Variation in the mu-opioid receptor gene (OPRM1) moderates the influence of maternal sensitivity on child attachment

The endogenous opioid system is thought to play an important role in mother-infant attachment. In infant rhesus macaques, variation in the μ-opioid receptor gene (OPRM1) is related to differences in attachment behavior that emerges following repeated separation from the mother; specifically, infants carrying at least one copy of the minor G allele of the OPRM1 C77G polymorphism show heightened and more persistent separation distress, as well as a pattern of increased contact-seeking behavior directed towards the mother during reunions (at the expense of affiliation with other group members). Research in adult humans has also linked the minor G allele of the analogous OPRM1 A118G polymorphism with greater interpersonal sensitivity. Adopting an interactionist approach, we examined whether OPRM1 A118G genotype and maternal (in)sensitivity are associated with child attachment style, predicting that children carrying the G allele may be more likely to develop an ambivalent attachment pattern in response to less sensitive maternal care. The sample consisted of 191 mothers participating with their children (n = 223) in the Maternal Adversity, Vulnerability and Neurodevelopment (MAVAN) project, a community-based, birth cohort study of Canadian mothers and their children assessed longitudinally across the child's development. Maternal sensitivity was coded from at-home mother-child interactions videotaped when the child was 18 months of age. Child attachment was assessed at 36 months using the Strange Situation paradigm. As predicted, G allele carriers, but not AA homozygotes, showed increasing odds of being classified as ambivalently attached with decreasing levels of maternal sensitivity. Paralleling earlier non-human animal research, this work provides support for the theory that endogenous opioids contribute to the expression of attachment behaviors in humans.

Natriuretic Peptide Receptor B Protects Against Atrial Fibrillation by Controlling Atrial cAMP Via Phosphodiesterase 2

BACKGROUND

β-AR (β-adrenergic receptor) stimulation regulates atrial electrophysiology and Ca2+ homeostasis via cAMP-dependent mechanisms; however, enhanced β-AR signaling can promote atrial fibrillation (AF). CNP (C-type natriuretic peptide) can also regulate atrial electrophysiology through the activation of NPR-B (natriuretic peptide receptor B) and cGMP-dependent signaling. Nevertheless, the role of NPR-B in regulating atrial electrophysiology, Ca2+ homeostasis, and atrial arrhythmogenesis is incompletely understood.

METHODS

Studies were performed using atrial samples from human patients with AF or sinus rhythm and in wild-type and NPR-B-deficient (NPR-B+/-) mice. Studies were conducted in anesthetized mice by intracardiac electrophysiology, in isolated mouse atrial preparations using high-resolution optical mapping, in isolated mouse and human atrial myocytes using patch-clamping and Ca2+ imaging, and in mouse and human atrial tissues using molecular biology.

RESULTS

Atrial NPR-B protein levels were reduced in patients with AF, and NPR-B+/- mice were more susceptible to AF. Atrial cGMP levels and PDE2 (phosphodiesterase 2) activity were reduced in NPR-B+/- mice leading to larger increases in atrial cAMP in the presence of the β-AR agonist isoproterenol. NPR-B+/- mice displayed larger increases in action potential duration and L-type Ca2+ current in the presence of isoproterenol. This resulted in the occurrence of spontaneous sarcoplasmic reticulum Ca2+ release events and delayed afterdepolarizations in NPR-B+/- atrial myocytes. Phosphorylation of the RyR2 (ryanodine receptor) and phospholamban was increased in NPR-B+/- atria in the presence of isoproterenol compared with the wildtypes. C-type natriuretic peptide inhibited isoproterenol-stimulated L-type Ca2+ current through PDE2 in mouse and human atrial myocytes.

CONCLUSIONS

NPR-B protects against AF by preventing enhanced atrial responses to β-adrenergic receptor agonists.

A systematic review of the evidence on the effect of parental communication about health and health behaviours on children's health and wellbeing

Parents report feeling unsure how best to talk with their children about sensitive health topics and may avoid such conversations; yet if children have questions or concerns about their health, talking to a parent could enhance their health and wellbeing. We investigated the effects of parental communications about health and health behaviours on children's health and wellbeing, and explored what strategies can encourage parents to communicate about health. We conducted a systematic review and narrative synthesis of research published between January 2008 and April 2020 from five databases. Of 14,007 articles identified, 16 met inclusion criteria focusing on five topics: diet and weight (n = 5), body image (n = 2), sexual health (n = 7), physical activity (n = 1) and bullying (n = 1). Positive child outcomes were associated with positive general parent-child communication characterised by warmth, openness and allowing children choice. Conversely, hostility, negative and inconsistent messaging were associated with poorer outcomes. Interventions to increase parent-child communication could be classified as providing single directive messages, media campaigns or intensive support. Single messages increased communication frequency; media campaigns and intensive interventions showed mixed outcomes. No differences in outcomes were found according to child's gender or socio-economic status. Generally, parents were less confident in initiating, rather than continuing, conversations and were more likely to initiate conversations when they felt they had good topic knowledge. While the relatively small, diverse sample limits the strength of these findings, this review provides provisional support for approaches to promote positive parent-child communication about health that are associated with better child health and wellbeing.

Natriuretic peptide receptor B maintains heart rate and sinoatrial node function via cyclic GMP-mediated signaling

AIMS

Heart rate (HR) is a critical indicator of cardiac performance that is determined by sinoatrial node (SAN) function and regulation. Natriuretic peptides, including C-type NP (CNP) have been shown to modulate ion channel function in the SAN when applied exogenously. CNP is the only NP that acts as a ligand for natriuretic peptide receptor-B (NPR-B). Despite these properties, the ability of CNP and NPR-B to regulate HR and intrinsic SAN automaticity in vivo, and the mechanisms by which it does so, are incompletely understood. Thus, the objective of this study was to determine the role of NPR-B signaling in regulating HR and SAN function.

