Journal article
Sleep in spontaneous dwarf rats
Brain research, Vol.1108(1), pp.133-146
2006
Handle:
https://hdl.handle.net/2376/113098
PMID: 16859658
Abstract
Spontaneous dwarf rats (SDRs) display growth hormone (GH) deficiency due to a mutation in the GH gene. This study investigated sleep in SDRs and their somatotropic axis and compared to Sprague–Dawley rats. SDRs had almost undetectable levels of plasma GH. Hypothalamic GH-releasing hormone (GHRH) mRNA was increased, whereas GHRH-receptor (GHRH-R) and somatostatin mRNAs were decreased in SDRs. Hypothalamic GHRH and somatostatin peptide content decreased in SDRs. Quantitative immunohistochemistry for GHRH and GHRH-R corroborated and extended these findings. In the arcuate nucleus, the number of GHRH-positive cells was significantly higher, whereas GHRH-R-positive perikarya were diminished in SDRs. Cortical GHRH and GHRH-R measurements showed similar expression characteristics as those found in the hypothalamus. SDRs had less rapid eye movement sleep (REMS) and more non-REMS (NREMS) than the control rats during the light period. The electroencephalogram (EEG) delta and theta power decreased during NREMS in the SDRs. After 4-h of sleep deprivation, SDRs had a significantly reduced REMS rebound compared to the controls, whereas NREMS rebound was normal in SDRs. The enhancement in delta power was significantly less than in the control group during recovery sleep. Intracerebroventricular (icv) administration of GHRH promoted NREMS in both strains of rats; however, increased REMS and EEG delta activity was observed only in control rats. Icv injection of insulin-like growth factor 1 increased NREMS in control rats, but not in the SDRs. These results support the ideas that GHRH is involved in NREMS regulation and that GH is involved in the regulation of REMS and in EEG slow wave activity regulation during NREMS.
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Details
- Title
- Sleep in spontaneous dwarf rats
- Creators
- Zoltan Peterfi - Department of Physiology, University of Szeged, A. Szent-Györgyi Medical Center, 6720 Szeged, HungaryFerenc Obal - Department of Physiology, University of Szeged, A. Szent-Györgyi Medical Center, 6720 Szeged, HungaryPing Taishi - Department of Veterinary and Comparative Anatomy, Pharmacology, and Physiology, College of Veterinary Medicine, Washington State University, PO Box 646520, Pullman, WA 99164-6520, USAJanos Gardi - Endocrine Unit, University of Szeged, A. Szent-Györgyi Medical Center, 6720 Szeged, HungaryBalint Kacsoh - Division of Basic Medical Sciences and Department of Pediatrics, Mercer University School of Medicine, Macon, GA, USATerry Unterman - University of Illinois at Chicago, College of Medicine and Jesse Brown VA Medical Center, Chicago, IL 60612, USAJames M Krueger - Department of Veterinary and Comparative Anatomy, Pharmacology, and Physiology, College of Veterinary Medicine, Washington State University, PO Box 646520, Pullman, WA 99164-6520, USA
- Publication Details
- Brain research, Vol.1108(1), pp.133-146
- Academic Unit
- Integrative Physiology and Neuroscience, Department of
- Publisher
- Elsevier B.V
- Identifiers
- 99900547694001842
- Language
- English
- Resource Type
- Journal article