Josée Seigneur

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Long-term plasticity contributes to memory formation and sleep plays a critical role in memory consolidation. However, it is unclear whether sleep slow oscillation by itself induces long-term plasticity that contributes to memory retention. Using in vivo prethalamic electrical stimulation at 1 Hz, which itself does not induce immediate potentiation of(More)
Neuronal synchronization can be defined as a correlated appearance in time of two or more events associated with various aspects of neuronal activity. Neuronal synchronization depends on chemical and electrical synaptic as well as ephaptic and non-specific interactions. We consider two distinct types of neuronal synchronization: local synchronization that(More)
This study aims at understanding complex interactions between cortical neurons, glia and blood supply developing during the transition from slow-wave sleep to wakefulness. In spite of essential advances from in vitro and culture preparations, the basic mechanisms of glial interactions with their cellular and ionic environment had remained uninvestigated in(More)
PURPOSE Seizures are associated with a reduction in extracellular Ca²(+) concentration ([Ca²(+) ](o) ) and an increase in extracellular K(+) concentration ([K(+) ](o) ). The long-range synchrony observed between distant electrodes during seizures is weak. We hypothesized that changes in extracellular ionic conditions during seizures are sufficient to alter(More)
Neocortical neurons can be classified in four major electrophysiological types according to their pattern of discharge: regular-spiking (RS), intrinsically-bursting (IB), fast-rhythmic-bursting (FRB), and fast-spiking (FS). Previously, we have shown that these firing patterns are not fixed and can change as a function of membrane potential and states of(More)
The neocortex is the site of origin of several forms of acquired epilepsy. Here we provide a brief review of experimental models that were recently developed to study neocortical epileptogenesis as well as some major results obtained with these methods. Most of neocortical seizures appear to be nocturnal and it is known that neuronal activities reveal high(More)
Neuronal synchronization occurs when two or more neuronal events are coordinated across time. Local synchronization produces field potentials. Long-range synchronization between distant brain sites contributes to the electroencephalogram. Neuronal synchronization depends on synaptic (chemical/electrical), ephaptic, and extracellular interactions. For an(More)
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