GLAST/EAAT1-induced glutamine release via SNAT3 in Bergmann glial cells: evidence of a functional and physical coupling.

Glutamate, the major excitatory transmitter in the vertebrate brain, is removed from the synaptic cleft by a family of sodium-dependent glutamate transporters profusely expressed in glial cells. Once internalized, it is metabolized by glutamine synthetase to glutamine and released to the synaptic space through sodium-dependent neutral amino acid carriers of the N System (SNAT3/slc38a3/SN1, SNAT5/slc38a5/SN2). Glutamine is then taken up by neurons completing the so-called glutamate/glutamine shuttle. Despite of the fact that this coupling was described decades ago, it is only recently that the biochemical framework of this shuttle has begun to be elucidated. Using the established model of cultured cerebellar Bergmann glia cells, we sought to characterize the functional and physical coupling of glutamate uptake and glutamine release. A time-dependent Na⁺-dependent glutamate/aspartate transporter/EAAT1-induced System N-mediated glutamine release could be demonstrated. Furthermore, D-aspartate, a specific glutamate transporter ligand, was capable of enhancing the co-immunoprecipitation of Na⁺-dependent glutamate/aspartate transporter and Na⁺-dependent neutral amino acid transporter 3, whereas glutamine tended to reduce this association. Our results suggest that glial cells surrounding glutamatergic synapses may act as sensors of neuron-derived glutamate through their contribution to the neurotransmitter turnover.

Interacción en niños con trastorno del espectro autista / Interaction in children with autism spectrum disorder

Actualmente existen investigaciones enfocadas en demostrar que la interacción es importante para favorecer el desarrollo cognoscitivo, del lenguaje, social y emocional de niños con desarrollo normal y de niños con Trastorno del Espectro Autista (TEA). Se ha propuesto que los padres de niños con TEA pueden actuar como coterapeutas de sus hijos en las interacciones cotidianas. El objetivo del estudio fue describir las características de comportamiento de niños con TEA al interactuar con su cuidador principal a través de juego libre. Participaron 16 niños con TEA de 4 a 12 años de edad con su cuidador principal. Se videograbó la interacción durante 15 minutos. A los padres se les indicó que establecieran un juego libre con sus hijos utilizando los materiales didácticos colocados en una caja. Se observó la videograbación para analizar la interacción considerando: actividad, movimientos estereotipados, contacto visual, respuesta impositiva o no impositiva, verbal, objetal, gestual, gestual-verbal o visual. Durante la interacción los niños estuvieron activos 80%. El 43% respondió en forma verbal, 35% a través de objetos y 22% utilizando gestos. Sólo en el 57% de la interacción los niños establecieron contacto visual. El estudio de la interacción en niños con TEA permite analizar las dificultades que presentan en lenguaje, interacción social y desarrollo cognoscitivo. La evaluación del desarrollo mediante pruebas estandarizadas en estos niños es compleja, por lo que el análisis de las interacciones posibilita describir el desarrollo y diseñar estrategias de apoyo para que los padres favorezcan el progreso del niño en la vida diaria.

Currently there is research focused on demonstrating that of interaction is important for the stimulation of cognitive, social, emotional and language development of typically developing children and children with Autism Spectrum Disorder (ASD). It has been proposed that the parents of children with ASD may act as co-therapists for their children in everyday interactions. The aim of this study was to describe the behavioral characteristics of children with ASD when than interact with their primary caregiver through free play. Participated 16 children with ASD from 4-12 years old with their primary caregiver. Interaction was videotaped for 15 minutes. Parents were then instructed to establish a free play with their children using teaching materials placed in a box. Interaction was analyzed by watching the video recording, considering: activity, stereotyped movements, eye contact, impositive response or not impositive response and whether interaction was verbal, objetal, gestural, verbal or gestural-visual. During the interaction the children were active 80%. 43% responded verbally, 35% using objects and 22% through gestures. Children in only 57% of the interaction established visual contact. The study of interaction in children with ASD to analysis of the difficulties presented in language, social interaction and cognitive development. Evaluation of developmental by standardized tests in these children is complex, so that the analysis of interactions permits the description of development and the design of support strategies for parents in order to encourage their child’s progress in daily life.