The prefrontal-limbic system: development, neuroanatomy, function, and implications for socioemotional development

Interventions to improve executive functions in children aged 3 years and under: A systematic review

BACKGROUND

Early executive functioning (EF) skills are foundational capabilities that predict school readiness, academic development and psychiatric risk. Early interventions enhancing these capabilities could have critical import in improving outcomes. However, to develop interventions, it is necessary to identify specific EF skills that will vary with child age. Thus, we aimed to examine the characteristics and efficacy of interventions targeting EF in infancy and early childhood up to age 3.

METHODS

A comprehensive search of PubMed, Embase, CINAHL and APA PsycINFO databases was performed for studies published before December 2022. Randomized and non-randomized studies of interventions designed to improve at least one EF skill in children ≤3 years were included. EF skills included attentional control, inhibition/self-regulation, activity initiation, working memory, cognitive flexibility, planning ability, problem-solving and performance monitoring. We independently extracted data, used the revised Cochrane Risk-of-Bias tool to assess the quality of the evidence and conducted Synthesis Without Meta-analysis (SWiM). The overall quality of the evidence and the strength of recommendations was determined using elements of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

RESULTS

Thirty-five studies met inclusion criteria (original n = 7467). Studies were highly variable in the EF skill targeted, target subject (i.e., child, parent and teacher), nature and dosage of the intervention, and timing of outcome assessment. Most interventions focused on improving impulse control and self-regulation. The overall quality of evidence was low to moderate with a high risk of bias, though six studies had low risk of bias but yielded mixed findings of efficacy.

CONCLUSIONS

The relatively small number of early EF intervention studies uses such variable methods that there is currently no converging evidence of efficacy to recommend a specific intervention. Thus, findings support the need for a more systematic, targeted approach to the design and implementation of early EF interventions for target populations.

Accuracy of Electronic Health Record Documentation of Parental Presence: A Data Validation and Quality Improvement Analysis

Parental presence in the neonatal intensive care unit (NICU) is known to improve the health outcomes of an admitted infant. The use of the electronic health record (EHR) to analyze associations between parental presence and sociodemographic factors could provide important insights to families at greatest risk for limited presence during their infant's NICU stay, but there is little evidence about the accuracy of nonvital clinical measures such as parental presence in these datasets. A data validation study was conducted comparing the percentage agreement of an observational log of parental presence to the EHR documentation. Overall, high accuracy values were found when combining two methods of documentation. Additional stratification using a more specific measure, each chart's complete accuracy, instead of overall accuracy, revealed that night shift documentation was more accurate than day shift documentation (76.3% accurate during night shifts, 55.2% accurate during day shifts) and that flowsheet (FS) recordings were more accurate than the free-text plan of care (POC) notes (82.4% accurate for FS, 75.1% accurate for POC notes). This research provides a preliminary look at the accuracy of EHR documentation of nonclinical factors and can serve as a methodological roadmap for other researchers who intend to use EHR data.

Resting-state functional MRI study of conventional MRI-negative intractable epilepsy in children

Objective

The study aimed at investigating functional connectivity strength (FCS) changes in children with MRI-negative intractable epilepsy (ITE) and evaluating correlations between aberrant FCS and both disease duration and intelligence quotient (IQ).

Methods

Fifteen children with ITE, 24 children with non-intractable epilepsy (nITE) and 25 matched healthy controls (HCs) were subjected to rs-fMRI. IQ was evaluated by neuropsychological assessment. Voxelwise analysis of covariance was conducted in the whole brain, and then pairwise comparisons were made across three groups using Bonferroni corrections.

Results

FCS was significantly different among three groups. Relative to HCs, ITE patients exhibited decreased FCS in right temporal pole of the superior temporal gyrus, middle temporal gyrus, bilateral precuneus, etc and increased FCS values in left triangular part of the inferior frontal gyrus, parahippocampal gyrus, supplementary motor area, caudate and right calcarine fissure and surrounding cortex and midbrain. The nITE patients presented decreased FCS in right orbital superior frontal gyrus, precuneus etc and increased FCS in bilateral fusiform gyri, parahippocampal gyri, etc. In comparison to nITE patients, the ITE patients presented decreased FCS in right medial superior frontal gyrus and left inferior temporal gyrus and increased FCS in right middle temporal gyrus, inferior temporal gyrus and calcarine fissure and surrounding cortex. Correlation analysis indicated that FCS in left caudate demonstrated correlation with verbal IQ (VIQ) and disease duration.

Conclusion

ITE patients demonstrated changed FCS values in the temporal and prefrontal cortices relative to nITE patients, which may be related to drug resistance in epilepsy. FCS in the left caudate nucleus associated with VIQ, suggesting the caudate may become a key target for improving cognitive impairment and seizures in children with ITE.

Parenting Influences on Frontal Lobe Gray Matter and Preterm Toddlers' Problem-Solving Skills

Children born preterm often face challenges with self-regulation during toddlerhood. This study examined the relationship between prematurity, supportive parent behaviors, frontal lobe gray matter volume (GMV), and emotion regulation (ER) among toddlers during a parent-assisted, increasingly complex problem-solving task, validated for this age range. Data were collected from preterm toddlers (n = 57) ages 15-30 months corrected for prematurity and their primary caregivers. MRI data were collected during toddlers' natural sleep. The sample contained three gestational groups: 22-27 weeks (extremely preterm; EPT), 28-33 weeks (very preterm; VPT), and 34-36 weeks (late preterm; LPT). Older toddlers became more compliant as the Tool Task increased in difficulty, but this pattern varied by gestational group. Engagement was highest for LPT toddlers, for older toddlers, and for the easiest task condition. Parents did not differentiate their support depending on task difficulty or their child's age or gestational group. Older children had greater frontal lobe GMV, and for EPT toddlers only, more parent support was related to larger right frontal lobe GMV. We found that parent support had the greatest impact on high birth risk (≤27 gestational weeks) toddler brain development, thus early parent interventions may normalize preterm child neurodevelopment and have lasting impacts.

Central Autonomic Network and heart rate variability in premature neonates

INTRODUCTION

The Central Autonomic Network (CAN) is a hierarchy of brain structures that collectively influence cardiac autonomic input, mediating the majority of brain-heart interactions, but has never been studied in premature neonates. In this study, we use heart rate variability (HRV), which has been described as the "primary output" of the CAN, and resting state functional MRI to characterize brain-heart relationships in premature neonates.

METHODS

We studied premature neonates who underwent resting state functional MRI (rsfMRI) at term, (37-weeks postmenstrual age [PMA] or above) and had HRV data recorded during the same week of their MRI. HRV was derived from continuous electrocardiogram data during the week of the rsfMRI scan. For rsfMRI, a seed-based approach was used to define regions of interest (ROI) pertinent to the CAN, and blood oxygen level-dependent signal was correlated between each ROI as a measure of functional connectivity. HRV was correlated with CAN connectivity (CANconn) for each region, and sub-group analysis was performed based on sex and clinical comorbidities.