METHODS AND RESULTS

We have used NPR-B deficient mice (NPR-B+/-) to study HR regulation and SAN function using telemetry in conscious mice, intracardiac electrophysiology in anesthetized mice, high resolution optical mapping in isolated SAN preparations, patch-clamping in isolated SAN myocytes, and molecular biology in isolated SAN tissue. These studies demonstrate that NPR-B+/- mice exhibit slow HR, increased corrected SAN recovery time, and slowed SAN conduction. Spontaneous AP firing frequency in isolated SAN myocytes was impaired in NPR-B+/- mice due to reductions in the hyperpolarization activated current (If) and L-type Ca2+ current (ICa,L). If and ICa,L were reduced due to lower cGMP levels and increased hydrolysis of cAMP by phosphodiesterase 3 (PDE3) in the SAN. Inhibiting PDE3 or restoring cGMP signaling via application of 8-Br-cGMP abolished the reductions in cAMP, AP firing, If, and ICa,L, and normalized SAN conduction, in the SAN in NPR-B+/- mice. NPR-B+/- mice did not exhibit changes in SAN fibrosis and showed no evidence of cardiac hypertrophy or changes in ventricular function.

CONCLUSIONS

NPR-B plays an essential physiological role in maintaining normal HR and SAN function by modulating ion channel function in SAN myocytes via a cGMP/PDE3/cAMP signaling mechanism.

Variability in opioid prescribing practices among cardiac surgeons and trainees

BACKGROUND AND AIM

The opioid epidemic has become a major public health crisis in recent years. Discharge opioid prescription following cardiac surgery has been associated with opioid use disorder; however, ideal practices remain unclear. Our aim was to examine current practices in discharge opioid prescription among cardiac surgeons and trainees.

METHODS

A survey instrument with open- and closed-ended questions, developed through a 3-round Delphi method, was circulated to cardiac surgeons and trainees via the Canadian Society of Cardiac Surgeons. Survey questions focused on routine prescription practices including type, dosage and duration. Respondents were also asked about their perceptions of current education and guidelines surrounding opioid medication.

RESULTS

Eighty-one percent of respondents reported prescribing opioids at discharge following routine sternotomy-based procedures, however, there remained significant variability in the type and dose of medication prescribed. The median (interquartile range) number of pills prescribed was 30 (20-30) with a median total dose of 135 (113-200) Morphine Milligram Equivalents. Informal teaching was the most commonly reported primary influence on prescribing habits and a lack of formal education regarding opioid prescription was associated with a higher number of pills prescribed. A majority of respondents (91%) felt that there would be value in establishing practice guidelines for opioid prescription following cardiac surgery.

CONCLUSIONS

Significant variability exists with respect to routine opioid prescription at discharge following cardiac surgery. Education has come predominantly from informal sources and there is a desire for guidelines. Standardization in this area may have a role in combatting the opioid epidemic.

Surgically positioned paravertebral catheters and postoperative analgesia after open abdominal aortic aneurysm repair

OBJECTIVE

To compare postoperative morphine equivalent intake after open abdominal aortic aneurysm (AAA) repair among analgesic modalities: systemic analgesia (SA) only with no regional anesthesia, surgically positioned paravertebral catheter (PVC), and thoracic epidural analgesia (TEA).

METHODS

This retrospective cohort study included patients undergoing elective open AAA at the Queen Elizabeth II Health Science Center, Halifax, Nova Scotia. Demographics, morphine equivalents, methods of analgesia administration, and outcomes data were collected on all patients from 2005 to 2016. Total morphine equivalent (MEQ) on postoperative days (PODs) 1, 2, and 3 were compared among patients with SA, PVC, and TEA. A multivariable zero-inflated log-linear regression was used to determine the association between analgesic modality and MEQ. Multivariable logistic regression models were used to determine associations between analgesic modality and postoperative pain, rates of discharge from intensive care within 1 day and opioid-related adverse events.

RESULTS

The study cohort included 355 patients: 177 retroperitoneal and 178 transperitoneal repairs; 173 patients underwent SA, 117 PVC, and 65 TEA. On POD1, median MEQs were 984 (interquartile range [IQR], 342-1525) for SA, 89 (33-246) for PVC, and 49 (0-90) for TEA. On POD2, the median MEQs were 105 (IQR, 57-210) for SA, 45 (15-99) for PVC, and 30 (0-64) for TEA. On POD3, the median MEQs were 45 (IQR, 15-120) for SA, 30 (0-60) for PVC, and 10 (0-45) for TEA. On multivariable log-linear regression, compared with SA, PVC and TEA were associated with increased odds of receiving no opioids on POD1 (odds ratio [OR], 66.85; 95% confidence interval [CI], 17.49-255.57; and OR, 214.68; 95% CI, 60.20-766.38; respectively), POD 2 (OR, 6.97; 95% CI, 3.61-13.46; and OR, 28.73; 95% CI, 15.68-52.62; respectively), and POD 3 (OR, 3.93; 95% CI, 2.72-5.67; and OR, 4.68; 95% CI, 3.20-6.86; respectively). If patients did receive opioids, compared with SA, PVC and TEA were associated with decreased consumption on POD1 (RR, 0.22; 95% CI, 0.18-0.27; and RR, 0.16; 95% CI, 0.12-0.20; respectively), POD2 (RR, 0.50; 95% CI, 0.42-0.58; and RR, 0.46; 95% CI, 0.37-0.56; respectively), and POD3 (RR, 0.78; 95% CI, 0.66-0.93; and RR, 0.76; 95% CI, 0.63-0.93; respectively). Compared with SA, PVC was associated with earlier discharge from intensive care (OR, 2.75; 95% CI, 1.17-6.45) and TEA was not (OR, 1.12; 95% CI, 0.56-2.2). Compared with TEA, PVC was not associated with increased rate of opioid-related adverse events (OR, 0.44; 95% CI, 0.08-2.44).

CONCLUSIONS

PVC and TEA are associated with decreased MEQ compared with SA. PVC is associated with earlier discharge from intensive care compared with SA and similar rates of opioid-related adverse events compared with TEA. Paravertebral analgesia appears to be a safe and effective analgesic modality in patients undergoing retroperitoneal approach for abdominal aneurysm repair.

