Median raphe nucleus

Brain: Median raphe nucleus
Latin	nucleus raphes medianus, nucleus centralis superior
NeuroNames	hier-557
NeuroLex ID	birnlex_889

The median raphe nucleus (also referred to as superior central nucleus, here abbreviated to MRN) is composed of polygonal, fusiform and pyriform neurons and exists rostral to the nucleus raphe pontis.

One trait of the MRN is its inhibition by lysergic acid diethylamide and psilocin, two serotonin antagonist hallucinogens. The inactivation of the nucleus centralis superior via LSD produces a dose dependent inactivation in the MRN, but not in the raphe pallidus.

The free-moving cats, in which this was discovered, exhibited dose dependent behavioral changes when researched by Dr. Michael Trulson of the neurology department at Texas A&M University Medical School.^[1].

References

^ 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

Human brain, rhombencephalon, metencephalon: pons (TA A14.1.05.101–604, GA 9.785)

Dorsal/
(tegmentum)

Surface	Cerebellopontine angle · Superior medullary velum · Sulcus limitans · Medial eminence · Facial colliculus

White: Sensory/ascending	Trapezoid body/VIII · Trigeminal lemniscus (Dorsal trigeminal tract, Ventral trigeminal tract) · Medial lemniscus · Lateral lemniscus MLF, III, IV and VI: Vestibulo-oculomotor fibers Anterior trigeminothalamic tract · Central tegmental tract

White: Motor/descending	ICP (Vestibulocerebellar tract) MLF, III, IV and VI: Vestibulospinal tract (Medial vestibulospinal tract, Lateral vestibulospinal tract)

Grey: Cranial nuclei	afferent: GSA: Principal V/Spinal V · VIII-c (Dorsal, Anterior)/VIII-v (Superior) efferent: SVE: Motor V · VII · GSE: VI · GVE: VII: Superior salivary nucleus

Other grey	Apneustic center · Pneumotaxic center (Medial parabrachial nucleus) · Lateral parabrachial nucleus · Superior olivary nucleus · Caerulean nucleus

Ventral/
(base)

Grey	Pontine nuclei

White: Motor/descending	Corticospinal tract · Corticobulbar tract · Corticopontine fibers MCP (Pontocerebellar fibers)

Surface	Basilar sulcus

Other grey: Raphe/
reticular

Reticular formation (Caudal, Oral, Tegmental, Paramedian) · Raphe nuclei (Median)

M: CNS

anat(n/s/m/p/4/e/b/d/c/a/f/l/g)/phys/devp

noco(m/d/e/h/v/s)/cong/tumr, sysi/epon, injr

proc, drug(N1A/2AB/C/3/4/7A/B/C/D)

Median raphe nucleus

See also

References