Synaptic Contacts
Mostrando 1-12 de 92 artigos, teses e dissertações.
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1. Estudo dos grânulos de lipofucsina e das sinapses do córtex temporal durante o envelhecimento / Study of lipofuscin granules and synapses in the temporal cortex during aging.
Alterações morfológicas e funcionais ocorrem durante o envelhecimento, período da vida com maior incidência de doenças neurodegenerativas. No presente trabalho acompanhou-se a evolução dos grânulos de lipofucsina durante o envelhecimento para investigar alterações sinápticas, assim como proteínas associadas com doenças neurodegenerativas (alfa-
Publicado em: 2011
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2. A balance between excitatory and inhibitory synapses is controlled by PSD-95 and neuroligin
Factors that control differentiation of presynaptic and postsynaptic elements into excitatory or inhibitory synapses are poorly defined. Here we show that the postsynaptic density (PSD) proteins PSD-95 and neuroligin-1 (NLG) are critical for dictating the ratio of excitatory-to-inhibitory synaptic contacts. Exogenous NLG increased both excitatory and inhibit
National Academy of Sciences.
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3. An anatomical substrate for experience-dependent plasticity of the rat barrel field cortex.
The objective of this study was to examine the influence of sensory experience on the synaptic circuitry of the cortex. For this purpose, the quantitative distribution of the overall and of the gamma-aminobutyric acid (GABA) population of synaptic contacts was investigated in each layer of the somatosensory barrel field cortex of rats which were sensory depr
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4. Remodeling of synaptic architecture during hippocampal "kindling".
The "kindling" phenomenon is associated with long-lasting facilitation of synaptic transmission. A possible mechanism of such facilitation could involve changes in the number of synaptic contacts. However, previous attempts to demonstrate a synaptic morphological alteration that could account for the long-term effects of kindling had failed, possibly due to
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5. Light and electron microscopic identification of nerve terminal sprouting and retraction in normal adult frog muscle.
A combined light and electron microscopic study was performed on neuromuscular junctions of normal adult frogs. In a previous investigation signs of new synapse formation, as well as abandoned former synaptic sites, have been observed in normal muscles (Wernig, Pécot-Dechavassine & Stöver, 1980a, b). Here we performed a detailed light and electron microsco
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6. Non-synaptic membrane specializations on the necks of Purkinje cell dentritic spines.
Non-synaptic membrane contacts were found on the necks of the Purkinje cell dendritic spines between the spine and astrocyte plasma membranes. They were tight- or gap-junction-like and disappeared after short periods of anoxia. No similar membrane contacts were found on the most common type of pyramidal cell dendrite spine. It is suggested that the described
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7. Physiology and anatomy of synaptic connections between thick tufted pyramidal neurones in the developing rat neocortex.
1. Dual voltage recordings were made from pairs of adjacent, synaptically connected thick tufted layer 5 pyramidal neurones in brain slices of young rat (14-16 days) somatosensory cortex to examine the physiological properties of unitary EPSPs. Pre- and postsynaptic neurones were filled with biocytin and examined in the light and electron microscope to quant
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8. An in vivo pharmacological study of single group Ia fibre contacts with motoneurones in the cat spinal cord.
1. Direct experimental evidence was obtained on the spatial distribution of active synaptic contacts from single Ia muscle afferents on the dendrites of lumbosacral motoneurones in anaesthetized cats. 2. An extracellular micropipette was used to pressure eject the AMPA/kainate receptor antagonists 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) or 2,3-dihydroxy-
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9. Connexions between hair follicle afferent fibres and spinocervical tract neurones in the cat: the synthesis of receptive fields.
1. Relationships between the terminal arborizations of hair follicle afferent fibres and dendritic trees of spinocervical tract (s.c.t.) neurones were studied using intra-axonal and intracellular injections of horseradish peroxidase in chloralose-anaesthetized, paralysed cats. 2. Seventeen afferent-neurone pairs were successfully stained and their receptive
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10. Synaptic endings and their postsynaptic targets in neostriatum: synaptic specializations revealed from analysis of serial sections.
Neostriatal tissue from rat brain was examined in ribbons of serial sections, using tissue from subjects in which the synaptic marker 5-hydroxydopamine had been injected into the lateral ventricle. A total of 440 synaptic terminals, identified by the presence of a population of vesicles, was studied, including those labeled by 5-hydroxydopamine and all those
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11. Ultrastructural localisation of substance P, vasoactive intestinal peptide and somatostatin immunoreactivities in the submucous plexus of guinea pig ileum.
The submucous neurons, especially those related to the lymphatic vessels, together with their associated synapses, were studied ultrastructurally with respect to their immunoreactivities for 3 types of neuropeptides, namely substance P (SP), vasoactive intestinal peptide (VIP) and somatostatin (SOM). With the antibodies directed against the 3 types of neurop
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12. Formation of synapses in cerebellar explants by axons from co-cultured medulla.
Explants of cerebellum from E12-E14 chick embryos were co-cultured with pieces of medulla from the same embryos for periods of up to 4 weeks and examined by EM with or without prior transection of the fibre bundles that formed rapidly between the co-cultured explants. The cerebellar explants developed a rich and complex neuropil within which a variety of pre