258 research outputs found
Risk-taking and decision-making in youth: Relationships to addiction vulnerability
Background:
Decision-making and risk-taking behavior undergo developmental changes during adolescence. Disadvantageous decision-making and increased risk-taking may lead to problematic behaviors such as substance use and abuse, pathological gambling and excessive internet use.
Methods:
Based on MEDLINE searches, this article reviews the literature on decision-making and risk-taking and their relationships to addiction vulnerability in youth.
Results:
Decision-making and risk-taking behaviors involve brain areas that undergo developmental changes during puberty and young adulthood. Individual differences and peer pressure also relate importantly to decision-making and risk-taking.
Conclusions:
Brain-based changes in emotional, motivational and cognitive processing may underlie risk-taking and decision-making propensities in adolescence, making this period a time of heightened vulnerability for engagement in addictive behaviors
Changes in Maternal Gene Expression in Olfactory Circuits in the Immediate Postpartum Period
Regulation of maternal behavior in the immediate postpartum period involves neural circuits in reward and homeostasis systems responding to cues from the newborn. Our aim was to assess one specific regulatory mechanism: the role that olfaction plays in the onset and modulation of parenting behavior. We focused on changes in gene expression in olfactory brain regions, examining nine genes found in previous knockout studies to be necessary for maternal behavior. Using a quantitative PCR (qPCR)-based approach, we assessed changes in gene expression in response to exposure to pups in 11 microdissected olfactory brain regions. Over the first postpartum days, all nine genes were detected in all 11 regions (at differing levels) and their expression changed in response to pup exposure. As a general trend, five genes (Dbh, Esr1, FosB, Foxb1, and Oxtr) were found to decrease their expression in most of the olfactory regions examined, while two genes (Mest and Prlr) were found to increase expression. Nos1 and Peg3 levels remained relatively stable except in the accessory olfactory bulb (AOB), where greater than fourfold increases in expression were observed. The largest magnitude expression changes in this study were found in the AOB, which mediates a variety of olfactory cues that elicit stereotypic behaviors such as mating and aggression as well as some non-pheromone odors. Previous analyses of null mice for the nine genes assessed here have rarely examined olfactory function. Our data suggest that there may be olfactory effects in these null mice which contribute to the observed maternal behavioral phenotypes. Collectively, these data support the hypothesis that olfactory processing is an important sensory regulator of maternal behavior
A prospective longitudinal study of perceived infant outcomes at 18-24 months: Neural and psychological correlates of parental thoughts and actions assessed during the first month postpartum
The first postpartum months constitute a critical period for parents to establish an emotional bond with their infants. Neural responses to infant-related stimuli have been associated with parental sensitivity. However, the associations among these neural responses, parenting, and later infant outcomes for mothers and fathers are unknown. In the current longitudinal study, we investigated the relationships between parental thoughts/actions and neural activation in mothers and fathers in the neonatal period with infant outcomes at the toddler stage. At the first month postpartum, mothers (n=21) and fathers (n=19) underwent a neuroimaging session during which they listened to their own and unfamiliar babyâs cry. Parenting-related thoughts/behaviors were assessed by interview twice at the first month and 3-4 months postpartum and infantsâ socioemotional outcomes were reported by mothers and fathers at 18-24 months postpartum. In mothers, higher levels of anxious thoughts/actions about parenting at the first month postpartum, but not at 3-4 months postpartum, were associated with infantâs low socioemotional competencies at 18-24 months. Anxious thoughts/actions were also associated with heightened responses in the motor cortex and reduced responses in the substantia nigra to own infant cry sounds. On the other hand, in fathers, higher levels of positive perception of being a parent at the first month postpartum, but not at 3-4 months postpartum, were associated with higher infant socioemotional competencies at 18-24 months. Positive thoughts were associated with heightened responses in the auditory cortex and caudate to own infant cry sounds. The current study provides evidence that parental thoughts are related to concurrent neural responses to their infants at the first month postpartum as well as their infantâs future socioemotional outcome at 18-24 months. Parent differences suggest that anxious thoughts in mothers and positive thoughts in fathers may be the targets for parenting-focused interventions very early postpartum
