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How can neural activity propagate through cortical networks built with weak, stochastic synapses? We find precise repetitions of spontaneous patterns of synaptic inputs in neocortical neurons in vivo and in vitro. These patterns repeat after minutes, maintaining millisecond accuracy. Calcium imaging of slices reveals reactivation of sequences of cells(More)
Brain-derived neurotrophic factor (BDNF) has been implicated in activity-dependent plasticity of neuronal function and network arrangement. To clarify how BDNF exerts its action, we evaluated the physiological, histological, and biochemical characteristics of cultured hippocampal neurons after long-term treatment with BDNF. Here we show that BDNF(More)
Synaptic inputs on dendrites are nonlinearly converted to action potential outputs, yet the spatiotemporal patterns of dendritic activation remain to be elucidated at single-synapse resolution. In rodents, we optically imaged synaptic activities from hundreds of dendritic spines in hippocampal and neocortical pyramidal neurons ex vivo and in vivo. Adjacent(More)
Temporal lobe epilepsy (TLE) is accompanied by an abnormal location of granule cells in the dentate gyrus. Using a rat model of complex febrile seizures, which are thought to be a precipitating insult of TLE later in life, we report that aberrant migration of neonatal-generated granule cells results in granule cell ectopia that persists into adulthood.(More)
lthough Zn 2 is contained in large amounts in the synaptic terminals of hippocampal mossy fibers (MFs), its physiological role in synaptic transmission is poorly understood. By using the newly developed high-sensitivity Zn 2 indicator ZnAF-2, the spatiotemporal dynamics of Zn 2 was monitored in rat hippocampal slices. When high-frequency stimulation was(More)
Large-scale recording from a population of neurons is a promising strategy for approaching the study of complex brain functions. Taking advantage of the fact that action potentials reliably evoke transient calcium fluctuations in the cell body, functional multineuron calcium imaging (fMCI) monitors the suprathreshold activity of hundreds of neurons.(More)
The mossy fibers (MFs) arising from dentate granule cells project primarily onto a narrow segment of the proximal dendrites of hippocampal CA3 pyramidal cells. The mechanisms underlying this specific MF target selection are not fully understood. To investigate the cellular basis for development of the stereotyped MF trajectories, we have arranged the fascia(More)
1. We investigated the possible involvement of phospholipase A(2) (PLA(2)) and its products in long-term potentiation (LTP) in the CA1 neurotransmission of rat hippocampal slices. 2. Inhibitors of Ca(2+)-independent PLA(2) (iPLA(2)) prevented the induction of LTP without affecting the maintenance phase of LTP whereas Ca(2+)-dependent PLA(2) inhibitors were(More)
Macroscopic changes in cerebral blood flow, such as those captured by functional imaging of the brain, require highly organized, large-scale dynamics of astrocytes, glial cells that interact with both neuronal and cerebrovascular networks. However, astrocyte activity has been studied mainly at the level of individual cells, and information regarding their(More)