RESULTS

Forty-seven premature neonates were included in this study, with a mean gestational age at birth of 28.1 +/- 2.6 weeks. Term CANconn was found to be significantly correlated with HRV in approximately one-fifth of CAN connections. Two distinct patterns emerged among these HRV-CANconn relationships. In the first, increased HRV was associated with stronger CANconn of limbic regions. In the second pattern, stronger CANconn at the precuneus was associated with impaired HRV maturation. These patterns were especially pronounced in male premature neonates.

CONCLUSION

We report for the first time evidence of brain-heart relationships in premature neonates and an emerging CAN, most striking in male neonates, suggesting that the brain-heart axis may be more vulnerable in male premature neonates. Signatures in the heart rate may eventually become an important non-invasive tool to identify premature males at highest risk for neurodevelopmental impairment.

Identifying misdiagnosed bipolar disorder using support vector machine: feature selection based on fMRI of follow-up confirmed affective disorders

Nearly a quarter of bipolar disorder (BD) patients were misdiagnosed as major depressive disorder (MDD) patients, which cannot be corrected until mania/hypomania develops. It is important to recognize these obstacles so that the appropriate treatment can be initiated. Thus, we sought to distinguish patients with BD from MDD, especially to identify misdiagnosed BD before mania/hypomania, and further explore potential trait features that allow accurate differential diagnosis independent of state matters. Functional magnetic resonance imaging scans were performed at baseline on 92 MDD patients and 48 BD patients. The MDD patients were then followed up for more than two years. After follow-up, 23 patients transformed into BD (tBD), and 69 patients whose diagnoses remained unchanged were eligible for unipolar depression (UD). A support vector machine classifier was trained on the amygdala-based functional connectivity (FC) of 48 BD and 50 UD patients using a novel region-based feature selection. Then, the classifier was tested on the dataset, encompassing tBD and the remaining UD. It performed well for known BD and UD and can also distinguish tBD from UD with an accuracy of 81%, sensitivity of 82.6%, specificity of 79%, and AUC of 74.6%, respectively. Feature selection results revealed that ten regions within the cortico-limbic neural circuit contributed most to classification. Furthermore, in the FC comparisons among diseases, BD and tBD shared almost overlapped FC patterns in the cortico-limbic neural circuit, and both of them presented pronounced differences in most regions within the circuit compared with UD. The FC values of the most discriminating brain regions had no prominent correlations with the severity of depression, anxiety, and mania/hypomania (FDR correction). It suggests that BD possesses some trait features in the cortico-limbic neural circuit, rendering it dichotomized by the classifier based on known-diagnosis data.

Postpartum Depression and Anxiety among Lebanese Women: Correlates and Scales Psychometric Properties

Background: We found that it was important to fill a gap in the literature and check the psychometric properties of the Edinburgh Postnatal Depression Scale (EPDS) and Perinatal Anxiety Screening Scale (PASS) in the Arabic language and delineate factors associated with postnatal depression (PPD) and anxiety (PPA) among Lebanese women 4−6 weeks after delivery. Methods: This cross-sectional study carried out between July 2018 and March 2019 enrolled 295 participants who came for a postnatal checkup at four clinics. Results: The EPDS and PASS scales’ items converged over two- and four-factor solutions, explaining 62.51% and 53.33% of the variance, respectively (KMO EPDS = 0.816, αCronbach EPDS = 0.826; KMO PASS = 0.878, αCronbach PASS = 0.920; Bartlett’s test of sphericity p < 0.001). Higher postpartum anxiety (Beta = 0.256), higher postpartum insomnia (Beta = 0.079), having hypotension during pregnancy (Beta = 2.760), and having a second (Beta = 1.663) or a third baby or more (Beta = 2.470) compared with the first one were significantly associated with higher postpartum depression. Higher postpartum depression (Beta = 1.33) was significantly associated with higher postpartum anxiety, whereas having a baby through a planned pregnancy (Beta = −4.365) and having a baby who ate regularly (Beta = −3.639) were significantly associated with lower postpartum anxiety. Conclusion: Depression and anxiety prevalence rates in the Lebanese population were higher compared with other countries, which may be due in part to the differences in regional, social and environmental culture.

Differences in moral reasoning among medical graduates, graduates with other degrees, and nonprofessional adults

BACKGROUND

Reasoning and moral action are necessary to resolve day-to-day moral conflicts, and there are certain professions where a greater moral character is expected, e.g., medicine. Thus, it is desirable that medical students develop skills in this field. Some studies have evaluated the level of moral reasoning among medical students; however, there are no comparative studies involving other types of populations. Therefore, the objective of this study was to compare the moral reasoning among medical graduates with that of a group of young graduates with other degrees and of a group of nonprofessional adults.

METHODS

An exploratory cross-sectional study was conducted. Pediatric residents and pediatric subspecialty residents at a pediatric hospital were invited to participate, forming the group of "medical graduates". A group of young people from a social program and students with a master's degree in a science from the same pediatric hospital were also invited to participate, comprising the group of "graduates with other degrees". Finally, a group of beneficiaries of a family clinic was invited to participate, which we categorized as "nonprofessionals". To evaluate the differences in moral reasoning between these 3 groups, we applied the Defining Issues Test (DIT), a moral reasoning questionnaire designed by James Rest using Kohlberg's theory of moral development.

RESULTS

The moral reasoning of 237 subjects-88 from the "medical graduates" group, 82 from the "graduates with other degrees" group and 67 from the "nonprofessionals" group- was evaluated. We found differences in the profiles of moral development of the groups. The profile of the "nonprofessionals" showed a very high predominance of subjects at the preconventional level, 70%, but only 4.5% at the postconventional level. Among the "medical graduates", we observed 37.5% at the preconventional level and 34% at the postconventional level (X² p < 0.001); this group had the highest percentage in this category. This large difference could be because the differences in the ages and socioeducational levels of nonprofessionals are much wider than those among medical graduates. However, significant differences were also found when the profiles of medical graduates were compared with those of graduates with other degrees, since the latter demonstrated 56% at the preconventional level and 18% at the postconventional level (X² test, p = 0.02).

CONCLUSIONS

Significant differences were found in moral reasoning among the groups that we evaluated. Among the group of medical graduates, there was a higher percentage of subjects at the postconventional level than among the group of graduates with other degrees and a much higher percentage than among the group of nonprofessionals. Our conclusions give the first evidence that studying medicine seems to influence the development of moral reasoning in its students. Therefore, we consider it relevant to develop educational strategies where the student is involved in simulated but realistic decision-making situations, where there are moral dilemmas to resolve from their early years of training.

