TY - JOUR
T1 - Differential effects of cardiac sympathetic afferent stimulation on neurons in the nucleus tractus solitarius
AU - Wang, Wei Zhong
AU - Gao, Lie
AU - Pan, Yan Xia
AU - Zucker, Irving H.
AU - Wang, Wei
N1 - Funding Information:
This study was supported by NIH grants RO-1 HL 077691 and PO-1 HL62222.
PY - 2006/12/1
Y1 - 2006/12/1
N2 - Activation of the cardiac "sympathetic afferent" reflex (CSAR) has been reported to depress the arterial baroreflex and enhance the arterial chemoreflex via a central mechanism. In the present study, we used single-unit extracellular recording techniques to examine the effects of stimulation of cardiac sympathetic afferents on baro- or chemosensitive neurons in the nucleus tractus solitarius (NTS) in anesthetized rats. Of 54 barosensitive NTS neurons tested for their response to epicardial application of capsaicin (0.4 μg), 38 were significantly (P < 0.01) inhibited by 38% while 16 did not respond. Of 42 NTS chemosensitive neurons tested for their response to capsaicin, 33 were significantly (P < 0.01) excited by 47% while 9 did not respond. In addition, of 12 both barosensitive and chemosensitive NTS neurons tested for capsaicin, 2 were excited, 7 were inhibited, and 3 did not respond. In conclusion, this study indicates that CSAR activation inhibited NTS barosensitive neurons and excited NTS chemosensitive neurons, suggesting that the NTS plays an important role in processing the interactions between these cardiovascular reflexes.
AB - Activation of the cardiac "sympathetic afferent" reflex (CSAR) has been reported to depress the arterial baroreflex and enhance the arterial chemoreflex via a central mechanism. In the present study, we used single-unit extracellular recording techniques to examine the effects of stimulation of cardiac sympathetic afferents on baro- or chemosensitive neurons in the nucleus tractus solitarius (NTS) in anesthetized rats. Of 54 barosensitive NTS neurons tested for their response to epicardial application of capsaicin (0.4 μg), 38 were significantly (P < 0.01) inhibited by 38% while 16 did not respond. Of 42 NTS chemosensitive neurons tested for their response to capsaicin, 33 were significantly (P < 0.01) excited by 47% while 9 did not respond. In addition, of 12 both barosensitive and chemosensitive NTS neurons tested for capsaicin, 2 were excited, 7 were inhibited, and 3 did not respond. In conclusion, this study indicates that CSAR activation inhibited NTS barosensitive neurons and excited NTS chemosensitive neurons, suggesting that the NTS plays an important role in processing the interactions between these cardiovascular reflexes.
KW - Baro-/chemosensitive neuron
KW - Capsaicin
KW - Cardiovascular reflexes
KW - Extracellular recording
KW - Sympathetic activity
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U2 - 10.1016/j.neulet.2006.09.032
DO - 10.1016/j.neulet.2006.09.032
M3 - Article
C2 - 17014954
AN - SCOPUS:33750345677
SN - 0304-3940
VL - 409
SP - 146
EP - 150
JO - Neuroscience Letters
JF - Neuroscience Letters
IS - 2
ER -