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We describe three experiments that explore the real-time access of verb-argument structures in a group of normal control subjects, a group of Broca's aphasic patients, and a group of Wernicke's aphasic patients. Specifically, we examine whether our subjects exhaustively access the thematic representations of verbs in active, passive, cleft-subject, and(More)
Our previous studies on the survival-promoting influence of elevated concentrations of extracellular K+ ([K+]e) on cultured cerebellar granule cells led to the proposal that depolarization in vitro mimics the effect of the earliest afferent inputs received by the granule cells in vivo. This, in turn, might be mediated through the stimulation of excitatory(More)
The survival and maturation of differentiating cerebellar granule cells in culture are known to be promoted by excitatory amino acids (EAAs) which, however, compromise the survival of mature cells. In contrast to the trophic effect, the toxic effect of alpha-amino-3-hydroxy-5-methyl-4-isoxasolepropiate (AMPA) could only be elicited when the desensitisation(More)
Cerebellar granule cells in culture develop survival requirements which can be met either by chronic membrane depolarization (25 mM K+) or by stimulation of ionotropic excitatory amino acid receptors. We observed previously that this trophic effect is mediated via Ca2+ influx, either through dihydropyridine-sensitive, voltage-dependent calcium channels(More)
Glutamate receptors coupled to polyphosphoinositide (PPI) hydrolysis (metabotropic glutamate receptors, mGluR), are highly efficient during the early stages of postnatal life and are thought to be involved in developmental plasticity. The dramatic decrease with age in mGluR activity suggests the existence of mechanisms that down-regulate this receptor after(More)
N-methyl-D-aspartate (NMDA) supplementation of cerebellar cultures enriched in granule neurones (about 90%) prevented the extensive cell loss which occurs when cultivation takes place, in serum containing media, in the presence of 'low' K+ (5-15 mM). Estimation of tetanus toxin receptors and N-CAM contents indicated that NMDA rescued primarily nerve cells.(More)
The survival of cerebellar granule cells in culture is promoted by chronic exposure to N-methyl-D-aspartate (NMDA). The effect is due to the stimulation of 'conventional' NMDA receptor-ionophore complex: it is concentration dependent, voltage dependent and blocked by the selective antagonists D-2-amino-5-phosphonovalerate, D-2-amino-7-phosphonoheptanoate,(More)
Growth conditions which promote the survival of cerebellar granule cells in culture, such as high K+ or N-methyl-D-aspartate (NMDA) treatment, also promote the functional expression of an NMDA-preferring subtype alone of the ionotropic glutamate receptors. The selective regulation of NMDA receptors detected electrophysiologically in individual cells, using(More)
Cultured cerebellar granule cells become vulnerable to excitatory amino acids, especially to NMDA and kainate, by 9 days in vitro. In the same time, the sensitivity of cells to (RS)-alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionate (AMPA), in terms of AMPA-induced toxicity or 45Ca2+ uptake, was very low. The low AMPA responsiveness was due to receptor(More)