Acute and chronic sleep restriction differentially modify maternal behavior and milk macronutrient composition in the postpartum rat.

BACKGROUNDS: Sleep restriction is considered a stressful condition itself, causing a wide variety of physiological alterations, from cognitive and hormonal to immunological status. In addition, it is established that stress in mother rats can modify milk ejection, milk composition, and maternal care of the pups. Also, sleep disturbances during the early stages of motherhood are a common feature of all studied species. In this context, while the impacts of sleep disruption in non-lactating animals were extensively investigated, its repercussions during the initial phases of motherhood have been poorly explored. Therefore, we wonder if maternal behavior, milk ejection and its macronutrient composition would be disrupted when mother rats are subjected to an additional acute or chronic sleep restriction to the already existing sleep disturbances. METHODS: Lactating rats were implanted with unilateral electrodes for polysomnographic recordings and for deep brain electrical stimulation into mesopontine waking-promoting area (for sleep deprivation). During the early postpartum period (postpartum day 5-9), mother rats were randomly assigned into one of three groups: chronic sleep restriction group (CSR; 6 h of sleep deprivation/day for five consecutive days), acute sleep restriction group (ASR; 6 h of sleep deprivation only for one day), or undisturbed group (control group). Active maternal behaviors (retrievals of the pups into the nest, mouthing, lickings [corporal and anogenital] and sniffing the pups) and passive maternal behaviors (kyphotic and supine nursing postures) were evaluated during a 30 min period without sleep restriction immediately after the sleep restriction or control period. The litter weight gain was assessed every day, and on the last experimental session mothers were milked for posterior macronutrients analysis (protein, carbohydrates and fat). RESULTS: When compared to control group, CSR decreased the amount of milk ejected in the middle days of the sleep restriction period, while ASR did not affect this parameter. Moreover, ASR reduced milk protein content compared to control and CSR groups. Finally, compared to the control group, CSR reduced active maternal behaviors towards the end of the treatment days. CONCLUSIONS: We demonstrated that not only acute but also chronic sleep restriction impacts on the postpartum period, each one affecting different aspects of maternal behavior and lactation. Our results suggest the existence of a homeostatic recovery mechanism in breastfeeding during CSR, possibly ensuring the survival of the litter, while the decline in active maternal behaviors appears to be cumulative.

Minimally invasive intraoral removal of mesiodens via a transnasal, non-endoscopic approach: a systematic review on the purpose of 10 cases.

Mesiodens, which emerge towards the nasal cavity, often require consultation in maxillofacial practice. Typically accessed through wide palatal flaps with ostectomy, this method involves limited visibility and poses the risk of damaging the roots and apex of adjacent dental structures. This study advocates a minimally invasive technique that involves vestibulotomy between the central incisors, facilitating direct and rapid access through nasal floor dissection, minimizing comorbidities. A systematic review was performed, following the PRISMA guidelines, apropos on ten clinical cases reported in this study. The MEDLINE/Pubmed and Web of Science databases were searched. Several variables were considered and are presented comprehensively in tables and figures. Additionally, 10 case reports with mesiodens in the maxilla were submitted to surgical treatment using a minimally invasive intraoral transnasal disinclusion. The initial literature search resulted in 37 articles, of which 9 met the inclusion criteria for the analysis. Regarding postoperative complications, no bone exposure, incisor root damage, extensive surgical approach, palatal or vestibular hematoma, or palatal necrosis was observed. However, 10% experienced superficial damage to the nasopalatine neurovascular, while 80% and 20% presented mild and moderate postoperative facial edema, respectively. Hypoesthesia in 20% of patients recovered in the first week, 40% in the first month and 40% at 3 months. The minimally invasive intraoral, transnasal, non-endoscopic approach emerges as a safe and predictable alternative to conventional surgical techniques. Presumes minimal postoperative complications, mitigating the risk of excessive bone removal and damage to adjacent structures.

Is sleep critical for lactation in rat?

Sleep deprivation is a feature shared by most studied mammals at some point during the postpartum period. Unlike the rabbit, the pig, or the human mother, sleep has been claimed as an essential state for milk ejection in mother rats, where sleep deprivation using gentle handling (GH) prevents milk ejection and pup weight gain. Though sleep deprivation is a stressful situation itself, most common methodologies used in laboratory animals, including GH, usually involve aversive stimulus to prevent sleep, adding further stress to the animal. Deep brain electrical stimulation (DBES) of the brainstem reticular formation is a less common technique used to prevent sleep, and while this methodology may also carry unwanted effects, it avoids stressful conditions. In the present study, we examined the relationship between sleep and nursing, and how different sleep deprivation methodologies impact nursing and lactation. For this purpose, we carried out two sets of experiments. First, we correlated sleep and waking states with different nursing parameters of lactating rats under undisturbed conditions. Second, we slept deprived another group of mother rats using two different techniques: GH and DBES. Our main findings show that sleeping time was positively correlated with the time devote to nurse the pups, but not either with milk ejection or pup weight gain. When mother rats were sleep deprived, maternal behavior was fragmented using both methods, but was substantially more disrupted when using GH. Additionally, lactating dams were capable of ejecting milk and their pups gained weight despite of being sleep deprived using both techniques, but these parameters were significantly reduced using GH compared to control values, while DBES did not differ from control group. Overall, these results suggest that sleep and nursing are behaviorally compatible, but in disagreement with previous findings, we concluded that sleep is not necessary for milk ejection. These observations have critical implications for using the rat as a model to explore sleep loss during the postpartum period.

