippocampal neurogenesis in this phenotype. On the other hand, irradiated mice explored less frequently the lit compartment of the dark-light box test irrespective of wheel running, suggesting that irradiation per se induced anxiety as well. Thus, our data suggest that intermediate levels of neurogenesis are related to the lowest levels of anxiety. Moreover, using c-Fos immunocytochemistry as cellular activity marker, we observed significantly different induction patterns between runners and sedentary controls when exposed to a strong anxiogenic stimulus. Again, this effect was altered by irradiation. In contrast, the well-known induction of brain-derived neurotrophic factor (BDNF) by voluntary exercise was not disrupted by focal irradiation, indicating that hippocampal BDNF levels were not correlated with anxiety under our experimental conditions. In summary, our data demonstrate to our knowledge for the first time that increased neurogenesis has a causative implication in the induction of anxiety

News Media Representations of Responsibility for Alcohol-Related Liver Disease Requiring Liver Transplantation

Alcohol-related liver disease (ARLD) is a common indication for liver transplantation yet it is considered ethically controversial in academic, clinical and public discourses. Various social groups consider people with ARLD as personally responsible for their condition and question whether they should have access to a scarce resource. How the news media constructs responsibility for ARLD may influence public opinions toward those who are ill as well as related healthcare policies. Since the organ transplantation system relies on the willingness of individuals to donate organs, understanding how the media portrays controversial issues is a matter of vital importance for public health and health policy. We investigated how responsibility for ARLD requiring liver transplantation is presented for public consumption in the news media. Using a keyword search of two online news databases, we selected 81 articles from the United Kingdom, Canada and the United States. We analyzed the articles using a discursive psychological approach. We found that the news media ascribed responsibility for ARLD to three main actors: individuals with ARLD, biological predisposition, and policy and industry representatives. How responsibility for ARLD requiring liver transplantation is presented in the news media may have implications for people diagnosed with other substance-related disorders who present for transplant candidacy or are on the transplant waiting list. Investigating how responsibility for ARLD is constructed in news media may provide insights into how responsibility is understood in other stigmatized health conditions and its potential implications for population health equity.Les maladies hépatiques liées à l’alcool (MHLA) sont une indication courante pour la transplantation du foie, mais elles sont considérées comme éthiquement controversées dans les discours universitaires, cliniques et publics. Divers groupes sociaux considèrent les personnes atteintes d’une MHLA comme personnellement responsables de leur état et se demandent alors si elles devraient avoir accès à une ressource rare. La manière dont les médias d’information établissent la responsabilité de la MHLA peut influencer l’opinion publique à l’égard des personnes malades ainsi que les politiques de santé qui s’y rapportent. Étant donné que le système de transplantation d’organes repose sur la volonté des individus à donner leurs organes, comprendre comment les médias présentent les questions controversées est une question d’importance vitale pour la santé publique et les politiques de santé. Nous avons donc étudié la manière dont la responsabilité des personnes souffrant de MHLA nécessitant une transplantation de foie est présentée au grand public dans les médias d’information. En utilisant une recherche par mot-clé dans deux bases de données d’information en ligne, nous avons sélectionné 81 articles du Royaume-Uni, du Canada et des États-Unis. Nous avons analysé les articles en utilisant une approche psychologique discursive. Notre analyse révèle que les médias d’information attribuent la responsabilité des MHLA à trois acteurs principaux : les individus ayant une MHLA, les prédispositions biologiques et les représentants des politiques et de l’industrie. Elle révèle également que la manière dont la responsabilité des MHLA nécessitant une transplantation de foie est présentée dans les médias peut avoir des implications pour les personnes diagnostiquées avec d’autres troubles liés à la consommation qui se présentent pour une candidature à une transplantation ou qui sont sur la liste d’attente de transplantation. Enfin, cette étude peut aussi nous donner une idée sur la manière dont le concept de responsabilité est compris pour d’autres maladies stigmatisées ainsi que ses implications potentielles sur l’équité en matière de santé des populations

Altered mnemonic functions and resistance to N-METHYL-d-Aspartate receptor antagonism by forebrain conditional knockout of glycine transporter 1

