131 research outputs found
Pavlovian Fear Conditioning Activates a Common Pattern of Neurons in the Lateral Amygdala of Individual Brains
Understanding the physical encoding of a memory (the engram) is a fundamental question in neuroscience. Although it has been established that the lateral amygdala is a key site for encoding associative fear memory, it is currently unclear whether the spatial distribution of neurons encoding a given memory is random or stable. Here we used spatial principal components analysis to quantify the topography of activated neurons, in a select region of the lateral amygdala, from rat brains encoding a Pavlovian conditioned fear memory. Our results demonstrate a stable, spatially patterned organization of amygdala neurons are activated during the formation of a Pavlovian conditioned fear memory. We suggest that this stable neuronal assembly constitutes a spatial dimension of the engram
Impact of protein supplementation during endurance training on changes in skeletal muscle transcriptome
Background: Protein supplementation improves physiological adaptations to endurance training, but the impact on adaptive changes in the skeletal muscle transcriptome remains elusive. The present analysis was executed to determine the impact of protein supplementation on changes in the skeletal muscle transcriptome following 5- weeks of endurance training. Results: Skeletal muscle tissue samples from the vastus lateralis were taken before and after 5-weeks of endurance training to assess changes in the skeletal muscle transcriptome. One hundred and 63 genes were differentially expressed after 5-weeks of endurance training in both groups (q-value 0.05). Endurance training primarily affected expression levels of genes related to extracellular matrix and these changes tended to be greater in PRO than in CON. Conclusions: Protein supplementation subtly impacts endurance training-induced changes in the skeletal muscle transcriptome. In addition, our transcriptomic analysis revealed that the extracellular matrix may be an important factor for skeletal muscle adaptation in response to endurance training. This trial was registered at clinicaltrials.gov as NCT03462381, March 12, 201
Early-Life Determinants of Total and HDL Cholesterol Concentrations in 8-Year-Old Children; The PIAMA Birth Cohort Study
BACKGROUND: Adult cholesterol concentrations might be influenced by early-life factors, such as breastfeeding and birth weight, referred to as "early programming". How such early factors exert their influence over the life course is still poorly understood. Evidence from studies in children and adolescents is scarce and conflicting. We investigated the influence of 6 different perinatal risk factors on childhood total and HDL cholesterol concentrations and total-to-HDL cholesterol ratio measured at 8 years of age, and additionally we studied the role of the child's current Body Mass Index (BMI). METHODS: Anthropometric measures and blood plasma samples were collected during a medical examination in 751 8-year-old children participating in the prospective Prevention and Incidence of Asthma and Mite Allergy (PIAMA) birth cohort study. Linear and logistic regression were performed to estimate associations of total and HDL cholesterol concentrations with breastfeeding, birth weight, infant weight gain, maternal overweight before pregnancy, gestational diabetes and maternal smoking during pregnancy, taking into account the child's current BMI. RESULTS: Linear regressions showed an association between total-to-HDL cholesterol ratio and maternal pre-pregnancy overweight (Ξ²β=β0.15, Confidence Interval 95% (CI): 0.02, 0.28), rapid infant weight gain (Ξ²β=β0.13, 95%CI: 0.01, 0.26), and maternal smoking during pregnancy (Ξ²β=β0.14, 95%CI: 0.00, 0.29). These associations were partly mediated by the child's BMI. CONCLUSION: Total-to-HDL cholesterol ratio in 8-year-old children was positively associated with maternal pre-pregnancy overweight, maternal smoking during pregnancy and rapid infant weight gain
Poor newborn care practices - a population based survey in eastern Uganda
BACKGROUND: Four million neonatal deaths are estimated to occur each year and almost all in low income countries, especially among the poorest. There is a paucity of data on newborn health from sub-Saharan Africa and few studies have assessed inequity in uptake of newborn care practices. We assessed socioeconomic differences in use of newborn care practices in order to inform policy and programming in Uganda. METHODS: All mothers with infants aged 1-4 months (n = 414) in a Demographic Surveillance Site were interviewed. Households were stratified into quintiles of socioeconomic status (SES). Three composite outcomes (good neonatal feeding, good cord care, and optimal thermal care) were created by combining related individual practices from a list of twelve antenatal/essential newborn care practices. Multiple logistic regression analysis was used to identify determinants of each dichotomised composite outcome. RESULTS: There were low levels of coverage of newborn care practices among both the poorest and the least poor. SES and place of birth were not associated with any of the composite newborn care practices. Of newborns, 46% had a facility delivery and only 38% were