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Hypothalamic osmoregulation is maintained across the wake–sleep cycle in the rat
Author(s) -
LUPPI MARCO,
MARTELLI DAVIDE,
AMICI ROBERTO,
BARACCHI FRANCESCA,
CERRI MATTEO,
DENTICO DANIELA,
PEREZ EMANUELE,
ZAMBONI GIOVANNI
Publication year - 2010
Publication title -
journal of sleep research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.297
H-Index - 117
eISSN - 1365-2869
pISSN - 0962-1105
DOI - 10.1111/j.1365-2869.2009.00810.x
Subject(s) - medicine , endocrinology , vasopressin , plasma osmolality , osmoregulation , homeostasis , cannula , tonicity , osmoreceptor , hypothalamus , biology , salinity , ecology , surgery
Summary In different species, rapid eye movement sleep (REMS) is characterized by a thermoregulatory impairment. It has been postulated that this impairment depends on a general insufficiency in the hypothalamic integration of autonomic function. This study aims to test this hypothesis by assessing the hypothalamic regulation of body fluid osmolality during the different wake–sleep states in the rat. Arginine‐vasopressin (AVP) plasma levels were determined following intracerebroventricular (ICV) infusions of artificial cerebrospinal fluid (aCSF), either isotonic or made hypertonic by the addition of NaCl at three different concentrations (125, 250 and 500 m m ). Animals were implanted with a cannula within a lateral cerebral ventricle for ICV infusions and with electrodes for the recording of the electroencephalogram. ICV infusions were made in different animals during Wake, REMS or non‐REM sleep (NREMS). The results show that ICV infusion of hypertonic aCSF during REMS induced an increase in AVP plasma levels that was not different from that observed during either Wake or NREMS. These results suggest that the thermoregulatory impairment that characterizes REMS does not depend on a general impairment in the hypothalamic control of body homeostasis.