title: Nucleus of the solitary tract in the C57BL/6J mouse: Subnuclear parcellation, chorda tympani nerve projections, and brainstem connections.
abstract: The nucleus of the solitary tract (NST) processes gustatory and related somatosensory information rostrally and general viscerosensory information caudally. To compare its connections with those of other rodents, this study in the C57BL/6J mouse provides a subnuclear cytoarchitectonic parcellation (Nissl stain) of the NST into rostral, intermediate, and caudal divisions. Subnuclei are further characterized by NADPH staining and P2X2 immunoreactivity (IR). Cholera toxin subunit B (CTb) labeling revealed those NST subnuclei receiving chorda tympani nerve (CT) afferents, those connecting with the parabrachial nucleus (PBN) and reticular formation (RF), and those interconnecting NST subnuclei. CT terminals are densest in the rostral central (RC) and medial (M) subnuclei; less dense in the rostral lateral (RL) subnucleus; and sparse in the ventral (V), ventral lateral (VL), and central lateral (CL) subnuclei. CTb injection into the PBN retrogradely labels cells in the aforementioned subnuclei; RC and M providing the largest source of PBN projection neurons. Pontine efferent axons terminate mainly in V and rostral medial (RM) subnuclei. CTb injection into the medullary RF labels cells and axonal endings predominantly in V at rostral and intermediate NST levels. Small CTb injections within the NST label extensive projections from the rostral division to caudal subnuclei. Projections from the caudal division primarily interconnect subnuclei confined to the caudal division of the NST; they also connect with the area postrema. P2X2 -IR identifies probable vagal nerve terminals in the central (Ce) subnucleus in the intermediate/caudal NST. Ce also shows intense NADPH staining and does not project to the PBN.
authors.affiliation: Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel-Aviv University, 69978, Ramat Aviv, Tel-Aviv, Israel.
authors.forename: Donald
authors.initials: D
authors.lastname: Ganchrow
authors.forename: Judith R
authors.initials: JR
authors.lastname: Ganchrow
authors.forename: Vanessa
authors.initials: V
authors.lastname: Cicchini
authors.forename: Dianna L
authors.initials: DL
authors.lastname: Bartel
authors.forename: Daniel
authors.initials: D
authors.lastname: Kaufman
authors.forename: David
authors.initials: D
authors.lastname: Girard
authors.forename: Mark C
authors.initials: MC
authors.lastname: Whitehead
mesh_terms: D000818:Animals; D001271:Atlases as Topic; D001369:Axons / Q000378:metabolism; D001933:Brain Stem / Q000033:anatomy & histology* / Q000378:metabolism; D048429:Cell Size; D002814:Chorda Tympani Nerve / Q000033:anatomy & histology* / Q000378:metabolism; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL / Q000033:anatomy & histology* / Q000378:metabolism; D018613:Microscopy, Confocal; D009249:NADP / Q000378:metabolism; D009434:Neural Pathways / Q000033:anatomy & histology; D056347:Neuroanatomical Tract-Tracing Techniques; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D010784:Photomicrography; D058476:Receptors, Purinergic P2X2 / Q000378:metabolism; D017552:Solitary Nucleus / Q000033:anatomy & histology* / Q000378:metabolism
chemical_list: D058476:Receptors, Purinergic P2X2; D009249:NADP
keywords: Nissl; cholera toxin B; cytoarchitectonics; fungiform taste bud; solitary nucleus atlas and projections; taste