Recall of spatial patterns stored in a hippocampal slice by long-term potentiation

Nervous systems are thought to encode information as patterns of electrical activity distributed sparsely through networks of neurons. These networks then process information by transforming one pattern of electrical activity into another. To store information as a pattern, a neural network must strengthen synapses between designated neurons so that activation of some of these neurons corresponding to some features of an object can spread to activate the larger group representing the complete object. This operation of pattern completion endows a neural network with autoassociative memory. Pattern completion by neural networks has been modeled extensively with computers and invoked in behavioral studies, but experiments have yet to demonstrate pattern completion in an intact neural circuit. In the present study, imaging with voltage-sensitive dye in the CA3 region of a hippocampal slice revealed different spatial patterns of activity elicited by electrical stimulation of different sites. Stimulation of two separate sites individually, or both sites simultaneously, evoked “partial” or “complete” patterns, respectively. A complete pattern was then stored by applying theta burst stimulation to both sites simultaneously to induce long-term potentiation (LTP) of synapses between CA3 pyramidal cells. Subsequent stimulation of only one site then activated an extended pattern. Quantitative comparisons between response maps showed that the post-LTP single-site patterns more closely resembled the complete dual-site pattern. Thus, LTP induction enabled the CA3 region to complete a dual-site pattern upon stimulation of only one site. This experiment demonstrated that LTP induction can store information in the CA3 region of the hippocampus for subsequent retrieval.

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Enhanced bursting activity in the CA3 region of the mouse hippocampal slice without long-term potentiation in the dentate gyrus after systemic pentylenetetrazole kindling

Experimental Neurology ◽

10.1016/0014-4886(86)90245-1 ◽

1986 ◽

Vol 94 (3) ◽

pp. 659-669 ◽

Cited By ~ 18

Author(s):

S. Piredda ◽

W. Yonekawa ◽

T.S. Whittingham ◽

H.J. Kupferberg

Keyword(s):

Dentate Gyrus ◽

Hippocampal Slice ◽

Long Term Potentiation ◽

Term Potentiation ◽

Bursting Activity ◽

Ca3 Region

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Multiplexed neurochemical transmission emulated using a dual-excitatory synaptic transistor

npj 2D Materials and Applications ◽

10.1038/s41699-021-00205-4 ◽

2021 ◽

Vol 5 (1) ◽

Author(s):

Mingxue Ma ◽

Yao Ni ◽

Zirong Chi ◽

Wanqing Meng ◽

Haiyang Yu ◽

...

Keyword(s):

Neural Network ◽

Central Nervous System ◽

Nervous System ◽

Long Term Potentiation ◽

Short Term ◽

Term Potentiation ◽

Binary Neural Network ◽

Neuromorphic Systems ◽

Human Brains

AbstractThe ability to emulate multiplexed neurochemical transmission is an important step toward mimicking complex brain activities. Glutamate and dopamine are neurotransmitters that regulate thinking and impulse signals independently or synergistically. However, emulation of such simultaneous neurotransmission is still challenging. Here we report design and fabrication of synaptic transistor that emulates multiplexed neurochemical transmission of glutamate and dopamine. The device can perform glutamate-induced long-term potentiation, dopamine-induced short-term potentiation, or co-release-induced depression under particular stimulus patterns. More importantly, a balanced ternary system that uses our ambipolar synaptic device backtrack input ‘true’, ‘false’ and ‘unknown’ logic signals; this process is more similar to the information processing in human brains than a traditional binary neural network. This work provides new insight for neuromorphic systems to establish new principles to reproduce the complexity of a mammalian central nervous system from simple basic units.