Reversal of stress fibre formation by Nitric Oxide mediated RhoA inhibition leads to reduction in the height of preformed thrombi

Evidence has emerged to suggest that thrombi are dynamic structures with distinct areas of differing platelet activation and inhibition. We hypothesised that Nitric oxide (NO), a platelet inhibitor, can modulate the actin cytoskeleton reversing platelet spreading, and therefore reduce the capability of thrombi to withstand a high shear environment. Our data demonstrates that GSNO, DEANONOate, and a PKG-activating cGMP analogue reversed stress fibre formation and increased actin nodule formation in adherent platelets. This effect is sGC dependent and independent of ADP and thromboxanes. Stress fibre formation is a RhoA dependent process and NO induced RhoA inhibition, however, it did not phosphorylate RhoA at ser188 in spread platelets. Interestingly NO and PGI₂ synergise to reverse stress fibre formation at physiologically relevant concentrations. Analysis of high shear conditions indicated that platelets activated on fibrinogen, induced stress fibre formation, which was reversed by GSNO treatment. Furthermore, preformed thrombi on collagen post perfused with GSNO had a 30% reduction in thrombus height in comparison to the control. This study demonstrates that NO can reverse key platelet functions after their initial activation and identifies a novel mechanism for controlling excessive thrombosis.

Intergenerational Transmission of Well Being–Genetic and Epigenetic Mechanisms

Introduction

Maternal mental well being influences offspring development. Research suggests that an interplay between genetic and environmental factors underlies this familial transmission of mental disorders.

Objectives

To explore an interaction between genetic and environmental factors to predict trajectories of maternal mental well being, and to examine whether these trajectories are associated with epigenetic modifications in mothers and their offspring.

Method

We assessed maternal childhood trauma and rearing experiences, prenatal and postnatal symptoms of depression and stress experience from 6 to 72 months postpartum, and genetic and epigenetic variation in a longitudinal birth-cohort study (n = 262) (Maternal adversity, vulnerability and neurodevelopment project). We used latent class modeling to describe trajectories in maternal depressive symptoms, parenting stress, marital stress and general stress, taking polygenetic risk for major depressive disorder (MDD), a composite score for maternal early life adversities, and prenatal depressive symptoms into account.

Results

Genetic risk for MDD associated with trajectories of maternal well being in the postpartum, conditional on the experience of early life adversities and prenatal symptoms of depression. We will explore whether these trajectories are also linked to DNA methylation patterns in mothers and their offspring. Preliminary analyses suggest that maternal early life adversities associate with offspring DNA methylation age estimates, which is mediated through maternal mental well being and maternal DNA methylation age estimates.

Conclusion

We found relevant gene-environment interactions associated with trajectories of maternal well being. Our findings inform research on mechanisms underlying familial transmission of vulnerability for psychopathology and might thus be relevant to prevention and early intervention programs.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Thinking and doing: the effects of dopamine and oxytocin genes and executive function on mothering behaviours

Animal and human studies suggest that initial expression of maternal behaviour depends on oxytocin and dopamine systems. However, the mechanism by which these systems affect parenting behaviours and the timing of these effects are not well understood. This article explores the role of mothers' executive function in mediating the relation between oxytocin and dopamine gene variants and maternal responsiveness at 48 months post-partum. Participants (n = 157) were mothers recruited in the Maternal Adversity, Vulnerability and Neurodevelopment Study, which assesses longitudinally two cohorts of mothers and children in Canada. We examined single nucleotide polymorphisms (SNPs) related to the dopamine and oxytocin systems (DRD1 rs686, DRD1 rs265976, OXTR rs237885 and OXTR rs2254298), assessed mothers' decision-making at 48 months using the Cambridge Neurological Automated Testing Battery (CANTAB) and evaluated maternal responsiveness from videotaped interactions during the Etch-A-Sketch co-operation task. Mediation analyses showed that OXTR rs2254298 A-carriers had an indirect effect on positive parenting which was mediated by mothers' performance on decision-making task (estimate = 0.115, P < 0.005), while OXTR rs2254298 A-carriers had both direct and indirect effects on physically controlling parenting, also mediated through enhanced performance on decision-making (estimate = -0.059, P < 0.005). Dopamine SNPs were not associated with any measure of executive function or parenting (all P > 0.05). While oxytocin has previously been associated with only the early onset of maternal behaviour, we show that an OXTR polymorphism is involved in maternal behaviour at 48 months post-partum through mothers' executive function. This research highlights the importance of the oxytocin system to maternal parenting beyond infancy.

Stress Physiology in Infancy and Early Childhood: Cortisol Flexibility, Attunement and Coordination

Research on stress physiology in infancy has assumed increasing importance due to its lifelong implications. In this review, we focus on measurement of hypothalamic-pituitary-adrenal (HPA) function, in particular, and on complementary autonomic processes. We suggest that the measure of HPA function has been overly exclusive, focusing on individual reactivity to single, pragmatically selected laboratory challenges. We advocate use of multiple, strategically chosen challenges and within-subject designs. By administering one challenge that typically does not provoke reactivity and another that does, it is possible to represent allostatic load in terms of "flexibility," the capacity to titrate response to challenge. We also recommend assessing infant reactivity in the context of the primary caregiver's physiological function. Infant-mother "attunement" is central to developmental psychology, permeating diverse developmental domains with varied consequences. A review of adrenocortical attunement suggests that attunement is a reliable process, manifest across varied populations. However, attunement appears stronger in the context of more highly stressful circumstances, such that administration of multiple, selected challenges may help evaluate the degree to which individuals titrate attunement to challenge and determine the correlates of this differential attunement. Finally, we advocate studying the "coordination" of HPA function with other aspects of stress physiology and variation in the degree of this coordination. The use of multiple stressors is important here because each stress system is differentially sensitive to different types of challenge. Therefore, use of single stressors in between-subject designs impedes full recognition of the role played by each system. Overall, we recommend measure of flexibility, attunement, and coordination in the context of multiple challenges to capture allostasis in environmental and physiological context. The simultaneous use of such inclusive and integrative metrics may yield more reliable findings than has hitherto been the case. The interrelation of these metrics can be understood in the context of the adaptive calibration model..