Altered Spontaneous Brain Activity in Left-Behind Children: A Resting-State Functional MRI Study

Background

Parental migration has been associated with a higher risk of cognitive and behavioral abnormalities in left-behind children (LBC). This study aimed to explore the spontaneous brain activity in LBC and reveal the mechanisms underlying behavioral and cognitive abnormalities.

Methods

Involved LBC (n = 36) and non-LBC (n = 22) underwent resting-state functional MRI (fMRI) examination and cognitive and behavioral assessment. The fMRI-based amplitude of low-frequency fluctuation (ALFF) and fractional ALFF (fALFF) were assessed to analyze the spontaneous brain activity pattern. The relationships among abnormal spontaneous brain activity, behavioral and cognitive deficits and altered family environment were assessed by partial correlation analysis.

Results

Compared with non-LBC, LBC exhibited increased amplitude of low-frequency fluctuations in the right lingual gyrus (LING), while a decreased ALFF was observed in the bilateral insula and right orbital part of the middle frontal gyrus (ORBmid) (two-tailed voxel-level p < 0.01 and cluster-level p <0.05, Gaussian Random Field (GRF) correction). The fALFF in LBC were significantly increased in the left cerebellum 9 (Cbe9) and right cerebellum Crus2 (CbeCru2), while it decreased in the right hippocampus and left superior temporal gyrus (STG) (two-tailed voxel-level p < 0.01 and cluster-level p < 0.05, GRF correction). The ALFF and fALFF values in abnormal brain regions were found to be correlated with the learning ability, except for the right insula, while the fALFF values of the left STG were positively correlated with the full-scale IQ scores (p < 0.05). Moreover, the ALFF and fALFF values in all abnormal brain regions correlated with the education level of caregivers (p < 0.05).

Conclusions

Our study provided empirical evidence that the lack of direct parental care during early childhood could affect brain function development involving cognition, behavior, and emotion. Our findings emphasized that intellectual and emotional cares are essential for LBC.

Decreased functional connectivity of hippocampal subregions and methylation of the NR3C1 gene in Han Chinese adults who lost their only child

BACKGROUND

Losing one's only child is a major traumatic life event that may lead to post-traumatic stress disorder (PTSD); however, the underlying mechanisms of its psychological consequences remain poorly understood. Here, we investigated subregional hippocampal functional connectivity (FC) networks based on resting-state functional magnetic resonance imaging and the deoxyribonucleic acid methylation of the human glucocorticoid receptor gene (NR3C1) in adults who had lost their only child.

METHODS

A total of 144 Han Chinese adults who had lost their only child (51 adults with PTSD and 93 non-PTSD adults [trauma-exposed controls]) and 50 controls without trauma exposure were included in this fMRI study (age: 40-67 years). FCs between hippocampal subdivisions (four regions in each hemisphere: cornu ammonis1 [CA1], CA2, CA3, and dentate gyrus [DG]) and methylation levels of the NR3C1 gene were compared among the three groups.

RESULTS

Trauma-exposed adults, regardless of PTSD diagnosis, had weaker positive FC between the left hippocampal CA1, left DG, and the posterior cingulate cortex, and weaker negative FC between the right CA1, right DG, and several frontal gyri, relative to healthy controls. Compared to non-PTSD adults, PTSD adults showed decreased negative FC between the right CA1 region and the right middle/inferior frontal gyri (MFG/IFG), and decreased negative FC between the right DG and the right superior frontal gyrus and left MFG. Both trauma-exposed groups showed lower methylation levels of the NR3C1 gene.

CONCLUSIONS

Adults who had lost their only child may experience disrupted hippocampal network connectivity and NR3C1 methylation status, regardless of whether they have developed PTSD.

"Live together, die alone": The effect of re-socialization on behavioural performance and social-affective brain-related proteins after a long-term chronic social isolation stress

Loneliness affects group-living mammals triggering a cascade of stress-dependent physiological disorders. Indeed, social isolation stress is a major risk factor for several neuropsychiatric disorders including anxiety and depression. Furthermore, social isolation has a negative impact on health and fitness. However, the neurobiological consequences of long-term chronic social isolation stress (LTCSIS) manifested during the adulthood of affected individuals are not fully understood. Our study assessed the impact of LTCSIS and social buffering (re-socialization) on the behavioural performance and social-affective brain-related proteins in diurnal, social, and long-lived Octodon degus (degus). Thereby, anxiety-like and social behaviour, and social recognition memory were assessed in male and female animals subjected to a variety of stress-inducing treatments applied from post-natal and post-weaning until their adulthood. Additionally, we evaluated the relationship among LTCSIS, Oxytocin levels (OXT), and OXT-Ca2+-signalling proteins in the hypothalamus, the hippocampus, and the prefrontal cortex. Our findings suggest that LTCSIS induces anxiety like-behaviour and impairs social novelty preference whereas sociability is unaffected. On the other hand, re-socialization can revert both isolation-induced anxiety and social memory impairment. However, OXT and its signalling remained reduced in the abovementioned brain areas, suggesting that the observed changes in OXT-Ca2+ pathway proteins were permanent in male and female degus. Based on these findings, we conclude degus experience social stress differently, suggesting the existence of sex-related mechanisms to cope with specific adaptive challenges.

Sleep, cognition and executive functioning in young children with cerebral palsy

Children with cerebral palsy (CP) are at higher risk for sleep disturbances than their typically developing peers. In typically developing young children, lack of sufficient sleep results in deficits in cognition, behavior and executive functioning. Unfortunately, research on sleep in infancy rarely focuses on children with neurodevelopmental disabilities. Studies of older children with CP demonstrate that roughly half of children with CP have a sleep disorder, though screening for sleep disorders in children with CP is not routinely performed. Given the high prevalence of sleep abnormalities in older children with CP and the resulting adverse effects on functioning, understanding sleep derangements and how they affect cognition and executive functioning in these children at earlier ages is critical. In this chapter, we present the state of the evidence for sleep characteristics, cognition and executive functions for infants and toddlers 0-3years old with CP.

Effects of long-lasting social isolation and re-socialization on cognitive performance and brain activity: a longitudinal study in Octodon degus

Social isolation is considered a stressful situation that results in increased physiological reactivity to novel stimuli, altered behaviour, and impaired brain function. Here, we investigated the effects of long-term social isolation on working memory, spatial learning/memory, hippocampal synaptic transmission, and synaptic proteins in the brain of adult female and male Octodon degus. The strong similarity between degus and humans in social, metabolic, biochemical, and cognitive aspects, makes it a unique animal model that can be highly applicable for further social, emotional, cognitive, and aging studies. These animals were socially isolated from post-natal and post-weaning until adulthood. We also evaluated if re-socialization would be able to compensate for reactive stress responses in chronically stressed animals. We showed that long-term social isolation impaired the HPA axis negative feedback loop, which can be related to cognitive deficits observed in chronically stressed animals. Notably, re-socialization restored it. In addition, we measured physiological aspects of synaptic transmission, where chronically stressed males showed more efficient transmission but deficient plasticity, as the reverse was true on females. Finally, we analysed synaptic and canonical Wnt signalling proteins in the hypothalamus, hippocampus, and prefrontal cortex, finding both sex- and brain structure-dependent modulation, including transient and permanent changes dependent on stress treatment.