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Induction of long-term potentiation without participation of N-methyl-D-aspartate receptors in kitten visual cortex

Journal of Neurophysiology ◽

10.1152/jn.1991.65.1.20 ◽

1991 ◽

Vol 65 (1) ◽

pp. 20-32 ◽

Cited By ~ 47

Author(s):

Y. Komatsu ◽

S. Nakajima ◽

K. Toyama

Keyword(s):

Nmda Receptors ◽

Stimulus Frequency ◽

Low Frequency ◽

Nmda Antagonist ◽

Long Term Potentiation ◽

Conditioning Stimulation ◽

Postsynaptic Potential ◽

Term Potentiation ◽

Stimulation Of

1. Intracellular recording was made from layer II-III cells in slice preparations of kitten (30-40 days old) visual cortex. Low-frequency (0.1 Hz) stimulation of white matter (WM) usually evoked an excitatory postsynaptic potential (EPSP) followed by an inhibitory postsynaptic potential (IPSP). The postsynaptic potentials (PSPs) showed strong dependence on stimulus frequency. Early component of EPSP and IPSP evoked by weak stimulation both decreased monotonically at frequencies greater than 0.5-1 Hz. Strong stimulation similarly depressed the early EPSP at higher frequencies (greater than 2 Hz) and replaced the IPSP with a late EPSP, which had a maximum amplitude in the stimulus frequency range of 2-5 Hz. 2. Very weak WM stimulation sometimes evoked EPSPs in isolation from IPSPs. The falling phase of the EPSP revealed voltage dependence characteristic to the responses mediated by N-methyl-D-aspartate (NMDA) receptors and was depressed by application of an NMDA antagonist DL-2-amino-5-phosphonovalerate (APV), whereas the rising phase of the EPSP was insensitive to APV. 3. The early EPSPs followed by IPSPs were insensitive to APV but were replaced with a slow depolarizing potential by application of a non-NMDA antagonist 6,7-dinitro-quinoxaline-2,3-dione (DNQX), indicating that the early EPSP is mediated by non-NMDA receptors. The slow depolarization was mediated by NMDA receptors because it was depressed by membrane hyperpolarization or addition of APV. 4. The late EPSP evoked by higher-frequency stimulation was abolished by APV, indicating that it is mediated by NMDA receptors, which are located either on the recorded cell or on presynaptic cells to the recorded cells. 5. Long-term potentiation (LTP) of EPSPs was examined in cells perfused with solutions containing 1 microM bicuculline methiodide (BIM), a gamma-aminobutyric acid (GABA) antagonist. WM was stimulated at 2 Hz for 15 min as a conditioning stimulus to induce LTP, and the resultant changes were tested by low-frequency (0.1 Hz) stimulation of WM. 6. LTP of early EPSPs occurred in more than one-half of the cells (8/13) after strong conditioning stimulation. The rising slope of the EPSP was increased 1.6 times on average. 7. To test involvement of NMDA receptors in the induction of LTP in the early EPSP, the effect of conditioning stimulation was studied in a solution containing 100 microM APV, which was sufficient to block completely synaptic transmission mediated by NMDA receptors. LTP occurred in the same frequency and magnitude as in control solution.

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Long-term potentiation facilitates behavioral responding to single-pulse stimulation of the perforant path.

Behavioral Neuroscience ◽

10.1037/0735-7044.99.4.603 ◽

1985 ◽

Vol 99 (4) ◽

pp. 603-620 ◽

Cited By ~ 17

Author(s):

Ronald W. Skelton ◽

James J. Miller ◽

Anthony G. Phillips

Keyword(s):

Single Pulse ◽

Long Term Potentiation ◽

Perforant Path ◽

Term Potentiation ◽

Pulse Stimulation ◽

Stimulation Of

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In vivo induction of striatal long-term potentiation by low-frequency stimulation of the cerebral cortex

Neuroscience ◽

10.1016/s0306-4522(98)00719-2 ◽

1999 ◽

Vol 91 (4) ◽

pp. 1209-1222 ◽

Cited By ~ 69

Author(s):

S Charpier ◽

S Mahon ◽

J.-M Deniau

Keyword(s):

Cerebral Cortex ◽

Low Frequency ◽

Long Term Potentiation ◽

Low Frequency Stimulation ◽

Term Potentiation ◽

Frequency Stimulation ◽

In Vivo Induction ◽

Stimulation Of

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On the Respective Roles of Nitric Oxide and Carbon Monoxide in Long-Term Potentiation in the Hippocampus

