José Luis Pérez Velazquez

Learn 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)
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)
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)
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)
A system-on-chip (SoC) neural recording interface with 64 channels, 64 16-tap programmable mixed-signal FIR filters and a fully integrated 915 MHz OOK/FSK PLL-based wireless transmitter is presented. Each recording channel has a fully differential amplifier with 54 dB gain and utilizes a tunable low-distortion subthreshold MOS-resistor to reject DC offsets(More)
The objective of the current study was to determine the origin of the slow spike and wave discharges (SSWD) in the transgenic mouse with postnatal over-expression of the GABA(B) receptor subunit R1a (GABA(B)R1a(tg)), a mutant animal with a characteristic phenotype consisting of atypical absence seizures and cognitive dysfunction. Using simultaneous(More)
We present a 320-channel active probe for high-spatial-resolution neuromonitoring and responsive neurostimulation. The probe comprises an integrated circuit (IC) cell array bonded to the back side of a pitch-matched microelectrode array. The IC enables up to 256-site neural recording and 64-site neural stimulation at the spatial resolution of 400 μ m and(More)
A rigorous characterization of the dynamic regimes underlying human seizures is needed to understand, and possibly control, the transition to seizure. Intra- or extracranial brain electrical activity was recorded in five patients with partial epilepsy, and the interictal and ictal activity analysed to determine the dynamics of seizures. We constructed(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)