Spontaneous EEG spikes in the normal hippocampus. I. Behavioral correlates, laminar profiles and bilateral synchrony

Suzuki, Shinya; Smith, Grant K.

doi:10.1016/0013-4694(87)90123-4

Cited by 109 publications

(64 citation statements)

References 44 publications

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“…While our results support theta frequency burst stimulation as an effective stimulus for LTP induction, we found that burst stimulation at slightly lower frequencies (2-3 Hz, or delta frequency) was even more effective. Although theta frequency activity is prominent in the hippocampus under some behavioral conditions, slower EEG frequencies dominate under other conditions, including slow wave sleep (Buzsáki 1986;Suzuki and Smith 1987;Wolansky et al 2006;Moroni et al 2007). Our results suggest that synchronized bursts of presynaptic activity, even at relatively low frequencies, could be quite effective for LTP induction.…”

Section: Discussionmentioning

confidence: 99%

“…Activation of GABA B autoreceptors during the priming stimulus suppresses GABA release during the following burst (Davies et al 1990;Lambert and Wilson 1994;Olpe et al 1994), allowing greater postsynaptic depolarization Pacelli et al 1989) and more effective NMDA receptor activation (Davies and Collingridge 1996). Consequently, temporal requirements for primed burst potentiation match the time course of GABA B autoreceptor-mediated suppression of GABA release (Davies et al 1990;Davies and Collingridge 1993;Mott et al 1993).Besides theta, hippocampal activity is observed at other frequencies, notably sharp waves (0.01-5 Hz) (Buzsáki 1986(Buzsáki , 1989Suzuki and Smith 1987) and low-frequency oscillations (#1 Hz) (Wolansky et al 2006;Moroni et al 2007). These lower frequencies dominate during slow wave sleep (Buzsáki 1986;Suzuki and Smith 1987;Wolansky et al 2006;Moroni et al 2007), and contribute to hippocampal memory processing (Buzsáki 1989;Pennartz et al 2002).…”

mentioning

confidence: 99%

“…These lower frequencies dominate during slow wave sleep (Buzsáki 1986;Suzuki and Smith 1987;Wolansky et al 2006;Moroni et al 2007), and contribute to hippocampal memory processing (Buzsáki 1989;Pennartz et al 2002). While synchronized population activity over frequencies from <1 Hz to 12 Hz is associated with hippocampal memory function, previous LTP studies have focused on theta.…”

mentioning

confidence: 99%

“…Besides theta, hippocampal activity is observed at other frequencies, notably sharp waves (0.01-5 Hz) (Buzsáki 1986(Buzsáki , 1989Suzuki and Smith 1987) and low-frequency oscillations (#1 Hz) (Wolansky et al 2006;Moroni et al 2007). These lower frequencies dominate during slow wave sleep (Buzsáki 1986;Suzuki and Smith 1987;Wolansky et al 2006;Moroni et al 2007), and contribute to hippocampal memory processing (Buzsáki 1989;Pennartz et al 2002).…”

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confidence: 99%

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LTP in hippocampal area CA1 is induced by burst stimulation over a broad frequency range centered around delta

Grover¹,

Kim²,

Cooke³

et al. 2009

Learn. Mem.

