Somatostatin inhibits nicotinic cholinoceptor mediated-excitation in rat ambigual motoneurons in vitro.
The interaction between somatostatin and acetylcholine, two putative transmitters in the nucleus ambiguus, was investigated on single ambigual neurons in a brainstem slice preparation. Somatostatin reversibly inhibited the nicotinic cholinoceptor-mediated depolarization and inward current induced by acetylcholine. This inhibition persisted in the presence of tetrodotoxin (TTX) or Mn2+. In contrast, somatostatin enhanced both the glutamate-evoked depolarization and spiking discharges generated by current injection. These results suggest that somatostatin exerts a differential action in modulating excitatory inputs to the nucleus ambiguus at the level of postsynaptic receptors.
Faculty of Medicine, Memorial University of Newfoundland, St. John's, Canada.
Y T
YT
Wang
R S
RS
Neuman
D
D
Bieger
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001933:Brain Stem / Q000166:cytology / Q000502:physiology*; D004594:Electrophysiology; D005971:Glutamates / Q000494:pharmacology; D018698:Glutamic Acid; D066298:In Vitro Techniques; D008297:Male; D009046:Motor Neurons / Q000502:physiology*; D051381:Rats; D011978:Receptors, Nicotinic / Q000502:physiology*; D013004:Somatostatin / Q000494:pharmacology*
D005971:Glutamates; D011978:Receptors, Nicotinic; D018698:Glutamic Acid; D013004:Somatostatin; D000109:Acetylcholine