AFFERENTS TO THE NUCLEUS-RETICULARIS PARVICELLULARIS OF THE CAT MEDULLA-OBLONGATA - A TRACT-TRACING STUDY WITH CHOLERA-TOXIN B-SUBUNIT

Citation
P. Fort et al., AFFERENTS TO THE NUCLEUS-RETICULARIS PARVICELLULARIS OF THE CAT MEDULLA-OBLONGATA - A TRACT-TRACING STUDY WITH CHOLERA-TOXIN B-SUBUNIT, Journal of comparative neurology, 342(4), 1994, pp. 603-618
Citations number
71
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Clinical Neurology
ISSN journal
0021-9967
Volume
342
Issue
4
Year of publication
1994
Pages
603 - 618
Database
ISI
SICI code
0021-9967(1994)342:4<603:ATTNPO>2.0.ZU;2-2
Abstract
The aim of this study was to examine anatomical evidence in cats of wh ether the nucleus reticularis parvicellularis (Pc) is part of the circ uit responsiblefor the inhibition of brainstem motoneurons during para doxical sleep. For this purpose, we made iontophoretic injections of t he retrograde and anterograde tracer cholera toxin B subunit (CTb) in the Pc. After CTb injections in the Pc, a large number of retrogradely labeled neurons were seen in the central nucleus of the amygdala, the lateral part of the bed nucleus of the stria terminalis, the posterio r hypothalamic areas, the mesencephalic reticular formation, the nucle us locus subcoeruleus, the nucleus pontis caudalis, other portions of the Pc, the nucleus reticularis dorsalis, the trigeminal sensory compl ex, and the nucleus of the solitary tract. We further found that the P c receives 1) serotoninergic afferents from the raphe dorsalis,magnus, and obscurus nuclei; 2) noradrenergic inputs from the dorsolateral po ntine tegmentum; 3) cholinergic afferents from the lateral medullary r eticularformation; 4) substance P-like afferents from the central nucl eus of the amygdala, bed nucleus of the stria terminalis, periaqueduct al gray, and nucleus ofthe solitary tract; and 5) methionine-enkephali n-like projections from the periaqueductal gray, the nucleus of the so litary tract, the lateral pontine and medullary reticular formation, a nd the spinal trigeminal nucleus. We further found that the Pc do not receive afferents from brainstem structures responsible for muscle ato nia, such as the ventromedial medulla and the dorsomedial pontine tegm entum, and therefore may not be part of the circuit inhibiting the bra instem motoneurons during paradoxical sleep. (C) 1994 Wiley-Liss, Inc.