Journal article
Different brain structures mediate drinking and sleep suppression elicited by the somatostatin analog, octreotide, in rats
Brain research, Vol.994(1), pp.115-123
2003
Handle:
https://hdl.handle.net/2376/110847
PMID: 14642455
Abstract
When injected into the cerebral ventricles, the somatostatin analog, octreotide (OCT) elicits prompt drinking, vasopressin secretion and increases in blood pressure that are attributed to the activation of the intracerebral angiotensinergic system. In addition, OCT induces sleep responses that might be mediated by an inhibition of hypothalamic neurons producing growth hormone-releasing hormone (GHRH). OCT (0.02 μg in 0.2 μl) was microinjected into various brain sites to determine the structures inducing drinking and/or sleep suppression in response to OCT in rats. Drinking (>1 ml water in 10 min) was elicited in 17 rats out of 86 tested. The positive drinking sites resided in or around the subfornical organ (SFO) and the paraventricular nucleus. Both structures are part of the reported angiotensinergic dipsogenic circuit of the brain. These microinjections failed to elicit consistent sleep effects. Sleep suppression (>10% recording time in hour 1) was observed after injection of OCT either into the arcuate nucleus (
n=7), where the majority of GHRHergic neurons reside, or into the medial preoptic area/anterior hypothalamus (
n=8), where GHRH acts to promote sleep. Administration of OCT into far lateral sites of the lateral preoptic area and lateral hypothalamus stimulated sleep in hour 1 (
n=10), perhaps via inhibiting cholinergic neurons previously implicated in arousal. The results are consistent with the hypothesis that somatostatin is involved in the regulation of both water intake and sleep, and suggest that different structures, and therefore different somatostatinergic neuronal pools, mediate these actions.
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Details
- Title
- Different brain structures mediate drinking and sleep suppression elicited by the somatostatin analog, octreotide, in rats
- Creators
- Ildiko Hajdu - Department of Physiology, A. Szent-Györgyi Center, University of Szeged, HungaryEva Szentirmai - Department of Physiology, A. Szent-Györgyi Center, University of Szeged, HungaryFerenc Obal - Department of Physiology, A. Szent-Györgyi Center, University of Szeged, HungaryJames M Krueger - Department of Veterinary and Comparative Anatomy, Pharmacology and Physiology, College of Veterinary Medicine, Washington State University, P.O. Box 646520, 205 Wegner Hall, Pullman, WA 99164-6520, USA
- Publication Details
- Brain research, Vol.994(1), pp.115-123
- Academic Unit
- Biomedical Sciences, Department of; Integrative Physiology and Neuroscience, Department of
- Publisher
- Elsevier B.V
- Identifiers
- 99900547122201842
- Language
- English
- Resource Type
- Journal article