1. Involvement of the cAMP-Dependent Pathway in Dextromethorphan-Induced Inhibition of Spontaneous Glutamate Transmission in the Nucleus Tractus Solitarius Neurons of Guinea Pigs.
- Author
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Ohi Y, Kodama D, and Haji A
- Subjects
- 8-Bromo Cyclic Adenosine Monophosphate pharmacology, Animals, Colforsin pharmacology, Ethylmaleimide pharmacology, Excitatory Postsynaptic Potentials drug effects, Guinea Pigs, Male, Miniature Postsynaptic Potentials drug effects, Neurons metabolism, Neurons physiology, Solitary Nucleus metabolism, Synaptic Transmission physiology, Cyclic AMP metabolism, Dextromethorphan pharmacology, Glutamates metabolism, Neurons drug effects, Solitary Nucleus drug effects, Solitary Nucleus physiology, Synaptic Transmission drug effects
- Abstract
Dextromethorphan (DEX) presynaptically decreases glutamatergic transmission in second-order neurons of the nucleus tractus solitarius (TS). To clarify the inhibitory mechanism of DEX, the present study examined the interaction of DEX with cAMP. The effects of DEX on miniature and TS-evoked excitatory postsynaptic currents (mEPSCs and eEPSCs) were recorded under activation of the cAMP-dependent pathway using the brainstem slices. An increase in cAMP by forskolin counteracted the inhibitory effect of DEX on mEPSCs. Eight-Bromo-cAMP and N-ethylmaleimide also attenuated the DEX effect. However, forskolin had negligible effects on the DEX-induced inhibition of eEPSCs. This suggests that DEX decreases spontaneous glutamate release by inhibiting the cAMP-dependent pathway and synchronous release by another unknown mechanism., (© 2018 S. Karger AG, Basel.)
- Published
- 2019
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