Electrophysiological characterization of medial preoptic neurons in lactating rats and its modulation by hypocretin-1.

The medial preoptic area (mPOA) undergoes through neuroanatomical changes across the postpartum period, during which its neurons play a critical role in the regulation of maternal behavior. In addition, this area is also crucial for sleep-wake regulation. We have previously shown that hypocretins (HCRT) within the mPOA facilitate active maternal behaviors in postpartum rats, while the blockade of endogenous HCRT in this area promotes nursing and sleep. To explore the mechanisms behind these HCRT actions, we aimed to evaluate the effects of juxta-cellular HCRT-1 administration on mPOA neurons in urethane-anesthetized postpartum and virgin female rats. We recorded mPOA single units and the electroencephalogram (EEG) and applied HCRT-1 juxta-cellular by pressure pulses. Our main results show that the electrophysiological characteristics of the mPOA neurons and their relationship with the EEG of postpartum rats did not differ from virgin rats. Additionally, neurons that respond to HCRT-1 had a slower firing rate than those that did not. In addition, administration of HCRT increased the activity in one group of neurons while decreasing it in another, both in postpartum and virgin rats. This study suggests that the mechanisms by which HCRT modulate functions controlled by the mPOA involve different cell populations.

Role of Hypocretin in the Medial Preoptic Area in the Regulation of Sleep, Maternal Behavior and Body Temperature of Lactating Rats.

Hypocretins (HCRT), also known as orexins, includes two neuroexcitatory peptides, HCRT-1 and HCRT-2 (orexin A y B, respectively), synthesized by neurons located in the postero-lateral hypothalamus, whose projections and receptors are widely distributed throughout the brain, including the medial preoptic area (mPOA). HCRT have been associated with a wide range of physiological functions including sleep-wake cycle, maternal behavior and body temperature, all regulated by the mPOA. Previously, we showed that HCRT in the mPOA facilitates certain active maternal behaviors, while the blockade of HCRT-R1 increases the time spent in nursing. As mother rats mainly sleep while they nurse, we hypothesize that HCRT in the mPOA of lactating rats reduce sleep and nursing, while intra-mPOA administration of a dual orexin receptor antagonist (DORA) would cause the opposite effect. Therefore, the aim of this study was to determine the role of HCRT within the mPOA, in the regulation and integration of the sleep-wake cycle, maternal behavior and body temperature of lactating rats. For that purpose, we assessed the sleep-wake states, maternal behavior and body temperature of lactating rats following microinjections of HCRT-1 (100 and 200 µM) and DORA (5 mM) into the mPOA. As expected, our data show that HCRT-1 in mPOA promote wakefulness and a slightly increase in body temperature, whereas DORA increases both NREM and REM sleep together with an increment of nursing and milk ejection. Taken together, our results strongly suggest that the endogenous reduction of HCRT within the mPOA contribute to the promotion of sleep, milk ejection and nursing behavior in lactating rats.

Factores familiares relacionados con habilidades sociales en adolescentes de una institución educativa estatal en Lima / Family factors related to social skills in teenagers of a educational institution in Lima

Objetivo: este estudio analiza los factores familiares relacionados a habilidades sociales en adolescentes de una Institución Educativa Estatal en Lima. Marco teórico: la familia es el elemento natural y fundamental de la sociedad y tiene de-recho a la protección de la sociedad y del Estado, de tal manera, que es el lugar primordial donde se comparten y gestionan los riesgos sociales de sus miembros. Las habilidades sociales constituyen conductas emitidas por un individuo en un contexto interpersonal que expresa sus sentimientos, actitudes, deseos de un modo adecuado a la situación. Material y métodos: estudio de enfoque cuantitativo, correlacional y transversal; la mues-tra fue de 236 adolescentes de una institución educativa estatal en Lima, siendo seleccio-nada mediante muestreo probabilístico aleatorio. Se realizó la recolección de datos a través de la aplicación de cuestionarios que incluyeron al Apgar Familiar y el Test de Habilidades Sociales, el análisis de los datos se efectuó aplicando estadística descriptiva e inferencial a través de Chi cuadrada. Resultados: los factores familiares de los adolescentes son en unos 66% desfavorables y un 34% favorables, como consecuencia de la estructura familiar el 47% son monoparentales, a su vez el 51% tiene disfunción moderada y el 66,00% trato inadecuado. En relación a las habilidades sociales las adolescentes presentan un 32% de nivel promedio, seguida del 20% de promedio bajo, el 18% bajo y 6% muy bajo. Los resultados del análisis correlacional evidencian una relación significativa entre los factores familiares y las habilidades sociales de las adolescentes