An exploratory study of positive and incongruent communication in young children with type 1 diabetes and their mothers

BACKGROUND

The incidence of type 1 diabetes is increasing in young children. However, they are overlooked in treatment adherence and intervention research despite evidence that parents often experience difficulty securing their treatment cooperation, especially with the diet. We investigated positive and incongruent (i.e. the co-occurrence of contradictory verbal and non-verbal messages) communication in the mother-child dyad and their association with child adjustment and dietary adherence outcomes.

METHODS

Participants were 23 6- to 8-year-old children with type 1 diabetes and their mothers. We conducted dietary adherence interviews with mothers and performed nutritional analyses to assess children's consumption of extrinsic sugars (e.g. confectionary). Mothers completed a standardized assessment of child psychological adjustment. Mothers and children engaged in a videotaped problem-solving task related to the dietary regimen, with maternal and child utterances and non-verbal behaviours analysed for positive dyadic and incongruent communication.

RESULTS

Positive dyadic communication correlated with lower levels of child incongruent communication, fewer behavioural problems and better overall adjustment. Higher levels of maternal and child incongruent communication correlated with more behavioural and emotional problems and poorer overall adjustment. Higher levels of maternal incongruent communication correlated with poorer dietary adherence.

CONCLUSIONS

Results converged to form a conceptually and empirically coherent pattern in that behavioural indices of poorer communication in both mother and child consistently correlated with poorer child adjustment outcomes. This study shows that specific features of dyadic, child and maternal communication could be targeted in developmentally sensitive interventions to promote positive communication in the home management of type 1 diabetes care for young children.

Low interrater agreement on the semantic base of textual material

The present paper describes three experiments which were conducted to determine whether independent raters could agree upon the semantic base of textual materials. These experiments were occasioned by an earlier experiment in which the investigators reported success in increasing the ability of students to extract the semantic base from textual materials. The present paper reports our unsuccessful attempts to obtain an acceptable level of agreement among independent raters about what constituted the semantic base of a number of texts. The paper concludes by raising some doubts about the strategy of extending behavior-analytic research to verbal behavior by combining behavior-change procedures with cognitive constructs.

Dopamine receptors D1 and D2 are related to observed maternal behavior

The dopamine pathway and especially the dopamine receptors 1 and 2 (DRD1 and DRD2) are implicated in the regulation of mothering in rats. Evidence for this in humans is lacking. Here, we show that genetic variation in both DRD1 and DRD2 genes in a sample of 187 Caucasian mothers predicts variation in distinct maternal behaviors during a 30-min mother-infant interaction at 6 months postpartum. Two DRD1 single-nucleotide polymorphisms (SNPs rs265981 and rs686) significantly associated with maternal orienting away from the infant (P = 0.002 and P = 0.003, respectively), as did DRD1 haplotypes (P = 0.03). Two DRD2 SNPs (rs1799732 and rs6277) significantly associated with maternal infant-directed vocalizing (P = 0.001 and P = 0.04, respectively), as did DRD2 haplotypes (P = 0.01). We present evidence for heterosis in DRD1 where heterozygote mothers orient away from their infants significantly less than either homozygote group. Our findings provide important evidence that genetic variation in receptors critical for mothering in non-human species also affect human maternal behaviors. The findings also highlight the importance of exploring multiple dimensions of the complex human mothering phenotype.

Serotonin transporter allelic variation in mothers predicts maternal sensitivity, behavior and attitudes toward 6-month-old infants

Maternal behavior in the new mother is a multidimensional set of responses to infant cues that are influenced by the mother's early life experiences. In this study, we wanted to test if mothers' early life experiences and mothers' genotype have interactive effects on maternal behaviors and attitudes, something which has not been previously explored. In a sample of 204 mothers, we assessed maternal genotype at the serotonin transporter-linked polymorphic region (5-HTTLPR) and an adjacent upstream polymorphism (rs25531), together giving rise to three alleles: short (S), L(G) and L(A). Controlling for maternal age and parity, we showed that this genotype can predict differences in maternal sensitivity at 6 months postpartum: mothers with an S (or the functionally similar L(G)) allele were more sensitive than mothers who lacked the allele during a 30-min recorded mother-infant interaction (F (4,140) = 3.43; P = 0.01). Furthermore, we found highly significant gene-environment interactions in association with maternal behavior, such that mothers with no S or L(G) alleles oriented away more frequently from their babies if they also reported more negative early care quality (F (5,138) = 3.28; P = 0.008). Finally, we found significant gene-environment associations with maternal attitudes; mothers with the S allele and with greater early care quality scored higher on ratings of their perceived attachment to their baby (F (5,125) = 3.27; P = 0.008). The regression results show significant interactions between the reported quality of care mothers received from their own parents and genotype on both their frequency of orienting away from the infant during the interaction (F(5, 138) = 3.28; P = 0.008, Fig. 1a) and their perceived attachment feelings to the infant (F(5, 125) = 3.27; P = 0.008, Fig. 1b); however the direction of the effects for these two outcome measures were different from one another. With increasing care quality, mothers with the L(A)L(A) genotype (no S or L(G) allele) oriented away less frequently, while S or L(G) allele carriers showed no significant change. In contrast, with increasing early care quality. L(A)L(A) (no S or L(G) allele) mothers scored lower on perceived attachment to their infants, whereas S or L(G) allele carrying mothers scored higher. [corrected].

