ABSTRACT
Objective To study the distribution of purinergic P2X_3 receptor immunoreactive afferent fibers in the rat pharyngeal mucosa and provide morphological evidence for exploring the role of ATP in the signal transduction of sensory stimuli. Methods Twelve adult Wistar rats were used and immunofluorescenthistochemical double-labeling technique combined laser confocal scanning microscope was applied in the present study. Results 1.P2X_3 immunoreactive fibers were observed on sections from all parts of pharyngeal mucosa. Two types of positive fibers were found. One was free nerve fibers covered with many varicosities. Another one ramified in mucosa and showed complex arborization endings. Nerve plexus in mucosa were formed by P2X_3 immunoreactive fiber ramifications. 2.Most calcitonin gene-related peptide (CGRP) positive fibers intermingled with P2X_3 immunoreactive fiber arborizations. A few P2X_3 immunoreactive fibers were covered with many varicosities co-localized with CGRP. 3.In petrosal ganglion, most neurons were stained with P2X_3 or CGRP immunoreactivity and small number of P2X_3 immunoreactive neurons co-stained with CGRP. Conclusion These results indicated that the different types of afferent fibers in rat pharyngeal mucosa expressed purinergic P2X_3 receptor immunoreactivity and ATP might be related to nociceptive or physiological signals transduction in rat pharyngeal mucosa.
ABSTRACT
Objective To study the expression of the capsaicin receptor,vanilloid receptor subtype 1(VR1) immunoreactivity,their morphology and distribution in afferent fibers of rat esophagus. Methods Laser scanning confocal microscope combined with immunohistochemical double labeling methods were used. Results VRl-like immunoreactivity was observed on nerve fibers and terminalis within mucosa,submucosa,muscle layer and surrounding blood vessel throughout esophagus.Their profiles were fine fibers with some spiny,possessing varicose-like swellings along their lengths.About(92.3?3.7)% VR1 positive fibers co-localized with CGRP immunoreactivity,which representing large majority of afferent fibers in the esophagus was extrinsic in origin with cell bodies located in dorsal root ganglia.In dorsal root ganglion,VR1 was expressed in small-and middle-sized cell bodies.About(41.5?4.5)% VRl-immunoreactive neurons co-stained with CGRP and(67.9?3.2)% CGRP positive neurons co-localized with VR1.In nodose ganglion,the expression of VR1 was similar with dorsal root ganglion,but CGRP immunoreactive neurons very few.Only(4.7?1.4)% VR1 positive neurons co-stained with CGRP.Conclusion These results suggest that VR1 is expressed in afferent fibers in the wall of the rat esophagus which is in origin in dorsal root ganglion.
ABSTRACT
The projection from the nucleus of solitary tract (Sol) to the nucleus accumbens (Acb) was examined by using HRP retrograde and anterograde tracing combined with immunocytochemical double-labeling technique. The following results were obtained: (1) when WGA-HRP was injected into the caudal part of the Sol, the labeled fibers, terminals and cell bodies were found in the ventromedial area of the caudal Acb. After injecting HRP into the ventromedial area of the caudal Acb, labeled cell bodies and terminals were found in the ipsilateral and contralateral caudal part of the Sol,mainly in the commissure nucleus and the medial subnucleus of nucleus of solitary tract. (2) After injecting HRP into the Acb and combined with immunocytochemical method, many HRP-TH, HRP-NT, and HRP-CCK double-labeled cell bodies were found in the caudal part of the Sol. The number of the HRP-TH double-labeled cell bodies was most numerous, HRP-NT cells was next and HRP-CCK cells was even less.