scholarly journals RECIPROCALLY INHIBITORY CIRCUITS OPERATING WITH DISTINCT MECHANISMS ARE DIFFERENTLY ROBUST TO PERTURBATION AND MODULATION

2021 ◽  
Author(s):  
Ekaterina O Morozova ◽  
Peter Newstein ◽  
Eve Marder
Keyword(s):  
Building Block ◽  
Temperature Increase ◽  
Reciprocal Inhibition ◽  
Stomatogastric Ganglion ◽  
Dynamic Clamp ◽  
Active Neuron ◽  
Inhibitory Circuits ◽  
Circuit Output

What features are important for circuit robustness? Reciprocal inhibition is a building block in many circuits. We used dynamic clamp to create reciprocally inhibitory circuits from GM neurons of the crab stomatogastric ganglion by injecting artificial synaptic and hyperpolarization-activated inward (H) currents. In "release", the active neuron controls the off/on transitions. In "escape", the inhibited neuron controls the transitions. We characterized the robustness of escape and release circuits to alterations in circuit parameters, temperature, and neuromodulation. Escape circuits rely on tight correlations between synaptic and H conductances to generate bursting but are resilient to temperature increase. Release circuits are robust to variations in synaptic and H conductances but fragile to temperature increase. The modulatory current (IMI) restores oscillations in release circuits but has little effect in escape. Thus, the same perturbation can have dramatically different effects depending on the circuits' mechanism of operation that may not be observable from circuit output.

scholarly journals Distinct co-modulation rules of synaptic and voltage-gated currents coordinates interactions of multiple neuromodulators

2018 ◽  
Author(s):  
Xinping Li ◽  
Dirk Bucher ◽  
Farzan Nadim
Keyword(s):  
Signaling Pathways ◽  
Ionic Currents ◽  
Evolutionary Conservation ◽  
Stomatogastric Ganglion ◽  
Cancer Borealis ◽  
Voltage Gated ◽  
Individual Effects ◽  
The Individual ◽  
Circuit Output ◽  
Dose Dependent

AbstractDifferent neuromodulators usually activate distinct receptors but can have overlapping targets. Consequently, circuit output depends on neuromodulator interactions at shared targets, a poorly understood process. We explored quantitative rules of co-modulation of two principal targets: voltage-gated and synaptic ionic currents. In the stomatogastric ganglion of the crab Cancer borealis, the neuropeptides proctolin and CCAP modulate synapses of the pyloric circuit, and activate a voltage-gated current (IMI) in multiple neurons. We examined the validity of a simple dose-dependent quantitative rule that co-modulation by proctolin and CCAP is predicted by the linear sum of the individual effects of each modulator, up to saturation. We found that this rule is valid for co-modulation of synapses, but not for the activation of IMI, where co-modulation was sublinear. Given the evolutionary conservation of neuromodulator receptors and signaling pathways, such distinct rules for co-modulation of different targets are likely to be common across neuronal circuits.

Dynamic clamp: computer-generated conductances in real neurons

1993 ◽  
Vol 69 (3) ◽  
pp. 992-995 ◽  
Author(s):  
A. A. Sharp ◽  
M. B. O'Neil ◽  
L. F. Abbott ◽  
E. Marder
Keyword(s):  
Stomatogastric Ganglion ◽  
Inhibitory Synapses ◽  
Dynamic Clamp ◽  
Gamma Aminobutyric Acid ◽  
Activation Curve ◽  
Maximal Conductance ◽  
Target Neuron ◽  
Voltage Dependent ◽  
Ganglion Neurons ◽  
At Will

1. We describe a new method, the dynamic clamp, that uses a computer as an interactive tool to introduce simulated voltage and ligand mediated conductances into real neurons. 2. We simulate a gamma-aminobutyric acid (GABA) response of a cultured stomatogastric ganglion neuron to illustrate that the dynamic clamp effectively introduces a conductance into the target neuron. 3. To demonstrate an artificial voltage-dependent conductance, we simulate the action of a voltage-dependent proctolin response on a neuron in the intact stomatogastric ganglion. We show that shifts in the activation curve and the maximal conductance of the response produce different effects on the target neuron. 4. The dynamic clamp is used to construct reciprocal inhibitory synapses between two stomatogastric ganglion neurons that are not coupled naturally, illustrating that this method can be used to form new networks at will.

