Autonomic Nervous SystemPontine projections of pulmonary slowly adapting receptor relay neurons in the catEzure, Kazuhisa1,2; Tanaka, Ikuko1; Miyazaki, Makoto1 Author Information 1Department of Neurobiology, Tokyo Metropolitan Institute for Neuroscience, 2–6 Musashidai, Fuchu, Tokyo 183, Japan 2Corresponding Author: Kazuhisa Ezure Website publication 3 February 1998 Received 12 November 1997; accepted 25 November 1997. NeuroReport: February 16, 1998 - Volume 9 - Issue 3 - p 411-414 Buy Abstract PONTINE projections of second-order neurons activated by vagal afferents originating from pulmonary slowly adapting receptors were studied electrophysiologically in Nembutal-anesthetized, paralyzed and artificially ventilated cats. Extracellular recordings from these neurons (referred to as P-cells) were made in the nucleus tractus solitarii. Antidromic mapping of the brain stem showed that many P-cells examined projected their axons to the ipsilateral pons as well as the medulla. Axonal arborizations were found in the parabrachial nucleus, i.e. in the area corresponding to the pontine respiratory group. In some P-cells, axonal arborizations were also found in the A5 area. The present results suggest that the P-cells are involved in pontine pneumotaxic mechanisms. © Lippincott-Raven Publishers.