Alterations of Spontaneous Brain Activity in Hemodialysis Patients

Cognitive impairment is prevalent in hemodialysis end-stage renal disease (ESRD) patients. It might be associated with poor prognosis. Nevertheless, the underlying mechanisms have not been completely clarified. This study explored spontaneous brain activity in ESRD patients on hemodialysis by using the amplitude of low-frequency fluctuation (ALFF). Nineteen ESRD patients on regular hemodialysis were included in this study. Eighteen age-, sex- and education level-matched volunteers were enrolled as the healthy control group. All participants had resting-state functional MRI scanning, neuropsychological tests, and laboratory testing. ALFF was used for assessing intrinsic brain activity. Independent samples t-test was used for obtaining group differences. Spearman correlation analysis was applied to assess the association between ALFF changes, neuropsychological, and clinical indices. Compared to the healthy control group, hemodialysis patients showed decreased ALFF in the precuneus, right angular gyrus/inferior lobule as well as increased ALFF in the left parahippocampus/hippocampus and right precentral/postcentral gyrus. The ALFF abnormalities in these regions were closely associated with hemoglobin levels. Also, increased ALFF in the left parahippocampus/hippocampus showed a negative correlation with the score of long-delayed free recall. Hemodialysis patients had aberrant ALFF in the default mode network (DMN) regions, particularly in the precuneus and parahippocampus/hippocampus, which may be correlated with neuropathological mechanisms involved in hemodialysis.

Structure-Function Connectomics Reveals Aberrant Developmental Trajectory Occurring at Preadolescence in the Autistic Brain

Accumulating neuroimaging evidence shows that age estimation obtained from brain connectomics reflects the level of brain maturation along with neural development. It is well known that autism spectrum disorder (ASD) alters neurodevelopmental trajectories of brain connectomics, but the precise relationship between chronological age (ChA) and brain connectome age (BCA) during development in ASD has not been addressed. This study uses neuroimaging data collected from 50 individuals with ASD and 47 age- and gender-matched typically developing controls (TDCs; age range: 5-18 years). Both functional and structural connectomics were assessed using resting-state functional magnetic resonance imaging and diffusion tensor imaging data from the Autism Brain Imaging Data Exchange repository. For each participant, BCA was estimated from structure-function connectomics through linear support vector regression. We found that BCA matched well with ChA in TDC children and adolescents, but not in ASD. In particular, our findings revealed that individuals with ASD exhibited accelerated brain maturation in youth, followed by a delay of brain development starting at preadolescence. Our results highlight the critical role of BCA in understanding aberrant developmental trajectories in ASD and provide the new insights into the pathophysiological mechanisms of this disorder.

Similarity and diversity of spontaneous brain activity in functional dyspepsia subtypes

BACKGROUND

Functional dyspepsia (FD) subtypes may differ in terms of pathophysiology, but the underlying mechanisms remain poorly understood.

PURPOSE

To explore spontaneous brain activity in two main FD subtypes, namely epigastric pain syndrome (EPS) and postprandial distress syndrome (PDS), using the amplitude of low-frequency fluctuation (ALFF).

MATERIAL AND METHODS

Thirty-one FD patients (18 EPS and 13 PDS) and 22 matched healthy controls (HC) underwent resting-state functional MRI scanning. Spontaneous brain activity was evaluated by measuring the ALFF and then compared among the EPS, PDS, and HC groups with ANOVA test. Pearson correlation analysis was performed between the ALFF values and clinical indices.

RESULTS

Compared to healthy controls, both EPS and PDS patients had increased ALFF in the bilateral precentral/postcentral gyri, insula, and thalami. Furthermore, only the EPS patients displayed increased ALFF in the right middle and inferior frontal gyri, and only the PDS patients showed increased ALFF in the left posterior cingulate cortex (PCC). The ALFF values in the left thalamus were positively correlated with the sleep disturbance in EPS patients, and the ALFF values in the right precentral/postcentral gyri showed a positive correlation with the symptom score in PDS patients.

CONCLUSION

EPS and PDS had similarities of higher spontaneous brain activity in the primary motor/sensory areas and homeostatic-afferent network regions, and differences in the prefrontal region and PCC, providing evidence to suggest the similarity and diversity of pathophysiology in FD subtypes.

Functional-structural relationship in large-scale brain networks of patients with end stage renal disease after kidney transplantation: A longitudinal study

It is unclear how the brain network changed after kidney transplantation (KT). We explored the patterns of large‐scale complex network after KT in end‐stage renal disease (ESRD) patients with resting‐state functional MRI (rs‐fMRI) and diffusion tensor imaging (DTI). Twenty‐one ESRD patients (14 men; mean age, 31.5 ± 9.9 years) scheduled for KT and 17 age‐ and gender‐matched healthy controls (HC) (8 men; mean age, 28.9 ± 7.2 years) were enrolled in this study. Each participant underwent rs‐fMRI and DTI scans in three time points (pre‐KT, 1 and 6 months after KT [for ESRD]). Graph theory analysis was used to characterize the topological properties by using functional and structural network connectivities intergroup correlation analysis was performed between functional/structural MR indexes and clinical markers. Compared with HC, pre‐KT ESRD patients showed an altered topological organization in both functional and structural networks. Compared with pre‐KT, increased node degree and node efficiency were observed for both functional and structural networks at 1 month after KT (all p < .05), which were further increased at 6 months after KT (p < .05). Both functional and structural networks did not recover completely at 6 months after KT (all p < .05). The patients showed an increased functional–structural connectivity coupling at 1 month after KT compared with HC (p = .041). A trend of progressive recovery of functional and structural connectivity networks was observed in ERSD patients after KT, which did not recover to the normal levels even in 6 months after KT. The study results underlie cognitive function recovery in ESRD patients following KT in the neuropathophysiological perspective.

