Developmental Changes of Brain Oscillatory Pattern in Children With and Without Epilepsy

Cross-sectional methodologies have revealed age-related deterioration in cognitive performance, reflecting progressive neurodegenerative change in a minority of children and adolescents with classic galactosemia (GAL). The application of longitudinal methodologies sensitive to age-related changes at the individual level is needed to determine the extent of any possible decline in function in children with GAL. The authors report on the developmental language outcomes of a 9-year-old female with GAL through an examination of her language development over a 7-year period using a performance tracking system based on the use of raw performance scores required for attainment at the 50th percentile for age. Raw scores typically increase systematically over time and are thus more sensitive to developmental changes. Results suggest that there was no decline in the child's language skills over the course of the investigation. For the case presented, the use of raw scores offered a means of examining the child's patterns of individual change, which revealed stable language skills over the period of monitoring, perhaps indicating a stable disease process for this particular child. The authors propose this descriptive application of raw performance scores that offers a means to determine neurodevelopmental outcomes in the disorder.

Developmental systems theories stress that, across the human life span, development involves the integration, or “fusion,” of changing relations among the multiple levels of organization that comprise the ecology of human life. These levels range from biology through culture and history. Indeed, the embeddedness of all levels within history provides a temporal component to human development; makes the potential for change a defining feature of human development; and as such assures that relative plasticity (i.e., the potential for systematic change across ontogeny) characterizes development across the human life span. Moreover, within this developmental system changes are interdependent. For instance, changes within one level of organization, e.g., developmental changes in personality or cognition within the individual, are reciprocally related to developmental changes within other levels, e.g., involving changes in caregiving patterns or spousal relationships within the familial level of organization. In turn, the reciprocal changes among levels of organization are both products and producers of the reciprocal changes within levels. These interrelations illustrate the need for integrated, multidisciplinary study across the life span of changes within and among the multiple levels of organization comprising the ecology of human life. The essence of such scholarship involves the conceptualization and investigation of the mutual regulation of change between person and context or, in other words, of the regulation of relations, of how structures function and how functions are structured over time. The lifespan model of this regulatory relational architecture—the model of selection, optimization, and compensation (SOC)—is thus an exemplary theoretical frame within which to study the human developmental system.

Amino acid metabolism in the early development of the sea urchin Paracentrotus lividus

How maternal and paternal parenting behaviors predict developmental changes in self-control and deviance during early adolescence

Although Attention Deficit/Hyperactivity Disorder (ADHD) has increasingly been studied in preschool-aged children, relatively few studies have provided a comprehensive evaluation of the factor structure and patterns of developmental changes in parent-reported ADHD symptomatology across the early childhood period. This study used confirmatory factor analyses to test for longitudinal measurement invariance of ADHD symptoms and semi-parametric finite mixture models to identify prototypic patterns of developmental changes in ADHD symptomatology from 3 to 5 years of age. Participants were 1155 children and their parents who participated in a prospective longitudinal study involving a representative sample of children who resided in six non-metropolitan counties in the United States. Results indicated that (1) ADHD symptomatology was best represented by a single latent factor that exhibited partial measurement invariance from 3 to 5 years of age, (2) 8.5 % of children exhibited sustained high levels of ADHD symptoms from age 3-5 years, and (3) a variety of risk factors differentiated children with sustained high from those with sustained low levels of ADHD, relatively few (most notably caregiver education) were able to differentiate children with sustained high levels of ADHD symptoms from all other groups. Children who exhibit persistent ADHD symptomatology across the early childhood period may define a clinically important group for etiologic research and/or early intervention efforts.

Age-dependent changes in the laminar distribution of cholinergic markers in rat visual cortex

Introduction Alterations in upper airway flow dynamics and sites of airway obstruction immediately after tonsillectomy and adenoidectomy (TA) have not been assessed. Identification of the changes in airway obstruction patterns after TA potentially improves the surgical management of children with obstructive sleep apnea (OSA).Objective To evaluate the effect of TA on upper airway obstruction patterns detected with drug-induced sleep endoscopy (DISE).Methods The medical records of patients who underwent pre-TA DISE during the induction of anesthesia and post-TA DISE at the end of TA were reviewed. Data pertaining to polysomnography and DISE findings were analyzed.Results Twenty-seven patients (15 male and 12 females aged between 2 and 18 years old) were identified. All patients had obstruction at multiple sites of the upper airway. Prior to TA, airway obstruction was at the level of the velum in 27 patients, of the oropharynx/lateral walls in 27, of the tongue in 7, and of the epiglottis in 4. After TA, airway obstruction was at the level of the velum in 24 patients, of the oropharynx/lateral walls in 16, of the tongue in 6, and of the epiglottis in 4. The degree of obstruction at the levels of the velum and oropharynx/lateral walls after TA was significantly decreased.Conclusions Drug-induced sleep endoscopy performed prior to TA revealed that most of the sites of airway obstruction persisted after TA in OSA children with multiple sites of airway obstruction. Further studies in larger group of children with OSA are needed to establish the value of DISE findings in predicting residual OSA after TA, surgical planning, determining the need for post TA sleep study, and counseling caregivers.

