|Brain: Nucleus raphe pallidus
| Section of the medulla oblongata at about the middle of the olive. (Raphe nuclei not labeled, but 'raphe' labeled at left.)
|| nucleus raphes pallidus
The nucleus raphe pallidus receives afferent connections from the periaqueductal gray, the paraventricular hypothalamic nucleus, central nucleus of the amygdala, lateral hypothalamic area, and parvocellular reticular nucleus.
Additional recommended knowledge
Also, the pallidus receives afferents from the medial preoptic area, median preoptic nucleus and lateral paragigantocellular reticular nuclei .
The pallidus has recently been shown to be involved in the activation of a fever as an immunoreaction. It has been implied that the preoptic area is constantly inhibiting the raphe pallidus, especially the rostral portion, with GABA.
When the preoptic area receives immune signals from the body, the inhibition stops and the rostral portion of the raphe pallidus excites the intermediolateral cell column, which induces a fever .
The raphe pallidus has also been known to mediate the tachycardia response, an extremely high heart rate known to be incited by emotional or psychological stress.
Microinjections of a GABA-a antagonist into the raphe pallidus, induces an increased heart rate.
Conversely, microinjections of muscimol, a GABA-a agonist, inhibit tachycardia in rats under air-stress stimuli.
In both of these cases, GABA is mediating two different sympathetic responses, so clearly the nucleus raphe pallidus is a far more a complex nucleus than previously thought.
- ^ Hermann, Dirk M. et al. Afferent projections to the rat nuclei raphe magnus, raphe pallidus and reticularis gigantocellularis pars demonstrated by iontophoretic application of choleratoxin (subunit b). Journal of Chemical Neuroanatomy Volume 13, Issue 1 , June 1997, Pages 1-21
- ^ Nakamura, Kazuhiro et al. The Rostral Raphe Pallidus Nucleus Mediates Pyrogenic Transmission from the Preoptic Area. The Journal of Neuroscience, June 1, 2002, 22(11):4600-4610
- ^ Zaretsky, Dmitry V. et al. Microinjection of muscimol into raphe pallidus suppresses tachycardia associated with air stress in conscious rats. Journal of Physiology (2003), 546.1, pp. 243-250
|Brain: rhombencephalon (hindbrain)|
anterior/ventral: Arcuate nucleus of medulla • Pyramid (Decussation) • Olivary body • Inferior olivary nucleus • Anterior median fissure • Ventral respiratory group
posterior/dorsal: VII,IX,X: Solitary/tract • XII, X: Dorsal • IX,X,XI: Ambiguus • IX: Inferior salivatory nucleus • Gracile nucleus/Cuneate nucleus/Accessory cuneate nucleus • Area postrema • Posterior median sulcus • Dorsal respiratory group
raphe/reticular: Sensory decussation • Reticular formation (Gigantocellular nucleus, Parvocellular reticular nucleus, Ventral reticular nucleus, Lateral reticular nucleus, Paramedian reticular nucleus) • Raphe nuclei (Obscurus, Magnus, Pallidus)
tracts: Corticospinal tract (Lateral, Anterior) • Inferior cerebellar peduncle • Olivocerebellar tract • Spinocerebellar (Dorsal, Ventral) • Spinothalamic tract • PCML (Posterior external arcuate fibers, Internal arcuate fibers, Medial lemniscus) • Extrapyramidal (Rubrospinal tract, Vestibulospinal tract, Tectospinal tract)
anterior/ventral: Superior olivary nucleus • Basis pontis (Pontine nuclei, Middle cerebellar peduncles)
posterior/dorsal: Pontine tegmentum (Trapezoid body, Superior medullary velum, Locus ceruleus, MLF, Vestibulocerebellar tract, V Principal Spinal & Motor, VI, VII, VII: Superior salivary nucleus) • VIII-c (Dorsal, Anterior)/VIII-v (Lateral, Superior, Medial, Inferior)
raphe/reticular: Reticular formation (Caudal pontine reticular nucleus, Oral pontine reticular nucleus, Tegmental pontine reticular nucleus, Paramedian pontine reticular formation) • Median raphe nucleus
Apneustic center • Pneumotaxic center
|Metencephalon/cerebellum||Vermis • Flocculus • Arbor vitae • Cerebellar tonsil • Inferior medullary velum|
Molecular layer (Stellate cell, Basket cell, Parallel fiber) • Purkinje cell layer (Purkinje cell) • Granule cell layer (Golgi cell) • Mossy fibers • Climbing fiber
Deep cerebellar nuclei (Dentate, Emboliform, Globose, Fastigial)
|Fourth ventricle||apertures (Median, Lateral) • Rhomboid fossa (Vagal trigone, Hypoglossal trigone, Obex, Sulcus limitans, Facial colliculus, Medial eminence) • Lateral recess|