Emulation of Biphasic Plasticity in Retinal Electrical Synapse for Light-Adaptive Pattern Pre-Processing

Nanoscale ◽  
2021 ◽  
Author(s):  
Lindong Wu ◽  
Zongwei Wang ◽  
Bowen Wang ◽  
Qingyu Chen ◽  
Lin Bao ◽  
...  

Electrical synapse provides rapid, bidirectional communication in nervous systems, accomplishing tasks distinct from and complementary to chemical synapses. Here, we demonstrate an artificial electrical synapse based on high-order conductance transition...

2017 ◽  
Author(s):  
Audrey J Marsh ◽  
Jennifer Carlisle Michel ◽  
Anisha P Adke ◽  
Emily L Heckman ◽  
Adam C Miller

AbstractNeuronal synaptic connections are electrical or chemical and together are essential to dynamically defining neural circuit function. While chemical synapses are well known for their biochemical complexity, electrical synapses are often viewed as comprised solely of neuronal gap junction channels that allow direct ionic and metabolic communication. However, associated with the gap junction channels are structures observed by electron microscopy called the Electrical Synapse Density (ESD). The ESD has been suggested to be critical for the formation and function of the electrical synapse, yet the biochemical makeup of these structures is poorly understood. Here we find that electrical synapse formation in vivo requires an intracellular scaffold called Tight Junction Protein 1b (Tjp1b). Tjp1b is localized to electrical synapses where it is required for the stabilization of the gap junction channels and for electrical synapse function. Strikingly, we find that Tjp1b protein localizes and functions asymmetrically, exclusively on the postsynaptic side of the synapse. Our findings support a novel model in which there is molecular asymmetry at the level of the intracellular scaffold that is required for building the electrical synapse. ESD molecular asymmetries may be a fundamental motif of all nervous systems and could support functional asymmetry at the electrical synapse.


Author(s):  
Liang Guo ◽  
Shuai Zhang ◽  
Jiankang Wu ◽  
Xinyu Gao ◽  
Mingkang Zhao ◽  
...  

Transcranial magnetic-acoustic electrical stimulation (TMAES) is a new technology with ultrasonic waves and a static magnetic field to generate an electric current in nerve tissues to modulate neuronal firing activities. The existing neuron models only simulate a single neuron, and there are few studies on coupled neurons models about TMAES. Most of the neurons in the cerebral cortex are not isolated but are coupled to each other. It is necessary to study the information transmission of coupled neurons. The types of neuron coupled synapses include electrical synapse and chemical synapse. A neuron model without considering chemical synapses is not comprehensive. Here, we modified the Hindmarsh-Rose (HR) model to simulate the smallest nervous system—two neurons coupled electrical synapses and chemical synapses under TMAES. And the environmental variables describing the synaptic coupling between two neurons and the nonlinearity of the nervous system are also taken into account. The firing behavior of the nervous system can be modulated by changing the intensity or the modulation frequency. The results show that within a certain range of parameters, the discharge frequency of coupled neurons could be increased by altering the modulation frequency, and intensity of stimulation, modulating the excitability of neurons, reducing the response time of chemical postsynaptic neurons, and accelerating the information transferring. Moreover, the discharge frequency of neurons was selective to stimulus parameters. These results demonstrate the possible theoretical regulatory mechanism of the neurons' firing frequency characteristics by TMAES. The study establishes the foundation for large-scale neural network modeling and can be taken as the theoretical basis for TMAES experimental and clinical application.


Biology ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1099
Author(s):  
Pepe Alcami ◽  
Santhosh Totagera ◽  
Nina Sohnius-Wilhelmi ◽  
Stefan Leitner ◽  
Benedikt Grothe ◽  
...  

Birdsong is a precisely timed animal behavior. The connectivity of song premotor neural networks has been proposed to underlie the temporal patterns of neuronal activity that control vo-cal muscle movements during singing. Although the connectivity of premotor nuclei via chemical synapses has been characterized, electrical synapses and their molecular identity remain unex-plored. We show with in situ hybridizations that GJD2 mRNA, coding for the major channel-form-ing electrical synapse protein in mammals, connexin 36, is expressed in the two nuclei that control song production, HVC and RA from canaries and zebra finches. In canaries’ HVC, GJD2 mRNA is extensively expressed in GABAergic and only a fraction of glutamatergic cells. By contrast, in RA, GJD2 mRNA expression is widespread in glutamatergic and GABAergic neurons. Remarkably, GJD2 expression is similar in song nuclei and their respective embedding brain regions, revealing the widespread expression of GJD2 in the avian brain. Inspection of a single-cell sequencing data-base from zebra and Bengalese finches generalizes the distributions of electrical synapses across cell types and song nuclei that we found in HVC and RA from canaries, reveals a differential GJD2 mRNA expression in HVC glutamatergic subtypes and its transient increase along the neurogenic lineage. We propose that songbirds are a suitable model to investigate the contribution of electrical synapses to motor skill learning and production.


