Effects of gastric distension and electrical stimulation of dorsomedial medulla on neurons in parabrachial nucleus of rats

Kazuhiko Suemori, Motoi Kobashi, Akira Adachi

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31 Citations (Scopus)


The effects of gastric distension and electrical stimulation of the dorsomedial medulla on neurons within the parabrachial nucleus (PB) were investigated electrophysiologically in urethane-chlorarose anesthetized rats. Among 74 neurons tested, electrical stimulation of the nucleus of the solitary tract (NTS) excited 30 neurons (excitatory neurons) and inhibited 14 neurons (inhibitory neurons). Fourteen neurons increased and 12 neurons decreased their discharge rates in response to gastric distension. Twenty-two neurons responded to both electrical stimulation of the NTS and gastric distension. Both excitatory and inhibitory neurons showed either an increase or a decrease in discharge rate responding to gastric distension. Furthermore, three neurons that decreased their discharge rates and two neurons that increased their discharge rates during gastric distension also responded to intravenous administration of metaraminol indicating some effect of baroreceptor activation on the neural activity. The responses of another 49 neurons in the PB to electrical stimulation of area postrema and gastric distension were analyzed. Electrical stimulation of the AP excited 14 neurons and inhibited only one neuron. Five neurons increased and seven neurons decreased their discharge rates in response to gastric distension. Only one inhibitory neuron responded to gastric distension. These observations suggested that the PB neurons received gastric mechanoreceptive inputs from the NTS.

Original languageEnglish
Pages (from-to)221-229
Number of pages9
JournalJournal of the Autonomic Nervous System
Issue number3
Publication statusPublished - Aug 1994



  • Area postrema
  • Gastric distension
  • Mechanoreceptor
  • Nucleus of the solitary tract
  • Parabrachial nucleus
  • Stomach

ASJC Scopus subject areas

  • Neuroscience(all)
  • Physiology
  • Clinical Neurology

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