Primary maternal preoccupation revisited: circuits, genes, and the crucial role of early life experience
Parental caregiving includes a set of highly conserved set of behaviors and mental states that may reflect both an individualâs genetic endowment and the early experience of being cared for as a child. This review first examines the mental and behavioral elements of early parental caregiving in humans. Second, we consider what is known of the neurobiological substrates of maternal behaviors in mammalian species including some limited human data. Third, we briefly review the evidence that specific genes encode proteins that are crucial for the development of the neural substrates that underlie specific features of maternal behavior. Fourth, we review the literature on the âprogrammingâ role of epigenetic factors in shaping subsequent maternal behavior. We conclude that there are critical developmental windows during which the genetically determined microcircuitry of key limbic-hypothalamic-midbrain structures are susceptible to early environmental influences and that these influences powerfully shape an individualâs responsivity to psychosocial stressors and their resiliency or vulnerability to various forms of human psychopathology later in life.South African Psychiatry Review - May 200
Fast pyrolysis of glucoseâbased carbohydrates with added NaCl part 1: Experiments and development of a mechanistic model
Sodium ions, one of the natural inorganic constituents in lignocellulosic biomass, significantly alter pyrolysis behavior and resulting chemical speciation. Here, experiments were conducted using a micropyrolyzer to investigate the catalytic effects of NaCl on fast pyrolysis of glucoseâbased carbohydrates (glucose, cellobiose, maltohexaose, and cellulose), and on a major product of cellulose pyrolysis, levoglucosan (LVG). A mechanistic model that addressed the significant catalytic effects of NaCl on the product distribution was developed. The model incorporated interactions of Na+ with cellulosic chains and low molecular weight species, reactions mediated by Na+ including dehydration, cyclic/Grob fragmentation, ringâopening/closing, isomerization, and char formation, and a degradation network of LVG in the presence of Na+. Rate coefficients of elementary steps were specified based on Arrhenius parameters. The mechanistic model for cellulose included 768 reactions of 222 species, which included 252 reactions of 150 species comprising the mechanistic model of glucose decomposition in the presence of NaCl
Fast pyrolysis of glucoseâbased carbohydrates with added NaCl part 2: Validation and evaluation of the mechanistic model
A mechanistic model considering the significant catalytic effects of Na+ on fast pyrolysis of glucoseâbased carbohydrates was developed in Part 1 of this study. A computational framework based on continuous distribution kinetics and mass action kinetics was constructed to solve the mechanistic model. Agreement between model yields of various pyrolysis products with experimental data from fast pyrolysis of glucoseâbased carbohydrates dosed with NaCl ranging from 0â0.34 mmol/g at 500 °C validated the model and demonstrated the robustness and extendibility of the mechanistic model. The model was able to capture the yields of major and minor products as well as their trends across NaCl concentrations. Modeling results showed that Na+ accelerated the rate of decomposition and reduced the time for complete thermoconversion of carbohydrates. The sharp reduction in the yield of levoglucosan (LVG) from fast pyrolysis of cellulose in the presence of NaCl was mainly caused by reduced decomposition of cellulose chains via endâchain initiation and depropagation due to Na+ favoring competing dehydration reactions. Analysis of the contributions of reaction pathways showed that the decomposition of LVG made a minor contribution to its yield reduction and contributed less than 0.5% to the final yield of glycolaldehyde from fast pyrolysis of glucoseâbased carbohydrates in the presence of NaCl
Development of a Short Version of the Modified Yale Preoperative Anxiety Scale
BACKGROUND: The modified Yale Preoperative Anxiety Scale (mYPAS) is the current âcriterion standardâ for assessing child anxiety during induction of anesthesia and has been used in \u3e100 studies. This observational instrument covers 5 items and is typically administered at 4 perioperative time points. Application of this complex instrument in busy operating room (OR) settings, however, presents a challenge. In this investigation, we examined whether the instrument could be modified and made easier to use in OR settings.
