A5015780200- Neuroscience and Neuropharmacology Research
- Memory and Neural Mechanisms
- Neural dynamics and brain function
- Sleep and Wakefulness Research
- Genetics and Neurodevelopmental Disorders
- Neuroscience and Neural Engineering
- RNA regulation and disease
- Memory Processes and Influences
- Neuroinflammation and Neurodegeneration Mechanisms
- Autism Spectrum Disorder Research
- Photoreceptor and optogenetics research
- Plant biochemistry and biosynthesis
- Neurogenesis and neuroplasticity mechanisms
- Identity, Memory, and Therapy
- RNA Research and Splicing
- Vestibular and auditory disorders
- Mitochondrial Function and Pathology
- Hearing, Cochlea, Tinnitus, Genetics
- Cholesterol and Lipid Metabolism
- Cognitive Functions and Memory
- Protein Degradation and Inhibitors
- Antioxidant Activity and Oxidative Stress
- RNA and protein synthesis mechanisms
The University of Texas Southwestern Medical Center
2007-2023
Southwestern Medical Center
2017-2023
Allen Institute for Brain Science
2022-2023
Johns Hopkins Medicine
2013-2016
Johns Hopkins University
2013-2016
Memory storage in neural networks Neuronal can store and retrieve discrete memories, but often fail to stored sequences. This is because error decreases over time for a static attractor, builds up drastically if patterns are not trained themselves the next item sequence. Pfeiffer Foster studied brain activity awake immobile rats. Recording simultaneously from large number of place cells hippocampal formation, they found that internally generated sequences alternated between periods hovering...
Significance Time cells are neurons in the hippocampus and entorhinal cortex that fire at specific moments within a cognitive task or experience. While many prominent theories of memory encoding offer time as source temporal component to memory, they have never been observed human recordings. We identify cell populations medial lobe humans during retrieval. Further, we demonstrate stability signal provided by influences ability temporally order memories
Neural networks display the ability to transform forward-ordered activity patterns into reverse-ordered, retrospective sequences. The mechanisms underlying this transformation remain unknown. We discovered that, during active navigation, rat hippocampal CA1 place cell ensembles are inherently organized produce independent forward- and reverse-ordered sequences within individual theta oscillations. This finding may provide a circuit-level basis for evaluation storage ongoing behavior. Theta...
The mevalonate pathway produces cholesterol and nonsterol isoprenoids, such as geranylgeraniol. In the brain, a fraction of is metabolized in neurons by enzyme 24-hydroxylase, this depletion activates pathway. Brains from mice lacking 24-hydroxylase excrete more slowly, tissue compensates suppressing Here we report that suppression causes defect learning. 24-Hydroxylase knockout exhibit severe deficiencies spatial, associative, motor learning, hippocampal long-term potentiation (LTP). Acute...
Fragile X syndrome, as well other forms of mental retardation and autism, is associated with altered dendritic spine number structure. syndrome caused by loss-of-function mutations in protein (FMRP), an RNA-binding that regulates synthesis vivo . It unknown whether FMRP plays a direct, cell-autonomous role regulation synapse number, function, or maturation. Here, we report acute postsynaptic expression Fmr1 knock-out (KO) neurons results decrease the functional structural synapses without...
Gq-coupled, M 1 muscarinic acetylcholine receptors (mAChRs) facilitate hippocampal learning, memory, and synaptic plasticity. mAChRs induce long-term depression (LTD), but little is known about the underlying mechanisms of mAChR-dependent LTD its link to cognitive function. Here, we demonstrate that chemical activation induces in area CA1, which relies on rapid protein synthesis, as well extracellular signal-regulated kinase mammalian target rapamycin translational pathways. Synaptic...
Place cell activity of hippocampal pyramidal cells has been described as the cognitive substrate spatial memory. Replay is observed during sharp-wave-ripple-associated population burst events (PBEs) and critical for consolidation recall-guided behaviors. PBE historically analyzed a phenomenon subordinate to place code. Here, we use hidden Markov models study PBEs in rats exploration both linear mazes open fields. We demonstrate that estimated are consistent with map environment, can even...
During a two-day Royal Society meeting entitled ‘ Memory reactivation: replaying events past, present and future ’ held at Chicheley Hall in May, 2019, we discussed defined set of terms for investigating reporting memory reactivations to facilitate common language thus simplifying comparison results. Here, the results discussion supply such as reactivation replay, which authors have reached consensus. This article is part Theo Murphy issue ‘Memory future’.
The hippocampus is critical for rapid acquisition of many forms memory, although the circuit-level mechanisms through which rapidly consolidates novel information are unknown. Here, activity large ensembles hippocampal neurons in adult male Long-Evans rats was monitored across a period spatial learning to assess how network changes during initial phases memory formation and retrieval. In contrast several reports, did not display enhanced representation goal location via accumulation place...
Abstract The organization of temporal information is critical for the encoding and retrieval episodic memories. In rodent hippocampus entorhinal cortex, recent evidence suggests that encoded by a population “time cells.” We identify time cells in humans using intracranial microelectrode recordings obtained from 27 human epilepsy patients who performed an memory task. show cell activity predicts A significant portion these exhibits phase precession, key phenomenon not previously seen...
Neuronal activity during experience is thought to induce plastic changes within the hippocampal network that underlie memory formation, although extent and details of such in vivo remain unclear. Here, we employed a temporally precise marker neuronal activity, CaMPARI2, label active CA1 neurons vivo, followed by immediate acute slice preparation electrophysiological quantification synaptic properties. Recently superficial sublayer stratum pyramidale displayed larger post-synaptic responses...
Episodic memories, or consciously accessible memories of unique events, represent a key aspect human cognition. Evidence from rodent models suggests that the neural representation these complex requires cooperative firing groups neurons on short time scales, organized by gamma oscillations. These co-firing groups, termed "neuronal assemblies," fundamental neurophysiological unit supporting memory. Using microelectrode data neurosurgical patients, we identify neuronal assemblies in MTL and...
Abstract The place cell activity of hippocampal pyramidal cells has been described as the cognitive map substrate spatial memory. Replay is observed during sharp-wave ripple-associated population burst events and critical for consolidation recall-guided behaviors. To present, event (PBE) analyzed a phenomenon subordinate to code. Here, we use hidden Markov models study PBEs exploration both linear mazes open fields. We demonstrate that estimated are consistent with temporal replay sequences...
Synaptic plasticity is hypothesized to underlie "replay" of salient experience during hippocampal sharp-wave/ripple (SWR)-based ensemble activity and facilitate systems-level memory consolidation coordinated by SWRs cortical sleep spindles. It remains unclear how molecular changes at synapses contribute experience-induced modification network function. The synaptic protein KIBRA regulates memory. To determine the impact KIBRA-regulated on circuit dynamics, we recorded in vivo neural from...