Time-place learning is altered by perinatal low-protein malnutrition in the adult rat.

Malnutrition produces changes in the central nervous system (CNS) of mammals during development, related to the intensity and timing of the malnutrition insult during the pre- or postnatal period. Protein malnutrition produces irreversible changes in hippocampal formation and some brain stem nuclei. The suprachiasmatic nucleus (SCN) is dramatically altered by low-protein diets during the gestational and perinatal periods. Also, it is known that circadian oscillators regulate physiological, behavioral, and cognitive processes and there is evidence that the time-place learning process exhibits a daily temporal distribution. The aim of this study was to determine the effects of chronic, prenatal, or postnatal malnutrition on daily patterns of the time-place learning process in the adult rat. Forty Sprague-Dawley male 90-day-old rats, were divided into four groups: 10 well nourished controls (Co), 10 chronically (CM), 10 prenatally malnourished (PrM), and 10 postnatally malnourished (PtM) rats. Efficiency in time-place learning was tested by using a behavioral T-maze. Each rat was assayed for 10 trials before considering the final probe of efficiency. Each trial was 60 seconds long, final efficiency was measured by the amount of time the rat took to reach the end of an arm containing a water pot. Each rat was tested in 2-hour spans until completion of a full 24-hour cycle. A Cosinor analysis was used to evaluate acrophase and percentage of rhythmicity. The obtained results suggest that time-place learning process is influenced by the circadian clock. The severity and timing of prenatal or chronic protein malnutrition modifies the acrophase and rhythmicity of the learning circadian pattern, which can impact important cognitive functions.

Protein malnutrition and aging affects entraining and intensity of locomotor activity and body temperature circadian rhythms in rats.

Independently, chronic protein malnutrition and aging have been shown to affect locomotor activity (LA) and body temperature (BT) rhythms in mammals. The objective of the present study was to ascertain the combined effects of these two factors by examining period, entrainment and other circadian parameters between LA and BT rhythms. Chronic protein malnourished (PM) and well-nourished (WN) male Sprague-Dawley rats (550-590 days of age) were implanted with activity temperature intraperitoneal radio transmitters (Mini Mitter) and exposed to different lighting protocols during at least 10 days - light-dark cycles (LD 12:12), constant darkness (DD), skeleton photoperiod (SP) and again LD. Results indicate that parametric entrainment, achieved by means of complete photoperiod, is not negatively affected in malnourished rats; however, it is affected under non-parametric entrainment like SP. A different free running period between the LA and BT circadian rhythms was detected for well-nourished and malnourished aged rats.

Prenatal malnutrition and sleep states in adult rats: effects of restraint stress.

Independently, prenatal malnutrition and psychological/physical stress have been shown to affect sleep architecture in adult rats. As malnutrition and stress commonly co-exist in malnourished human populations, the objective of the present study was to ascertain the combined effects of these two insults by examining sleep-wake parameters following a brief restraint stress in prenatally protein malnourished rats. The male offspring of rats provided with a protein deficient diet (6% casein) for 5 weeks prior to mating and throughout pregnancy were implanted with recording electrodes beginning at postnatal day 90. Polygraph recordings were obtained to quantify sleep states during the first 4 h of the dark phase of the cycle on 2 consecutive days. The first followed a 24-h habituation session to the recording chamber (baseline). The second occurred at the same time of day but followed 20 min of restraint stress in a Plexiglas tube. During baseline, prenatally malnourished rats spent more time in rapid eye movement sleep (REMS) in the first 2 h after "lights off" (block 1), and greater amounts of wakefulness (W) with a corresponding reduction in slow wave sleep (SWS) in the second two hours (block 2), as compared with controls. Following stress, the sleep architecture of both groups of rats remained unaltered in block 1 relative to their baseline day. In block 2, both groups exhibited significant reductions in SWS and REMS with significantly greater reductions being expressed in the prenatally malnourished group (most dramatically, REMS was completely eliminated). These findings suggest that sleep disturbances may be more severe in those malnourished human populations subjected to acutely stressful experiences.

Intervención educativa para elevar el nivel de conocimiento sobre hipertensión arterial en adolescentes / Educational intervention to raise the level of knowledge on arterial hypertension in adolescents

