title: Prokineticin 2 regulates the electrical activity of rat suprachiasmatic nuclei neurons.
abstract: Neuropeptide signaling plays roles in coordinating cellular activities and maintaining robust oscillations within the mammalian suprachiasmatic nucleus (SCN). Prokineticin2 (PK2) is a signaling molecule from the SCN and involves in the generation of circadian locomotor activity. Prokineticin receptor 2 (PKR2), a receptor for PK2, has been shown to be expressed in the SCN. However, very little is known about the cellular action of PK2 within the SCN. In the present study, we investigated the effect of PK2 on spontaneous firing and miniature inhibitory postsynaptic currents (mIPSCs) using whole cell patch-clamp recording in the SCN slices. PK2 dose-dependently increased spontaneous firing rates in most neurons from the dorsal SCN. PK2 acted postsynaptically to reduce γ-aminobutyric acid (GABA)-ergic function within the SCN, and PK2 reduced the amplitude but not frequency of mIPSCs. Furthermore, PK2 also suppressed exogenous GABA-induced currents. And the inhibitory effect of PK2 required PKC activation in the postsynaptic cells. Our data suggest that PK2 could alter cellular activities within the SCN and may influence behavioral and physiological rhythms.
authors.affiliation: Department of Pharmacology, Xianning College, Xianning, Hubei, People's Republic of China.
authors.forename: Ping
authors.initials: P
authors.lastname: Ren
authors.forename: Huiping
authors.initials: H
authors.lastname: Zhang
authors.forename: Fang
authors.initials: F
authors.lastname: Qiu
authors.forename: Yu-Qiang
authors.initials: YQ
authors.lastname: Liu
authors.forename: Huaiyu
authors.initials: H
authors.lastname: Gu
authors.forename: Diane K
authors.initials: DK
authors.lastname: O'Dowd
authors.forename: Qun-Yong
authors.initials: QY
authors.lastname: Zhou
authors.forename: Wang-Ping
authors.initials: WP
authors.lastname: Hu
mesh_terms: D000818:Animals; D004553:Electric Conductivity; D055724:Electrophysiological Phenomena / Q000187:drug effects; D005768:Gastrointestinal Hormones / Q000378:metabolism*; D066298:In Vitro Techniques; D053444:Inhibitory Postsynaptic Potentials / Q000187:drug effects; D008297:Male; D009474:Neurons / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D009479:Neuropeptides / Q000378:metabolism*; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011963:Receptors, GABA-A / Q000378:metabolism; D013493:Suprachiasmatic Nucleus / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
chemical_list: D005768:Gastrointestinal Hormones; D009479:Neuropeptides; D047428:Protein Kinase Inhibitors; D011963:Receptors, GABA-A; C513686:prokineticin 2, rat; D005680:gamma-Aminobutyric Acid; D011493:Protein Kinase C