The anterolateral projections of the medial basal hypothalamus affect sleep

Abstract

Peterfi Z, Makara GB, Obál F Jr, Krueger JM. The anterolateral projections of the medial basal hypothalamus affect sleep. Am J Physiol Regul Integr Comp Physiol 296: R1228 -R1238, 2009. First published February 4, 2009 doi:10.1152/ajpregu.90958.2008-The role of the medial basal hypothalamus (MBH) and the anterior hypothalamus/preoptic area (AH/POA) in sleep regulation was investigated using the Halász knife technique to sever MBH anterior and lateral projections in rats. If both lateral and anterior connections of the MBH were cut, rats spent less time in non-rapid eye movement sleep (NREMS) and rapid eye movement sleep (REMS). In contrast, if the lateral connections remained intact, the duration of NREMS and REMS was normal. The diurnal rhythm of NREMS and REMS was altered in all groups except the sham control group. Changes in NREMS or REMS duration were not detected in a group with pituitary stalk lesions. Water consumption was enhanced in three groups of rats, possibly due to the lesion of vasopressin fibers entering the pituitary. EEG delta power during NREMS and brain temperatures (Tbr) were not affected by the cuts during baseline or after sleep deprivation. In response to 4 h of sleep deprivation, only one group, that with the most anterior-to-posterior cuts, failed to increase its NREMS or REMS time during the recovery sleep. After deprivation, Tbr returned to baseline in most of the treatment groups. Collectively, results indicate that the lateral projections of the MBH are important determinants of duration of NREMS and REMS, while more anterior projections are concerned with the diurnal distribution of sleep. Further, the MBH projections involved in sleep regulation are distinct from those involved in EEG delta activity, water intake, and brain temperature.anterior hypothalamus/preoptic area; sleep regulation; non-rapid eye movement sleep A RELATIONSHIP BETWEEN THE somatotropic axis and sleep was first recognized 40 years ago when the association between plasma growth hormone (GH) levels and non-rapid eye movement sleep (NREMS) was described by Takahashi et al. (77). Subsequently, much evidence has supported the hypothesis that hypothalamic growth hormone releasing hormone (GHRH) is involved in NREMS sleep regulation and, through its induction of pituitary release of GH, rapid eye movement sleep (REMS) as well (reviewed in Ref. 55). Within the hypothalamus, the majority of the GHRH-containing perikarya resides in the arcuate nucleus (ARC) (50,51,66). A smaller number of GHRH-containing neurons are found around the ventral border of the ventromedial nucleus, the dorsomedial nucleus, and in the parvocellular portion of the paraventricular nucleus (PVN), and the posterior hypothalamus. Previously, we showed that microinjection of GHRH into the medial preoptic region/anterior hypothalamus promotes NREMS, while injection of a GHRH antagonist peptide inhibited NREMS (80). The stimulated areas likely included the rostral portion of the periventricular (PeV) nucleus due to diffusion. Sites in the posterior...

Circadian integration of sleep-wake and feeding requires NPY receptor-expressing neurons in the mediobasal hypothalamus

“…12, 24, 33, 46, 53, 69, 70, 79), as the lesion differentially affected the circadian distribution of these states. In addition, our findings concur with the proposal that these triggering mechanisms lie elsewhere than in the NPY-sensitive MBH neurons (59,76,91) since these sleep-wake states themselves were not abolished by the NPY-SAP lesion. Moreover, our findings indicate that these lesions did not alter the total amount of wake, NREMS, or REMS under any of the conditions we tested, suggesting that the mechanisms underlying homeostatic control of total sleep time are distinct from those controlling its circadian distribution, and further, that the homeostatic control of total sleep time does not require MBH NPY-sensitive neurons.…”

“…For example, it is not likely that the effects of the NPY-SAP lesion are due to damage to the median eminence. Although such damage is possible and even likely with NPY-SAP or other lesions directed at the Arc, previous work has shown that transection of the pituitary stalk does not alter either REMS or NREMS (59). Moreover, we show here that corticosterone response to glucoprivation is still present after Arc-directed NPY-SAP lesions, suggesting that the pathway to the median eminence from the paraventricular corticotropin releasing hormone neurons remains functional in the lesioned rats.…”

“…Lesions of the SCN (26; reviewed in Ref. 43) or ventral subperiventricular zone (38), knife-cut isolation of the SCN (81), MSG-induced destruction of the Arc (54), and MBH knife cuts (59,97) all reduce day-night differences in NREMS. These sites are reciprocally interconnected (6,71) and appear to form an afferent/ efferent loop, the integrity of which may be required for control of day-night distribution of REMS and NREMS.…”

“…The anatomical connections of the MBH, including its reciprocal connectivity with the SCN (95,96,98), are consistent with an integrative function related to rhythm generation. Furthermore, MBH lesions produced by various methods result in hyperphagia and disruption of the diurnal patterning of both feeding (29,44) and sleep (54,59). Finally, a very early study, and one of the few studies that has examined sites of integration of feeding and sleep-wake, found that rats with lesions in this hypothalamic area exhibited associated changes in sleep events and meal parameters (13).…”

Una visión psiconeuroinmunológica de la fibromialgia

“…Somos conscientes de que existe una paradoja difícil de salvar cognitivamente: por una parte el SFM no es una enfermedad mental ni es el producto de un confl icto psicológico, por otra es necesario un abordaje ciado con el sueño profundo no REM, la propia GH lo está con la fase REM, equilibrando entre ambos el anabolismo tisular durante el sueño (Obal y Krueger, 2004). La secreción de GH-RH depende de la región preóptica del hipotá-lamo anterior, precisamente la misma zona que se ocupa de la regulación del sueño (Peterfi , Makara, Obal, y Krueger, 2009). Finalmente, el SI de hombres y mujeres funciona de manera ligeramente diferente, resultando cambios tanto del sueño como inmunes durante las diferentes fases del ciclo menstrual, lo que parece tener especial signifi cado en el SFM.…”