TY - JOUR
T1 - Serotonin augments the cationic current Ih in central neurons
AU - Bobker, Daniel H.
AU - Williams, John T.
N1 - Funding Information:
We thank R. A. North, C. L. Westbrook, and M. G. Lacry tar help ful suggestions concerning this work. This project was supported by grants USDHHS DA 04523 (1. T. W.) and NIH HL 07596 (D. H. B.1 from the National Institutes of Health.
PY - 1989/6
Y1 - 1989/6
N2 - Serotinin (5-HT) induced a slow depolarization when superfused onto neurons of the rat brainstem nucleus prepositus hypoglossi (PH) in vitro. The depolarization was associated with a decrease in cell input resistance. In voltage clamp, 5-HT caused an inward current that activated at approximately -50 mV and was present only at potentials negative to this. With hyperpolarizing voltage-clamp steps, PH neurons exhibited a slow inward current relaxation. The properties of this conductance were consistent with the cationic, nonselective current, Ih Bath-applied 5-HT augmented Ih. Extracellular CsCI blocked both Ih and the inward current produced by 5-HT. In addition, forskolin, isobutylmethylxanthine, and 8-bromo-CAMP mimicked the inward current seen with 5-HT. The 5-HT1 agonist 5-carboxamidotryptamine produced a similar inward current. We conclude that 5-HT excites PH neurons by augmenting Ih, probably through receptor-mediated stimulation of adenylate cyclase. As Ih is found in many types of neurons, this mechanism may be a common mode of regulating cell excitability.
AB - Serotinin (5-HT) induced a slow depolarization when superfused onto neurons of the rat brainstem nucleus prepositus hypoglossi (PH) in vitro. The depolarization was associated with a decrease in cell input resistance. In voltage clamp, 5-HT caused an inward current that activated at approximately -50 mV and was present only at potentials negative to this. With hyperpolarizing voltage-clamp steps, PH neurons exhibited a slow inward current relaxation. The properties of this conductance were consistent with the cationic, nonselective current, Ih Bath-applied 5-HT augmented Ih. Extracellular CsCI blocked both Ih and the inward current produced by 5-HT. In addition, forskolin, isobutylmethylxanthine, and 8-bromo-CAMP mimicked the inward current seen with 5-HT. The 5-HT1 agonist 5-carboxamidotryptamine produced a similar inward current. We conclude that 5-HT excites PH neurons by augmenting Ih, probably through receptor-mediated stimulation of adenylate cyclase. As Ih is found in many types of neurons, this mechanism may be a common mode of regulating cell excitability.
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U2 - 10.1016/0896-6273(89)90041-X
DO - 10.1016/0896-6273(89)90041-X
M3 - Article
C2 - 2483327
AN - SCOPUS:0024678320
SN - 0896-6273
VL - 2
SP - 1535
EP - 1540
JO - Neuron
JF - Neuron
IS - 6
ER -