Efferent projections of prokineticin 2 expressing neurons in the mouse suprachiasmatic nucleus

• Published in: PloS one Vol. 4; no. 9; p. e7151
• Main Authors: Zhang, Chengkang, Truong, Kimberly K, Zhou, Qun-Yong
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 28.09.2009; Public Library of Science (PLoS)
• Subjects: Animals; Artificial chromosomes; Bacteria; Bacterial artificial chromosomes; Body temperature; Brain; Brain - metabolism; Chromosomes, Artificial, Bacterial; Circadian rhythm; Circadian rhythms; Cloning; Fluorescence; Gastrointestinal Hormones - biosynthesis; Gene expression; Gene Expression Regulation; Genes, Reporter; Genetic engineering; Green Fluorescent Proteins - metabolism; Hypothalamus; Hypothalamus (lateral); Hypothalamus - metabolism; In Situ Hybridization, Fluorescence; Localization; Mice; Mice, Transgenic; Nervous system; Neurogenesis; Neurons; Neurons - metabolism; Neuropeptides - biosynthesis; Neuroscience; Neuroscience/Behavioral Neuroscience; Neuroscience/Neuronal and Glial Cell Biology; Oscillometry; Paraventricular nucleus; Pharmacology; Physiology; Polypeptides; Preoptic area; Promoter Regions, Genetic; Reporter gene; Rodents; Septum; Suprachiasmatic nucleus; Suprachiasmatic Nucleus - metabolism; Thalamus; Transgenic animals; Transgenic mice; Transplants & implants; Trends; Vasopressins - metabolism; United States > US; California
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0007151

The suprachiasmatic nucleus (SCN) in the hypothalamus is the predominant circadian clock in mammals. To function as a pacemaker, the intrinsic timing signal from the SCN must be transmitted to different brain regions. Prokineticin 2 (PK2) is one of the candidate output molecules from the SCN. In this study, we investigated the efferent projections of PK2-expressing neurons in the SCN through a transgenic reporter approach. Using a bacterial artificial chromosome (BAC) transgenic mouse line, in which the enhanced green fluorescence protein (EGFP) reporter gene expression was driven by the PK2 promoter, we were able to obtain an efferent projections map from the EGFP-expressing neurons in the SCN. Our data revealed that EGFP-expressing neurons in the SCN, hence representing some of the PK2-expressing neurons, projected to many known SCN target areas, including the ventral lateral septum, medial preoptic area, subparaventricular zone, paraventricular nucleus, dorsomedial hypothalamic nucleus, lateral hypothalamic area and paraventricular thalamic nucleus. The efferent projections of PK2-expressing neurons supported the role of PK2 as an output molecule of the SCN.