Actions of galanin on neurotransmission in the submucous plexus of guinea pig small intestine

Sumei Liu, Hong Zhen Hu, Chuanyun Gao, Na Gao, Yun Xia, Jackie D. Wood*

*Corresponding author for this work

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Electrophysiologic recording methods were used to study the actions of galanin on synaptic transmission in the submucous plexus of guinea pig ileum. Exposure to galanin resulted in concentration-dependent suppression of slow noradrenergic inhibitory postsynaptic potentials and fast nicotinic excitatory postsynaptic potentials in the majority of neurons. Failure of galanin to suppress nicotinic depolarizing responses to micropressure pulses of acetylcholine and failure to suppress hyperpolarizing responses to micropressure pulses of norepinephrine suggested that galanin acted at presynaptic inhibitory receptors to suppress release of acetylcholine and norepinephrine. Galanin suppressed slow excitatory postsynaptic potentials in eight of eight neurons with AH (after-hyperpolarization) type electrical behavior and in none of 26 neurons with S (synaptic) type electrical behavior. Suppression of excitatory neurotransmission in AH neurons was always associated with membrane hyperpolarization. Excitatory responses caused by experimentally applied substance P were also inhibited by galanin. Galanin-(1-16) and galanin-like peptide mimicked the inhibitory actions of galanin on neurotransmission. The selective galanin GAL2 receptor agonist [D-Trp2]galanin was inactive. The chimeric peptides, galanin-(1-13)-spantide I, galantide, galanin-(1-13)-neuropeptide Y(25-36) amide, galanin-(1-13)-bradykinin-(2-9)amide and galanin-(1-13)-Pro-Pro-Ala-Leu-Ala-Leu-Ala amide all produced varying degrees of suppression of the synaptic potentials. The evidence suggests that the galanin GAL1 receptor, but not the galanin GAL2 receptor, mediated the presynaptic and postsynaptic inhibitory actions of galanin.

Original languageEnglish
Pages (from-to)49-58
Number of pages10
JournalEuropean Journal of Pharmacology
Volume471
Issue number1
DOIs
Publication statusPublished - 13 Jun 2003
Externally publishedYes

Keywords

  • Enteric nervous system
  • Galanin
  • Small intestine
  • Submucous plexus
  • Synaptic transmission

Fingerprint Dive into the research topics of 'Actions of galanin on neurotransmission in the submucous plexus of guinea pig small intestine'. Together they form a unique fingerprint.

  • Cite this