Studies on respiratory-related neurons within the nucleus raphe obscurus in the cat

• Main Authors: Wu, Ying Ping, 吳英賓
• Other Authors: Ji-Chuu Hwang
• Format: Others
• Language: zh-TW
• Published: 1993
• Online Access: http://ndltd.ncl.edu.tw/handle/99119035538025145150

碩士 === 國立師範大學 === 生物學研究所 === 81 === The purpose of this work was to examine whether respiratory- related neurons are existed in the nucleus raphe obscurus (NRO) and their response to hypercapnia and vagal afferent stimulation. Cats were decerebrated, paralyzed, vagotomized and ventilated. End-tidal fractional concentration of CO2 (FETCO2) was maintained at hyperoxic normocapnia. The phrenic nerve was isolated and its activity was monitored. Single unit activity within the NRO was recorded with metal microelectrode. Activity of the neuron was evaluated in response to hypercapnia or vagal afferent excitation. Fifty three of 120 neurons recorded showed respiratory-related activities. They were classified as expiratory-inspiratory (EI), inspiratory-expiratory (IE), tonic inspiratory-expiratory(T-IE) and tonic expiratory-inspiratory (T-EI) and expiratory (E) patterns according to the phrenic discharge. Forty of those respiratory- related neurons were tested their response to hypercapnia. Eighteen of them reduced their discharge rate (p<0.05) whereas eight enchanced. The remainders displayed irregular respone. With vagal stimulation, nine of 13 neurons reduced their discharge rate (p<0.05), three elevated, and the other one were unaffected. These results indicate that respiratory-related neurons within the NRO can be modulated by the inputs from the chemoreceptor and vagal afferents. It also suggest that the NRO may play a role in the regulation of respiration.