Effects of COMT rs4680 and BDNF rs6265 polymorphisms on brain degree centrality in Han Chinese adults who lost their only child

Losing one's only child is a major traumatic life event that may lead to posttraumatic stress disorder (PTSD); however, not all parents who experience this trauma develop PTSD. Genetic variants are associated with the risk of developing PTSD. Catechol-O-methyltransferase (COMT) rs4680 and brain-derived neurotrophic factor (BDNF) rs6265 are two most well-described single-nucleotide polymorphisms that relate to stress response; however, the neural mechanism underlying their effects on adults who lost an only child remains poorly understood. Two hundred and ten Han Chinese adults who had lost their only child (55 with PTSD and 155 without PTSD) were included in this imaging genetics study. Participants were divided into subgroups according to their COMT rs4680 and BDNF rs6265 genotypes. Degree Centrality (DC)-a resting-state fMRI index reflecting the brain network communication-was compared with a three-way (PTSD diagnosis, COMT, and BDNF polymorphisms) analysis of covariance. Diagnosis state had a significant effect on DC in bilateral inferior parietal lobules and right middle frontal gyrus (MFG), where PTSD adults showed weaker DC. BDNF × diagnosis interaction effect was found in the right MFG and hippocampus, and these two regions were reversely modulated. Also, there was a significant COMT × BDNF interaction effect in left cuneus, middle temporal gyrus, right inferior occipital gyrus, and bilateral putamen, independent of PTSD diagnosis. These findings suggest that the modulatory effect of BDNF polymorphism on the MFG and hippocampus may contribute to PTSD development in bereaved adults. Interactions of COMT × BDNF polymorphisms modulate some cortices and basal ganglia, irrespective of PTSD development.

Effects of hypogonadism on brain development during adolescence in girls with Turner syndrome

Gonadal steroids play an important role in brain development, particularly during puberty. Girls with Turner syndrome (TS), a genetic disorder characterized by the absence of all or part of the second X chromosome, mostly present a loss of ovarian function and estrogen deficiency, as well as neuroanatomical abnormalities. However, few studies have attempted to isolate the indirect effects of hormones from the direct genetic effects of X chromosome insufficiency. Brain structural (i.e., gray matter [GM] morphology and white matter [WM] connectivity) and functional phenotypes (i.e., resting-state functional measures) were investigated in 23 adolescent girls with TS using multimodal MRI to assess the role of hypogonadism in brain development in TS. Specifically, all girls with TS were divided into a hormonally subnormal group and an abnormal subgroup according to their serum follicle-stimulating hormone (FSH) levels, with the karyotypes approximately matched between the two groups. Statistical analyses revealed significant effects of the "group-by-age" interaction on GM volume around the left medial orbitofrontal cortex and WM diffusion parameters around the bilateral corticospinal tract, anterior thalamic radiation, left superior longitudinal fasciculus, and cingulum bundle, but no significant "group-by-age" or group differences were observed in resting-state functional measures. Based on these findings, estrogen deficiency has a nontrivial impact on the development of the brain structure during adolescence in girls with TS. Our present study provides novel insights into the mechanism by which hypogonadism influences brain development during adolescence in girls with TS, and highlights the important role of estrogen replacement therapy in treating TS.

iTRAQ-based quantitative proteomic analysis provides insight for molecular mechanism of neuroticism

Background

Neuroticism is a core personality trait and a major risk factor for several mental and physical diseases, particularly in females, who score higher on neuroticism than men, on average. However, a better understanding of the expression profiles of proteins in the circulating blood of different neurotic female populations may help elucidate the intrinsic mechanism of neurotic personality and aid prevention strategies on mental and physical diseases associated with neuroticism.

Methods

In our study, female subjects were screened for inclusion by the Eysenck Personality Questionnaire (EPQ), Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI) scales and routine physical examination. Subjects who passed the examination and volunteered to participate were grouped by neuroticism using EPQ scores (0 and 1 = low neuroticism group; > 5 = high neuroticism group). Proteins in serum samples of the two neuroticism groups were identified using isobaric tags for relative and absolute quantification (iTRAQ) technology.

Results

A total of 410 proteins exhibited significant differences between high and low neuroticism, 236 proteins were significantly upregulated and 174 proteins were significantly downregulated. Combine the results of GO and KEGG enrichment analysis of differences proteins between high and low neuroticism with the PPI network, it could be observed that the Alpha-synuclein (SNCA), ATP7A protein (ATP7A), Guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-2 (GNG2), cyclin-dependent kinase 6 (CDK6), myeloperoxidase (MPO), azurocidin (AZU1), Histone H2B type 1-H (HIST1H2BH), Integrin alpha-M (ITGAM) and Matrix metalloproteinase-9 (MMP9) might participate in the intrinsic mechanism of neuroticism by regulating response to catecholamine stimulus, catecholamine metabolic process, limbic system development and transcriptional misregulation in cancer pathway.

Conclusions

Our study revealed the characteristics of the neurotic personality proteome, which might be intrinsic mechanism of the neurotic population.

Intrinsic Frontolimbic Connectivity and Mood Symptoms in Young Adult Cannabis Users

Objective: The endocannbinoid system and cannabis exposure has been implicated in emotional processing. The current study examined whether regular cannabis users demonstrated abnormal intrinsic (a.k.a. resting state) frontolimbic connectivity compared to non-users. A secondary aim examined the relationship between cannabis group connectivity differences and self-reported mood and affect symptoms.

Method: Participants included 79 cannabis-using and 80 non-using control emerging adults (ages of 18–30), balanced for gender, reading ability, and age. Standard multiple regressions were used to predict if cannabis group status was associated with frontolimbic connectivity after controlling for site, past month alcohol and nicotine use, and days of abstinence from cannabis.

Results: After controlling for research site, past month alcohol and nicotine use, and days of abstinence from cannabis, cannabis users demonstrated significantly greater connectivity between left rACC and the following: right rACC (p = 0.001; corrected p = 0.05; f² = 0.55), left amygdala (p = 0.03; corrected p = 0.47; f² = 0.17), and left insula (p = 0.03; corrected p = 0.47; f² = 0.16). Among cannabis users, greater bilateral rACC connectivity was significantly associated with greater subthreshold depressive symptoms (p = 0.02).

Conclusions: Cannabis using young adults demonstrated greater connectivity within frontolimbic regions compared to controls. In cannabis users, greater bilateral rACC intrinsic connectivity was associated with greater levels of subthreshold depression symptoms. Current findings suggest that regular cannabis use during adolescence is associated with abnormal frontolimbic connectivity, especially in cognitive control and emotion regulation regions.

Nurturing the preterm infant brain: leveraging neuroplasticity to improve neurobehavioral outcomes

An intrinsic feature of the developing brain is high susceptibility to environmental influence-known as plasticity. Research indicates cascading disruption to neurological development following preterm (PT) birth; yet, the interactive effects of PT birth and plasticity remain unclear. It is possible that, with regard to neuropsychological outcomes in the PT population, plasticity is a double-edged sword. On one side, high plasticity of rapidly developing neural tissue makes the PT brain more vulnerable to injury resulting from events, including inflammation, hypoxia, and ischemia. On the other side, plasticity may be a mechanism through which positive experience can normalize neurological development for PT children. Much of the available literature on PT neurological development is clinically weighted and focused on diagnostic utility for predicting long-term outcomes. Although diagnostic utility is valuable, research establishing neuroprotective factors is equally beneficial. This review will: (1) detail specific mechanisms through which plasticity is adaptive or maladaptive depending on the experience; (2) integrate research from neuroimaging, intervention, and clinical science fields in a summary of findings suggesting inherent plasticity of the PT brain as a mechanism to improve child outcomes; and (3) summarize how responsive caregiving experiences situate parents as agents of change in normalizing PT infant brain development.