Association of potassium channel Kv3.4 subunits with pre- and post-synaptic structures in brainstem and spinal cord

Voltage-gated K+ channels (Kv) are divided into eight subfamilies (Kv1-8) and play a major role in determining the excitability of neurones. Members of the Kv3 subfamily are highly abundant in the CNS, with each Kv3 gene (Kv3.1-Kv3.4) exhibiting a unique pattern of expression, although single neurones can express more than one subtype. Of the Kv3 subunits relatively little is known of the Kv3.4 subunit distribution in the nervous system, particularly in the brainstem and spinal cord of the rat. We performed immunohistochemistry to determine both the cellular and sub-cellular distribution of the Kv3.4 subunit in these areas. Kv3.4 subunit immunoreactivity (Kv3.4-IR) was widespread, with dense, punctate staining in many regions including the intermediolateral cell column (IML) and the dorsal vagal nucleus (DVN), nucleus ambiguus (NA) and nucleus tractus solitarius (NTS). In the ventral horn a presynaptic location was confirmed by co-localization of Kv3.4-IR with the synaptic vesicle protein, SV2 and also with the glutamate vesicle markers vesicular glutamate transporter (VGluT) 1, VGluT2 or the glycine transporter GlyT2, suggesting a role for the channel in both excitatory and inhibitory neurotransmission. Electron microscopy confirmed a presynaptic terminal location of Kv3.4-IR in the VH, IML, DVN, NA and NTS. Interestingly however, patches of Kv3.4-IR were also revealed postsynaptically in dendritic and somatic structures throughout these areas. This staining was striking due to its localization at synaptic junctions at terminals with morphological features consistent with excitatory functions, suggesting an association with the postsynaptic density. Therefore the pre and postsynaptic localization of Kv3.4-IR suggests a role both in the control of transmitter release and in regulating neuronal excitability.

Differential co-localisation of the P2X7 receptor subunit with vesicular glutamate transporters VGLUT1 and VGLUT2 in rat CNS

Presynaptic P2X(7) receptors are thought to play a role in the modulation of transmitter release and have been localised to terminals with the location and morphology typical of excitatory boutons. To test the hypothesis that this receptor is preferentially associated with excitatory terminals we combined immunohistochemistry for the P2X(7) receptor subunit (P2X(7)R) with that for two vesicular glutamate transporters (VGLUT1 and VGLUT2) in the rat CNS. This confirmed that P2X(7)R immunoreactivity (IR) is present in glutamatergic terminals; however, whether it was co-localised with VGLUT1-IR or VGLUT2-IR depended on the CNS region examined. In the spinal cord, P2X(7)R-IR co-localised with VGLUT2-IR. In the brainstem, co-localisation of P2X(7)R-IR with VGLUT2-IR was widespread, but co-localisation with VGLUT1-IR was seen only in the external cuneate nucleus and spinocerebellar tract region of the ventral medulla. In the cerebellum, P2X(7)R-IR co-localised with both VGLUT1 and VGLUT2-IR in the granular layer. In the hippocampus it was co-localised only with VGLUT1-IR, including in the polymorphic layer of the dentate gyrus and the substantia radiatum of the CA3 region. In other forebrain areas, P2X(7)R-IR co-localised with VGLUT1-IR throughout the amygdala, caudate putamen, striatum, reticular thalamic nucleus and cortex and with VGLUT2-IR in the dorsal lateral geniculate nucleus, amygdala and hypothalamus. Dual labelling studies performed using markers for cholinergic, monoaminergic, GABAergic and glycinergic terminals indicated that in certain brainstem and spinal cord nuclei the P2X(7)R is also expressed by subpopulations of cholinergic and GABAergic/glycinergic terminals. These data support our previous hypothesis that the P2X(7)R may play a role in modulating glutamate release in functionally different systems throughout the CNS but further suggest a role in modulating release of inhibitory transmitters in some regions.

Formal versus informal interventions for challenging behaviour in persons with intellectual disabilities

BACKGROUND

Although effective, humane treatments exist for persons with intellectual disabilities (ID) who have challenging behaviour, little research has examined the extent to which clients receive formal, documented vs. undocumented interventions.

METHODS

Caregivers (of 625 persons with ID living in community and institutional residences in Ontario, Canada) were interviewed to examine the prevalence of different types of interventions.

RESULTS

Overall, 55% of the 2506 different interventions (for 1464 target behaviours) were informal (i.e. lacking documented input from a professional, written intervention plans, and systematic evaluation). No significant differences emerged on formality of intervention across participant gender, age, level of ID, and type of residence. There were significantly more informal than formal behavioural interventions and counselling/psychotherapy, and no significant difference in the overall prevalence of formal and informal intrusive procedures. Behaviour control medications were paired more often with formal (67%) than informal interventions for dangerous behaviours. Formal interventions were associated with higher caregiver-reported estimates of behavioural improvement, higher inter-rater agreement on the descriptions of an individual client's target behaviours and interventions, and more caregiver training and supervision.

CONCLUSIONS

The low levels of intervention accountability, training and supervision may place many clients with challenging behaviour at increased risk for ineffective and unnecessary restrictive interventions, and physical abuse. The results of this survey stimulated the government to write province-wide standards (that have yet to be implemented).

Subcellular localization of neuronal nitric oxide synthase in the rat nucleus of the solitary tract in relation to vagal afferent inputs

In the nucleus of the solitary tract (NTS), nitric oxide (NO) modulates neuronal circuits controlling autonomic functions. A proposed source of this NO is via nitric oxide synthase (NOS) present in vagal afferent fibre terminals, which convey visceral afferent information to the NTS. Here, we first determined with electron microscopy that neuronal NOS (nNOS) is present in both presynaptic and postsynaptic structures in the NTS. To examine the relationship of nNOS to vagal afferent fibres the anterograde tracer biotinylated dextran amine was injected into the nodose ganglion and detected in brainstem sections using peroxidase-based methods. nNOS was subsequently visualised using a pre-embedding immunogold procedure. Ultrastructural examination revealed nNOS immunoreactivity in dendrites receiving vagal afferent input. However, although nNOS-immunoreactive terminals were frequently evident in the NTS, none were vagal afferent in origin. Dual immunofluorescence also confirmed lack of co-localisation. Nevertheless, nNOS immunoreactivity was observed in vagal afferent neurone cell bodies of the nodose ganglion. To determine if these labelled cells in the nodose ganglion were indeed vagal afferent neurones nodose ganglion sections were immunostained following application of cholera toxin B subunit to the heart. Whilst some cardiac-innervating neurones were also nNOS immunoreactive, nNOS was never detected in the central terminals of these neurones. These data show that nNOS is present in the NTS in both pre- and postsynaptic structures. However, these presynaptic structures are unlikely to be of vagal afferent origin. The lack of nNOS in vagal afferent terminals in the NTS, yet the presence in some vagal afferent cell bodies, suggests it is selectively targeted to specific regions of the same neurones.