1987 ◽  
Vol 133 (1) ◽  
pp. 353-370
Author(s):  
W. J. HEITLER ◽  
K. FRASER

A recent claim that the giant fibre of the hermit crab excites its contralateral motor giant neurone through a chemical rather than an electrical synapse (Stephens, 1986) was re-examined. We found that the reported increased latency (relative to the electrical ipsilateral synapse) was postsynaptic in origin, as was the increased spike ‘jitter’. There was no difference in synaptic latency between the electrical synapse and the supposed chemical one. We did not find a consistent resistance to N-ethylmaleimide (an uncoupler of electrical synapses) by the supposed chemical synapse, but the synapse was resistant to 2 mmol 1−1 cadmium, which blocks known chemical synapses in the system. Sub-threshold depolarizing current passed from the presynaptic giant fibre to the postsynaptic contralateral motor giant, and hyperpolarizing current passed antidromically. We conclude that the synapse is electrical and not chemical in nature.


1986 ◽  
Vol 123 (1) ◽  
pp. 217-228
Author(s):  
PHILIP J. STEPHENS

1. An examination is made of the characteristics of the synapses between the single pair of giant interneurones (GIs) and the giant flexor motor neurones (GFMNs) in the fused thoracic-abdominal (TA) ganglion of the hermit crab Pagurus pollicaris. 2. There is an electrical synapse between each GI and its ipsilateral GFMN. Evidence for this includes (a) dye (Lucifer Yellow CH) coupling between the two neurones, (b) a short synaptic (0.2 ms) delay between spikes in the two axons, (c) the ability to pass hyperpolarizing current between the two neurones and (d) the sensitivity of the connection to bath applications of N-ethylmaleimide. This synaptic connection is rectifying, since a GFMN spike does not provoke an action potential in the GI. 3. There is a connection between the GI and the contralateral GFMN. Data indicating that this synaptic connection is chemical includes (a) a synaptic delay of between 0.6 and 0.8 ms, (b) transmission i9 easily and irreversibly fatigued, (c) the synapse is insensitive to N-ethylmaleimide and (d) there is no dye coupling between the two neurones. 4. Branches of the GFMN come in close proximity with the GI on both sides of the TA ganglion. However, it is not known whether there is a direct connection or an intervening neurone between the GI and the contralateral GFMN.


Author(s):  
Aliyu Isah ◽  
A. S. Tchakoutio Nguetcho ◽  
S. Binczak ◽  
J.M. Bilbault

As the memristor device is asymmetrical in nature, it is not a bilateral element like the resistor in terms of circuit functionality. Thus, it causes hindrance in some memristor-based applications such as in cellular nonlinear network neighborhood connections and in some application areas where its orientation is essentially expected to act as a bilateral circuit element reliable for bidirectional communication, for example, in signal and image processing or in electrical synapse devices. We introduce a memristor-based network for each purpose where we replace the conventional series resistances by memristors. The memristor asymmetry is described from the circuit point of view allowing us to observe its interaction within the network. Moreover, a memristor fuse is proposed in order to achieve the memristive effect with symmetry, which is formed basically by connecting two memristors antiserially. We, therefore, analyze the memristor fuse from its basic principle along with the theoretical analysis and then observe the response from the circuit point of view.


2019 ◽  
Author(s):  
May Dobosiewicz ◽  
Cornelia I. Bargmann

ABSTRACTThe central nervous system transforms sensory information into representations that are salient to the animal. Here we define the logic of this transformation in a Caenorhabditis elegans integrating interneuron. AIA interneurons receive input from multiple chemosensory neurons that detect attractive odors. We show that reliable AIA responses require the coincidence of two sensory inputs: activation of AWA olfactory neurons that are activated by attractive odors, and inhibition of one or more chemosensory neurons that are inhibited by attractive odors. AWA activates AIA through an electrical synapse, while the disinhibitory pathway acts through glutamatergic chemical synapses. The resulting AIA interneuron responses have uniform magnitude and dynamics, suggesting that AIA activation is a stereotyped response to an integrated stimulus. Our results indicate that AIA interneurons combine sensory information using AND-gate logic, requiring coordinated activity from multiple chemosensory neurons. We propose that AIA encodes positive odor valence based on an integrated sensory state.


1990 ◽  
Vol 19 (6) ◽  
pp. 929-936 ◽  
Author(s):  
B. Leitch ◽  
W. J. Heitler ◽  
J. L. S. Cobb ◽  
R. M. Pitman

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
May Dobosiewicz ◽  
Qiang Liu ◽  
Cornelia I Bargmann

The central nervous system transforms sensory information into representations that are salient to the animal. Here we define the logic of this transformation in a Caenorhabditis elegans integrating interneuron. AIA interneurons receive input from multiple chemosensory neurons that detect attractive odors. We show that reliable AIA responses require the coincidence of two sensory inputs: activation of AWA olfactory neurons that are activated by attractive odors, and inhibition of one or more chemosensory neurons that are inhibited by attractive odors. AWA activates AIA through an electrical synapse, while the disinhibitory pathway acts through glutamatergic chemical synapses. AIA interneurons have bistable electrophysiological properties consistent with their calcium dynamics, suggesting that AIA activation is a stereotyped response to an integrated stimulus. Our results indicate that AIA interneurons combine sensory information using AND-gate logic, requiring coordinated activity from multiple chemosensory neurons. We propose that AIA encodes positive valence based on an integrated sensory state.


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