Investigating the Correspondence of Clinical Diagnostic Grouping With Underlying Neurobiological and Phenotypic Clusters Using Unsupervised Machine Learning

Many brain-based disorders are traditionally diagnosed based on clinical interviews and behavioral assessments, which are recognized to be largely imperfect. Therefore, it is necessary to establish neuroimaging-based biomarkers to improve diagnostic precision. Resting-state functional magnetic resonance imaging (rs-fMRI) is a promising technique for the characterization and classification of varying disorders. However, most of these classification methods are supervised, i.e., they require a priori clinical labels to guide classification. In this study, we adopted various unsupervised clustering methods using static and dynamic rs-fMRI connectivity measures to investigate whether the clinical diagnostic grouping of different disorders is grounded in underlying neurobiological and phenotypic clusters. In order to do so, we derived a general analysis pipeline for identifying different brain-based disorders using genetic algorithm-based feature selection, and unsupervised clustering methods on four different datasets; three of them-ADNI, ADHD-200, and ABIDE-which are publicly available, and a fourth one-PTSD and PCS-which was acquired in-house. Using these datasets, the effectiveness of the proposed pipeline was verified on different disorders: Attention Deficit Hyperactivity Disorder (ADHD), Alzheimer's Disease (AD), Autism Spectrum Disorder (ASD), Post-Traumatic Stress Disorder (PTSD), and Post-Concussion Syndrome (PCS). For ADHD and AD, highest similarity was achieved between connectivity and phenotypic clusters, whereas for ASD and PTSD/PCS, highest similarity was achieved between connectivity and clinical diagnostic clusters. For multi-site data (ABIDE and ADHD-200), we report site-specific results. We also reported the effect of elimination of outlier subjects for all four datasets. Overall, our results suggest that neurobiological and phenotypic biomarkers could potentially be used as an aid by the clinician, in additional to currently available clinical diagnostic standards, to improve diagnostic precision. Data and source code used in this work is publicly available at https://github.com/xinyuzhao/identification-of-brain-based-disorders.git.

Altered spontaneous brain activity in MRI-negative refractory temporal lobe epilepsy patients with major depressive disorder: A resting-state fMRI study

OBJECTIVE

To investigate alterations in spontaneous brain activity in MRI-negative refractory temporal lobe epilepsy patients with major depressive disorder using resting-state functional magnetic resonance imaging (RS-fMRI).

METHODS

Eighteen MRI-negative refractory temporal lobe epilepsy patients with major depressive disorder (PDD), 17 MRI-negative refractory temporal lobe epilepsy patients without major depressive disorder (nPDD), and 21 matched healthy controls (HC) were recruited from West China Hospital of SiChuan University from April 2016 to June 2017. The Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) and 17-item Hamilton Depression Rating Scale were employed to confirm the diagnosis of major depressive disorder and assess the severity of depression. All participants underwent RS-fMRI scans using a 3.0T MRI system. MRI data were compared and analyzed using the amplitude of low-frequency fluctuations (ALFF) and regional homogeneity (ReHo) to measure spontaneous brain activity. These two methods were both used to evaluate spontaneous cerebral activity.

RESULTS

The PDD group showed significantly altered spontaneous brain activity in the bilateral mesial prefrontal cortex, precuneus, angular gyrus, right parahippocampal gyrus, and right temporal pole. Meanwhile, compared with HC, the nPDD group demonstrated altered spontaneous brain activity in the temporal neocortex but no changes in mesial temporal structures.

CONCLUSION

The PDD group showed regional brain activity alterations in the prefrontal-limbic system and dysfunction of the default mode network. The underlying pathophysiology of PDD may be provided for further studies.

Alteration of cortico-limbic-striatal neural system in major depressive disorder and bipolar disorder

BACKGROUND

It is often difficult to differentiate major depressive disorder (MDD) and bipolar disorder (BD) merely according to clinical symptoms. Similarities and differences in neural activity between the two disorders remain unclear. In current study, we use amplitude of low-frequency fluctuations (ALFF) to compare neural activation changes between MDD and BD patients.

METHODS

One hundred and eighty-three adolescents and young adults (57 MDD, 46 BD and 80 healthy controls, HC) were scanned during resting state. The ALFF for each participant was calculated, and were then compared among all groups using voxel-based analysis.

RESULTS

There was a significant effect of diagnosis in the core regions of cortico-limbic-striatal neural system. Furthermore, MDD showed left-sided abnormal neural activity while BD showed a bilateral abnormality in this neural system.

LIMITATIONS

This study was underpowered to consider medications, mood states and neural developmental effects on the neural activation.

CONCLUSIONS

Differences in lateralization of ALFF alterations were found. Alterations predominated in the left hemisphere for MDD, whereas alterations were bilateral for BD.

Quality of attachment in infants less than 1500g or less than 32weeks. Related factors

BACKGROUND

Prematurity carries a high risk of mortality and sequelae, altering the bonding process and leading to repercussions in terms of attachment.

OBJECTIVE

To assess the type of attachment in children under 32weeks' gestational age (GA) or below 1500g, in hospitals where development-centred care has been implemented and to study the association between various types of attachment and certain neonatal and family characteristics.

METHOD

Children <1500g or <32weeks GA who were born or admitted before 48h of life to one of two hospitals in Madrid between January and December 2012 were candidates for the study. The type of attachment was assessed through the strange situation procedure (SSP). Attachment was classified according to three types: secure (B), avoidant (A), or resistant/ambivalent (C). Insecure attachment was considered to be A+C. Children were assessed at a corrected age of 2years using the Bayley III Scales and SSP. Data on the characteristics of the parents and children were collected.

RESULTS

A total of 59% (117/199) of the children <1500g or <32weeks GA born in 2012 in the two study hospitals were able to be evaluated. Secure attachment was found in 64% (75/117), avoidant attachment in 12.8% (15/117), and resistant/ambivalent in 23.1% (27/117). The children with secure attachment had a score of 107.6±16 in the cognitive area of the Bayley's Scale versus 98.8±18.8 in those with insecure attachment (p 0.007). Frequency of secure attachment at ≤26weeks GA was 23% (3/13) versus 69% (72/104) in children >26weeks GA (p 0.003).