Mastery motivation in young children with Down's syndrome: relations with cognitive and adaptive competence

BACKGROUND

Prior research on relations between motivation and competence have focused on cognitive competence, despite theoretical predictions that mastery motivation spurs behaviour that is effective in meeting the demands of one's environment, i.e. adaptive competence. Issues of adaptive competence are especially relevant for children with developmental delay since functional independence is an important long-term goal for these children.

METHODS

In the present study, mastery motivation was examined in relation to both cognitive and adaptive competence in 5-year-old children with Down's syndrome (n = 41).

RESULTS

Scores on mastery task and parent-report measures of mastery motivation were generally low, but positively related to scores on standardized measures of cognitive competence and adaptive competence.

CONCLUSIONS

This is the first study of motivation-competence relations in pre-school-age children. The findings have implications for both developmental theory and early intervention efforts, and the authors hope that they will serve as a stimulus for future research on cross-domain relationships in atypical populations.

Neuronal P2X7 receptors are targeted to presynaptic terminals in the central and peripheral nervous systems

The ionotropic ATP receptor subunits P2X(1-6) receptors play important roles in synaptic transmission, yet the P2X(7) receptor has been reported as absent from neurons in the normal adult brain. Here we use RT-PCR to demonstrate that transcripts for the P2X(7) receptor are present in extracts from the medulla oblongata, spinal cord, and nodose ganglion. Using in situ hybridization mRNA encoding, the P2X(7) receptor was detected in numerous neurons throughout the medulla oblongata and spinal cord. Localizing the P2X(7) receptor protein with immunohistochemistry and electron microscopy revealed that it is targeted to presynaptic terminals in the CNS. Anterograde labeling of vagal afferent terminals before immunohistochemistry confirmed the presence of the receptor in excitatory terminals. Pharmacological activation of the receptor in spinal cord slices by addition of 2'- and 3'-O-(4-benzoylbenzoyl)adenosine 5'-triphosphate (BzATP; 30 microm) resulted in glutamate mediated excitation of recorded neurons, blocked by P2X(7) receptor antagonists oxidized ATP (100 microm) and Brilliant Blue G (2 microm). At the neuromuscular junction (NMJ) immunohistochemistry revealed that the P2X(7) receptor was present in motor nerve terminals. Furthermore, motor nerve terminals loaded with the vital dye FM1-43 in isolated NMJ preparations destained after application of BzATP (30 microm). This BzATP evoked destaining is blocked by oxidized ATP (100 microm) and Brilliant Blue G (1 microm). This indicates that activation of the P2X(7) receptor promotes release of vesicular contents from presynaptic terminals. Such a widespread distribution and functional role suggests that the receptor may be involved in the fundamental regulation of synaptic transmission at the presynaptic site.

Advances in neurotrauma in Australia 1970-2000

The management of neurotrauma in Australia has been one of the significant public health triumphs during the last 30 years of the 20th century. State and national government agencies act in a coordinated fashion to collect data and to promote research or how to manage neurotrauma patients. Between 1970 and 1995, fatalities from road accidents decreased by 47%. Hospital admissions have decreased by 40% despite a 40% increase in the population and a 120% increase in registered vehicles. Fatalities per 10,000 registered vehicles were 8.05% in 1970 and they fell to 1.84% per vehicles in 1995, while fatalities per 10,000 population were 3 in 1970 falling to 1.11 in 1995. Hospitalization from road crashes decreased 23% between March 1988 and March 1997. Public education has steadily improved, backed by the state public health sources. A uniform code of road safety laws has been adopted, backed by legislation and legal penalties and increasing police enforcement. Clinical care of patients has improved as a result of faster communications, tele-medicine, trauma systems, the CT scanner, intensive care units, and improved monitoring. Patient rehabilitation and counseling are now carried out at units accredited by the Australian Council on Health Care Standards.

Comorbidity of psychiatric and substance use disorders in late adolescence: a cluster analytic approach

Cluster analysis was used to identify subgroups of youths with past-year substance and/or psychiatric disorders (N = 110, mean age 19.0 years). Data for this study came from a community-based, prospective longitudinal investigation of speech/language (S/L) impaired children and matched controls who participated in extensive diagnostic and psychosocial assessments at entry into the study at 5 years of age and again at follow-up. Clustering variables were based on five DSM diagnostic categories assessed at age 19with the University of Michigan Composite International Diagnostic Interview. Using Ward's method, the five binary variables were entered into a hierarchical cluster analysis. An iterative clustering method (K-means) was then used to refine the Ward solution. Finally, a series of analyses of variance (ANOVAs) were run to analyze group differences between clusters on measures of Global Assessment of Functioning (GAF), criminal involvement, anxiety and depressive symptomatology, and frequency of drug use and heavy drinking. The analysis yielded eight replicable cluster groups, which were labeled as follows: (a) anxious (20.9%); (b) anxious drinkers (5.5%); (c) depressed (16.4%); (d) depressed drug abusers (10%); (e) antisocial (16.4%); (f) antisocial drinkers (10%); (g) drug abusers (8.2%); (h) problem drinkers (12.7%). These groups were differentiated by external criteria, thus supporting the validity of our cluster solution. Cluster membership was associated with a history of S/L impairment: A large proportion of the depressed drug abusers and the antisocial cluster group had S/L impairment that was identified at age 5. Clarification of the developmental progress of the youths in these cluster groups can inform our approach to early intervention and treatment.

Errorless compliance training with physically abusive mothers: a single-case approach

OBJECTIVE

"Errorless compliance training" is a recently developed, success-based approach for teaching children to comply with parental requests without the use of coercive consequences. Two mothers were trained to use this intervention to reduce severe child defiance that was precipitating mother/child confrontations and physical abuse.