scholarly journals Change in Reciprocal Inhibition of the Forearm with Motor Imagery among Patients with Chronic Stroke

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Michiyuki Kawakami ◽  
Kohei Okuyama ◽  
Yoko Takahashi ◽  
Miho Hiramoto ◽  
Atsuko Nishimura ◽  
...  
Keyword(s):  
Motor Imagery ◽  
Reciprocal Inhibition ◽  
Chronic Stroke ◽  
Mental Practice ◽  
Cortical Lesion ◽  
Lesion Group ◽  
Stroke Patients ◽  
Inhibitory Circuits ◽  
Machine Interface ◽  
Extensor Carpi Radialis

We investigated cortically mediated changes in reciprocal inhibition (RI) following motor imagery (MI) in short- and long(er)-term periods. The goals of this study were (1) to describe RI during MI in patients with chronic stroke and (2) to examine the change in RI after MI-based brain-machine interface (BMI) training. Twenty-four chronic stroke patients participated in study 1. All patients imagined wrist extension on the affected side. RI from the extensor carpi radialis to the flexor carpi radialis (FCR) was assessed using a FCR H reflex conditioning-test paradigm. We calculated the “MI effect score on RI” (RI value during MI divided by that at rest) and compared that score according to lesion location. RI during MI showed a significant enhancement compared with RI at rest. The MI effect score on RI in the subcortical lesion group was significantly greater than that in the cortical lesion group. Eleven stroke patients participated in study 2. All patients performed BMI training for 10 days. The MI effect score on RI at a 20 ms interstimulus interval was significantly increased after BMI compared with baseline. In conclusion, mental practice with MI may induce plastic change in spinal reciprocal inhibitory circuits in patients with stroke.

Microbe Engineering of Guaia-6,10(14)-diene as a Building Block for the Semisynthetic Production of Plant-Derived (−)-Englerin A

2019 ◽  
Author(s):  
Thomas Siemon ◽  
Zhangqian Wang ◽  
Guangkai Bian ◽  
Tobias Seitz ◽  
Ziling Ye ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Synthetic Biology ◽  
Chemical Synthesis ◽  
Building Block ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Economical Method ◽  
Englerin A ◽  
Transient Receptor

Herein, we report the semisynthetic production of the potent transient receptor potential canonical (TRPC) channel agonist (−)-englerin A (EA), using guaia-6,10(14)-diene as the starting material. Guaia-6,10(14)-diene was systematically engineered in Escherichia coli and Saccharomyces cerevisiae using the CRISPR/Cas9 system and produced with high titers. This provided us the opportunity to execute a concise chemical synthesis of EA and the two related guaianes (−)-oxyphyllol and (+)-orientalol E. The potentially scalable approach combines the advantages of synthetic biology and chemical synthesis and provides an efficient and economical method for producing EA as well as its analogs.

Microbe Engineering of Guaia-6,10(14)-diene as a Building Block for the Semisynthetic Production of Plant-Derived (−)-Englerin A

2019 ◽  
Author(s):  
Thomas Siemon ◽  
Zhangqian Wang ◽  
Guangkai Bian ◽  
Tobias Seitz ◽  
Ziling Ye ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Synthetic Biology ◽  
Chemical Synthesis ◽  
Building Block ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Economical Method ◽  
Englerin A ◽  
Transient Receptor

Herein, we report the semisynthetic production of the potent transient receptor potential canonical (TRPC) channel agonist (−)-englerin A (EA), using guaia-6,10(14)-diene as the starting material. Guaia-6,10(14)-diene was systematically engineered in Escherichia coli and Saccharomyces cerevisiae using the CRISPR/Cas9 system and produced with high titers. This provided us the opportunity to execute a concise chemical synthesis of EA and the two related guaianes (−)-oxyphyllol and (+)-orientalol E. The potentially scalable approach combines the advantages of synthetic biology and chemical synthesis and provides an efficient and economical method for producing EA as well as its analogs.

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