scholarly journals Action potential alterations induced by single F11 neuronal cell loading

2021 ◽  
Author(s):  
Miren Tamayo-Elizalde ◽  
Haoyu Chen ◽  
Majid Malboubi ◽  
Hua Ye ◽  
Antoine Jerusalem
Keyword(s):  
Action Potential ◽  
Neuronal Cell ◽  
Cell Loading

scholarly journals Modeling Neuronal Systems as an Open Quantum System

Symmetry ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1603
Author(s):  
Yu-Juan Sun ◽  
Wei-Min Zhang
Keyword(s):  
Action Potential ◽  
Open Quantum Systems ◽  
Continuous Distribution ◽  
Neuronal Cell ◽  
Neuronal Model ◽  
Collective State ◽  
Neuronal System ◽  
Open Quantum ◽  
Neuronal Cell Bodies ◽  
Master Equation Approach

We propose a physical model for neurons to describe how neurons interact with one another through the surrounding materials of neuronal cell bodies. We model the neuronal cell surroundings, include the dendrites, the axons and the synapses, as well as the surrounding glial cells, as a continuous distribution of oscillating modes inspired from the electric circuital picture of neuronal action potential. By analyzing the dynamics of this neuronal model by using the master equation approach of open quantum systems, we investigated the collective behavior of neurons. After applying stimulations to the neuronal system, the neuron collective state is activated and shows the action potential behavior. We find that this model can generate random neuron–neuron interactions and is appropriate for describing the process of information transmission in the neuronal system, which may pave a potential route toward understanding the dynamics of nervous system.

Physiological studies of small mediastinal ganglia in the cardiopulmonary nerves of dogs

1984 ◽  
Vol 62 (9) ◽  
pp. 1244-1248 ◽  
Author(s):  
J. A. Armour
Keyword(s):  
Action Potential ◽  
Neuronal Cell ◽  
Compound Action Potential ◽  
Transitional Region ◽  
High Frequencies ◽  
Neuronal Cell Bodies ◽  
Wave Forms ◽  
Local Injections ◽  
Compound Action ◽  
Stimulation Of

Stimulation of the cranial end of a decentralized canine cardiopulmonary nerve results in the generation of a compound action potential which can be recorded at the caudal end. A region has been identified which, on stimulation, produces a compound action potential with complex configuration which is different from simpler wave forms obtained by stimulating 1 mm or more in either the rostral or caudal direction. Histological examination reveals that clusters of neuronal cell bodies are localized to this region of the nerve, whereas none is found to either side. Characteristics of the different wave forms evoked by changing the site of stimulation and reversing the stimulation and recording electrodes provide evidence for the existence of both afferent and efferent synaptic pathways. The compound action potential evoked by the most rostral stimulations and presumed to contain synaptic components was not altered by intravenously administered cholinergic and adrenergic pharmacological blocking agents (hexamethonium, atropine, phentolamine, or propranolol). It was, however, depressed by local injections of chymotrypsin or manganese into the functionally identified transitional region. It is concluded that synapses, which can be activated at relatively high frequencies (1–10 Hz) and may be important for rapidly changing local neural regulation of the heart and lungs, appear to exist within the course of cardiopulmonary nerves.

scholarly journals Pharmacologically Targeting the Fibroblast Growth Factor 14 Interaction Site on the Voltage-Gated Na+ Channel 1.6 Enables Isoform-Selective Modulation

2021 ◽  
Vol 22 (24) ◽  
pp. 13541
Author(s):  
Nolan M. Dvorak ◽  
Cynthia M. Tapia ◽  
Aditya K. Singh ◽  
Timothy J. Baumgartner ◽  
Pingyuan Wang ◽  
...  
Keyword(s):  
Growth Factor ◽  
Action Potential ◽  
Fibroblast Growth Factor ◽  
Neuronal Cell ◽  
Fibroblast Growth ◽  
Α Subunit ◽  
Interaction Site ◽  
Voltage Gated ◽  
Selective Modulation ◽  
Nav Channels