judged to have had good cord care, 42% optimal thermal care, and 57% were considered to have had adequate neonatal feeding. Mothers were putting powder on the cord; using a bottle to feed the baby; and mixing/replacing breast milk with various substitutes. Multiparous mothers were less likely to have safe cord practices (OR 0.5, CI 0.3 - 0.9) as were mothers whose labour began at night (OR 0.6, CI 0.4 - 0.9). CONCLUSION: Newborn care practices in this setting are low and do not differ much by socioeconomic group. Despite being established policy, most neonatal interventions are not reaching newborns, suggesting a "policy-to-practice gap". To improve newborn survival, newborn care should be integrated into the current maternal and child interventions, and should be implemented at both community and health facility level as part of a universal coverage strategy
A Transcriptional Enhancer from the Coding Region of ADAMTS5
The revelation that the human genome encodes only approximately 25,000 genes and thus cannot account for phenotypic complexity has been one of the biggest surprises in the post-genomic era. However, accumulating evidence suggests that transcriptional regulation may be in large part responsible for this observed mammalian complexity. Consequently, there has been a strong drive to locate cis-regulatory regions in mammalian genomes in order to understand the unifying principles governing these regions, including their genomic distribution. Although a number of systematic approaches have been developed, these all discount coding sequence.Using the computational tool PRI (Pattern-defined Regulatory Islands), which does not mask coding sequence, we identified a regulatory region associated with the gene ADAMTS5 that encompasses the entirety of the essential coding exon 2. We demonstrate through a combination of chromatin immunoprecipitation and reporter gene studies that this region can not only bind the myogenic transcription factors MYOD and myogenin and the E-protein HEB but can also function as a very strong myogenic transcriptional enhancer.Thus, we report the identification and detailed characterization of an exonic enhancer. Ultimately, this leads to the interesting question of why evolution would be so parsimonious in the functional assignment of sequence
An investigation into the validity of cervical spine motion palpation using subjects with congenital block vertebrae as a 'gold standard'
BACKGROUND: Although the effectiveness of manipulative therapy for treating back and neck pain has been demonstrated, the validity of many of the procedures used to detect joint dysfunction has not been confirmed. Practitioners of manual medicine frequently employ motion palpation as a diagnostic tool, despite conflicting evidence regarding its utility and reliability. The introduction of various spinal models with artificially introduced 'fixations' as an attempt to introduce a 'gold standard' has met with frustration and frequent mechanical failure. Because direct comparison against a 'gold standard' allows the validity, specificity and sensitivity of a test to be calculated, the identification of a realistic 'gold standard' against which motion palpation can be evaluated is essential. The objective of this study was to introduce a new, realistic, 'gold standard', the congenital block vertebra (CBV) to assess the validity of motion palpation in detecting a true fixation. METHODS: Twenty fourth year chiropractic students examined the cervical spines of three subjects with single level congenital block vertebrae, using two commonly employed motion palpation tests. The examiners, who were blinded to the presence of congenital block vertebrae, were asked to identify the most hypomobile segment(s). The congenital block segments included two subjects with fusion at the C2β3 level and one with fusion at C5-6. Exclusion criteria included subjects who were frankly symptomatic, had moderate or severe degenerative changes in their cervical spines, or displayed signs of cervical instability. Spinal levels were marked on the subject's skin overlying the facet joints from C1 to C7 bilaterally and the motion segments were then marked alphabetically with 'A' corresponding to C1-2. Kappa coefficients (K) were calculated to determine the validity of motion palpation to detect the congenitally fused segments as the 'most hypomobile' segments. Sensitivity and specificity of the diagnostic procedure were also calculated. RESULTS: Kappa coefficients (K) showed substantial overall agreement for identification of the segment of greatest hypomobility (K = 0.65), with substantial (K = 0.76) and moderate (K = 0.46) agreement for hypomobility at C2-3 and C5-6 respectively. Sensitivity ranged from 55% at the C5-6 CBV to 78% at the C2-3 level. Specificity of the procedure was high (91 β 98%). CONCLUSION: This study indicates that relatively inexperienced examiners are capable of correctly identifying inter-segmental fixations (CBV) in the cervical spine using 2 commonly employed motion palpation tests. The use of a 'gold standard' (CBV) in this study and the substantial agreement achieved lends support to the validity of motion palpation in detecting major spinal fixations in the cervical spine
What traits are carried on mobile genetic elements, and why?