CONCLUSIONS

Nearly two-thirds of the children studied presented secure attachment, which was associated with better cognitive development. The frequency of secure attachment is lower in the children born more preterm.

Pain Perception in Buddhism Perspective

Dhamma, which Lord Buddha has presented to people after his enlightenment, analyzes every phenomenon and objects into their ultimate elements. The explanation of sensory system is also found in a part of Dhamma named Abhidhammapitaka, the Book of the Higher Doctrine in Buddhism. To find out the relationship between explanation of pain in the present neuroscience and the explanation of pain in Abhidhamma, the study was carried out by the use of a comprehensive review. The comparisons were in terms of peripheral stimulation, signal transmission, modulation, perception, suffering, determination and decision making for the responding to pain. We found that details of the explanation on pain mechanism and perception in Abhidhamma could associate well with our present scientific knowledge. Furthermore, more refinement information about the process and its function in particular aspects of pain perception were provided in Abhidhammapitaka.

On cognitive ecology and the environmental factors that promote Alzheimer disease: lessons from Octodon degus (Rodentia: Octodontidae)

Cognitive ecologist posits that the more efficiently an animal uses information from the biotic and abiotic environment, the more adaptive are its cognitive abilities. Nevertheless, this approach does not test for natural neurodegenerative processes under field or experimental conditions, which may recover animals information processing and decision making and may explain, mechanistically, maladaptive behaviors. Here, we call for integrative approaches to explain the relationship between ultimate and proximate mechanisms behind social behavior. We highlight the importance of using the endemic caviomorph rodent Octodon degus as a valuable natural model for mechanistic studies of social behavior and to explain how physical environments can shape social experiences that might influence impaired cognitive abilities and the onset and progression of neurodegenerative disorders such as Alzheimer disease. We consequently suggest neuroecological approaches to examine how key elements of the environment may affect neural and cognitive mechanisms associated with learning, memory processes and brain structures involved in social behavior. We propose the following three core objectives of a program comprising interdisciplinary research in O. degus, namely: (1) to determine whether diet types provided after weaning can lead to cognitive impairment associated with spatial memory, learning and predisposing to develop Alzheimer disease in younger ages; (2) to examine if early life social experience has long term effects on behavior and cognitive responses and risk for development Alzheimer disease in later life and (3) To determine if an increase of social interactions in adult degu reared in different degree of social stressful conditions alter their behavior and cognitive responses.

Estrogen- and progesterone-mediated structural neuroplasticity in women: evidence from neuroimaging

There is substantial evidence that the ovarian sex hormones, estrogen and progesterone, which vary considerably over the course of the human female lifetime, contribute to changes in brain structure and function. This structured, quantitative literature reviews aims to summarize neuroimaging literature addressing physiological variation in brain macro- and microstructure across an array of hormonal transitions including the menstrual cycle, use of hormonal contraceptives, pregnancy, and menopause. Twenty-five studies reporting structural neuroimaging of women, addressing variation across hormonal states, were identified from a structured search of PUBMED and were systematically reviewed. Although the studies are heterogenous with regard to methodology, overall the results point to overlapping areas of hormone related effects on brain structure particularly affecting the structures of the limbic system. These findings are in keeping with functional data that point to a role for estrogen and progesterone in mediating emotional processing.

Early unpredictability predicts increased adolescent externalizing behaviors and substance use: A life history perspective

According to evolutionary life history models, environmental harshness and unpredictability can both promote a fast life history strategy characterized by increased risk taking and enacting short-term, opportunistic behaviors. The current longitudinal study tests whether environmental unpredictability during childhood has stronger effects on risky behavior during adolescence than harshness, and whether there may be an early "sensitive period" during which unpredictability has particularly strong and unique effects on these outcomes. Using data from the Minnesota Longitudinal Study of Risk and Adaptation, prospective assessments of environmental unpredictability (changes in residence, cohabitation, and parental occupation) and harshness (mean socioeconomic status) from birth into adolescence were used to predict self-reported externalizing behaviors and substance use at age 16 (N = 220). Exposure to greater early unpredictability (between ages 0 and 5) predicted more externalizing behaviors as well as more alcohol and marijuana use at age 16, controlling for harshness and later unpredictability (between ages 6 and 16). Harshness predicted adolescent substance use, and later unpredictability predicted adolescent externalizing behaviors at the trend level. Early unpredictability and harshness also interacted, such that the highest levels of risk taking occurred in individuals who experienced more early unpredictability and lived in harsher environments. Age 16 externalizing behaviors, but not substance use, mediated the association between early unpredictability and externalizing/criminal behaviors at age 23. We discuss how exposure to early environmental unpredictability may alter biological and social-cognitive functioning from a life history perspective.

Altered cortical and subcortical local coherence in PTSD: evidence from resting-state fMRI

BACKGROUND

Post-traumatic stress disorder (PTSD) is often characterized by region-specific brain activation/deactivation and functional abnormalities in corticolimbic circuitry, as elucidated by task-dependent functional neuroimaging. However, little is known about the abnormalities in the local coherence of cortical and subcortical activity occurring during the resting state.

PURPOSE

To evaluate the functional discrepancy of local coherence between cortical and subcortical regions in PTSD patients using resting-state functional magnetic resonance imaging (fMRI).

MATERIAL AND METHODS

Resting-state fMRI (RS-fMRI) was performed on 14 outpatients with PTSD, along with 14 age- and sex-matched normal control subjects. Regional homogeneity (ReHo), a measurement of the coherence of spontaneous RS-fMRI signal oscillations within spatially neighboring voxels, was examined.

RESULTS

Compared with the normal controls, PTSD patients showed increased local coherence in subcortical regions, including amygdala, hippocampus, thalamus, and putamen, and decreased local coherence in cortical regions, including medial prefrontal cortex and dorsolateral prefrontal cortex. Moreover, a correlation analysis of the ReHo measurement versus the severity of the disorder was performed, and highly positive correlation were observed in the right amygdala.

CONCLUSION

The present study identified a functional discrepancy of local coherence between cortical and subcortical regions in PTSD patients compared with normal controls. The findings revealed that resting-state abnormalities might lead to further improvement of the understanding of the neural substrates of cognitive impairment and symptoms in PTSD.

The effect of severe stress on early brain development, attachment, and emotions: a psychoanatomical formulation

Child abuse is the most extreme form of stress in childhood and adolescence, and has severe effects on the child's development. Limbic nuclei and circuitry development are especially vulnerable to child abuse and neglect during the first year of life. Development at the neuronal level can be severely disturbed by trauma during early infancy, resulting in maladaptive synaptic formation, impeding experience-expectant brain development. Development of basic emotions may favor the development of negative instead of positive emotions. The new concept of psychoanatomical formulation is introduced. A case vignette is presented and analyzed, based on the disturbed neuroanatomy underlying symptom expression.

