scholarly journals Biosensing Motor Neuron Membrane Potential in Live Zebrafish Embryos

10.3791/55297 ◽  
2017 ◽  
Author(s):  
Lorena Benedetti ◽  
Anna Ghilardi ◽  
Laura Prosperi ◽  
Maura Francolini ◽  
Luca Del Giacco
Keyword(s):  
Membrane Potential ◽  
Motor Neuron ◽  
Zebrafish Embryos ◽  
Neuron Membrane

scholarly journals The hyperpolarization-activated current shifts the dynamic range of a voltage-dependent electrical synapse

2021 ◽  
Author(s):  
Wolfgang Stein ◽  
Margaret DeMaegd ◽  
Lena Yolanda Braun ◽  
Andrés G Vidal-Gadea ◽  
Allison L Harris ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Motor Neuron ◽  
Axon Terminal ◽  
Voltage Dependence ◽  
Dynamic Range ◽  
Complex Dynamics ◽  
Ionic Current ◽  
Electrical Synapse ◽  
Resting Membrane Potential ◽  
Voltage Dependent

Like their chemical counterparts, electrical synapses show complex dynamics such as rectification and voltage dependence that interact with other electrical processes in neurons. The consequences arising from these interactions for the electrical behavior of the synapse, and the dynamics they create, remain largely unexplored. Using a voltage-dependent electrical synapse between a descending modulatory projection neuron (MCN1) and a motor neuron (LG) in the crustacean stomatogastric ganglion, we find that the influence of the hyperpolarization-activated inward current (Ih) is critical to the function of the electrical synapse. When we blocked Ih with CsCl, the voltage dependence of the electrical synapse shifted by 18.7 mV to more hyperpolarized voltages, placing the dynamic range of the electrical synapse outside of the range of voltages used by the LG motor neuron (-60.2 mV to -44.9 mV). With dual electrode current- and voltage-clamp recordings, we demonstrate that this voltage shift is due to a sustained effect of Ih on the presynaptic MCN1 axon terminal membrane potential. Ih-induced depolarization of the axon terminal membrane potential increased the electrical postsynaptic potentials and currents. With Ih present, the axon terminal resting membrane potential depolarized, shifting the dynamic range of the electrical synapse towards the functional range of the motor neuron. We thus demonstrate that the function of an electrical synapse is critically influenced by a voltage-dependent ionic current (Ih).

Role of an Identified Looming-Sensitive Neuron in Triggering a Flying Locust's Escape

2006 ◽  
Vol 95 (6) ◽  
pp. 3391-3400 ◽  
Author(s):  
Roger D. Santer ◽  
F. Claire Rind ◽  
Richard Stafford ◽  
Peter J. Simmons
Keyword(s):  
Membrane Potential ◽  
Motor Neuron ◽  
High Frequency ◽  
Escape Behavior ◽  
Excitatory Input ◽  
Movement Detector ◽  
Stimulus Meaning ◽  
Contralateral Movement ◽  
Flight Motor

Flying locusts perform a characteristic gliding dive in response to predator-sized stimuli looming from one side. These visual looming stimuli trigger trains of spikes in the descending contralateral movement detector (DCMD) neuron that increase in frequency as the stimulus gets nearer. Here we provide evidence that high-frequency (>150 Hz) DCMD spikes are involved in triggering the glide: the DCMD is the only excitatory input to a key gliding motor neuron during a loom; DCMD-mediated EPSPs only summate significantly in this motor neuron when they occur at >150 Hz; when a looming stimulus ceases approach prematurely, high-frequency DCMD spikes are removed from its response and the occurrence of gliding is reduced; and an axon important for glide triggering descends in the nerve cord contralateral to the eye detecting a looming stimulus, as the DCMD does. DCMD recordings from tethered flying locusts showed that glides follow high-frequency spikes in a DCMD, but analyses could not identify a feature of the DCMD response alone that was reliably associated with glides in all trials. This was because, for a glide to be triggered, the high-frequency spikes must be timed appropriately within the wingbeat cycle to coincide with wing elevation. We interpret this as flight-gating of the DCMD response resulting from rhythmic modulation of the flight motor neuron's membrane potential during flight. This means that the locust's escape behavior can vary in response to the same looming stimulus, meaning that a predator cannot exploit predictability in the locust's collision avoidance behavior.

