Effects of inactivation and stimulation of locus coeruleus on respiratory activity of neonatal rat

Haruhiko Hakuno, Yoshitaka Oyamada, Michie Murai, Yoko Ito, Kazuhiro Yamaguchi

Research output: Contribution to journalArticlepeer-review

10 Citations (Scopus)


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.

Original languageEnglish
Pages (from-to)9-18
Number of pages10
JournalRespiratory Physiology and Neurobiology
Issue number1
Publication statusPublished - 2004 Apr 20
Externally publishedYes


  • Development, respiratory rate
  • Mammals, rat
  • Mediators, noradrenaline
  • Nucleus, locus coeruleus
  • Pattern of breathing, locus coeruleus inactivation
  • Pharmacological agents, TTX

ASJC Scopus subject areas

  • Neuroscience(all)
  • Physiology
  • Pulmonary and Respiratory Medicine


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