METHOD

To determine probability of child compliance to specific requests, we observed mothers delivering requests to their child. We then developed a hierarchy of compliance probabilities for each child. Mothers were trained to deliver a high density of Level 1 requests (those that typically yielded compliance), and provide praise for child compliance. Lower probability request levels were introduced gradually, at a slow enough pace to preclude noncompliant responses, reducing the need for mothers to respond aversively to child behavior.

RESULTS

At treatment completion and follow-up, both children demonstrated substantial improvements in compliance.

CONCLUSIONS

The errorless approach may be well suited to managing parenting deficits and child opposition commonly associated with family violence.

P2X(2) receptor immunoreactivity in the dorsal vagal complex and area postrema of the rat

Adenosine 5'-triphosphate (ATP) can function as a fast synaptic transmitter through its actions on ionotropic (P2X) and metabotropic (P2Y) receptors in neuronal tissue. The ionotropic receptors have been classified into seven subtypes (P2X(1)-P2X(7)) by molecular cloning. However, they are difficult to distinguish pharmacologically owing to an absence of specific agonists and antagonists. In this study we used neuroanatomical methods to determine the origin and neurochemical phenotype of the P2X(2) subtype of purinoceptor in the dorsal medulla of the rat. Using immunohistochemistry we observed dense networks of P2X(2) receptor immunoreactive labelled fibres and terminals in the dorsal vagal complex and area postrema, as well as labelled cell bodies in the dorsal vagal nucleus and the area postrema. The P2X(2) receptor was localized presynaptically in vagal afferent fibres and terminals in the nucleus tractus solitarius at the ultrastructural level by combining injections of an anterograde tracer (biotin dextran amine) into the nodose ganglion with pre-embedding immunogold visualization of P2X(2) immunoreactivity. Terminals immunoreactive for the P2X(2) receptor in the nucleus tractus solitarius were found to contain glutamate, but not GABA immunoreactivity by post-embedding immunogold-labelling techniques. In cell bodies in the area postrema, dual immunofluorescence also indicated that P2X(2) receptor immunoreactive cells are glutamatergic but not GABAergic. The P2X(2) receptor was localized to vagal preganglionic neurons in the dorsal vagal nucleus that were identified by prior intraperitoneal injections of the retrograde tracer FluoroGold. No cells immunoreactive for the P2X(2) receptor were observed in the nucleus tractus solitarius. The localization of P2X(2) receptor immunoreactivity presynaptically in vagal afferent terminals indicates that the receptor may be involved in modulating transmitter release from vagal afferent fibres. Furthermore, the presence of the P2X(2) receptor in vagal preganglionic cells and in glutamatergic cells of the area postrema implies that it may, respectively, play a role in regulation of vagal efferent cell activity and modulation of excitatory outputs from the area postrema to other brain regions.

Fourteen-year follow-up of speech/language-impaired and control children: psychiatric outcome

OBJECTIVE

To examine the association between early childhood speech and language disorders and young adult psychiatric disorders.

METHOD

In a longitudinal community study conducted in the Ottawa-Carleton region of Ontario, Canada, interviewers administered structured psychiatric interviews to age 19 participants who were originally identified as speech-impaired only, language-impaired, or nonimpaired at age 5. The first stage of the study took place in 1982 when participants were 5 years old, and the latest stage of the study took place between 1995 and 1997 when participants had a mean age of 19 years. This report examines the association between early childhood speech/language status and young adult psychiatric outcome.

RESULTS

Children with early language impairment had significantly higher rates of anxiety disorder in young adulthood compared with nonimpaired children. The majority of participants with anxiety disorders had a diagnosis of social phobia. Trends were found toward associations between language impairment and overall and antisocial personality disorder rates. Males from the language-impaired group had significantly higher rates of antisocial personality disorder compared with males from the control group. Age of onset and comorbidity did not differ by speech/language status. The majority of participants with a disorder had more than one.

CONCLUSIONS

Results support the association between early childhood speech and language functioning and young adult psychiatric disorder over a 14-year period. This association underscores the importance of effective and early interventions.

Child-parent attachment and children's peer relations: a quantitative review

The central premise of attachment theory is that the security of the early child-parent bond is reflected in the child's interpersonal relationships across the life span. This meta-analysis was based on 63 studies that reported correlations between child-parent attachment and children's peer relations. The overall effect size (ES) for child-mother attachment was in the small-to-moderate range and was quite homogeneous. ESs were similar in studies that featured the Strange Situation and Q-sort methods. The effects were larger for peer relations in middle childhood and adolescence than for peer relations in early childhood. ESs were also higher for studies that focused on children's close friendships rather than on relations with other peers. Gender and cultural differences in ESs were minimal. The results for the few studies on father-child attachment were inconclusive.

Attachment security: a meta-analysis of maternal mental health correlates

This meta-analysis addresses the association between attachment security and each of three maternal mental health correlates. The meta-analysis is based on 35 studies, 39 samples, and 2,064 mother-child pairs. Social-marital support (r = .14; based on 16 studies involving 17 samples and 902 dyads), stress (r = .19; 13 studies, 14 samples, and 768 dyads), and depression (r = .18; 15 studies, 19 samples, and 953 dyads) each proved significantly related to attachment security. All constructs showed substantial variance in effect size. Ecological factors and approach to measuring support may explain the heterogeneity of effect sizes within the social-marital support literature. Effect sizes for stress varied according to the time between assessment of stress and assessment of attachment security. Among studies of depression, clinical samples yielded significantly larger effect sizes than community samples. We discuss these results in terms of measurement issues (specifically, overreliance on self-report inventories) and in terms of the need to study the correlates of change in attachment security, rather than just the correlates of attachment security per se.

Success-based, noncoercive treatment of oppositional behavior in children from violent homes

OBJECTIVES

Errorless compliance training is a success-based, noncoercive intervention for children with severe oppositional behavior. The strategy involves hierarchical introduction of more demanding parental requests at a gradual pace that greatly reduces noncompliance and obviates the need for constraining consequences (e.g., time-out). In this study, this approach was evaluated as a treatment for severe disciplinary problems in children from violent homes.