Voltage-gated Na+ (Nav) channels are the primary molecular determinant of the action potential. Among the nine isoforms of the Nav channel α subunit that have been described (Nav1.1-Nav1.9), Nav1.1, Nav1.2, and Nav1.6 are the primary isoforms expressed in the central nervous system (CNS). Crucially, these three CNS Nav channel isoforms display differential expression across neuronal cell types and diverge with respect to their subcellular distributions. Considering these differences in terms of their localization, the CNS Nav channel isoforms could represent promising targets for the development of targeted neuromodulators. However, current therapeutics that target Nav channels lack selectivity, which results in deleterious side effects due to modulation of off-target Nav channel isoforms. Among the structural components of the Nav channel α subunit that could be pharmacologically targeted to achieve isoform selectivity, the C-terminal domains (CTD) of Nav channels represent promising candidates on account of displaying appreciable amino acid sequence divergence that enables functionally unique protein–protein interactions (PPIs) with Nav channel auxiliary proteins. In medium spiny neurons (MSNs) of the nucleus accumbens (NAc), a critical brain region of the mesocorticolimbic circuit, the PPI between the CTD of the Nav1.6 channel and its auxiliary protein fibroblast growth factor 14 (FGF14) is central to the generation of electrical outputs, underscoring its potential value as a site for targeted neuromodulation. Focusing on this PPI, we previously developed a peptidomimetic derived from residues of FGF14 that have an interaction site on the CTD of the Nav1.6 channel. In this work, we show that whereas the compound displays dose-dependent effects on the activity of Nav1.6 channels in heterologous cells, the compound does not affect Nav1.1 or Nav1.2 channels at comparable concentrations. In addition, we show that the compound correspondingly modulates the action potential discharge and the transient Na+ of MSNs of the NAc. Overall, these results demonstrate that pharmacologically targeting the FGF14 interaction site on the CTD of the Nav1.6 channel is a strategy to achieve isoform-selective modulation, and, more broadly, that sites on the CTDs of Nav channels interacted with by auxiliary proteins could represent candidates for the development of targeted therapeutics.

The morphology of the sensory neuron in the cockroach femoral tactile spine

1993 ◽  
Vol 69 (3) ◽  
pp. 669-673 ◽  
Author(s):  
A. S. French ◽  
A. R. Klimaszewski ◽  
L. L. Stockbridge
Keyword(s):  
Action Potential ◽  
Sensory Neuron ◽  
Cell Body ◽  
Computer Software ◽  
Neuronal Cell ◽  
Neuronal Morphology ◽  
Neuronal Cell Body ◽  
Intracellular Recordings ◽  
Neuronal Nucleus ◽  
Spine Structure

1. The cockroach femoral tactile spine contains a single bipolar sensory neuron. The mechanosensitive dendrite in the wall of the spine leads through the spine lumen to a cell body, and then to an axon that proceeds proximally along the femur. The ultrastructure of the sensory ending has been examined before with electron microscopy. However, the morphology of the complete neuron and its relationship to the general spine structure have not been described before. 2. The tactile spine neuron has been extensively used in electrophysiological studies, including intracellular recordings. Action-potential amplitudes and thresholds were variable and inversely related in intracellular recordings, which could be caused by variability in the location of the action-potential initiation region, the position of the recording electrode, or the neuronal morphology. Attempts to observe the complete neuronal morphology by dye injection were hampered by the opaque and autofluorescent cuticle surrounding the neuron. 3. We examined 10 tactile spine neurons, and their surrounding structures, by taking serial 1-micron sections through the base of the spine, normal to its long axis. The sections were examined with light microscopy, digitized by tracing onto a graphics tablet, and then reassembled with the use of computer software. Reconstructions were made of the borders of the spine cuticle, neuron, neuronal nucleus, glial wrappings, and the main trachea in the spine lumen. 4. There was considerable variability in the size and shape of the neuronal cell body, although the sensory dendrite and axon had more consistent morphologies.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Activity-dependent mismatch between axo-axonic synapses and the axon initial segment controls neuronal output

2015 ◽  
Vol 112 (31) ◽  
pp. 9757-9762 ◽  
Author(s):  
Winnie Wefelmeyer ◽  
Daniel Cattaert ◽  
Juan Burrone
Keyword(s):  
Action Potential ◽  
Hippocampal Neurons ◽  
Initial Segment ◽  
Pyramidal Neurons ◽  
Neuronal Cell ◽  
Axon Initial Segment ◽  
Action Potential Generation ◽  
Potential Generation ◽  
Auditory Nucleus

