TY - JOUR
T1 - Effects of inactivation and stimulation of locus coeruleus on respiratory activity of neonatal rat
AU - Hakuno, Haruhiko
AU - Oyamada, Yoshitaka
AU - Murai, Michie
AU - Ito, Yoko
AU - Yamaguchi, Kazuhiro
N1 - Funding Information:
This study was partly funded by Keio University (Grant-in-Aid for Encouragement of Young Medical Scientists), the Ministry of Education, Science and Culture of Japan (11770027), and by Takeda Science Foundation.
PY - 2004/4/20
Y1 - 2004/4/20
N2 - We examined the effects of pharmacological inactivation and electrical stimulation of the locus coeruleus (LC) on the respiratory rate (RR) in isolated brainstem-spinal cord preparations of the neonatal rat. The brainstem and spinal cord were isolated en bloc from neonatal (days 1-4) Sprague-Dawley rats and superfused with artificial cerebrospinal fluid (ACSF) equilibrated with a gas mixture containing 2% CO2 (pH 7.8). Pharmacological inactivation of the bilateral LC by means of microinjection of tetrodotoxin or noradrenaline elicited a significant decrease in RR in preparations obtained from rats aged 3-4 days, but not in preparations of rats aged 1-2 days. Stimulation of the bilateral LC with a train of electrical pulses (25-50μA, 30ms, 0.5Hz, 3-4min) caused a marginal but significant increase in RR on days 3-4, but not on days 1-2. These results indicate that the LC exerts an excitatory effect on the medullary respiratory rhythm generator in an age-dependent manner.
AB - We examined the effects of pharmacological inactivation and electrical stimulation of the locus coeruleus (LC) on the respiratory rate (RR) in isolated brainstem-spinal cord preparations of the neonatal rat. The brainstem and spinal cord were isolated en bloc from neonatal (days 1-4) Sprague-Dawley rats and superfused with artificial cerebrospinal fluid (ACSF) equilibrated with a gas mixture containing 2% CO2 (pH 7.8). Pharmacological inactivation of the bilateral LC by means of microinjection of tetrodotoxin or noradrenaline elicited a significant decrease in RR in preparations obtained from rats aged 3-4 days, but not in preparations of rats aged 1-2 days. Stimulation of the bilateral LC with a train of electrical pulses (25-50μA, 30ms, 0.5Hz, 3-4min) caused a marginal but significant increase in RR on days 3-4, but not on days 1-2. These results indicate that the LC exerts an excitatory effect on the medullary respiratory rhythm generator in an age-dependent manner.
KW - Development, respiratory rate
KW - Mammals, rat
KW - Mediators, noradrenaline
KW - Nucleus, locus coeruleus
KW - Pattern of breathing, locus coeruleus inactivation
KW - Pharmacological agents, TTX
UR - https://www.scopus.com/pages/publications/1942486916
UR - https://www.scopus.com/pages/publications/1942486916#tab=citedBy
U2 - 10.1016/j.resp.2003.11.009
DO - 10.1016/j.resp.2003.11.009
M3 - Article
C2 - 15109924
AN - SCOPUS:1942486916
SN - 1569-9048
VL - 140
SP - 9
EP - 18
JO - Respiratory Physiology and Neurobiology
JF - Respiratory Physiology and Neurobiology
IS - 1
ER -