title: Dual projections of tuberomammillary neurons to whisker-related, sensory and motor regions of the rat.
abstract: The primary goal of this study was to examine in the rat whether neurons in the tuberomammillary nucleus (TMN) provide axon collaterals to whisker-related, sensorimotor regions at cortical and brainstem levels, using two different retrograde tracers. When injections were made at primary sensory (S1) barrel field/primary whisker motor (M1) cortices, dual-projecting TMN neurons were observed mainly in the ventrolateral subdivision; the projection was almost exclusively ipsilateral. On the other hand, following injections of tracers into whisker-related, principal sensory trigeminal (Pr5)/lateral facial motor (Mo7) nuclei, dual-projecting cells were observed mainly in the dorsomedial subdivision; the projection was bilateral with a slight contralateral dominance. Taken together, the present observation demonstrated that each subdivision of the TMN possessed a differential functional organization with respect to its collateral projection to whisker-related sensorimotor targets, suggesting that the histaminergic projection might play a modulatory role in vibrissal sensorimotor integration, which allows the guidance of behavioral action essential for the survival of the animal.
authors.affiliation: Department of Anatomy, College of Medicine, Konkuk University, Hwayang-dong, Gwangjin-gu, 143-701 Seoul, Korea.
authors.forename: Eun Y
authors.initials: EY
authors.lastname: Hong
authors.forename: Suk K
authors.initials: SK
authors.lastname: Beak
authors.forename: Hyun S
authors.initials: HS
authors.lastname: Lee
mesh_terms: D000818:Animals; D002452:Cell Count; D005260:Female; D007026:Hypothalamic Area, Lateral / Q000502:physiology*; D007150:Immunohistochemistry; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology; D056325:Neuronal Tract-Tracers; D009474:Neurons / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D016622:Silver Staining; D013003:Somatosensory Cortex / Q000502:physiology*; D014278:Trigeminal Nuclei / Q000502:physiology; D014738:Vibrissae / Q000502:physiology*
chemical_list: D056325:Neuronal Tract-Tracers