Longitudinal trajectories of hippocampal and prefrontal contributions to episodic retrieval: Effects of age and puberty

Udpgalactose:Ceramide galactosyltransferase in cultured oligodendrocytes: An enzymological and immunological study

A large field visual motion pattern (optic flow) with a radial pattern provides a compelling perception of self-motion; a radially expanding/contracting optic flow generates the perception of forward/backward locomotion. Moreover, the focus of a radial optic flow, particularly an expansive flow, is an important visual cue to perceive and control the heading direction during human locomotion. Previous research has shown that human gaze patterns have an “expansion bias”: a tendency to be more attracted to the focus of expansive flow than to the focus of contractive flow. We investigated the development of the expansion bias in children (N = 240, 1–12 years) and adults (N = 20). Most children aged ≥ 5 years and adults showed a significant tendency to shift their gaze to the focus of an expansive flow, whereas the youngest group (1-year-old children) showed a significant but opposing tendency; their gaze was more attracted to the focus of contractive flow than to the focus of expansive flow. The relationship between the developmental change from the “contraction bias” in early toddlerhood to the expansion bias in the later developmental stages and possible factors (e.g., global visual motion processing abilities and locomotor experiences) are discussed.

Mechanical forces from blood flow and pressure (hemodynamic forces) contribute to the formation and shaping of the blood vascular network during embryonic development. Previous studies have demonstrated that hemodynamic forces regulate signaling and gene expression in endothelial cells that line the inner surface of vascular tubes, thereby modifying their cellular state and behavior. Given its important role in vascular development, we still know very little about the quantitative aspects of hemodynamics that endothelial cells experience due to the difficulty in measuring forces in vivo. In this study, we sought to determine the magnitude of wall shear stress (WSS) exerted on ECs by blood flow in different vessel types and how it evolves during development. Utilizing the zebrafish as a vertebrate model system, we have established a semi-automated high-throughput fluorescent imaging system to capture the flow of red blood cells in an entire zebrafish between 2- and 6-day post-fertilization (dpf). This system is capable of imaging up to 50 zebrafish at a time. A semi-automated analysis method was developed to calculate WSS in zebrafish trunk vessels. This was achieved by measuring red blood cell flow using particle tracking velocimetry analysis, generating a custom-made script to measure lumen diameter, and measuring local tube hematocrit levels to calculate the effective blood viscosity at each developmental stage. With this methodology, we were able to determine WSS magnitude in different vessels at different stages of embryonic and larvae growth and identified developmental changes in WSS, with absolute levels of peak WSS in all vessel types falling to levels below 0.3 Pa at 6 dpf. Additionally, we discovered that zebrafish display an anterior-to-posterior trend in WSS at each developmental stage.

Sleep patterns in infancy and early childhood vary greatly and change rapidly during development. In adults, sleep patterns are regulated by interactions between neuronal populations in the brainstem and hypothalamus, driven by the circadian and sleep homeostatic processes. However, the neurophysiological mechanisms underlying the sleep patterns and their variations across infancy and early childhood are poorly understood. We investigated whether a well-established mathematical model for sleep regulation in adults can model infant sleep characteristics and explain the physiological basis for developmental changes. By fitting longitudinal sleep data spanning 2 to 540 days after birth, we inferred parameter trajectories across age. We found that the developmental changes in sleep patterns are consistent with a faster accumulation and faster clearance of sleep homeostatic pressure in infancy and a weaker circadian rhythm in early infancy. We also find greater sensitivity to phase-delaying effects of light in infancy and early childhood. These findings reveal fundamental mechanisms that regulate sleep in infancy and early childhood. Given the critical role of sleep in healthy neurodevelopment, this framework could be used to pinpoint pathophysiological mechanisms and identify ways to improve sleep quality in early life.

Reduced synaptophysin immunoreactivity in the dentate gyrus of prepulse inhibition-impaired isolation-reared rats

Homogenates and plasma membranes were isolated from the livers of male Fischer 344 rats ranging in age from 19 hr to 92 days postnatal. These plasma membranes exhibited comparable levels of purity: protein yields were 2-2.5%; relative specific activities of 5'-nucleotidase and ouabain-sensitive Na+/K(+)-ATPase were from 8-11 and from 12-19, respectively. 5'-nucleotidase and ouabain-sensitive Na+ K(+)-ATPase displayed distinct and different developmental patterns. The activity of gamma-glutamyltranspeptidase was found to be at exceptionally high levels in isolated plasma membranes immediately after birth and to decline precipitously thereafter achieving and maintaining low levels from days 3-21 postnatal. Liver plasma membrane gamma-glutamyltranspeptidase activity was observed to increase 9.2 fold from this low point, first rising on day 21, peaking on day 40 and returning to low levels by day 56. From day 56 day to 92 postnatal, gamma-glutamyltranspeptidase activity was expressed at a uniformly low level but a level 2 fold higher than that preceding the rise at day 40. The hormone determinants of these developmental changes in gamma-glutamyltranspeptidase activity are discussed.

Developmental changes in expression, subcellular distribution, and function of Drosophila N-cadherin, guided by a cell-intrinsic program during neuronal differentiation