METHOD

Participants were 15 children (aged 3-10 years) and their mothers. All participants had experienced long-term family violence. Using a multiple-baseline design, the authors trained parents in a group format and conducted observations of child compliance in the home throughout the intervention.

RESULTS

Observations indicated improvements in generalized child compliance that were maintained up to 6 months posttreatment. Pre-/post maternal reports indicated significant reductions in maternal perception of child noncompliance, externalizing and internalizing problems, and parenting stress.

CONCLUSIONS

Researchers have noted a dearth of empirically supported interventions for children from violent homes. Errorless compliance training may help to fill this void, as it appears well suited to treatment of difficulties encountered by these youngsters and their parents.

Adolescent substance use disorders: findings from a 14-year follow-up of speech/language-impaired and control children

Intervening on the development of adolescent addiction requires an understanding of the role of precursors. In a community sample of youth with and without early childhood speech/language (S/L) impairments, 12.7% of participants had a substance use disorder (SUD). Among these participants, 42.0% met criteria for more than 1 SUD. Interestingly, rates of SUDs did not differ by S/L status. However, S/L-impaired participants did show greater psychiatric comorbidity and poorer functioning. A total of 80% of S/L participants with SUDs had a concurrent diagnosis of antisocial personality disorder, compared with 43.8% of SUDs controls. In a logistic regression analysis, we found age 5 mother-rated problem behavior scores and an interaction between S/L status and teacher-rated conduct problem scores were predictive of SUDs. High conduct scores were predictive of SUDs development among control participants but not among S/L-impaired participants. First substance use and initial SUDs symptoms suggest that a window of opportunity exists to reach these troubled young people before they spiral into addiction.

Fourteen-year follow-up of children with and without speech/language impairments: speech/language stability and outcomes

This report concerns the speech and language outcomes of young adults (N = 242) who participated in a 14-year, prospective, longitudinal study of a community sample of children with (n = 114) and without (n = 128) speech and/or language impairments. Participants were initially identified at age 5 and subsequently followed at ages 12 and 19. Direct assessments were conducted in multiple domains (communicative, cognitive, academic, behavioral, and psychiatric) at all three time periods. Major findings included (a) high rates of continued communication difficulties in those with a history of impairment; (b) considerable stability in language performance over time; (c) better long-term outcomes for those with initial speech impairments than for those with language impairments; and (d) more favorable prognoses for those with specific language impairments than for those with impairments secondary to sensory, structural, neurological, or cognitive deficits. These general conclusions held when either a liberal or a more stringent criterion for language impairment was employed. Some of these findings are consistent with those from earlier follow-up studies, which used less optimal methods. Thus, the present replication and extension of these findings with a sound methodology enables greater confidence in their use for prognostic, planning, and research purposes.

Double-strand conformation polymorphism (DSCP) analysis of the mitochondrial control region generates highly variable markers for population studies in a social insect

Genetic markers were obtained for the termite Nasutitermes corniger by DSCP (double-strand conformation polymorphism) analysis of PCR-amplified mitochondrial control region DNA. This procedure revealed twenty-one haplotypes in forty-four colonies, whereas a restriction fragment length polymorphism analysis detected only nine haplotypes. Sequence analysis of DSCP fragments of contrasting mobilities suggests that the electrophoretic haplotypes are caused by DNA curvature in this highly AT-rich region. DSCP markers showed that some termite colonies contained maternally unrelated queens, each of which produced worker offspring. This pattern is consistent with nest founding by unrelated queens. Due to the availability of conserved primers for the mtDNA control region, DSCP analysis may readily reveal comparatively high levels of variation in a wide variety of organisms.

Serum LH concentrations in hypogonadal men during transdermal testosterone replacement through scrotal skin: further evidence that ageing enhances testosterone negative feedback. The Testoderm Study Group

OBJECTIVE

The present study was designed to explore further the mechanism for the decline in androgen production as men age by studying the influence of ageing on testosterone negative feedback control of gonadotrophin secretion.

DESIGN

Circulating testosterone, dihydrotestosterone, oestradiol, SHBG and LH concentrations were measured during long-term treatment of men with primary hypogonadism using transdermal testosterone via scrotal skin.

PATIENTS

Results were compared in 12 hypogonadal men below age 40 years (34 +/- 1.1 years; mean +/- SEM), 13 middle-aged men, aged 51 +/- 2.2 years, and 10 men age 64 years or older (68 +/- 1.4 years).

RESULTS

During the course of therapy, circulating LH levels were suppressed 48% (F = -2.42, P = 0.018) from 19.6 +/- 6.0 IU/I at baseline to 10 +/- 7.7 IU/I during month 15 in elderly men. By contrast, LH levels were unchanged (F = 0.31; P = 0.97) in young men (20.3 +/- 7.4 IU/I at baseline and 17.7 +/- 14.9 IU/I during treatment month 15). Intermediate results were observed in middle-aged men in whom LH levels declined slightly (F = 1.34; P = 0.24). Transdermal testosterone treatment produced similar circulating testosterone levels (F = 1.49; P = 0.24) and oestradiol levels (F = 0.60; P = 0.42) in elderly and young men. Mean plasma DHT levels were approximately 20% higher (F = 9.91; P = 0.01) during treatment in elderly men overall mean values of 8.03 +/- 0.37 nmol/l) than in young men (6.68 +/- 0.08 nmol/l). When total DHT was adjusted for higher plasma SHBG levels in elderly men, the free DHT index during treatment was similar (F = 0.23; P = 0.64) in both groups.

CONCLUSIONS

These data provide further evidence that the set point for androgen negative feedback control of gonadotrophin accretion in men is altered by ageing. Taken together with previous findings, these results provide a potential explanation for the unchanged or slightly increased plasma LH levels and reduced testosterone production characteristic of elderly men. Accordingly, ageing-associated Leydig cell insufficiency leads to a decline in testosterone production, but circulating LH levels do not rise appropriately because the set-point for negative feedback is decreased.