Median raphe nucleus
|Median raphe nucleus|
|Latin||nucleus raphes medianus, nucleus centralis superior|
|Anatomical terms of neuroanatomy|
The median raphe nucleus (MRN or MnR) (also known as the nucleus raphes medianus (NRM) or superior central nucleus) is composed of polygonal, fusiform and piriform neurons and exists rostral to the nucleus raphes pontis.
Inhibition of the MRN in cats by lysergic acid diethylamide (LSD) and psilocin, two serotonin agonist hallucinogens, leads to dose dependent behavioral changes, indicating the MRN may be an important site of action for humans hallucinations.
The median raphe nucleus projects extensively to the hippocampus, which is known to be essential for the formation of long-term memory. One recent study found that this raphe-hippocampus pathway plays a critical role in regulation of hippocampal activity and likely associated memory consolidation processes.
- Federative Committee on Anatomical Terminology (FCAT) (1998). Terminologia Anatomica. Stuttgart: Thieme
- Trulson, M.E., Preussler DW and Trulson V.M. Differential effects of hallucinogenic drugs on the activity of serotonin-containing neurons in the nucleus centralis superior and nucleus raphe pallidus in free-moving cats. American Society for Pharmacology and Experimental Therapeutics Volume 228, Issue 1, pp. 94-102, 1 January 1984
- 4. Wang, D.V., Yau, H., Broker, C.J., Tsou, J., Bonci, A. & Ikemoto, S. Mesopontine median raphe regulates hippocampal ripple oscillation and memory consolidation. Nature Neuroscience 18, 728-735, 2015