Pump neurons of the nucleus of the solitary tract project widely to the medulla.
Axonal projections of pump neurons (P-cells) of the nucleus of the solitary tract were studied in Nembutal-anesthetized, paralyzed, and artificially ventilated cats. Extracellular recordings were made from single P-cells which were monosynaptically activated by electrical stimulation of the ipsilateral vagal afferents and distributed in close proximity to the solitary tract. Antidromic stimulation of the medulla showed that all P-cells examined projected their axons to the ipsilateral ventrolateral medulla. Axonal arborizations were found in respiration-related areas and their vicinity between the level of the retrofacial nucleus and the level a few millimeters caudal to the obex. Some of these P-cells sent axon collaterals to the contralateral nucleus of the solitary tract (NTS) as well. This study is the first to show wide spread medullary projections of P-cell axons.
Department of Neurobiology, Tokyo Metropolitan Institute for Neuroscience, Japan.
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Ezure
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Tanaka
D000344:Afferent Pathways; D000818:Animals; D001369:Axons / Q000502:physiology; D001931:Brain Mapping; D002415:Cats; D004558:Electric Stimulation; D004594:Electrophysiology; D008239:Lysine / Q000031:analogs & derivatives; D009474:Neurons / Q000502:physiology*; D017552:Solitary Nucleus / Q000166:cytology*
C013411:biocytin; D008239:Lysine