Early Bifrontal Brain Injury: Disturbances in Cognitive Function Development

We describe six psychomotor, language, and neuropsychological sequential developmental evaluations in a boy who sustained a severe bifrontal traumatic brain injury (TBI) at 19 months of age. Visuospatial, drawing, and writing skills failed to develop normally. Gradually increasing difficulties were noted in language leading to reading and spontaneous speech difficulties. The last two evaluations showed executive deficits in inhibition, flexibility, and working memory. Those executive abnormalities seemed to be involved in the other impairments. In conclusion, early frontal brain injury disorganizes the development of cognitive functions, and interactions exist between executive function and other cognitive functions during development

From traumatic childhood to cocaine abuse: the critical function of the immune system

Background: Experiencing traumatic childhood is a risk factor for developing substance use disorder (SUD), but the mechanisms that underlie this relationship have not been determined. Adverse childhood experiences affect the immune system and the immune system mediates the effects of psychostimulants. However, whether this system is involved in the etiology of SUD in individuals who have experience early life stress is unknown. Methods:In this study, we performed a series of ex vivo and in vivo experiments in mice and humans to define the function of the immune system in the early-life stress-induced susceptibility to the neurobehavioral effects of cocaine. Results: We provide evidence that exposure to social-stress (S-S) at an early age permanently sensitizes the peripheral (splenocytes) and brain (microglia) immune responses to cocaine in mice. In the brain, microglial activation in the ventral tegmental area (VTA) of S-S mice was associated with functional alterations in dopaminergic neurotransmission, as measured by whole-cell voltage clamp recordings in dopamine (DA) neurons. Notably, preventing immune activation during the S-S exposure reverted the effects of DA in the VTA and the cocaine-induced behavioral phenotype to control levels. In humans, cocaine modulated Toll-like receptor 4-mediated innate immunity, an effect that was enhanced in cocaine addicts who had experienced a difficult childhood. Conclusions Collectively, our findings demonstrate that sensitization to cocaine in early-life-stressed individuals involves brain and peripheral immune responses and that this mechanism is shared between mice and humans

Intact procedural motor sequence learning in developmental coordination disorder

The purpose of the present study was to explore the possibility of a procedural learning deficit among children with developmental coordination disorder (DCD). We tested 34 children aged 6–12 years with and without DCD using the serial reaction time task, in which the standard keyboard was replaced by a touch screen in order to minimize the impact of perceptuomotor coordination difficulties that characterize this disorder. The results showed that children with DCD succeed as well as control children at the procedural sequence learning task. These findings challenge the hypothesis that a procedural learning impairment underlies the difficulties of DCD children in acquiring and automatizing daily activities. We suggest that the previously reported impairment of children with DCD on the serial reaction time task is not due to a sequence learning deficit per se, but rather due to methodological factors such as the response mode used in these studies.Peer reviewe

Microglia maintain structural integrity during fetal brain morphogenesis

Microglia (MG), the brain-resident macrophages, play major roles in health and disease via a diversity of cellular states. While embryonic MG display a large heterogeneity of cellular distribution and transcriptomic states, their functions remain poorly characterized. Here, we uncovered a role for MG in the maintenance of structural integrity at two fetal cortical boundaries. At these boundaries between structures that grow in distinct directions, embryonic MG accumulate, display a state resembling post-natal axon-tract-associated microglia (ATM) and prevent the progression of microcavities into large cavitary lesions, in part via a mechanism involving the ATM-factor Spp1. MG and Spp1 furthermore contribute to the rapid repair of lesions, collectively highlighting protective functions that preserve the fetal brain from physiological morphogenetic stress and injury. Our study thus highlights key major roles for embryonic MG and Spp1 in maintaining structural integrity during morphogenesis, with major implications for our understanding of MG functions and brain development.</p

Is classroom noise always bad for children? The contribution of age and selective attention to creative performance in noise.

Creativity is considered an important skill in learning but little is known about the environmental factors affecting it in classroom settings. Extending adult findings, this study assessed whether moderate multi-talker noise promotes children’s creativity, and whether this is moderated by children’s age, working memory, and selective attention. Forty-four elementary school children between 5 and 11 years of age, divided into younger and older age groups, participated in this within-subjects’ study. The children completed two idea generation tasks; each participant performed the task both in silence and in moderate (64dB) classroom noise. Selective attention skills, verbal and visuospatial working memory were assessed with behavioural tasks. Results showed that there were no conditions in which classroom noise promoted children’s creativity whilst some negative effects of noise were observed. Younger children (between 5 and 8 years of age) with low selective attention skills were especially at risk: they gave fewer ideas in the presence of noise, and these ideas were rated as less original. Children with good selective attention skills were globally protected against the effects of noise, performing similarly in silence and noise. Future studies about children’s specific creative strategies might help shed light on the mechanisms underlying these effects

Differentiation in prefrontal cortex recruitment during childhood:Evidence from cognitive control demands and social contexts

Emerging cognitive control during childhood is largely supported by the development of distributed neural networks in which the prefrontal cortex (PFC) is central. The present study used fNIRS to examine how PFC is recruited to support cognitive control in 5–6 and 8-9-year-old children, by (a) progressively increasing cognitive control demands within the same task, and (b) manipulating the social context in which the task was performed (neutral, cooperative, or competitive), a factor that has been shown to influence cognitive control. Activation increased more in left than right PFC with cognitive control demands, a pattern which was more pronounced in older than younger children. In addition, activation was higher in left PFC in competitive than cooperative contexts, and higher in right PFC in cooperative and neutral than competitive contexts. These findings suggest that increasingly efficient cognitive control during childhood is supported by more differentiated recruitment of PFC as a function of cognitive control demands with age. Keywords: Prefrontal cortex, Cognitive control, Cooperation, Competition, Children, Functional near-infrared spectroscopy (fNIRS

Community-based interventions for adolescents following traumatic brain injury: a systematic review

Background: Chronic impairment following childhood traumatic brain injury has the potential to increase risk of negative outcomes. This highlights potential value of community-based rehabilitation programs. Objectives: To identify research studies examining existing intervention programmes available in community-based rehabilitation to adolescents following TBI to assist with the transition back into the community. Methods: A systematic review of community-based interventions was conducted across different national contexts. All included studies involved a clinical population with TBI, aged 11 to 25 years inclusive. Risk of bias was rated for each included study. Results: Seventeen studies were identified for inclusion in the review, of these eleven distinct interventions were found. The quality of evidence was largely weak and highly variable. Conclusion: The results suggest some improvement in adolescent outcomes following community-based interventions, however higher quality evidence is needed to support specific interventions