Southern Illinois University School of Medicine

About: Southern Illinois University School of Medicine is a education organization based out in Springfield, Illinois, United States. It is known for research contribution in the topics: Population & Cancer. The organization has 3747 authors who have published 5977 publications receiving 209115 citations. The organization is also known as: SIU School of Medicine.

The Contribution of Executive Functions to Emergent Mathematic Skills in Preschool Children.

Abstract: Mathematical ability is related to both activation of the prefrontal cortex in neuroimaging studies of adults and to executive functions in school-age children. The purpose of this study was to determine whether executive functions were related to emergent mathematical proficiency in preschool children. Preschool children (N = 96) were administered an executive function battery that was reduced empirically to working memory (WM), inhibitory control (IC), and shifting abilities by calculating composite scores derived from principal component analysis. Both WM and IC predicted early arithmetic competency, with the observed relations robust after controlling statistically for child age, maternal education, and child vocabulary. Only IC accounted for unique variance in mathematical skills, after the contribution of other executive functions were controlled statistically as well. Specific executive functions are related to emergent mathematical proficiency in this age range. Longitudinal studies using structural equation modeling are necessary to better characterize these ontogenetic relations.

Serum-free B27/neurobasal medium supports differentiated growth of neurons from the striatum, substantia nigra, septum, cerebral cortex, cerebellum, and dentate gyrus

Abstract: Two fundamental questions about neuron cell culture were addressed. Can one serum-free medium that was developed for optimum growth of hippocampal neurons support the growth of neurons from other regions of the brain? Is the region specific state of differentiation maintained in culture? To answer these questions, we isolated neurons from six other rat brain regions, placed them in culture in B27/Neurobasal defined medium, and analyzed their morphology and growth dependence on cell density after 4 days in culture. Neuronal identity was confirmed by immunostaining with antibodies to neurofilament 200. Neurons from each brain region maintained distinctive morphologies in culture in the virtual absence of glia. Cells isolated from embryonic day 18 cerebral cortex by digestion with papain showed the same high survival as hippocampal neurons, e.g., 70% survival for cells plated at 160/mm2. At this age and density, neurons from the septum showed slightly lower survival, 45%. Survival of dentate granule neurons from postnatal day four brains was 30-40%, significantly lower, and relatively independent of plating density. This suggests an absence of dependence on trophic factors or contact for dentate granule neurons. Growth of cerebellar granule neurons isolated from postnatal day 7, 8, or 9 brains in B27/Neurobasal was compared to growth in BME/10% serum. Viability in serum-free medium at 4 days was much better than that in serum, did not require KCl elevated to 25 mM, and occurred without substantial growth of glia. Cerebellar granule neurons plated at 1,280 cells/mm2 were maintained in culture for three weeks with 17% of the original cell density surviving. Survival of cells isolated from embryonic day 18 substantia nigra was 50% at 160 cells/mm2 after 4 days, similar to that of striatum, but slightly less than hippocampal neuron survival. The dopaminergic phenotype of the substantia nigral neurons was maintained over 2 weeks in culture as judged by immunoreactivity with antibodies to tyrosine hydroxylase. During this time, immunoreactivity was found in the processes as they grew out from the soma. Together, these studies suggest that B27/Neurobasal will be a useful medium for maintaining the differentiated growth of neurons from many brain regions. Potential applications of a common growth medium for different neurons are discussed.

Neurodevelopmental outcomes of infants born prematurely.

Abstract: Long-term follow-up of infants born prematurely is necessary to determine neurodevelopmental outcomes, particularly with the expansion of interest from major disabilities to high prevalence/low severity dysfunctions. Models of pathogenesis include changes due to developmental disruptions and to injury, the magnitude and type of change influenced by the infant's age, and central nervous system recovery and reorganization. Alterations in neurogenesis, migration, myelination, cell death, and synaptogenesis occur even in the absence of insult. Despite increased knowledge regarding these processes, the functional significance of brain abnormalities is unclear. Because of methodologic problems in follow-up studies, it is difficult to characterize outcome definitively. Nonetheless, an acceptable degree of agreement across studies is found with regard to specific neurodevelopmental outcomes: motor/neurologic function, visuomotor integrative skills, IQ, academic achievement, language, executive function, and attention-deficit hyperactivity disorder/behavioral issues. In general, children born prematurely have more problems in these areas than do their normal birth weight counterparts. Suggestions for improved analyses and clarification of outcomes include use of cluster analysis, structural equation modeling, growth curve analysis, developmental epidemiologic approaches, and better control of background variables using risk indexes and factor scores. Better assessment techniques measuring functions documented to be at higher risk of problems are discussed.

Enhanced recognition memory following vagus nerve stimulation in human subjects.

Abstract: Neuromodulators associated with arousal modulate learning and memory, but most of these substances do not freely enter the brain from the periphery. In rodents, these neuromodulators act in part by initiating neural messages that travel via the vagus nerve to the brain, and electrical stimulation of the vagus enhances memory. We now extend that finding to human verbal learning. We examined word-recognition memory in patients enrolled in a clinical study evaluating the capacity of vagus nerve stimulation to control epilepsy. Stimulation administered after learning significantly enhanced retention. These findings confirm in humans the hypothesis that vagus nerve activation modulates memory formation similarly to arousal.