Although similar to any other organism, prokaryotes can transfer genes vertically from mother cell to daughter cell, they can also exchange certain genes horizontally. Genes can move within and between genomes at fast rates because of mobile genetic elements (MGEs). Although mobile elements are fundamentally self-interested entities, and thus replicate for their own gain, they frequently carry genes beneficial for their hosts and/or the neighbours of their hosts. Many genes that are carried by mobile elements code for traits that are expressed outside of the cell. Such traits are involved in bacterial sociality, such as the production of public goods, which benefit a cell's neighbours, or the production of bacteriocins, which harm a cell's neighbours. In this study we review the patterns that are emerging in the types of genes carried by mobile elements, and discuss the evolutionary and ecological conditions under which mobile elements evolve to carry their peculiar mix of parasitic, beneficial and cooperative genes
The Virtual-Spine PlatformβAcquiring, visualizing, and analyzing individual sitting behavior
Back pain is a serious medical problem especially for those people sitting over long periods during their daily work. Here we present a system to help users monitoring and examining their sitting behavior. The Virtual-Spine Platform (VSP) is an integrated system consisting of a real-time body position monitoring module and a data visualization module to provide individualized, immediate, and accurate sitting behavior support. It provides a comprehensive spine movement analysis as well as accumulated data visualization to demonstrate behavior patterns within a certain period. The two modules are discussed in detail focusing on the design of the VSP system with adequate capacity for continuous monitoring and a web-based interactive data analysis method to visualize and compare the sitting behavior of different persons. The data was collected in an experiment with a small group of subjects. Using this method, the behavior of five subjects was evaluated over a working day, enabling inferences and suggestions for sitting improvements. The results from the accumulated data module were used to elucidate the basic function of body position recognition of the VSP. Finally, an expert user study was conducted to evaluate VSP and support future developments
Age-dependent effects of low-dose nicotine treatment on cocaine-induced behavioral plasticity in rats
Epidemiological evidence of early adolescent tobacco use, prior to that of marijuana and other illicit drugs, has led to the hypothesis that nicotine is a βgatewayβ drug that sensitizes reward pathways to the addictive effects of other psychostimulants.
To test this hypothesis, we have compared the effect of a brief, low-dose nicotine pretreatment of adolescent and adult rats on subsequent locomotor response to acute and chronic cocaine.
Adolescents, aged postnatal day (P) 28, and adults, aged P86, were given four daily injections of saline or nicotine (0.06 mg/kg, i.v.). At P32 and P90, rats were given acute injections of cocaine (0, 0.4 or 1.0 mg/kg, i.v.) and monitored for locomotor activity in either a habituated or novel test environment. To examine cocaine sensitization, rats were treated for 3 days with saline or cocaine (0.4 mg/kg, i.v.), and, after 1 day of withdrawal, were given a challenge dose of cocaine (0.4 mg/kg, i.v.).
Nicotine pretreatment did not affect acute, drug-induced locomotor activity at either age. However, age differences in cocaine response were observed, with adolescent animals showing enhanced locomotor activity in the novel environment. Adolescent controls did not exhibit cocaine-induced locomotor sensitization, whereas adults did. Nicotine pretreatment during adolescence promoted the development and expression of a sensitized response to repeated cocaine exposure similar to that observed in saline-pretreated adult controls.
These findings show that brief pretreatment with nicotine, in a low dose comparable to that inhaled in 2β4 cigarettes, enhances cocaine-induced behavioral plasticity in adolescent rats
Differences in Muscle Protein Synthesis and Anabolic Signaling in the Postabsorptive State and in Response to Food in 65β80 Year Old Men and Women
Women have less muscle than men but lose it more slowly during aging. To discover potential underlying mechanism(s) for this we evaluated the muscle protein synthesis process in postabsorptive conditions and during feeding in twenty-nine 65β80 year old men (nβ=β13) and women (nβ=β16). We discovered that the basal concentration of phosphorylated eEF2Thr56 was βΌ40% less (P<0.05) and the basal rate of MPS was βΌ30% greater (Pβ=β0.02) in women than in men; the basal concentrations of muscle phosphorylated AktThr308, p70s6kThr389, eIF4ESer209, and eIF4E-BP1Thr37/46 were not different between the sexes. Feeding increased (P<0.05) AktThr308 and p70s6kThr389 phosphorylation to the same extent in men and women but increased (P<0.05) the phosphorylation of eIF4ESer209 and eIF4E-BP1Thr37/46 in men only. Accordingly, feeding increased MPS in men (P<0.01) but not in women. The postabsorptive muscle mRNA concentrations for myoD and myostatin were not different between sexes; feeding doubled myoD mRNA (P<0.05) and halved that of myostatin (P<0.05) in both sexes. Thus, there is sexual dimorphism in MPS and its control in older adults; a greater basal rate of MPS, operating over most of the day may partially explain the slower loss of muscle in older women
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