Intraganglionic distribution of the primary afferent neurons in the frog glossopharyngeal nerve and its transganglionic projection to the rhombencephalon studied by HPR method.
Anterograde transport of horseradish peroxidase (HRP) along the bullfrog IXth nerve was studied 6-16 days after application of HRP to the cut end of either the IXth nerve trunk or its distal 2 branches. The jugular and IXth nerve ganglia attached to the rhombencephalon were removed after fixation and serial sections of 50 microns in thickness were stained by the Graham and Karnovsky method. Of all the primary afferent neurons in the IXth nerve, 62% of the cell bodies were distributed within the IXth nerve ganglion, the remaining 38%, within the jugular ganglion. Similar distribution was found with the cells belonging to each of the IXth nerve branches. A part of the transganglionic IXth nerve fibers entering the medulla oblongata ascended to the cerebellar peduncle while the majority descended along the fasciculus solitarius. Some of the descending fibers in the fasciculus extended to the dorsal field of the spinal cord at the third spinal nerve, while some others run to join the descending tract of trigeminal nerve.
D000344:Afferent Pathways / Q000033:anatomy & histology; D000818:Animals; D005727:Ganglia, Spinal / Q000033:anatomy & histology*; D005930:Glossopharyngeal Nerve / Q000033:anatomy & histology*; D008526:Medulla Oblongata / Q000033:anatomy & histology*; D009046:Motor Neurons / Q000648:ultrastructure; D009412:Nerve Fibers / Q000648:ultrastructure; D009474:Neurons / Q000648:ultrastructure; D011892:Rana catesbeiana; D013116:Spinal Cord / Q000033:anatomy & histology; D013126:Spinal Nerve Roots / Q000033:anatomy & histology; D014276:Trigeminal Nerve / Q000033:anatomy & histology; D014630:Vagus Nerve / Q000033:anatomy & histology