scholarly journals Short‐term potentiation of GABAergic synaptic inputs to vasopressin and oxytocin neurones

2014 ◽  
Vol 592 (19) ◽  
pp. 4221-4233 ◽  
Author(s):  
Linda A. Morton ◽  
Ion R. Popescu ◽  
Juhee Haam ◽  
Jeffrey G. Tasker
Keyword(s):  
Short Term ◽  
Synaptic Inputs ◽  
Term Potentiation ◽  
Oxytocin Neurones

scholarly journals Long- and Short-Term Conductance Control of Artificial Polymer Wire Synapses

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 312
Author(s):  
Naruki Hagiwara ◽  
Shoma Sekizaki ◽  
Yuji Kuwahara ◽  
Tetsuya Asai ◽  
Megumi Akai-Kasaya
Keyword(s):  
Artificial Intelligence ◽  
Human Brain ◽  
High Speed ◽  
Conductive Polymer ◽  
Long Term Potentiation ◽  
Short Term ◽  
Synaptic Functions ◽  
Term Potentiation ◽  
Artificial Brain ◽  
External Stimuli

Networks in the human brain are extremely complex and sophisticated. The abstract model of the human brain has been used in software development, specifically in artificial intelligence. Despite the remarkable outcomes achieved using artificial intelligence, the approach consumes a huge amount of computational resources. A possible solution to this issue is the development of processing circuits that physically resemble an artificial brain, which can offer low-energy loss and high-speed processing. This study demonstrated the synaptic functions of conductive polymer wires linking arbitrary electrodes in solution. By controlling the conductance of the wires, synaptic functions such as long-term potentiation and short-term plasticity were achieved, which are similar to the manner in which a synapse changes the strength of its connections. This novel organic artificial synapse can be used to construct information-processing circuits by wiring from scratch and learning efficiently in response to external stimuli.

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.

Entrainment pattern between sympathetic and phrenic nerve activities in the Sprague-Dawley rat: hypoxia-evoked sympathetic activity during expiration

2004 ◽  
Vol 286 (6) ◽  
pp. R1121-R1128 ◽  
Author(s):  
Thomas E. Dick ◽  
Y.-H. Hsieh ◽  
Shaun Morrison ◽  
Sharon K. Coles ◽  
Nanduri Prabhakar
Keyword(s):  
Phrenic Nerve ◽  
Sympathetic Activity ◽  
Respiratory Pattern ◽  
Sprague Dawley ◽  
Short Term ◽  
Nerve Activity ◽  
Term Potentiation ◽  
Motor Activities ◽  
Respiratory Modulation ◽  
Activity Dependent

Sympathetic and respiratory motor activities are entrained centrally. We hypothesize that this coupling may partially underlie changes in sympathetic activity evoked by hypoxia due to activity-dependent changes in the respiratory pattern. Specifically, we tested the hypothesis that sympathetic nerve activity (SNA) expresses a short-term potentiation in activity after hypoxia similar to that expressed in phrenic nerve activity (PNA). Adult male, Sprague-Dawley (Zivic Miller) rats ( n = 19) were anesthetized (Equithesin), vagotomized, paralyzed, ventilated, and pneumothoracotomized. We recorded PNA and splanchnic SNA (sSNA) and generated cycle-triggered averages (CTAs) of rectified and integrated sSNA before, during, and after exposures to hypoxia (8% O2 and 92% N2 for 45 s). Inspiration (I) and expiration (E) were divided in half, and the average and area of integrated sSNA were calculated and compared at the following time points: before hypoxia, at the peak breathing frequency during hypoxia, immediately before the end of hypoxia, immediately after hypoxia, and 60 s after hypoxia. In our animal model, sSNA bursts consistently followed the I-E phase transition. With hypoxia, sSNA increased in both halves of E, but preferentially in the second rather than the first half of E, and decreased in I. After hypoxia, sSNA decreased abruptly, but the coefficient of variation in respiratory modulation of sSNA was significantly less than that at baseline. The hypoxic-evoked changes in sympathetic activity and respiratory pattern resulted in sSNA in the first half of E being correlated negatively to that in the second half of E ( r = −0.65, P < 0.05) and positively to Te ( r = 0.40, P < 0.05). Short-term potentiation in sSNA appeared not as an increase in the magnitude of activity but as an increased consistency of its respiratory modulation. By 60 s after hypoxia, the variability in the entrainment pattern had returned to baseline. The preferential recruitment of late expiratory sSNA during hypoxia results from either activation by expiratory-modulated neurons or by non-modulated neurons whose excitatory drive is not gated during late E.