METHODS: This study used qualitative methods, principal component analyses, Cronbach αs, and effect sizes to create the mYPAS-Short Form (mYPAS-SF) and reduce time points of assessment. Data were obtained from multiple patients (N = 3798; Mage = 5.63) who were recruited in previous investigations using the mYPAS over the past 15 years.
RESULTS: After qualitative analysis, the âuse of parentâ item was eliminated due to content overlap with other items. The reduced item set accounted for 82% or more of the variance in child anxiety and produced the Cronbach α of at least 0.92. To reduce the number of time points of assessment, a minimum Cohen d effect size criterion of 0.48 change in mYPAS score across time points was used. This led to eliminating the walk to the OR and entrance to the OR time points.
CONCLUSIONS: Reducing the mYPAS to 4 items, creating the mYPAS-SF that can be administered at 2 time points, retained the accuracy of the measure while allowing the instrument to be more easily used in clinical research settings
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Emotional eating and instructed food-cue processing in adolescents: an ERP study
We examined the P3 (250-500ms) and Late Positive Potential (LPP; 500-2000ms) event-related potentials (ERPs) to food vs. nonfood cues among adolescents reporting on emotional eating (EE) behavior. Eighty-six adolescents 10-17 years old were tested using an instructed food versus nonfood cue viewing task (imagine food taste) during high-density EEG recording. Self-report data showed that EE increased with age in girls, but not in boys. Both P3 and LPP amplitudes were greater for food vs. nonfood cues (food-cue bias). Exploratory analyses revealed that, during the LPP time period, greater EE was associated with a more positive food-cue bias in the fronto-central region. This heightened fronto-central food-cue bias LPP is in line with a more activated prefrontal attention system. The results suggest that adolescents with higher EE may engage more top-down cognitive resources to regulate their automatic emotional response to food cues, and/or they may exhibit greater reward network activation to food cues than do adolescents with lower EE, even in the absence of an emotional mood induction
Perceived quality of maternal care in childhood and structure and function of mothers' brain
Animal studies indicate that early maternal care has long-term effects on brain areas related to social attachment and parenting, whereas neglectful mothering is linked with heightened stress reactivity in the hippocampus across the lifespan. The present study explores the possibility, using magnetic resonance imaging, that perceived quality of maternal care in childhood is associated with brain structure and functional responses to salient infant stimuli among human mothers in the first postpartum month. Mothers who reported higher maternal care in childhood showed larger grey matter volumes in the superior and middle frontal gyri, orbital gyrus, superior temporal gyrus and fusiform gyrus. In response to infant cries, these mothers exhibited higher activations in the middle frontal gyrus, superior temporal gyrus and fusiform gyrus, whereas mothers reporting lower maternal care showed increased hippocampal activations. These findings suggest that maternal care in childhood may be associated with anatomy and functions in brain regions implicated in appropriate responsivity to infant stimuli in human mothers.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79249/1/j.1467-7687.2009.00923.x.pd
Neutrinos from Dark Matter annihilations at the Galactic Centre
We discuss the prospects for detection of high energy neutrinos from dark
matter annihilation at the Galactic centre. Despite the large uncertainties
associated with our poor knowledge of the distribution of dark matter in the
innermost regions of the Galaxy, we determine an upper limit on the neutrino
flux by requiring that the associated gamma-ray emission does not exceed the
observed flux. We conclude that if dark matter is made of neutralinos, a
neutrino flux from dark matter annihilations at the GC will not be observable
by Antares. Conversely, the positive detection of such a flux would either
require an alternative explanation, in terms of astrophysical processes, or the
adoption of other \DM candidates, disfavouring the case for neutralinos.Comment: 8 pages, 7 figures, submitted to PR
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