Horseradish peroxidase localization of XXXX .

@entity4485 @entity15989 @entity299 @entity1233 @entity468 @entity3057
Cardiac vagal preganglionic somata were labeled in @entity468 by the horseradish peroxidase (HRP) technique. The anatomical characteristics of cell bodies with axons in the left and right cervical vagi compared. HRP was injected subepicardially in three groups of @entity4485 anesthetized animals. In two test groups, injections were made after a left and right cervical vagotomy, respectively. In a control group, peripheral @entity299 were performed prior to HRP injection. The controls served to determine the number of somata labeled by HRP uptake via vagal fibers innervating viscera closely approximating the myocardium. After a 48 h survival period the @entity468 were reanesthetized, perfused and fixed. Brain stems were removed, cut in the transverse or sagittal plane and developed with @entity15989 . Control @entity468 had 6.8% the number of labeled cell bodies identified in animals with an intact vagus. Thus, few labeled somata in test @entity468 were associated with noncardia tissue. The number, distribution and sizes of labeled cell bodies in test @entity468 were similar. Somata were located ipsilateral to the intact vagus in three regions: the nucleus ambiguus (NA), the dorsal motor nucleus of the vagus ( @entity1233 ) and an intermediate zone (IZ) between the NA and @entity1233 . The NA contained the maximum number of cell bodies while successively fewer somata were located in the @entity1233 and IZ. Somata of the NA were heterogeneously distributed along the @entity3057 . The region of maximal cell body concentration was between 1.0 and 1.8 mm rostral to the obex. Somata of the @entity1233 and IZ were homogeneously and sparsely distributed along the neuraxis. The long and short axes of NA somata were larger than corresponding dimensions of cell bodies in the @entity1233 or IZ. However, the dimensions of somata in the @entity1233 and IZ were similar. The identification of labeled cell bodies in three medullary regions and the size differences of the somata in these regions may reflect a central physiological organization of cardia vagal somata.