Converging evidence from pharmacological and molecular studies has led to the suggestion that inhibition of glycine transporter 1 (GlyT1) constitutes an effective means to boost N-methyl-d-aspartate receptor (NMDAR) activity by increasing the extra-cellular concentration of glycine in the vicinity of glutamatergic synapses. However, the precise extent and limitation of this approach to alter cognitive function, and therefore its potential as a treatment strategy against psychiatric conditions marked by cognitive impairments, remain to be fully examined. Here, we generated mutant mice lacking GlyT1 in the entire forebrain including neurons and glia. This conditional knockout system allows a more precise examination of GlyT1 downregulation in the brain on behavior and cognition. The mutation was highly effective in attenuating the motor-stimulating effect of acute NMDAR blockade by phencyclidine, although no appreciable elevation in NMDAR-mediated excitatory postsynaptic currents (EPSC) was observed in the hippocampus. Enhanced cognitive performance was observed in spatial working memory and object recognition memory while spatial reference memory and associative learning remained unaltered. These findings provide further credence for the potential cognitive enhancing effects of brain GlyT1 inhibition. At the same time, they indicated potential phenotypic differences when compared with other constitutive and conditional GlyT1 knockout lines, and highlighted the possibility of a functional divergence between the neuronal and glia subpopulations of GlyT1 in the regulation of learning and memory processes. The relevance of this distinction to the design of future GlyT1 blockers as therapeutic tools in the treatment of cognitive disorders remains to be further investigated

Equivalent Decline in Inflammation Markers with Tenofovir Disoproxil Fumarate vs. Tenofovir Alafenamide

Background: Initiation of antiretroviral therapy (ART) and subsequent virologic suppression reduces immune activation and systemic inflammation. Methods: We examined longitudinal changes in biomarkers of monocyte activation (sCD14, sCD163), and systemic (IL-6, hsCRP, sTNFR-I and D-dimer) and vascular (Lp-PLA2) inflammation in a subgroup (N = 100 per arm) of participants enrolled in a randomized, placebo-controlled trial comparing elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide (E/C/F/TAF; TAF) to E/C/F/tenofovir disoproxil fumarate (E/C/F/TDF; TDF) in treatment-naïve adults. Results: For 194 participants (TAF, 98; TDF, 96), baseline levels of biomarkers did not differ by treatment arm; there were no differences in biomarker values between groups at weeks 12, 24, or 48 (p > 0.05), except IL-6 at week 12 (p = 0.012). Among all participants (combining groups), there were statistically significant declines from baseline observed for D-dimer, sCD163, and sTNFR-1 by week 12 and IL-6 by week 24. The proportion of participants with Lp-LA2 levels < 200 ng per mL (p = 0.250) or hsCRP levels <3000 mg per L (p = 0.586) was unchanged through week 48. Conclusions: We observed equivalent declines in biomarkers of monocyte activation and systemic inflammation in treatment-naïve adults treated with TAF or TDF for 48 weeks, suggesting that TAF and TDF have equivalent impact on immune activation and inflammation

Restructuring Skin Cancer Care in Ontario: A Provincial Plan

There is a global rise in skin cancer incidence, resulting in an increase in patient care needs and healthcare costs. To optimize health care planning, costs, and patient care, Ontario Health developed a provincial skin cancer plan to streamline the quality of care. We conducted a systematic review and a grey literature search to evaluate the definitions and management of skin cancer within other jurisdictions, as well as a provincial survey of skin cancer care practices, to identify care gaps. The systematic review did not identify any published comprehensive skin cancer management plans. The grey literature search revealed skin cancer plans in isolated regions of the United Kingdom (U.K.), National Institute for Health and Care Excellence (NICE) guidelines for skin cancer quality indicators and regional skin cancer biopsy clinics, and wait time guidelines in Australia and the U.K. With the input of the Ontario Cancer Advisory Committee (CAC), unique definitions for complex and non-complex skin cancers and the appropriate cancer services were created. A provincial survey of skin cancer care yielded 44 responses and demonstrated gaps in biopsy access. A skin cancer pathway map was created and a recommendation was made for regional skin cancer biopsy clinics. We have created unique definitions for complex and non-complex skin cancer and a skin cancer pathways map, which will allow for the implementation of both process and performance metrics to address identified gaps in care