Acoustic radiation
Radiatio acustica
- Latin synonym: Fibrae geniculotemporales
- Synonym: Geniculotemporal fibers
Definition
Acoustic radiation (a.k.a. auditory radiation) represents an important component of the sensory auditory (cochlear) pathway in the brain. It contains thalamocortical neuronal projections which convey auditory signals from the medial geniculate nucleus in the thalamus to the primary auditory cortex (Broadman’s areas 41, 42). The latter comprises of one or two small transverse temporal gyri, which are situated on the surface of the superior temporal gyrus and are deeply buried into the Sylvian (lateral) fissure, as part of its temporal lip.
Looking at the neuroanatomy of cochlear pathway, we find that rostral to the cochlear nuclei, right and left ears are represented in the brain on both sides of the midline due to extensive decussation of neural pathways. Hence, lesions to the acoustic radiation or primary auditory cortex on one side usually leads to a partial (cortical) deafness only–and never a complete one.
References
Text written by Muhammad A. Javaid, MD, PhD © 2022 IMAIOS.
Snell, R.S. (2010). ‘Chapter 8: The Structure and Functional Localization of the Cerebral Cortex’, in Clinical Neuroanatomy. (7th ed.) Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins, pp. 261-262.
Vanderah, T.W. and Gould, D.J. (2021). ‘Chapter 22: Cerebral Cortex’ in Nolte’s The Human Brain: An Introduction to its Functional Anatomy (8th ed.) Elsevier 1600 John F. Kennedy Blvd. Ste 1800 Philadelphia, PA 19103-2899 (link)