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

Short-Term Potentiation of Miniature Excitatory Synaptic Currents Causes Excitation of Supraoptic Neurons

2000 ◽  
Vol 83 (5) ◽  
pp. 2542-2553 ◽  
Author(s):  
Samuel B. Kombian ◽  
Michiru Hirasawa ◽  
Didier Mouginot ◽  
Xihua Chen ◽  
Quentin J. Pittman
Keyword(s):  
Nmda Receptors ◽  
Postsynaptic Membrane ◽  
High Frequency Stimulation ◽  
Excitatory Synapses ◽  
Short Term ◽  
Cell Excitability ◽  
Term Potentiation ◽  
Before And After ◽  
Frequency Stimulation ◽  
Supraoptic Neurons

Magnocellular neurons (MCNs) of the hypothalamic supraoptic nucleus (SON) secrete vasopressin and oxytocin. With the use of whole-cell and nystatin-perforated patch recordings of MCNs in current- and voltage-clamp modes, we show that high-frequency stimulation (HFS, 10–200 Hz) of excitatory afferents induces increases in the frequency and amplitude of 2,3-dioxo-6-nitro-1,2,3,4-tetrahydrobenzo(f)quinoxaline-7-sulfonamide (NBQX)-sensitive miniature excitatory postsynaptic currents (mEPSCs) lasting up to 20 min. This synaptic enhancement, referred to as short-term potentiation (STP), could be induced repeatedly; required tetrodotoxin (TTX)-dependent action potentials to initiate, but not to maintain; and was independent of postsynaptic membrane potential, N-methyl-d-aspartate (NMDA) receptors, or retrograde neurohypophyseal neuropeptide release. STP was not accompanied by changes in the conductance of the MCNs or in the responsiveness of the postsynaptic non-NMDA receptors, as revealed by brief application of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and kainate. mEPSCs showed similar rise times before and after HFS and analysis of amplitude distributions of mEPSCs revealed one or more peaks pre-HFS and the appearance of additional peaks post-HFS, which were equidistant from the first peak. STP of mEPSCs was not associated with enhanced evoked responses, but was associated with an NBQX-sensitive increase in spontaneous activity of MCNs. Thus we have identified a particularly long-lasting potentiation of excitatory synapses in the SON, which has a presynaptic locus, is dissociated from changes in evoked release, and which regulates postsynaptic cell excitability.

Time-dependent phrenic nerve responses to carotid afferent activation: intact vs. decerebellate rats

1993 ◽  
Vol 265 (4) ◽  
pp. R811-R819 ◽  
Author(s):  
F. Hayashi ◽  
S. K. Coles ◽  
K. B. Bach ◽  
G. S. Mitchell ◽  
D. R. McCrimmon
Keyword(s):  
Phrenic Nerve ◽  
Carotid Sinus ◽  
Carotid Sinus Nerve ◽  
Short Term ◽  
Nerve Activity ◽  
A Value ◽  
Afferent Activation ◽  
Term Potentiation ◽  
Long Term Facilitation

The objectives were to determine 1) respiratory responses to carotid chemoreceptor inputs in anesthetized rats and 2) whether the cerebellar vermis plays a role in these responses. A carotid sinus nerve was stimulated (20 Hz) with five 2-min trains, each separated by approximately 3 min. During stimulation, respiratory frequency (f), peak amplitude of integrated phrenic nerve activity (integral of Phr), and their product (f x integral of Phr) immediately increased. As stimulation continued, integral of Phr progressively increased to a plateau [short-term potentiation (STP)], but f and f x integral of Phr decreased [short-term depression (STD)] to a value still above control. Upon stimulus termination, integral of Phr progressively decreased but remained above control; f and f x integral of Phr transiently decreased below baseline. After the final stimulation, integral of Phr remained above control for at least 30 min [long-term facilitation (LTF)]. Repeated 5-min episodes of isocapnic hypoxia also elicited STP, STD, and LTF. Vermalectomy lowered the CO2-apneic threshold and eliminated LTF. In conclusion, carotid chemoreceptor activation in rats elicits STP and LTF similar to that in cats; the vermis may play a role in LTF. A new response, STD, was observed.

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