scholarly journals Implementation of Neuro-Memristive Synapse for Long-and Short-Term Bio-Synaptic Plasticity

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 644
Author(s):  
Zubaer I. Mannan ◽  
Hyongsuk Kim ◽  
Leon Chua
Keyword(s):  
Synaptic Plasticity ◽  
Diffusion Processes ◽  
Long Term Potentiation ◽  
Synaptic Potentiation ◽  
Short Term ◽  
Term Potentiation ◽  
Voltage Dependent ◽  
Strong Stimulation ◽  
Synaptic Responses

In this paper, we propose a complex neuro-memristive synapse that exhibits the physiological acts of synaptic potentiation and depression of the human-brain. Specifically, the proposed neuromorphic synapse efficiently imitates the synaptic plasticity, especially long-term potentiation (LTP) and depression (LTD), and short-term facilitation (STF) and depression (STD), phenomena of a biological synapse. Similar to biological synapse, the short- or long-term potentiation (STF and LTP) or depression (STD or LTD) of the memristive synapse are distinguished on the basis of time or repetition of input cycles. The proposed synapse is also designed to exhibit the effect of reuptake and neurotransmitters diffusion processes of a bio-synapse. In addition, it exhibits the distinct bio-realistic attributes, i.e., strong stimulation, exponentially decaying conductance trace of synapse, and voltage dependent synaptic responses, of a neuron. The neuro-memristive synapse is designed in SPICE and its bio-realistic functionalities are demonstrated via various simulations.

scholarly journals Group III metabotropic glutamate receptors gate long-term potentiation and synaptic tagging/capture in rat hippocampal area CA2

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Ananya Dasgupta ◽  
Yu Jia Lim ◽  
Krishna Kumar ◽  
Nimmi Baby ◽  
Ka Lam Karen Pang ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Glutamate Receptors ◽  
Metabotropic Glutamate Receptors ◽  
Long Term Potentiation ◽  
Synaptic Potentiation ◽  
Group Iii ◽  
Metabotropic Glutamate ◽  
Term Potentiation ◽  
Hippocampal Area

Metabotropic glutamate receptors (mGluRs) play an important role in synaptic plasticity and memory and are largely classified based on amino acid sequence homology and pharmacological properties. Among group III metabotropic glutamate receptors, mGluR7 and mGluR4 show high relative expression in the rat hippocampal area CA2. Group III metabotropic glutamate receptors are known to down-regulate cAMP-dependent signaling pathways via the activation of Gi/o proteins. Here, we provide evidence that inhibition of group III mGluRs by specific antagonists permits an NMDA receptor- and protein synthesis-dependent long-lasting synaptic potentiation in the apparently long-term potentiation (LTP)-resistant Schaffer collateral (SC)-CA2 synapses. Moreover, long-lasting potentiation of these synapses transforms a transient synaptic potentiation of the entorhinal cortical (EC)-CA2 synapses into a stable long-lasting LTP, in accordance with the synaptic tagging/capture hypothesis (STC). Furthermore, this study also sheds light on the role of ERK/MAPK protein signaling and the downregulation of STEP protein in the group III mGluR inhibition-mediated plasticity in the hippocampal CA2 region, identifying them as critical molecular players. Thus, the regulation of group III mGluRs provides a conducive environment for the SC-CA2 synapses to respond to events that could lead to activity-dependent synaptic plasticity.

scholarly journals Neuraminidase Inhibition Primes Short-Term Depression and Suppresses Long-Term Potentiation of Synaptic Transmission in the Rat Hippocampus

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Alina Savotchenko ◽  
Arthur Romanov ◽  
Dmytro Isaev ◽  
Oleksandr Maximyuk ◽  
Vadym Sydorenko ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Synaptic Plasticity ◽  
Science Studies ◽  
Hippocampal Slices ◽  
Control Level ◽  
Specific Inhibitor ◽  
Long Term Potentiation ◽  
Short Term ◽  
Term Potentiation