The axon initial segment (AIS) is a structure at the start of the axon with a high density of sodium and potassium channels that defines the site of action potential generation. It has recently been shown that this structure is plastic and can change its position along the axon, as well as its length, in a homeostatic manner. Chronic activity-deprivation paradigms in a chick auditory nucleus lead to a lengthening of the AIS and an increase in neuronal excitability. On the other hand, a long-term increase in activity in dissociated rat hippocampal neurons results in an outward movement of the AIS and a decrease in the cell’s excitability. Here, we investigated whether the AIS is capable of undergoing structural plasticity in rat hippocampal organotypic slices, which retain the diversity of neuronal cell types present at postnatal ages, including chandelier cells. These interneurons exclusively target the AIS of pyramidal neurons and form rows of presynaptic boutons along them. Stimulating individual CA1 pyramidal neurons that express channelrhodopsin-2 for 48 h leads to an outward shift of the AIS. Intriguingly, both the pre- and postsynaptic components of the axo-axonic synapses did not change position after AIS relocation. We used computational modeling to explore the functional consequences of this partial mismatch and found that it allows the GABAergic synapses to strongly oppose action potential generation, and thus downregulate pyramidal cell excitability. We propose that this spatial arrangement is the optimal configuration for a homeostatic response to long-term stimulation.

Neurophysiology of Multiple Sclerosis

2016 ◽  
Author(s):  
Jefferson C. Slimp
Keyword(s):  
Ion Channels ◽  
Action Potential ◽  
Neural Development ◽  
Neuronal Cell ◽  
Signal Propagation ◽  
Synaptic Function ◽  
Resting Potential ◽  
Neuronal Membrane ◽  
Sodium Influx ◽  
Voltage Change

Any discussion of the pathomechanisms and treatments of MS benefits from an understanding of the physiology of the neuronal membrane and the action potential. Neurons and glia, are important for signal propagation, synaptic function, and neural development. The neuronal cell membrane, maintains different ionic environments inside and outside the cell, separating charge across the membrane and facilitating electrical excitability. Ion channels allow flow of sodium, potassium, and calcium ions across the membrane at selected times. At rest, potassium ion efflux across the membrane establishes the nerve membrane resting potential. When activated by a voltage change to threshold, sodium influx generates an action potential, or a sudden alteration in membrane potentials, that can be conducted along an axon. The myelin sheaths around an axon, increase the speed of conduction and conserve energy. The pathology of MS disrupts the myelin structures, disturbs conduction, and leads to neurodegeneration. Ion channels have been the target of investigation for both restoration of conduction and neuroprotection.

The Red Neuronal Pigment in the Nervous System of the Mussel, Mytilus Edulis: Localization and Its Effect on Lateral Ciliary Activity with Spectral and Analytical Changes

1981 ◽  
Vol 39 ◽  
pp. 494-495
Author(s):  
Anthony A. Paparo ◽  
Judith A. Murphy
Keyword(s):  
Nervous System ◽  
Mytilus Edulis ◽  
Neuronal Cell ◽  
Ciliary Activity ◽  
Neuronal Cell Bodies ◽  
The Central Nervous System ◽  
Intracellular Organelles ◽  
The Common ◽  
The Individual ◽  
Cryostat Sections

The purpose of this study was to localize the red neuronal pigment in Mytilus edulis and examine its role in the control of lateral ciliary activity in the gill. The visceral ganglia (Vg) in the central nervous system show an over al red pigmentation. Most red pigments examined in squash preps and cryostat sec tions were localized in the neuronal cell bodies and proximal axon regions. Unstained cryostat sections showed highly localized patches of this pigment scattered throughout the cells in the form of dense granular masses about 5-7 um in diameter, with the individual granules ranging from 0.6-1.3 um in diame ter. Tissue stained with Gomori's method for Fe showed bright blue granular masses of about the same size and structure as previously seen in unstained cryostat sections.Thick section microanalysis (Fig.l) confirmed both the localization and presence of Fe in the nerve cell. These nerve cells of the Vg share with other pigmented photosensitive cells the common cytostructural feature of localization of absorbing molecules in intracellular organelles where they are tightly ordered in fine substructures.

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