Characterization of post-traumatic stress disorder using resting-state fMRI with a multi-level parametric classification approach

Functional neuroimaging studies have found intra-regional activity and inter-regional connectivity alterations in patients with post-traumatic stress disorder (PTSD). However, the results of these studies are based on group-level statistics and therefore it is unclear whether PTSD can be discriminated at single-subject level, for instance using the machine learning approach. Here, we proposed a novel framework to identify PTSD using multi-level measures derived from resting-state functional MRI (fMRI). Specifically, three levels of measures were extracted as classification features: (1) regional amplitude of low-frequency fluctuations (univariate feature), which represents local spontaneous synchronous neural activity; (2) temporal functional connectivity (bivariate feature), which represents the extent of similarity of local activity between two regions, and (3) spatial functional connectivity (multivariate feature), which represents the extent of similarity of temporal correlation maps between two regions. Our method was evaluated on 20 PTSD patients and 20 demographically matched healthy controls. The experimental results showed that the features of each level could successfully discriminate PTSD patients from healthy controls. Furthermore, the combination of multi-level features using multi-kernel learning can further improve the classification performance. Specifically, the classification accuracy obtained by the proposed framework was 92.5 %, which was an increase of at least 5 and 17.5 % from the two-level and single-level feature based methods, respectively. Particularly, the limbic structure and prefrontal cortex provided the most discriminant features for classification, consistent with results reported in previous studies. Together, this study demonstrated for the first time that patients with PTSD can be identified at the individual level using resting-state fMRI data. The promising classification results indicated that this method may provide a complementary approach for improving the clinical diagnosis of PTSD.

Abnormalities in whole-brain functional connectivity observed in treatment-naive post-traumatic stress disorder patients following an earthquake

BACKGROUND

Convergent studies have highlighted the dysfunction of the amygdala, prefrontal cortex and hippocampus in post-traumatic stress disorder (PTSD). However, only a few studies have investigated the functional connectivity between brain regions in PTSD patients during the resting state, which may improve our understanding of the neuropathophysiology of PTSD. The aim of this study was to investigate patterns of whole-brain functional connectivity in treatment-naive PTSD patients without co-morbid conditions who experienced the 8.0-magnitude earthquake in the Sichuan province of China.

METHOD

A total of 72 PTSD patients and 86 trauma-exposed non-PTSD controls participated in the resting-state functional magnetic resonance imaging study. All these subjects were recruited from the disaster zone of the 2008 Sichuan earthquake. Functional connectivities between 90 paired brain regions in PTSD patients were compared with those in trauma-exposed non-PTSD controls. Furthermore, Pearson correlation analysis was performed between significantly abnormal connectivities in PTSD patients and their clinician-administered PTSD scale (CAPS) scores.

RESULTS

Compared with non-PTSD controls, PTSD patients showed weaker positive connectivities between the middle prefrontal cortex (mPFC) and the amygdala, hippocampus, parahippocampal gyrus and rectus, as well as between the inferior orbitofrontal cortex and the hippocampus. In addition, PTSD patients showed stronger negative connectivity between the posterior cingulate cortex (PCC) and the insula. The CAPS scores in PTSD patients correlated negatively with the connectivity between the amygdala and the mPFC.

CONCLUSIONS

PTSD patients showed abnormalities in whole-brain functional connectivity, primarily affecting the connectivities between the mPFC and limbic system, and connectivity between the PCC and insula.

Regional cerebral blood flow in children from 3 to 5 months of age

BACKGROUND AND PURPOSE

Understanding the relationship between brain and behavior in early childhood requires a probe of functional brain development. We report the first large study of regional CBF by use of arterial spin-labeling in young children.

MATERIALS AND METHODS

Cerebral blood flow by use of arterial spin-labeling was measured in 61 healthy children between the ages of 3 and 5 months. Blood flow maps were parcellated into 8 broadly defined anatomic regions of each cerebral hemisphere.

RESULTS

There was no sex effect; however, group analysis demonstrated significantly greater CBF in the sensorimotor and occipital regions compared with dorsolateral prefrontal, subgenual, and orbitofrontal areas (P < .0001). A significant age effect was also identified, with the largest increase in blood flow between 3 and 5 months occurring in the following regions: orbitofrontal (P < .009), subgenual (P < .002), and inferior occipital lobe (P = .001).

CONCLUSIONS

These results are consistent with prior histologic studies demonstrating regional variation in brain maturation and suggest that arterial spin-labeling is sensitive to regional as well as age-related differences in CBF in young children.

Octodon degus (Molina 1782): a model in comparative biology and biomedicine

One major goal of integrative and comparative biology is to understand and explain the interaction between the performance and behavior of animals in their natural environment. The Caviomorph, Octodon degu, is a native rodent species from Chile, and represents a unique model to study physiological and behavioral traits, including cognitive and sensory abilities. Degus live in colonies and have a well-structured social organization, with a mostly diurnal-crepuscular circadian activity pattern. More notable is the fact that in captivity, they reproduce and live between 5 and 7 yr and show hallmarks of neurodegenerative diseases (including Alzheimer's disease), diabetes, and cancer.

Ontogeny of contextual fear memory formation, specificity, and persistence in mice

Pinpointing the precise age when young animals begin to form memories of aversive events is valuable for understanding the onset of anxiety and mood disorders and for detecting early cognitive impairment in models of childhood-onset disorders. Although these disorders are most commonly modeled in mice, we know little regarding the development of learning and memory in this species because most previous studies have been restricted to rats. Therefore, in the present study, we constructed an ontogenetic timeline of contextual fear memory ranging from infancy to adulthood in mice. We found that the ability of mice to form long-term context-shock associations emerged ∼13-14 d of age, which is several days earlier than previously reported for rats. Although the ability to form contextual fear memories remained stable from infancy into adulthood, infant mice had shorter-lasting memories than adolescent and adult mice. Furthermore, we found that mice subjected to fetal alcohol exposure showed a delay in the developmental emergence of contextual fear memory, illustrating the utility of this ontogenetic approach in detecting developmental delays in cognitive function stemming from maladaptive early life experience.

Closeness and separation in neonatal intensive care

In this paper, we highlight the need for acknowledging the importance and impact of both physical and emotional closeness between the preterm infant and parent in the neonatal intensive care unit. Physical closeness refers to being spatially close and emotional closeness to parental feelings of being emotionally connected to the infant (experiencing feelings of love, warmth and affection). Through consideration of the literature in this area, we outline some of the reasons why physical closeness and emotional closeness are crucial to the physical, emotional and social well-being of both the infant and the parent. These include positive effects on infant brain development, parent psychological well-being and on the parent–infant relationship. The influence of the neonatal unit environment and culture on physical and emotional closeness is also discussed.