Orexin-A excites pyramidal neurons in layer 2/3 of the rat prefrontal cortex
| Autor: | Zhian Hu, Jianxia Xia, Dan Zhang, Chao He, Jie Yan |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
Receptors
Neuropeptide Patch-Clamp Techniques Potassium Channels Prefrontal Cortex In Vitro Techniques Ion Channels Sodium-Calcium Exchanger Receptors G-Protein-Coupled Orexin-A Orexin Receptors Postsynaptic potential mental disorders Animals Patch clamp Rats Wistar Reversal potential Prefrontal cortex Orexins Chemistry Pyramidal Cells General Neuroscience Neuropeptides digestive oral and skin physiology Intracellular Signaling Peptides and Proteins Depolarization Orexin receptor Rats nervous system Excitatory postsynaptic potential Neuroscience psychological phenomena and processes |
| Zdroj: | Neuroscience Letters. 520:92-97 |
| ISSN: | 0304-3940 |
| DOI: | 10.1016/j.neulet.2012.05.038 |
| Popis: | The arousal peptides, orexins, play an important role in regulating the function of the prefrontal cortex (PFC). Although orexins have been shown to increase the excitability of deep-layer neurons in the medial prefrontal cortex (mPFC), little is known about their effect on layer 2/3, the main intracortical processing layer. In this study, we investigated the effect of orexin-A on pyramidal neurons in layer 2/3 of the mPFC using whole-cell recordings in rat brain slices. We observed that orexin-A reversibly depolarized layer 2/3 pyramidal neurons through a postsynaptic action. This depolarization was concentration-dependent and mediated via orexin receptor 1. In voltage-clamp recordings, the orexin-A-induced current was reduced by the replacement of internal K(+) with Cs(+), removal of external Na(+), or an application of flufenamic acid (an inhibitor of nonselective cation channels). A blocker of Na(+)/Ca(2+) exchangers (SN-6) did not influence the excitatory effect of orexin-A. Moreover, the current induced by orexin-A reversed near E(k) when the external solution contained low levels of Na(+). When recording with Cs(+)-containing pipettes in normal external solution, the reversal potential of the current was approximately -25 mV. These data suggest an involvement of both K(+) channels and nonselective cation channels in the effect of orexin-A. The direct excitatory action of orexin-A on layer 2/3 mPFC neurons may contribute to the modulation of PFC activity, and play a role in cognitive arousal. |
| Databáze: | OpenAIRE |
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