RESUMEN Introducción: la hipertensión arterial del adulto tiene sus inicios en la niñez, por lo que la percepción de riesgo debe aumentar en las edades pediátricas. Objetivo: elevar el nivel de conocimiento sobre hipertensión arterial en adolescentes de la Escuela Secundaria Básica Antonio Rodríguez, del municipio Colón, provincia de Matanzas. Materiales y métodos: se realizó un estudio de intervención educativa en 80 estudiantes de 8vo grado, en el período de febrero de 2017 a junio de 2018. Se aplicó un cuestionario para medir percepción de riesgo de enfermar, conocimientos sobre factores de riesgo y síntomas de hipertensión arterial antes y después de la intervención. Se crearon cuatro grupos de 20 adolescentes, que tuvieron una sesión semanal durante 6 semanas. Se desarrollaron seis temas relacionados con la enfermedad, en los que se utilizaron técnicas participativas de educación para la salud. Resultados: el 96,1 % de los adolescentes no percibían el riesgo de enfermar de hipertensión arterial antes de la intervención. Luego de esta, la percepción de riesgo se presentó en el 65,4 %. Un 43,6 % de los participantes desconocían los factores de riesgo, y el 69,2 % no conocían los síntomas. Después de la intervención, el 73 % de la muestra tenían un conocimiento parcial sobre los factores de riesgo; el 57,7 % conocían los síntomas, y el 37,2 % los conocían parcialmente. Conclusiones: la intervención educativa sobre hipertensión arterial contribuyó a elevar los conocimientos y la percepción de riesgo en los adolescentes. Se aportaron elementos para modificar estilos de vida poco saludables (AU).

ABSTRACT Introduction: the adults' arterial hypertension begins in childhood, therefore the risk perception must increase in pediatric ages. Objective: to raise knowledge level on arterial hypertension in adolescents from the high school Antonio Rodriguez, municipality of Colon, province of Matanzas. Materials and methods: an educational interventional study was carried out in 80 8th-grade students, in the period from February 2017 to June 2018. A survey was applied to measure risk perception of developing the disease, knowledge on risk factors and symptoms of arterial hypertension before and after intervention. Four groups of 20 teenagers were created, having a weekly session during six weeks. Six themes related to the disease were developed, using different participatory techniques of health education. Results: 96.1% of adolescents did not perceive the risk of developing hypertension before the intervention. After it, risk perception was present in 65.4% of them. 43.6% of participants did not know the risk factors, and 69.2 % did not know the symptoms. After the intervention, 73% of the sample had partial knowledge on risk factors; 57.7% knew the symptoms, and 37.2% knew them partially. Conclusions: the educational intervention on arterial hypertension contributed to raise knowledge and risk perception in adolescents. Elements were given to modify unhealthy lifestyles (AU).

Changes in sleep-waking cycle after striatal excitotoxic lesions.

Huntington's disease (HD) patients show severe diurnal choreic movements, while during slow-wave sleep (SWS) abnormal movements subside. Sleep disturbances in HD, including irregular delta activity and decreases in SWS, have also been reported. Striatal excitotoxic lesions have been shown to induce increased nocturnal spontaneous locomotor activity in rodents. In order to characterize the changes in circadian activity and sleep patterns and their correlation with motor activity after striatal excitotoxic lesions, Sprague-Dawley rats were implanted and lesioned; their locomotor and EEG activities were recorded for either 4 or 24 h during baseline or 7 and 30 days post-lesion. Locomotor activity increased significantly at 7 days post-lesion during the dark phase of the light-dark cycle. In contrast, total time spent in wakefulness (W) increased at 30 days post-lesion during the light phase of the cycle. This increase was at the expense of SWS duration. No disruption of the circadian curves was observed. Increases in the number of W-bouts and decreases in the duration of SWS-bouts were also observed. These results suggest the possible participation of the striatum in the regulation of the sleep-waking cycle, independent of locomotor activity. The increase in W could be due to loss of inhibition of target structures involved in regulation of the sleep-waking cycle.

Prenatal protein malnutrition decreases mossy fibers-CA3 thorny excrescences asymmetrical synapses in adult rats.

Prenatal protein malnutrition has deleterious effects on hippocampal structure and function that likely result from decreased synapse number. We thus evaluated long-term effects of prenatal protein malnutrition on the mossy fibers-CA3 thorny excrescences asymmetrical synapses in 220-day-old rats. Protein malnourished rats born from pregnant dams fed with 6% casein diet were cross-fostered to lactating control rats at birth. Control animals were fed with a 25% casein diet. Timm's stained material was used to estimate the total reference volume of the mossy fiber system suprapyramidal bundle by means of stereology. The mossy fiber-CA3 asymmetrical synapse numerical density was obtained by electron microscopy, using the physical disector method. The total number of mossy fiber-CA3 asymmetrical synapses was determined on the basis of the total reference volume of the mossy fiber system suprapyramidal bundle and the mossy fiber-CA3 asymmetrical synapse numerical density. Prenatal protein malnutrition produced long-lasting, significant decreases in the volume of the mossy fiber system suprapyramidal bundle and in the numerical density of mossy fiber-CA3 asymmetrical synapse, suggesting a reduction in the total number of this synapse type. Hence, prenatal protein malnutrition induces long lasting deleterious effects on the progression of developmental programs controlling synaptogenesis and/or synaptic consolidation, likely by affecting a myriad of cellular processes.

Protein malnutrition differentially alters the number of glutamic acid decarboxylase-67 interneurons in dentate gyrus and CA1-3 subfields of the dorsal hippocampus.

