Plasticity in D1-Like Receptor Expression Is Associated with Different Components of Cognitive Processes

Dopamine D1-like receptors consist of D1 (D1A) and D5 (D1B) receptors and play a key role in working memory. However, their possibly differential contribution to working memory is unclear. We combined a working memory training protocol with a stepwise increase of cognitive subcomponents and real-time RT-PCR analysis of dopamine receptor expression in pigeons to identify molecular changes that accompany training of isolated cognitive subfunctions. In birds, the D1-like receptor family is extended and consists of the D1A, D1B, and D1D receptors. Our data show that D1B receptor plasticity follows a training that includes active mental maintenance of information, whereas D1A and D1D receptor plasticity in addition accompanies learning of stimulus-response associations. Plasticity of D1-like receptors plays no role for processes like response selection and stimulus discrimination. None of the tasks altered D2 receptor expression. Our study shows that different cognitive components of working memory training have distinguishable effects on D1-like receptor expression

Research data supporting Dopamine D2-like receptor stimulation blocks negative feedback in visual and spatial reversal learning in the rat: behavioural and computational evidence

We tested the hypotheses that D2R agonism impairs reversal learning by blocking negative feedback and that antagonism of D1-like receptors (D1R) impairs learning from positive feedback. Male Lister Hooded rats were trained on a novel visual reversal learning task. Performance on “probe trials”, during which the correct or incorrect stimulus was presented with a third, probabilistically rewarded (50% of trials) and therefore intermediate stimulus, revealed individual learning curves for the processes of positive and negative feedback. The effects of D2R and D1R agonists and antagonists were evaluated. A separate cohort was tested on a spatial probabilistic reversal learning (PRL) task after D2R agonism. There are eight .csv files in this folder, corresponding to the following experiments: (refer to Table 1 in the manuscript) Alsio_2019_quinpirole_PRL.csv -- Cohort VI probabilistic reversal learning Alsio_2019_quinpirole_VPVD_groups.csv -- Cohort II+III quinpirole experiment Alsio_2019_quinpirole_VPVD_trials.csv -- Cohort II+III quinpirole experiment Alsio_2019_Raclo_SCH39166_TSVR_trials.csv -- Cohort IV (TSVR experiment) Alsio_2019_Raclopride_SCH39166_VPVD_groups.csv Cohort IV+V (VPVD experiment) Alsio_2019_raclopride_SCH39166_VPVD_trials.csv Cohort IV+V (VPVD experiment) Alsio_2019_SKF81297_VPVD_groups.csv -- Cohort II+III SKF81297 experiment Alsio_2019_SKF81297_VPVD_trials.csv -- Cohort II+III SKF81297 experimentThis research was funded by a Wellcome Trust Senior Investigator award to TWR (104631/Z/14/Z). All experiments were conducted at the Behavioural and Clinical Neuroscience Institute, which was jointly funded by the Medical Research Council (MRC) and the Wellcome Trust. This research was also supported in part by the UK National Health Service (NHS) National Institute for Health Research (NIHR) Cambridge Biomedical Research Centre; the views expressed are those of the authors and not necessarily those of the NHS, the NIHR, or the Department of Health and Social Care. An MRC Clinical Research Infrastructure award supported part of this work. J.S.B. was supported by a PhD scholarship from the La Caixa Foundation, Spain, and a studentship from Boehringer Ingelheim Pharma GmbH, Germany

Association of TMEM18 variants with BMI and waist circumference in children and correlation of mRNA expression in the PFC with body weight in rats

Genome-wide association studies have shown a strong association of single-nucleotide polymorphisms (SNPs) in the near vicinity of the TMEM18 gene. The effects of the TMEM18-associated variants are more readily observed in children. TMEM18 encodes a 3TM protein, which locates to the nuclear membrane. The functional context of TMEM18 and the effects of its associated variants are as of yet undetermined. To further explore the effects of near-TMEM18 variants, we have genotyped two TMEM18-associated SNPs, rs6548238 and rs4854344, in a cohort of 2352 Greek children (Healthy Growth Study). Included in this study are data on anthropomorphic traits body weight, BMI z-score and waist circumference. Also included are dietary energy and macronutrient intake as measured via 24-h recall interviews. Major alleles of rs6548238 and rs4854344 were significantly associated with an increased risk of obesity (odds ratio=1.489 (1.161-1.910) and 1.494 (1.165-1.917), respectively), and positively correlated to body weight (P=0.017, P=0.010) and waist circumference (P=0.003, P=0.003). An association to energy and macronutrient intake was not observed in this cohort. We also correlated food intake and body weight in a food choice model in rats to Tmem18 expression in central regions involved in feeding behavior. We observed a strong positive correlation between TMEM18 expression and body weight in the prefrontal cortex (PFC) (r=0.5694, P=0.0003) indicating a potential role for TMEM18 in higher functions related to feeding involving the PFC. European Journal of Human Genetics (2012) 20, 192-197; doi:10.1038/ejhg.2011.176; published online 28 September 201