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Long-term potentiation (LTP) is typically studied using either continuous high-frequency stimulation or theta burst stimulation. Previous studies emphasized the physiological relevance of theta frequency; however, synchronized hippocampal activity occurs over a broader frequency range. We therefore tested burst stimulation at intervals from 100 msec to 20 sec (10 Hz to 0.05 Hz). LTP at Schaffer collateral-CA1 synapses was obtained at intervals from 100 msec to 5 sec, with maximal LTP at 350-500 msec (2-3 Hz, delta frequency). In addition, a short-duration potentiation was present over the entire range of burst intervals. We found that N-methyl-D-aspartic acid (NMDA) receptors were more important for LTP induction by burst stimulation, but L-type calcium channels were more important for LTP induction by continuous high-frequency stimulation. NMDA receptors were even more critical for short-duration potentiation than they were for LTP. We also compared repeated burst stimulation with a single primed burst. In contrast to results from repeated burst stimulation, primed burst potentiation was greater when a 200-msec interval (theta frequency) was used, and a 500-msec interval was ineffective. Whole-cell recordings of postsynaptic membrane potential during burst stimulation revealed two factors that may determine the interval dependence of LTP. First, excitatory postsynaptic potentials facilitated across bursts at 500-msec intervals but not 200-msec or 1-sec intervals. Second, synaptic inhibition was suppressed by burst stimulation at intervals between 200 msec and 1 sec. Our data show that CA1 synapses are more broadly tuned for potentiation than previously appreciated.Long-term potentiation (LTP) is used as a model for studying synaptic events during learning and memory (Bliss and Collingridge 1993;Morris 2003;Lynch 2004). At most synapses, LTP is triggered by postsynaptic Ca 2+ influx through N-methyl-D-aspartic acid (NMDA) glutamate receptors (Collingridge et al. 1983;Harris et al. 1984;Herron et al. 1986) and, under some conditions, through L-type voltage-gated Ca 2+ channels Teyler 1990, 1994;Morgan and Teyler 1999). LTP was discovered in the dentate gyrus (Bliss and Lomo 1973) following several seconds of 10-100 Hz stimulation of the perforant path. Since then, many LTP studies have used similar long, high-frequency stimulation (HFS) protocols, most typically 100 Hz, 1 sec (Bliss and Collingridge 1993). Although effective, HFS does not resemble physiological patterns of activity (Albensi et al. 2007). Patterned stimulation resembling physiological activity, in particular theta burst stimulation, is also effective for LTP induction Staubli and Lynch 1987;Capocchi et al. 1992;Nguyen and Kandel 1997). Theta burst stimulation consists of short bursts (4-5 stimuli at 100 Hz) repeated at 5 Hz, which lies within the hippocampal theta frequency range (4-12 Hz) (Bland 1986;Buzsáki 2002). Primed burst stimulation, another form of patterned stimulation, involves delivery of a priming stimulus followed by a single shor...

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Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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LTP in hippocampal area CA1 is induced by burst stimulation over a broad frequency range centered around delta

Grover¹,

Kim²,

Cooke³

et al. 2009

Learn. Mem.

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“…The deactivated EEG patterns are characterized by large-amplitude slow irregular oscillatory activity. Intermittent, large-amplitude transients (30 -120 ms) called hippocampal "sharp waves" (Buzsáki, 1986;Suzuki and Smith, 1987) are characteristic of this state. In our experiments robust theta oscillations were observed in unperturbed urethane-anesthetized mice.…”

Section: Ttc Stainingmentioning

confidence: 99%

Changes in Hippocampal Neuronal Activity During and After Unilateral Selective Hippocampal IschemiaIn Vivo

Barth¹,

Módy²

2011

J. Neurosci.

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The hippocampal formation is one of the brain regions most sensitive to ischemic damage. However, there are no studies about changes in hippocampal neuronal activity during and after a selective unilateral hippocampal ischemia. We developed a novel unilateral cerebrovascular ischemia model in mice that selectively shuts down blood supply to the ipsilateral hippocampal formation. Using a modified version of the photothrombotic method, we stereotaxically targeted the initial ascending part of the longitudinal hippocampal artery in urethane anesthetized and rose bengal-injected mice. To block blood flow in the targeted artery, we photoactivated the rose bengal by illuminating the longitudinal hippocampal artery through an optical fiber inserted into the brain. In vivo field potential recordings in the CA1 region of the hippocampus before, during and after the induction of ischemia demonstrated a high-frequency discharge (HFD) reaching frequencies of Ͼ300 Hz and lasting 7-24 s during the illumination consistent with a massive synchronous neuronal activity. The HFD was invariably followed by a DC voltage shift and a decreased activity at both low (30 -57 Hz)-and high (63-119 Hz)-gamma frequencies. This decrease in gamma activity lasted for the entire duration of the recordings (ϳ160 min) following ischemia. The contralateral hippocampus displayed HFDs but with different frequency spectra and without DC voltage shifts or long-lasting decreases in gamma oscillations. Our findings reveal for the first time the acute effects of unilateral hippocampal ischemia on ensemble hippocampal neuronal activities.

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Feed-forward and feed-back activation of the dentate gyrus in vivo during dentate spikes and sharp wave bursts

et al. 1998

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Spontaneous EEG spikes in the normal hippocampus. I. Behavioral correlates, laminar profiles and bilateral synchrony

Cited by 109 publications

References 44 publications

LTP in hippocampal area CA1 is induced by burst stimulation over a broad frequency range centered around delta

LTP in hippocampal area CA1 is induced by burst stimulation over a broad frequency range centered around delta

Changes in Hippocampal Neuronal Activity During and After Unilateral Selective Hippocampal IschemiaIn Vivo

Feed-forward and feed-back activation of the dentate gyrus in vivo during dentate spikes and sharp wave bursts

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