A5039441824- Neural dynamics and brain function
- Neuroscience and Neuropharmacology Research
- Photoreceptor and optogenetics research
- Neuroscience and Neural Engineering
- Sleep and Wakefulness Research
- Visual perception and processing mechanisms
- EEG and Brain-Computer Interfaces
- Memory and Neural Mechanisms
- Ion channel regulation and function
- Functional Brain Connectivity Studies
- Advanced Memory and Neural Computing
- Neurobiology and Insect Physiology Research
- Organ Transplantation Techniques and Outcomes
- Advanced Fluorescence Microscopy Techniques
- Electrochemical Analysis and Applications
- stochastic dynamics and bifurcation
- Renal Transplantation Outcomes and Treatments
- Receptor Mechanisms and Signaling
- Organ Donation and Transplantation
- Neurological disorders and treatments
- Cellular Mechanics and Interactions
- Circadian rhythm and melatonin
- Pancreatic function and diabetes
- Optical Imaging and Spectroscopy Techniques
- Agricultural and Food Production Studies
University of Pennsylvania
2015-2025
Universidad de Santiago de Chile
2017-2024
Stanford University
2024
California University of Pennsylvania
2021
Laboratoire de Physique de l'ENS
2019
École Normale Supérieure - PSL
2019
Pontificia Universidad Católica de Chile
2011-2015
Sociedad Española de Farmacología Clínica
2012
Philadelphia University
2001-2010
Yale University
2001-2010
A slow oscillation (< 1 Hz) has recently been described in intracellular recordings from the neocortex and thalamus (Steriade et al., 1993c-e). The aim of present study was to determine phase relations between cortical thalamic neuronal activities during EEG oscillation. Intracellular were performed anesthetized cats neurons motor somatosensory areas, rostrolateral sector reticular (RE) nucleus, thalamocortical (TC) cells ventrolateral (VL) nucleus. used as time reference for alignment...
We investigated the synchronization of fast spontaneous oscillations (mainly 30-40 Hz) in anesthetized and behaving cats by means simultaneous extra- intracellular recordings from multiple neocortical areas. Fast Fourier transforms, auto- cross-correlations, spike- or wave-triggered averages were used to determine frequency temporal coherence that outlasted stimulation ascending activating systems occurred naturally during behavioral states waking rapid eye movement (REM) sleep but also...
As most afferent axons to the thalamus originate in cerebral cortex, we assumed that slow (< 1 Hz) cortical oscillation described two companion articles is reflected reticular (RE) thalamic and thalamocortical cells. We hypothesized cortically generated rhythm would appear conjunction with delta spindle oscillations arising from intrinsic network properties of neurons. Intracellular recordings have been obtained anesthetized cats RE (n = 51) projecting 240) cells were physiologically...
The electroencephalogram displays various oscillation patterns during wake and sleep states, but their spatiotemporal distribution is not completely known. Local field potentials (LFPs) multiunits were recorded simultaneously in the cerebral cortex (areas 5-7) of naturally sleeping awake cats. Slow-wave (SWS) was characterized by oscillations slow (<1 Hz) delta (1-4 frequency range. high-amplitude slow-wave complexes consisted a positivity depth LFP, associated with neuronal silence,...
The mammalian thalamus is the gateway to cortex for most sensory modalities. Nearly all thalamic nuclei also receive massive feedback projections from cortical region which they project. In this study, spatiotemporal properties of synchronized spindle oscillations (7 14 hertz) were investigated in barbiturate-anesthetized cats, before and after removal cortex. After complete ipsilateral decortication, long-range synchronization spindles intact hemisphere changed into disorganized patterns...
To better understand population phenomena in thalamocortical neuronal ensembles, we have constructed a preliminary network model with 3,560 multicompartment neurons (containing soma, branching dendrites, and portion of axon). Types included superficial pyramids (with regular spiking [RS] fast rhythmic bursting [FRB] firing behaviors); RS spiny stellates; (FS) interneurons, basket-type axoaxonic types connectivity, located deep cortical layers; low threshold (LTS) which contacted principal...