Neuraminidase (NEU) is a key enzyme that cleaves negatively charged sialic acid residues from membrane proteins and lipids. Clinical and basic science studies have shown that an imbalance in NEU metabolism or changes in NEU activity due to various pathological conditions parallel with behavior and cognitive impairment. It has been suggested that the decreases of NEU activity could cause serious neurological consequences. However, there is a lack of direct evidences that modulation of endogenous NEU activity can impair neuronal function. Using combined rat entorhinal cortex/hippocampal slices and a specific inhibitor of NEU, 2-deoxy-2,3-dehydro-N-acetylneuraminic acid (NADNA), we examined the effect of downregulation of NEU activity on different forms of synaptic plasticity in the hippocampal CA3-to-CA1 network. We show that NEU inhibition results in a significant decrease in long-term potentiation (LTP) and an increase in short-term depression. Synaptic depotentiation restores LTP in NADNA-pretreated slices to the control level. These data suggest that short-term NEU inhibition produces the LTP-like effect on neuronal network, which results in damping of further LTP induction. Our findings demonstrate that downregulation of NEU activity could have a major impact on synaptic plasticity and provide a new insight into the cellular mechanism underlying behavioral and cognitive impairment associated with abnormal metabolism of NEU.

Brivaracetam Prevents the Over-expression of Synaptic Vesicle Protein 2A and Rescues the Deficits of Hippocampal Long-term Potentiation In Vivo in Chronic Temporal Lobe Epilepsy Rats

2020 ◽  
Vol 17 (4) ◽  
pp. 354-360 ◽  
Author(s):  
Yu-Xing Ge ◽  
Ying-Ying Lin ◽  
Qian-Qian Bi ◽  
Yu-Juan Chen
Keyword(s):  
Synaptic Plasticity ◽  
Temporal Lobe Epilepsy ◽  
Synaptic Vesicle ◽  
Long Term Potentiation ◽  
Synaptic Dysfunction ◽  
Over Expression ◽  
Term Potentiation ◽  
Synaptic Vesicle Protein 2A

Background: Patients with temporal lobe epilepsy (TLE) usually suffer from cognitive deficits and recurrent seizures. Brivaracetam (BRV) is a novel anti-epileptic drug (AEDs) recently used for the treatment of partial seizures with or without secondary generalization. Different from other AEDs, BRV has some favorable properties on synaptic plasticity. However, the underlying mechanisms remain elusive. Objective: The aim of this study was to explore the neuroprotective mechanism of BRV on synaptic plasticity in experimental TLE rats. Methods: The effect of chronic treatment with BRV (10 mg/kg) was assessed on Pilocarpine induced TLE model through measurement of the field excitatory postsynaptic potentials (fEPSPs) in vivo. Differentially expressed synaptic vesicle protein 2A (SV2A) were identified with immunoblot. Then, fast phosphorylation of synaptosomal-associated protein 25 (SNAP-25) during long-term potentiation (LTP) induction was performed to investigate the potential roles of BRV on synaptic plasticity in the TLE model. Results: An increased level of SV2A accompanied by a depressed LTP in the hippocampus was shown in epileptic rats. Furthermore, BRV treatment continued for more than 30 days improved the over-expression of SV2A and reversed the synaptic dysfunction in epileptic rats. Additionally, BRV treatment alleviates the abnormal SNAP-25 phosphorylation at Ser187 during LTP induction in epileptic ones, which is relevant to the modulation of synaptic vesicles exocytosis and voltagegated calcium channels. Conclusion: BRV treatment ameliorated the over-expression of SV2A in the hippocampus and rescued the synaptic dysfunction in epileptic rats. These results identify the neuroprotective effect of BRV on TLE model.

scholarly journals Multiplexed neurochemical transmission emulated using a dual-excitatory synaptic transistor

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.

