Synapse (New York, N.Y.), 2008-08, Vol.62 (8), p.601-615
2008
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- Autor(en) / Beteiligte
- Titel
- Serotoninergic dorsal raphe neurons possess functional postsynaptic nicotinic acetylcholine receptors
- Ist Teil von
- Synapse (New York, N.Y.), 2008-08, Vol.62 (8), p.601-615
- Ort / Verlag
- Hoboken: Wiley Subscription Services, Inc., A Wiley Company
- Erscheinungsjahr
- 2008
- Quelle
- Wiley-Blackwell Full Collection
- Beschreibungen/Notizen
- Very few neurons in the telencephalon have been shown to express functional postsynaptic nicotinic acetylcholine receptors (nAChRs), among them, the noradrenergic and dopaminergic neurons. However, there is no evidence for postsynaptic nAChRs on serotonergic neurons. In this study, we asked if functional nAChRs are present in serotonergic (5‐HT) and nonserotonergic (non‐5‐HT) neurons of the dorsal raphe nucleus (DRN). In rat midbrain slices, field stimulation at the tegmental pedunculopontine (PPT) nucleus evoked postsynaptic currents (eEPSCs) with different components in DRN neurons. After blocking the glutamatergic and GABAergic components, the remaining eEPSCs were blocked by mecamylamine and reduced by either the selective α7 nAChR antagonist methyllycaconitine (MLA) or the selective α4β2 nAChR antagonist dihydro‐β‐eritroidine (DHβE). Simultaneous addition of MLA and DHβE blocked all eEPSCs. Integrity of the PPT‐DRN pathway was assessed by both anterograde biocytin tracing and antidromic stimulation from the DRN. Inward currents evoked by the direct application of acetylcholine (ACh), in the presence of atropine and tetrodotoxin, consisted of two kinetically different currents: one was blocked by MLA and the other by DHβE; in both 5‐HT and non‐5‐HT DR neurons. Analysis of spontaneous (sEPSCs) and evoked (eEPSCs) synaptic events led to the conclusion that nAChRs were located at the postsynaptic membrane. The possible implications of these newly described nAChRs in various physiological processes and behavioral events, such as the wake‐sleep cycle, are discussed. Synapse 62:601–615, 2008. © 2008 Wiley‐Liss, Inc.
- Sprache
- Englisch
- Identifikatoren
- ISSN: 0887-4476eISSN: 1098-2396DOI: 10.1002/syn.20526Titel-ID: cdi_proquest_miscellaneous_71637616
- Format
- –
- Schlagworte
- Acetylcholine - metabolism, alpha7 Nicotinic Acetylcholine Receptor, Animals, dorsal raphe nucleus, Electric Stimulation, Excitatory Postsynaptic Potentials - drug effects, Excitatory Postsynaptic Potentials - physiology, Mesencephalon - metabolism, Neural Pathways - drug effects, Neural Pathways - metabolism, Neurons - drug effects, Neurons - metabolism, nicotinic acetylcholine receptor, Nicotinic Antagonists - pharmacology, Organ Culture Techniques, Patch-Clamp Techniques, Pedunculopontine Tegmental Nucleus - metabolism, Raphe Nuclei - cytology, Raphe Nuclei - drug effects, Raphe Nuclei - metabolism, Rats, Rats, Wistar, Receptors, Nicotinic - drug effects, Receptors, Nicotinic - metabolism, serotonergic neurons, Serotonin - metabolism, Synapses - drug effects, Synapses - metabolism, Synaptic Membranes - drug effects, Synaptic Membranes - metabolism, Synaptic Transmission - drug effects, Synaptic Transmission - physiology, Wakefulness - drug effects, Wakefulness - physiology