We investigated in anesthetized cats the progressive development from EEG-synchronized sleep patterns to low-frequency (< 15 Hz) paroxysmal activities, most of them consisting epileptic-like seizures with spike-wave (SW) complexes at 2-4 Hz. used multisite extra- and intracellular recordings neocortical, reticular thalamic (RE), thalamocortical (TC) neurons, including dual impalements cortical TC cells. A subsample (40%) cells discharged spike bursts Hz, close time relation spiky,...
The synchronization of fast (mainly 30 to 40 Hz) oscillations in intrathalamic and thalamocortical (TC) networks cat was studied under ketamine-xylazine anesthesia behaving animals by means field potential, extra- intracellular recordings from multiple sites the thalamic reticular (RE) nucleus, dorsal (sensory, motor, intralaminar) nuclei, related neocortical areas. Far being restricted tonically activated behavioral states, also appeared during resting sleep deep anesthesia, when they...
Destexhe, Alain, Diego Contreras, and Mircea Steriade. Mechanisms underlying the synchronizing action of corticothalamic feedback through inhibition thalamic relay cells. J. Neurophysiol. 79: 999–1016, 1998. Early studies have shown that spindle oscillations are generated in thalamus synchronized over wide cortical territories. More recent experiments this large-scale synchrony depends on integrity feedback. Previously proposed mechanisms emphasized exclusively intrathalamic to generate...
1. To explore the nature of long‐lasting hyperpolarizations that characterize slow oscillations in corticothalamic circuits vivo, intracellular recordings were obtained under ketamine‐xylazine anaesthesia from cortical (Cx) cells cat precruciate motor cortex, thalamic reticular (RE) rostrolateral sector, and thalamocortical (TC) ventrolateral (VL) nucleus. 2. Measurements three cell types showed input resistance (Rin) to be highest during correspond depth‐positive waves EEG. Rin was lowest...
Steriade, Mircea and Diego Contreras. Spike-wave complexes fast components of cortically generated seizures. I. Role neocortex thalamus. J. Neurophysiol. 80: 1439–1455, 1998. We explored the relative contributions cortical thalamic neuronal networks in generation electrical seizures that include spike-wave (SW) polyspike-wave (PSW) complexes. Seizures were induced by systemic or local injections bicuculline, a γ-aminobutyric acid-A (GABA A ) antagonist, cats under barbiturate anesthesia....
Spindle oscillations (7-14 Hz) appear in the thalamus and cortex during early stages of sleep. They are generated by combination intrinsic properties connectivity patterns thalamic neurons distributed to cortical territories thalamocortical axons. The corticothalamic feedback is a major factor producing coherent spatiotemporal maps spindle widespread territories. Here we have investigated spontaneously occurring evoked spindles means multisite field potential unit recordings intact...
1. The oscillatory properties of the isolated reticular (RE) thalamus were modeled with use compartmental models RE cells. Hodgkin-Huxley type kinetic ionic channels derived from voltage- and current-clamp data Interactions between interconnected cells simulated a model gamma-aminobutyric acid (GABA) inhibitory synapses. 2. intrinsic bursting in due to presence low-threshold Ca2+ current two Ca(2+)-activated currents. these compared neurons recorded intracellularly vivo cats. 3. Model...
1. Spindles represent an oscillatory activity (7-14 Hz) of the electroencephalogram (EEG) originating in thalamus and appearing during early stages sleep. We investigated: (i) phase relations between thalamic cortical neurons this rhythm; (ii) patterns spindles under different anaesthetics their modifications at various levels membrane potential (Vm); (iii) potentiating role corticothalamic feedback genesis spindles. Intra- extracellular recordings were performed cats from reticular dorsal...
In layer 4 (L4) of the rat barrel cortex, a single whisker deflection evokes stereotyped sequence excitation followed by inhibition, hypothesized to result in narrow temporal window for spike output. However, awake rats sweep their whiskers across objects, activating cortex at frequencies known induce short-term depression both excitatory and inhibitory synapses within L4. Although periodic causes frequency-dependent reduction cortical response magnitude, whether this adaptation involves...
Thalamic reticular (RE) neurons are involved in the genesis of synchronized thalamocortical oscillations, which depend part on their complex bursting properties. We have investigated intrinsic properties RE cells using computational models based morphological and electrophysiological data. Simulations a reconstructed were compared directly with recordings from same cell to obtain precise values for passive parameters. In first series experiments, low-threshold calcium current (I(Ts)) was...