Circulating Fibroblast Growth Factor-23 Is Associated With Fat Mass and Dyslipidemia in Two Independent Cohorts of Elderly Individuals

Objective-Disturbances in mineral metabolism define an increased cardiovascular risk in patients with chronic kidney disease. Fibroblast growth factor-23 (FGF23) is a circulating regulator of phosphate and vitamin D metabolism and has recently been implicated as a putative pathogenic factor in cardiovascular disease. Because other members of the FGF family play a role in lipid and glucose metabolism, we hypothesized that FGF23 would associate with metabolic factors that predispose to an increased cardiovascular risk. The goal of this study was to investigate the relationship between FGF23 and metabolic cardiovascular risk factors in the community. Methods and Results-Relationships between serum FGF23 and body mass index (BMI), waist circumference, waist-to-hip ratio, serum lipids, and fat mass were examined in 2 community-based, cross-sectional cohorts of elderly whites (Osteoporotic Fractures in Men Study: 964 men aged 75 +/- 3.2; Prospective Investigation of the Vasculature in Uppsala Seniors study: 946 men and women aged 70). In both cohorts, FGF23 associated negatively with high-density lipoprotein and apolipoprotein A1 (7% to 21% decrease per 1-SD increase in log FGF23; P < 0.01) and positively with triglycerides (11% to 14% per 1-SD increase in log FGF23; P < 0.01). A 1-SD increase in log FGF23 was associated with a 7% to 20% increase in BMI, waist circumference, and waist-to-hip ratio and a 7% to 18% increase in trunk and total body fat mass (P < 0.01) as determined by whole-body dual x-ray absorptiometry. FGF23 levels were higher in subjects with the metabolic syndrome compared with those without (46.4 versus 41.2 pg/ mL; P < 0.05) and associated with an increased risk of having the metabolic syndrome (OR per 1-SD increase in log FGF23, 1.21; 95% CI, 1.04 to 1.40; P < 0.05). Conclusion-We report for the first time on associations between circulating FGF23, fat mass, and adverse lipid metabolism resembling the metabolic syndrome, potentially representing a novel pathway(s) linking high FGF23 to an increased cardiovascular risk. (Arterioscler Thromb Vasc Biol. 2011;31:219-227.

Cloche is a bHLH-PAS transcription factor that drives haemato-vascular specification

Vascular and haematopoietic cells organize into specialized tissues during early embryogenesis to supply essential nutrients to all organs and thus play critical roles in development and disease. At the top of the haemato-vascular specification cascade lies cloche, a gene that when mutated in zebrafish leads to the striking phenotype of loss of most endothelial and haematopoietic cells(1-4) and a significant increase in cardiomyocyte numbers(5). Although this mutant has been analysed extensively to investigate mesoderm diversification and differentiation(1-7) and continues to be broadly used as a unique avascular model, the isolation of the cloche gene has been challenging due to its telomeric location. Here we used a deletion allele of cloche to identify several new cloche candidate genes within this genomic region, and systematically genome-edited each candidate. Through this comprehensive interrogation, we succeeded in isolating the cloche gene and discovered that it encodes a PAS-domain-containing bHLH transcription factor, and that it is expressed in a highly specific spatiotemporal pattern starting during late gastrulation. Gain-of-function experiments show that it can potently induce endothelial gene expression. Epistasis experiments reveal that it functions upstream of etv2 and tal1, the earliest expressed endothelial and haematopoietic transcription factor genes identified to date. A mammalian cloche orthologue can also rescue blood vessel formation in zebrafish cloche mutants, indicating a highly conserved role in vertebrate vasculogenesis and haematopoiesis. The identification of this master regulator of endothelial and haematopoietic fate enhances our understanding of early mesoderm diversification and may lead to improved protocols for the generation of endothelial and haematopoietic cells in vivo and in vitro