A5046923054- Neural dynamics and brain function
- Neuroscience and Neuropharmacology Research
- Advanced Memory and Neural Computing
- Visual perception and processing mechanisms
- Neural Networks and Applications
- Retinal Development and Disorders
- Receptor Mechanisms and Signaling
- Photoreceptor and optogenetics research
- stochastic dynamics and bifurcation
- Neuroscience and Music Perception
- Memory and Neural Mechanisms
- Neuroscience and Neural Engineering
- Neural and Behavioral Psychology Studies
- Protein Kinase Regulation and GTPase Signaling
- Ion channel regulation and function
- Neural Networks and Reservoir Computing
- Functional Brain Connectivity Studies
- RNA Research and Splicing
- Gene Regulatory Network Analysis
- Neurobiology and Insect Physiology Research
- EEG and Brain-Computer Interfaces
- Blind Source Separation Techniques
- Neurobiology of Language and Bilingualism
- Underwater Acoustics Research
- Estrogen and related hormone effects
Rice University
2022-2025
The University of Texas Health Science Center at Houston
2012-2025
The University of Texas at Austin
2007-2021
University of Tennessee Health Science Center
2014
Brown University
1998-2009
Providence College
2008
John Brown University
2002-2006
Bryant University
2004
Howard Hughes Medical Institute
2002
University of Maryland, College Park
2001
Synapses in the brain are bidirectionally modifiable, but routes of induction diverse. In various experimental paradigms, N-methyl-d-aspartate receptor-dependent long-term depression and potentiation have been induced selectively by varying membrane potential postsynaptic neurons during presynaptic stimulation a constant frequency, rate stimulation, timing pre- action potentials. this paper, we present mathematical embodiment bidirectional synaptic plasticity that is able to explain diverse...
Spike timing dependent plasticity (STDP) is a phenomenon in which the precise of spikes affects sign and magnitude changes synaptic strength. STDP often interpreted as comprehensive learning rule for synapse - "first law" plasticity. This interpretation made explicit theoretical models total produced by complex spike patterns results from superposition effects all pairs. Although such are appealing their simplicity, they can fail dramatically. For example, measured single-spike between...
Current advances in neuromorphic engineering have made it possible to emulate complex neuronal ion channel and intracellular ionic dynamics real time using highly compact power-efficient complementary metal-oxide-semiconductor (CMOS) analog very-large-scale-integrated circuit technology. Recently, there has been growing interest the emulation of spike-timing-dependent plasticity (STDP) Hebbian learning rule by phenomenological modeling CMOS, memristor or other devices. Here, we propose a...
PKMζ is a persistently active PKC isoform proposed to maintain late-LTP and long-term memory. But memory are maintained without in PKMζ-null mice. Two hypotheses can account for these findings. First, unimportant LTP or Second, essential wild-type mice, mice recruit compensatory mechanisms. We find that whereas increases maintenance PKCι/λ, gene-product closely related PKMζ, Using pharmacogenetic approach, we PKMζ-antisense hippocampus blocks spatial but not the target mRNA. Conversely,...
In many regions of the brain, including mammalian cortex, magnitude and direction activity-dependent changes in synaptic strength depend on frequency presynaptic stimulation (synaptic plasticity), as well history activity at those synapses (metaplasticity). We present a model molecular mechanism bidirectional plasticity based observation that long-term potentiation (LTP) depression (LTD) correlate with phosphorylation/dephosphorylation sites α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic...
How can short-lived molecules selectively maintain the potentiation of activated synapses to sustain long-term memory? Here, we find kidney and brain expressed adaptor protein (KIBRA), a postsynaptic scaffolding genetically linked human memory performance, complexes with kinase Mzeta (PKMζ), anchoring kinase’s potentiating action late-phase (late-LTP) at synapses. Two structurally distinct antagonists KIBRA-PKMζ dimerization disrupt established late-LTP spatial memory, yet neither measurably...
Abstract The dominant theoretical framework to account for reinforcement learning in the brain is temporal difference (TD) learning, whereby certain units signal reward prediction errors (RPE). TD algorithm has been traditionally mapped onto dopaminergic system, as firing properties of dopamine neurons can resemble RPEs. However, predictions are inconsistent with experimental results, and previous implementations have made unscalable assumptions regarding stimulus-specific fixed bases. We...
Modifications in the strengths of synapses are thought to underlie memory, learning, and development cortical circuits. Many cellular mechanisms synaptic plasticity have been investigated which differential elevations postsynaptic calcium concentrations play a key role determining direction magnitude changes. We previously described model that uses currents mediated by N -methyl- d -aspartate receptors as associative signal for Hebbian learning. However, this is not completely stable. Here,...
The ability to represent time is an essential component of cognition but its neural basis unknown. Although extensively studied both behaviorally and electrophysiologically, a general theoretical framework describing the elementary mechanisms used by brain learn temporal representations lacking. It commonly believed that underlying cellular reside in high order cortical regions recent studies show sustained activity primary sensory cortices can timing expected reward. Here, we local networks...
Theoretical studies have shown that calcium influx through N-methyl-D-aspartate (NMDA) receptors is a sufficient signal to account for various induction protocols of bidirectional synaptic plasticity, including spike time-dependent plasticity (STDP). The STDP curves obtained by these different models exhibits form long-term depression occurs when presynaptic precedes the postsynaptic (pre-post LTD). We previously proposed this novel LTD can serve as an experimental test validity models....
In many regions of the brain, including mammalian cortex, strength synaptic transmission can be bidirectionally regulated by cortical activity (synaptic plasticity). One line evidence indicates that long-term potentiation (LTP) and depression (LTD), correlate with phosphorylation/dephosphorylation sites on α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunit protein GluR1. Bidirectional plasticity induced different frequencies presynaptic stimulation, but there is...
Memories that last a lifetime are thought to be stored, at least in part, as persistent enhancement of the strength particular synapses. The synaptic mechanism these changes, late long-term potentiation (L-LTP), depends on state and number specific proteins. Synaptic proteins, however, have limited dwell times due molecular turnover diffusion, leading fundamental question: how can this transient machinery store memories lasting lifetime? Because changes efficacy synapse-specific, underlying...
Current models of word-production in Broca's area (i.e. left ventro-lateral prefrontal cortex, VLPFC) posit that sequential and staggered semantic, lexical, phonological articulatory processes precede articulation. Using millisecond-resolution intra-cranial recordings, we evaluated spatiotemporal dynamics high frequency functional interconnectivity between VLPFC regions during single-word production. Through the systematic variation retrieval, selection, loads, identified specific activation...
Underwater mammal sound classification is demonstrated using a novel application of wavelet time-frequency decomposition and feature extraction Bienenstock, Cooper, Munro (1982) (BCM) unsupervised network. Different methods different representations are studied. The system achieves outstanding performance even when tested with sounds recorded at very locations (from those used for training). improved results suggest that nonlinear from outperforms linear choices basis functions.