In 30- and 90-day-old rats, using immunohistochemistry for glutamic acid decarboxylase 67 (GAD-67), we have tested whether malnutrition during different periods of hippocampal development produces deleterious effects on the population of GABA neurons in the dentate gyrus (DG) and cornu Ammonis (CA1-3) of the dorsal hippocampus. Animals were under one of four nutritional conditions: well-nourished controls (Con), prenatal protein malnourished (PreM), postnatal protein malnourished (PostM), and chronic protein malnourished (ChroM). We found that the number of GAD-67-positive (GAD-67+) interneurons was higher in the DG than in the CA1-3 areas of both Con and malnourished groups. Regarding the DG, the number of GAD-67+ interneurons was increased in PreM and PostM and decreased in ChroM at 30 days. At 90 days of age the number of GAD-67+ interneurons was increased in PostM and ChroM and remained unchanged in PreM. With respect to CA1-3, the number of labeled interneurons was decreased in PostM and ChroM at 30 days of age, but no change was found in PreM. At 90 days no changes in the number of these interneurons were found in any of the groups. These observations suggest that 1) the cell death program starting point is delayed in DG GAD-67+ interneurons, and 2) protein malnutrition differentially affects GAD-67+ interneuron development throughout the dorsal hippocampus. Thus, these changes in the number of GAD-67+ interneurons may partly explain the alterations in modulation of dentate granule cell excitability, as well as in the emotional, motivational, and memory disturbances commonly observed in malnourished rats.

Circadian rhythm of sleep in normal and undernourished rats

El propósito del presente trabajo fue investigar el efecto que produce la desnutrición proteínoca crónica instalada pre y posnatalmente en la rata sobre los diferentes estados de vigilancia: vigilia (VIG), sueño de ondas lentas (SOL) y sueño de movimientos oculares rápidos (MOR) y su ritmicidad circádica. Para el estudio se emplearon animales de 60,120 y 220 días de edad y se sometieron a un ciclo de 12h luz y 12 h oscuridad (LD 12:12) durante un periodo control de 4 días y a oscuridad cocntinua (00) durante un período experimental de 8 días. La desnutrición proteínica crónica, no produjo cambios significativos en el valor del período de los ciclos de los estados de vigilancia, lo cual está de acuerdo con la idea bien establecida de que los ritmos circadianos suelen variar muy poco aante múltiples cambios ambientales. En general, los valores promedio de la amplitud del ritmo circádico de los estados de vigilancia fueron mayores en los animales desnutridos que en los animales normales. Asimismo fueron mayores en los días de fotoperiodo que en los días de oscuridad continua. La acrofase de los estados de vigilancia de los animales desnutridos presentó mayores retardos en los días de oscuridad continua, que en los días de fotoperiodo. al medir la relación del SOL y del sueño MOR, entre los períodos de actividad (alfa) y de reposo (p), relación alfa/p, durante los días de oscuridad constante y del fotoperiodo se encontraron diferencias significativas en esta relación entre ambos estados por edad. El análisis del patrón de cada estado de vigilancia, reveló que la amplitud de cada uno de ello surante los momentos de cambio, alcanza su valor máximo o mínimo en un tiempo menor en los animales desnutridos que en los normales, lo que sugiere que éstos últimos se anticpan a dichos cambios, aum cuando tardan más en llegar a su nuevo estado de vigilancia que los desnutridos

Anatomical study of the parrakeet (Aratinga canalicularis)

De estudios recientes sobre la organización del telencéfalo de las aves se sabe que esta estructura tiene muchas similitudes cocn el cerebro de los mamíferos. Tambíen se conoce que la porción del hiperestriado dorsal conocida como la wulst así cocmo la porción lateral, identificada como el lado ventricular dorsal, tiene un papel importante en la integración sensorial, el aprendizaje y la producción del canto en las aves. Aunque ambas estructuras no poseen laminación como la de la neocorteza de los mamíferos, sin embargp, ciertas aves como el búho muestran una clara pseudolaminación. En la literatura no hay descripciones anatómicas de la wulst en preicos, por lo que el objetivo del presente trabajo fue estudiar esta estructura en la ewpecie. Aratinga canicularis. Se identificaron tres tipos celulares y, mediante métodos morfométricos efectuados en un total de 240 células por cada estrato, se midieron 10 parámetros distintos y se distinguieron tres estratos, a los que se les denominó dorsal, medial y ventral. Cada uno de los tres tipos celulares presentaron características específicas. Las células multipolares y triangulares mostraron un patrón dendrítico ramificado y abundantes espinas dendríticas. Las triangulares difieron en cuanto a la extensión de sus dendritas y la ramificación de su axón en ángulos rectos dirigidos hacia el estrato suprayacente. Las células ovoides fueron las mas pequeñas con pocas ramas y espinas. Estas células son similares a las del hiperestriatum accesorio del buho, las que a su vez son análogas a las células granulares de la corteza visual de los mamíferos