Tachykinins mediate slow excitatory postsynaptic transmission in guinea pig sphincter of Oddi ganglia.
Am J Physiol Gastrointest Liver Physiol
; 281(2): G357-64, 2001 Aug.
Article
en En
| MEDLINE
| ID: mdl-11447015
ABSTRACT
Intracellular recording techniques were used to test whether tachykinins could be mediators of slow excitatory postsynaptic potentials (EPSPs) in guinea pig sphincter of Oddi (SO) ganglia. Application of the tachykinin substance P (SP) onto SO neurons caused a prolonged membrane depolarization that was reminiscent of the slow EPSP in these cells. Pressure ejection of the neurokinin 3 (NK3) receptor-specific agonist senktide caused a similar depolarization; however, no responses were detected on application of NK1 or NK2 receptor agonists. The NK3 receptor antagonist SR-142801 (100 nM) significantly inhibited both SP-induced depolarization and the stimulation-evoked slow EPSP, as did NK3 receptor desensitization with senktide. Capsaicin, which causes the release of SP from small-diameter afferent fibers, induced a depolarization that was similar to the evoked slow EPSP in both amplitude and duration. The capsaicin-induced depolarization was significantly attenuated in the presence of SR-142801. These data indicate that tachykinins, released from extrinsic afferent fibers, act via NK3 receptors to provide slow excitatory synaptic input to SO neurons.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Taquicininas
/
Sustancia P
/
Transmisión Sináptica
/
Potenciales Postsinápticos Excitadores
/
Esfínter de la Ampolla Hepatopancreática
Límite:
Animals
Idioma:
En
Revista:
Am J Physiol Gastrointest Liver Physiol
Asunto de la revista:
FISIOLOGIA
/
GASTROENTEROLOGIA
Año:
2001
Tipo del documento:
Article
País de afiliación:
Estados Unidos