Learning & Memory ◽

10.1101/lm.6.1.63 ◽

1999 ◽

Vol 6 (1) ◽

pp. 63-76 ◽

Cited By ~ 1

Author(s):

Min Zhuo ◽

Jarmo T. Laitinen ◽

Xiao-Ching Li ◽

Robert D. Hawkins

Keyword(s):

Nitric Oxide ◽

Carbon Monoxide ◽

Heme Oxygenase ◽

Guanylyl Cyclase ◽

Hippocampal Slices ◽

Long Term Potentiation ◽

No Synthase ◽

Term Potentiation ◽

Stimulation Of

Perfusion of hippocampal slices with an inhibitor nitric oxide (NO) synthase blocked induction of long-term potentiation (LTP) produced by a one-train tetanus and significantly reduced LTP by a two-train tetanus, but only slightly reduced LTP by a four-train tetanus. Inhibitors of heme oxygenase, the synthetic enzyme for carbon monoxide (CO), significantly reduced LTP by either a two-train or four-train tetanus. These results suggest that NO and CO are both involved in LTP but may play somewhat different roles. One possibility is that NO serves a phasic, signaling role, whereas CO provides tonic, background stimulation. Another possibility is that NO and CO are phasically activated under somewhat different circumstances, perhaps involving different receptors and second messengers. Because NO is known to be activated by stimulation of NMDA receptors during tetanus, we investigated the possibility that CO might be activated by stimulation of metabotropic glutamate receptors (mGluRs). Consistent with this idea, long-lasting potentiation by the mGluR agonist tACPD was blocked by inhibitors of heme oxygenase but not NO synthase. Potentiation by tACPD was also blocked by inhibitors of soluble guanylyl cyclase (a target of both NO and CO) or cGMP-dependent protein kinase, and guanylyl cyclase was activated by tACPD in hippocampal slices. However, biochemical assays indicate that whereas heme oxygenase is constitutively active in hippocampus, it does not appear to be stimulated by either tetanus or tACPD. These results are most consistent with the possibility that constitutive (tonic) rather than stimulated (phasic) heme oxygenase activity is necessary for potentiation by tetanus or tACPD, and suggest that mGluR activation stimulates guanylyl cyclase phasically through some other pathway.

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Type I adenylyl cyclase functions as a coincidence detector for control of cyclic AMP response element-mediated transcription: synergistic regulation of transcription by Ca2+ and isoproterenol

Molecular and Cellular Biology ◽

10.1128/mcb.14.12.8272-8281.1994 ◽

1994 ◽

Vol 14 (12) ◽

pp. 8272-8281

Author(s):

S Impey ◽

G Wayman ◽

Z Wu ◽

D R Storm

Keyword(s):

Cyclic Amp ◽

Adenylyl Cyclase ◽

Long Term Potentiation ◽

Regulation Of Transcription ◽

Type I ◽

Hek 293 ◽

293 Cells ◽

Term Potentiation ◽

Stimulation Of

Studies carried out with mammals and invertebrates suggest that Ca(2+)-sensitive adenylyl cyclases may be important for neuroplasticity. Long-term potentiation in the hippocampus requires increases in intracellular Ca2+ which are accompanied by elevated cyclic AMP (cAMP). Furthermore, activation of cAMP-dependent protein kinase is required for the late stage of long-term potentiation in the CA1 region of the hippocampus, which is also sensitive to inhibitors of transcription. Therefore, some forms of synaptic plasticity may require coordinate regulation of transcription by Ca2+ and cAMP. In this study, we demonstrate that the expression of type I adenylyl cyclase in HEK-293 cells allows Ca2+ to stimulate reporter gene activity mediated through the cAMP response element. Furthermore, simultaneous activation by Ca2+ and isoproterenol caused synergistic stimulation of transcription in HEK-293 cells and cultured neurons. We propose that Ca2+ and neurotransmitter stimulation of type I adenylyl cyclase may play a role in synaptic plasticity by generating optimal cAMP signals for regulation of transcription.

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