José Luis Pérez Velazquez

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Free radical (FR) production, a major step in calcium-dependent neurodegeneration, has been linked to the generation of epileptiform activity and seizure-induced cell death. However, direct evidence of FR production in neurons during seizures has never been presented. Using hippocampal cultured slices we demonstrate that FRs are produced in CA3 but not CA1(More)
The epilepsy that occurs in SSADH deficiency has a seizure phenotype similar to that occurring in the SSADH(-/-) mouse. We examined the expression and function of the GABA(A) receptor (GABA(A)R) in SSADH-deficient mice. A selective decrease in binding of [(35)S]tert-butylbicyclophosphorothionate was observed in SSADH(-/-) mice at postnatal day 7 that was(More)
Succinic semialdehyde dehydrogenase (SSADH) deficiency is a heritable disorder of GABA degradation characterized by ataxia, psychomotor retardation and seizures. To date, there is no effective treatment for SSADH deficiency. We tested the hypothesis that a ketogenic diet (KD) would improve outcome in an animal model of SSADH deficiency, the SSADH knockout(More)
BACKGROUND Succinic semialdehyde dehydrogenase (SSADH) deficiency is an inborn error of GABA metabolism characterized clinically by ataxia, psychomotor retardation and seizures. A mouse model of SSADH deficiency, the Aldh5a1(-/-) mouse, has been used to study the pathophysiology and treatment of this disorder. Recent work from our group has shown that the(More)
Increasing experimental evidence indicates that gap junctions can be modulated by neurotransmitters, in particular dopamine. To examine possible modulation of gap junctional communication in the rat hippocampus by neurotransmitters, we studied dye coupling and electrotonic transmission in the CA1 area in the presence of carbachol, a cholinergic agonist, and(More)
Much work now emphasizes the concept that interneuronal networks play critical roles in generating synchronized, oscillatory behavior. Experimental work has shown that functional inhibitory networks alone can produce synchronized activity, and theoretical work has demonstrated how synchrony could occur in mutually inhibitory networks. Even though gap(More)
The sudden and transient hypersynchrony of neuronal firing that characterizes epileptic seizures can be considered as the transitory stabilization of metastable states present within the dynamical repertoire of a neuronal network. Using an in vitro model of recurrent spontaneous seizures in the rat horizontal hippocampal slice preparation, we present an(More)
Epileptic seizures represent a sudden and transient change in the synchronised firing of neuronal brain ensembles. While the transition of the collective neuronal activity towards the ictal event is not well understood, some progress has been made using nonlinear time series analysis methods. We present here an analysis of the dynamical regimes of the(More)
Phase synchrony analysis is a relatively new concept that is being increasingly used on neurophysiological data obtained through different methodologies. It is currently believed that phase synchrony is an important signature of information binding between distant sites of the brain, especially during cognitive tasks. Electroencephalographic (EEG)(More)
An ultra wideband (UWB) 64-channel responsive neural stimulator system-on-chip (SoC) is presented. It demonstrates the first on-chip neural vector analyzer capable of wirelessly monitoring magnitude, phase and phase synchronization of neural signals. In a closed-loop, abnormal phase synchrony triggers the programmable-waveform biphasic current-mode neural(More)