ABSTRACT
Brain and nervous system development in human infants during the first 1000days (conception to two years of age) is critical, and compromised development during this time (such as from under nutrition or poverty) can have life-long effects on physical growth and cognitive function. Cortical mapping of cognitive function during infancy is poorly understood in resource-poor settings due to the lack of transportable and low-cost neuroimaging methods. Having established a signature cortical response to social versus non-social visual and auditory stimuli in infants from 4 to 6 months of age in the UK, here we apply this functional Near Infrared Spectroscopy (fNIRS) paradigm to investigate social responses in infants from the first postnatal days to the second year of life in two contrasting environments: rural Gambian and urban UK. Results reveal robust, localized, socially selective brain responses from 9 to 24 months of life to both the visual and auditory stimuli. In contrast at 0-2 months of age infants exhibit non-social auditory selectivity, an effect that persists until 4-8 months when we observe a transition to greater social stimulus selectivity. These findings reveal a robust developmental curve of cortical specialisation over the first two years of life.
Subject(s)
Brain/physiopathology , Cognition/physiology , Neuroimaging/methods , Spectroscopy, Near-Infrared/methods , Child, Preschool , Cohort Studies , Female , Gambia , Humans , Infant , Infant, Newborn , MaleABSTRACT
A pilot study was conducted to assess the feasibility of using fNIRS as an alternative to behavioral assessments of cognitive development with infants in rural Africa. We report preliminary results of a study looking at working memory in 12-16-month-olds and discuss the benefits and shortcomings for the potential future use of fNIRS to investigate the effects of nutritional insults and interventions in global health studies.
Subject(s)
Memory, Short-Term , Spectroscopy, Near-Infrared/methods , Africa , Humans , Infant , Pilot Projects , Rural PopulationABSTRACT
This article presents a summary of incident management guidelines for traumatically injured teeth during orthodontic treatment. In addition, treatment of a 17-year-old patient with traumatic extrusion and palatal displacement of the permanent maxillary incisors while undergoing active orthodontic treatment is reported.
Subject(s)
Incisor/injuries , Tooth Avulsion/therapy , Tooth Movement Techniques/methods , Adolescent , Bicycling/injuries , Clinical Protocols , Cone-Beam Computed Tomography/methods , Follow-Up Studies , Humans , Male , Orthodontic Retainers , Orthodontic Wires , Radiography, Bitewing/methods , Tooth Mobility/therapyABSTRACT
Cortical mapping of cognitive function during infancy is poorly understood in low-income countries due to the lack of transportable neuroimaging methods. We have successfully piloted functional near infrared spectroscopy (fNIRS) as a neuroimaging tool in rural Gambia. Four-to-eight month old infants watched videos of Gambian adults perform social movements, while haemodynamic responses were recorded using fNIRS. We found distinct regions of the posterior superior temporal and inferior frontal cortex that evidenced either visual-social activation or vocally selective activation (vocal > non-vocal). The patterns of selective cortical activation in Gambian infants replicated those observed within similar aged infants in the UK. These are the first reported data on the measurement of localized functional brain activity in young infants in Africa and demonstrate the potential that fNIRS offers for field-based neuroimaging research of cognitive function in resource-poor rural communities.
Subject(s)
Cognition/physiology , Public Health Surveillance , Spectroscopy, Near-Infrared , Africa , Cerebral Cortex/physiology , Female , Hemodynamics , Humans , Infant , Male , Neuroimaging , Oxyhemoglobins/metabolism , Rural Health , Spectroscopy, Near-Infrared/methodsABSTRACT
Extra-Corporeal Membrane Oxygenation (ECMO) is a life support system for infants and children with cardio-respiratory failure. During ECMO it is possible to have unstable cerebral haemodynamics, due to strong oscillations in the systemic variables, among other factors, which may lead to brain damage in the patients. Therefore, monitoring the coupling between cerebral haemodynamics and systemic signals might alert us of possible imminent brain damage. In this study we explore the use of orthogonal and oblique subspace projections in the decoupling of these variables, by assessing the ratio between the projections of the haemodynamic variables, onto the subspace spanned by the systemic variables, and the original signals. The coupling of these two systems may differ as different protection mechanisms protect the peripheral system and the brain. Subspace projection was able to decompose the heamodynamic variables as a sum of components related to each systemic variable, separately. As expected, stronger coupling was found between the peripheral haemodynamic and the systemic variables.
Subject(s)
Brain/physiology , Extracorporeal Membrane Oxygenation , Hemodynamics , Child , Child, Preschool , Humans , Infant , Infant, NewbornABSTRACT
Second-stage larvae of the soybean cyst nematodeHeterodera glycines Race 3 were attracted in an in vitro bioassay to pooled leachates of soybean roots that were expressed as root gram-hours (1 g of root/hr/vol). Their responses were dosage dependent with maximal attraction to a 5 root g-hr/ml source. Optimal bioassay conditions used 24 hr for gradient formation and 1.5 hr for larval movement. Individual plants produced leachate with little variation in biological activity. Production was constant for five days of preparation. The attractive activity of root leachate declined with storage at 4 °C and heating over 30 °C, but loss of activity was reduced by freezing. Extraction and Sep-Pak fractionation indicated that the attractions(s) was water-soluble. Larvae were attracted also to several ionic solutions.
