Apex of posterior horn
Apex cornus posterioris
- Latin synonym: Nucleus marginalis; Apex columnae posterioris
- Synonym: Marginal nucleus; Marginal zone
- Related terms: Spinal lamina I; Marginal nucleus; Spinal lamina I
Definition
The tip or the apex of posterior horn refers to the posterior-most region of the posterior (or dorsal) horn of spinal cord. From a cytoarchitectural perspective, the apex of posterior horn coincides with Rexed lamina I. It contains a column of neuronal cell bodies called the marginal zone (or marginal nucleus), a.k.a. posteromarginal nucleus or lamina marginalis.
The marginal zone (and the substantia gelatinosa) primarily processes sensory information related to pain and temperature from afferent fibers (the first-order sensory neurons). This nucleus serves as a relay point, sending signals to higher brain centers - the thalamus and primary sensory cortex - via ascending pathways such as the spinothalamic tract.
References
Snell, R.S. (2010). ‘Chapter 4: The Spinal Cord and the Ascending and Descending Tracts’, in Clinical Neuroanatomy. (7th ed.) Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins, pp. 137-142.
Byrne, J.H. and Dafny, N. ‘Chapter 2: Anatomy of the Spinal Cord. [Content reviewed and revised 07 Oct 2020]. In Neuroanatomy Online, an open-access electronic laboratory for the neurosciences. McGovern Medical School at UTHealth; Accessed 2022 Oct 22. Available from: https://nba.uth.tmc.edu/neuroscience/m/s2/chapter03.html
Brown, A.G. (1982). Review article the dorsal horn of the spinal cord. Quarterly Journal of Experimental Physiology: Translation and Integration, 67(2), pp.193-212. https://doi.org/10.1113/expphysiol.1982.sp002630
Ganapathy, M.K., Reddy, V. and Tadi, P. Neuroanatomy, Spinal Cord Morphology. [Updated 2021 Oct 30]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK545206/
