Disfunción del transportador de glutamato / Glutamate Transporter disfunction

El glutamato, principal neurotransmisor excitatorio, está involucrado en mecanismos de plasticidad sináptica, memoria y muerte neuronal o glial, y el adecuado mantenimiento de sus niveles extracelulares es esencial para evitar la excitotoxicidad. En los últimos años se han producido muchos avances en el estudio de los transportadores de glutamato (VGLUTs y EAATs) encargados de su re-captura en las sinapsis. Haremos una revisión bibliográfica de sus propiedades, alteraciones producidas por su disfunción y posibles alternativas de neuroprotección. Así mismo revisaremos otro aspecto importante, la liberación de glutamato por los astrocitos bajo diversas situaciones patológicas, descubrimiento este de las últimas décadas de investigación sobre la glia

Glutamate, the major excitatory neurotransmitter, is involved in synaptic plasticity, memory and neuronal or glial death, and it is essential to proper maintenance of extracellular levels to prevent excitotoxicity. In recent years there have been many advances in the study of glutamate transporters (EAATs and VGLUTs) responsable for its re-capture at synapses. We will do a bibliographic review of their properties, changes caused by their dysfunction and possible alternatives for neuroprotection. We will also review antoher important aspect, the release of glutamate by astrocytes under different pathological conditions, discovered on the last decades by the research on glia

Glutaminergic neurons expressing c-Fos in the brainstem and amygdala participate in signal transmission and integration of sweet taste / 南方医科大学学报

<p><b>OBJECTIVE</b>To examine the role of glutaminergic neurons in the transmission and integration of the sweat taste information in the brain stem and the amygdala.</p><p><b>METHODS</b>Conscious Sprague-Dawley rats were subjected to oral sweet taste or water (control) stimulations. The activated neurons were identified by detecting c-Fos expression in taste-related brain areas, and the glutaminergic neurons by detecting vesicular glutamate transpoter-3 (VGLUT3).</p><p><b>RESULTS</b>Compared with control group, the rats with oral sucrose solution stimulation exhibited significantly increased c-Fos-expressing and double-labeled neurons in the nucleus of the solitary tract (NST), the parabrachial nucleus (PBN) and the amygdala.</p><p><b>CONCLUSION</b>Neurons in the NST, PBN and amygdala are activated after oral sweet taste stimulation. The sweet taste perception at different levels in the CNS is partly mediated by glutamate.</p>

Localization of vesicular glutamate transporters in the peripheral vestibular system of rat / 神经科学通报·英文版

<p><b>OBJECTIVE</b>To examine the vesicular glutamate transporters (VGluTs: VGluT1-VGluT3) in the peripheral vestibular system.</p><p><b>METHODS</b>The vestibular structures, including Scarpa's ganglion (vestibular ganglion, VG), maculae of utricle and saccule, and ampullary cristae, from normal Sprague-Dawley rats were processed immunohistochemically for VGluTs, by avidin-biotinylated peroxidase complex method, with 3-3'-diaminobenzidine (DAB) as chromogen.</p><p><b>RESULTS</b>(1) VGluT1 was localized to partial neurons of VG and to the putative primary afferent fibers innervating vestibular end-organs. (2) Intense VGluT3 immunoreactivity was detected in large number of sensory epithelia cells, and weak labeling of VGluT3-positive afferent fibers was in the maculae and ampullary cristae. (3) No or very weak VGluT2 immunoreactivity was observed in the VG and acoustic maculae.</p><p><b>CONCLUSION</b>These results provide the morphological support that glutamate exists in the peripheral vestibular system, and it may play an important role in the centripetal vestibular transmission.</p>