Axon Initial Segment
Axon Initial Segment - Related Videos
07:40
Measuring Properties of the Membrane Periodic Skeleton of the Axon Initial Segment using 3D-Structured Illumination Microscopy (3D-SIM)
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Cited by 4 •
2022
The present protocol describes a method to visualize and measure actin rings and other components of the membrane periodic skeleton of the axon initial segment using cultured rat hippocampal neurons and 3D-structured illumination microscopy (3D-SIM).
06:53
Use of Primary Cultured Hippocampal Neurons to Study the Assembly of Axon Initial Segments
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Cited by 1 •
2021
Here, we described a protocol to quantitatively study the assembly and structure of the axon initial segments (AIS) of hippocampal neurons that lack pre-assembled AIS due to the absence of a giant ankyrin-G.
05:58
In vivo Visualization of Synaptic Vesicles Within Drosophila Larval Segmental Axons
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Cited by 16 •
2010
This protocol discusses the live dissection of Drosophila larvae for the purpose of imaging the movement of GFP tagged axonal vesicles on microtubule tracks.
10:45
In Situ Visualization of Axon Growth and Growth Cone Dynamics in Acute Ex Vivo Embryonic Brain Slice Cultures
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Cited by 4 •
2021
This protocol demonstrates a straightforward and robust method to study in situ axon growth and growth cone dynamics. It describes how to prepare ex vivo physiologically relevant acute brain slices and provides a user-friendly analysis pipeline.
02:33
Initiation of Translation
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2020
Initiating translation is complex because it involves multiple molecules. Initiator tRNA, ribosomal subunits, and eukaryotic initiation factors (eIFs) are all required to assemble on the initiation codon of mRNA. This process consists of several steps that are mediated by different eIFs. First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
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Channel organization allows the AIS to convert a depolarizing change in membrane voltage into a rapid electrical event. Voltage-gated sodium channels provide the depolarizing drive, while potassium channels contribute to the specialized electrical behavior of this region. Ankyrin-G and associated cytoskeletal proteins keep these components organized, helping the neuron initiate signals consistently when synaptic input reaches threshold.
Filtering at the AIS means that electrical influences arriving from dendrites and the soma do not automatically produce an axonal signal. Their combined effect must bring the membrane to threshold at this specialized site. This makes the AIS a control point where the neuron integrates incoming excitation with its own excitability, linking cellular input patterns to action-potential output.
Ankyrin-G serves as a central organizing component within the AIS. Its association with cytoskeletal proteins helps maintain the arrangement of voltage-gated sodium and potassium channels in this region. That organization matters because channel concentration and placement support rapid membrane depolarization, allowing synaptic and somatic influences to be translated into reliable neuronal signaling.
Structural plasticity gives the AIS a way to adjust neuronal excitability without changing the neuron’s basic anatomical identity. Because the region organizes the channels and cytoskeletal proteins needed for action-potential initiation, changes in its structure may influence how effectively synaptic and somatic inputs reach firing threshold. This makes AIS plasticity relevant to changing neural activity.
An AIS-focused study can examine two linked features: molecular organization and structural plasticity. Molecular analysis addresses how ankyrin-G, cytoskeletal proteins, and voltage-gated channels are arranged, whereas structural analysis asks how the region changes. Relating these features to excitability connects AIS architecture with action-potential initiation and provides a framework for interpreting neuronal signaling.
At the circuit level, AIS research helps connect cellular excitability with how neurons participate in neural circuits and process sensory information. The region is also relevant during development, when neuronal signaling properties are being studied, and in disorders involving abnormal neuronal firing. These applications make its molecular organization and plasticity useful targets for neuroscience investigation.
Because the AIS governs the transition from synaptic and somatic voltage changes to action-potential output, altered organization or plasticity can provide a cellular context for abnormal firing. Studying this relationship may help researchers connect molecular and structural observations with changes in neuronal excitability. The approach is therefore relevant to disorders in which firing patterns are disrupted.