Prenatal stress in rats attenuates hippocampal long-term potentiation and induces deficits in synaptic plasticity

2006 ◽  
Vol 16 ◽  
pp. S52
Author(s):  
S. Salomon ◽  
Y. Nachum-Biala ◽  
Y. Bogush ◽  
M. Lineal ◽  
H. Matzner ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Prenatal Stress ◽  
Long Term Potentiation ◽  
Term Potentiation

scholarly journals Synaptic plasticity-dependent competition rule influences memory formation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yire Jeong ◽  
Hye-Yeon Cho ◽  
Mujun Kim ◽  
Jung-Pyo Oh ◽  
Min Soo Kang ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Fear Conditioning ◽  
Long Term Potentiation ◽  
Memory Formation ◽  
Specific Pattern ◽  
Memory Encoding ◽  
Competition Rule ◽  
Term Potentiation ◽  
Input Activity

AbstractMemory is supported by a specific collection of neurons distributed in broad brain areas, an engram. Despite recent advances in identifying an engram, how the engram is created during memory formation remains elusive. To explore the relation between a specific pattern of input activity and memory allocation, here we target a sparse subset of neurons in the auditory cortex and thalamus. The synaptic inputs from these neurons to the lateral amygdala (LA) are not potentiated by fear conditioning. Using an optogenetic priming stimulus, we manipulate these synapses to be potentiated by the learning. In this condition, fear memory is preferentially encoded in the manipulated cell ensembles. This change, however, is abolished with optical long-term depression (LTD) delivered shortly after training. Conversely, delivering optical long-term potentiation (LTP) alone shortly after fear conditioning is sufficient to induce the preferential memory encoding. These results suggest a synaptic plasticity-dependent competition rule underlying memory formation.

scholarly journals Altered Short-Term Synaptic Plasticity in Mice Lacking the Metabotropic Glutamate Receptor mGlu7

2002 ◽  
Vol 2 ◽  
pp. 730-737 ◽  
Author(s):  
Trevor J. Bushell ◽  
Gilles Sansig ◽  
Valerie J. Collett ◽  
Herman van der Putten ◽  
Graham L. Collingridge
Keyword(s):  
Synaptic Plasticity ◽  
Molecular Mechanisms ◽  
Pyramidal Neurons ◽  
Metabotropic Glutamate Receptor ◽  
Long Term Potentiation ◽  
Short Term ◽  
Metabotropic Glutamate ◽  
Term Potentiation ◽  
Commissural Pathway ◽  
Frequency Facilitation

Eight subtypes of metabotropic glutamate (mGlu) receptors have been identified of which two, mGlu5 and mGlu7, are highly expressed at synapses made between CA3 and CA1 pyramidal neurons in the hippocampus. This input, the Schaffer collateral-commissural pathway, displays robust long-term potentiation (LTP), a process believed to utilise molecular mechanisms that are key processes involved in the synaptic basis of learning and memory. To investigate the possible function in LTP of mGlu7 receptors, a subtype for which no specific antagonists exist, we generated a mouse lacking this receptor, by homologous recombination. We found that LTP could be induced in mGlu7-/- mice and that once the potentiation had reached a stable level there was no difference in the magnitude of LTP between mGlu7-/- mice and their littermate controls. However, the initial decremental phase of LTP, known as short-term potentiation (STP), was greatly attenuated in the mGlu7-/- mouse. In addition, there was less frequency facilitation during, and less post-tetanic potentiation following, a high frequency train in the mGlu7-/- mouse. These results show that the absence of mGlu7 receptors results in alterations in short-term synaptic plasticity in the hippocampus.

scholarly journals Differential modulation of short-term synaptic dynamics by long-term potentiation at mouse hippocampal mossy fibre synapses

2007 ◽  
Vol 585 (3) ◽  
pp. 853-865 ◽  
Author(s):  
Anja Gundlfinger ◽  
Christian Leibold ◽  
Katja Gebert ◽  
Marion Moisel ◽  
Dietmar Schmitz ◽  
...  
Keyword(s):  
Long Term Potentiation ◽  
Mossy Fibre ◽  
Differential Modulation ◽  
Short Term ◽  
Term Potentiation ◽  
Synaptic Dynamics
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