Nonspiking local interneuron in the motor pattern generator for the crayfish swimmeret

1985 ◽  
Vol 54 (1) ◽  
pp. 28-39 ◽  
Author(s):  
D. H. Paul ◽  
B. Mulloney
Keyword(s):  
Nervous System ◽  
Membrane Potential ◽  
Motor Neuron ◽  
Motor Pattern ◽  
Pattern Generator ◽  
Local Interneuron ◽  
Postsynaptic Potentials ◽  
Essential Component ◽  
Local Interneurons

We describe a type of nonspiking premotor local interneuron (interneuron IA) in the abdominal nervous system of Pacifasticus leniusculus. All of its branches are restricted to one side of the midline. These interneurons are identifiable and occur as bilateral pairs, one neuron on each side of abdominal ganglia 3, 4, and 5. The membrane potential of interneuron IA oscillated in phase with the swimmeret rhythm, a motor pattern generated in each of these ganglia, because the neuron received postsynaptic potentials in phase with the rhythm. Sustained hyperpolarization of an individual interneuron IA initiated generation of the swimmeret rhythm in all the ganglia of a quiescent nervous system. Sustained depolarization stopped the swimmeret rhythm in all the active ganglia of a nervous system that was generating the rhythm. Currents injected into one interneuron reset the rhythm. Comparisons of the shapes of the IA interneurons in different ganglia showed that they are similar to each other and distinct from other local interneurons in these ganglia. Interneuron IA has a large integrative segment and relatively few branches that are largely restricted to the lateral neuropil, to which all other kinds of swimmeret neurons also project. We conclude that this interneuron occurs only once in each hemiganglion in abdominal segments 3, 4, and 5, and that it is identifiable. Furthermore, this interneuron is an essential component of the circuit in each hemiganglion that generates the swimmeret rhythm. The interneuron was dye coupled to a particular identifiable motor neuron and not to any other neurons. The motor neuron was not dye-coupled to any other local interneurons. The ability of this motor neuron to reset the rhythm is attributed to its being electrically coupled to interneuron IA in its ganglion.

Effects of metal exposure on motor neuron development, neuromasts and the escape response of zebrafish embryos

2015 ◽  
Vol 50 ◽  
pp. 33-42 ◽  
Author(s):  
Laura Sonnack ◽  
Sebastian Kampe ◽  
Elke Muth-Köhne ◽  
Lothar Erdinger ◽  
Nicole Henny ◽  
...  
Keyword(s):  
Motor Neuron ◽  
Escape Response ◽  
Metal Exposure ◽  
Zebrafish Embryos ◽  
Neuron Development

Effects of midazolam on ion currents and membrane potential in differentiated motor neuron-like NSC-34 and NG108-15 cells

2014 ◽  
Vol 724 ◽  
pp. 152-160 ◽  
Author(s):  
Edmund Cheung So ◽  
King Chuen Wu ◽  
Feng Chen Kao ◽  
Sheng Nan Wu
Keyword(s):  
Membrane Potential ◽  
Motor Neuron ◽  
Ion Currents

Monosynaptic activation of different portions of the motor neuron membrane

1960 ◽  
Vol 198 (4) ◽  
pp. 693-703 ◽  
Author(s):  
Ettore Fadiga ◽  
John M. Brookhart
Keyword(s):  
Motor Neuron ◽  
Cell Body ◽  
Motor Neurons ◽  
Dorsal Root ◽  
Time Course ◽  
Intracellular Recordings ◽  
Neuron Membrane ◽  
Lateral Column ◽  
Root Stimulation

Using isolated frog spinal cords, treated with pentobarbital to silence internuncial discharge, intracellular recordings from motor neurons reveal differences in dendritically initiated EPSP evoked by dorsal root stimulation and somatically initiated EPSP evoked by lateral column stimulation. Under these conditions, dorsal root EPSP never reached motor neuron threshold whereas threshold was easily reached by lateral column EPSP. EPSP's initiated by dorsal root volleys were slower in their time course and smaller in their amplitude than those initiated by lateral column volleys. EPSP's initiated by lateral column volleys reduced the amplitude of antidromic spikes, while those produced by dorsal root stimulation did not. Lateral column induced EPSP was also capable of reducing the amplitude of orthodromic spikes. Some observations on duration of transmitter action are reported. It is concluded that dendritic excitation following a dorsal root volley influences the level of polarization of the cell body by electrotonic propagation of the resulting EPSP.

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