Anatomy

Axon Initial Segment

First segment of axon that connects distal axon segments to the neuronal CELL BODY at the axon hillock region. The axon initial segment is not protected by the MYELIN SHEATH and has properties critical for axonal growth. The axon initial segment and the axon hillock form an axonal trigger zone.

National Library of MedicineMedical Subject Headings2026

Structured Summary

Abstract

First segment of axon that connects distal axon segments to the neuronal CELL BODY at the axon hillock region. The axon initial segment is not protected by the MYELIN SHEATH and has properties critical for axonal growth. The axon initial segment and the axon hillock form an axonal trigger zone.

MeSH Record

Classification

Broader headings

Related Concepts

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MeSH Record

Synonyms

6 entry terms
  • Axon Initial Segments
  • Axon Hillock
  • Axonal Trigger Zone
  • Axon Hillocks
  • Axonal Trigger Zones
  • Trigger Zone, Axonal

MeSH Record

Aspects Covered

14 allowable subheadings

Indexed with the subheadings chemistry, classification, drug effects, enzymology, immunology, metabolism, microbiology, parasitology, pathology, physiology, radiation effects, transplantation, ultrastructure, virology.

MeSH Record

History Note

2017

MeSH Record

Previous Indexing

  • Axons (1973-2016)

MeSH Hierarchy

Tree Numbers

  1. A08w.675w.542w.145w.250
  2. A11w.284w.180.075w.125
  3. A11w.671w.501w.145w.250

AMA Style

References

  1. National Library of Medicine. Axon Initial Segment. Medical Subject Headings (MeSH). 2026. Unique ID D000071040. http://id.nlm.nih.gov/mesh/2026/D000071040
  2. Axon Initial Segment. In: Wikidata. https://www.wikidata.org/wiki/Q14862704