Activation of the central but not the medial and cortical amygdala during anticipation for daily nursing in the rabbit.

Rabbits have remarkable nursing behavior: after parturition, does visit daily their pups for nursing only once with circadian periodicity. Before the nursing events, they present increased activity and arousal, which shift according to the timing of scheduled nursing, either during the day or night. Brain areas related to maternal behavior and neuroendocrine cells for milk secretion are also entrained. The daily return of the doe for nursing at approximately the same hour suggests a motivational drive with circadian periodicity. Previously, we reported the activation of the mesolimbic system at the time of nursing, but not 12 h before that. Aiming at a better understanding of the mechanism of this anticipatory behavior, we explored the participation of the limbic regions of the amygdala and the bed nucleus of the stria terminalis, as well as the possible activation of the hypothalamic-pituitaryadrenal axis, specifically the corticotropin-releasing factor cells in the hypothalamic paraventricular nucleus of does at different times before and after nursing. The medial and cortical amygdala, the bed nucleus of the stria terminalis, and corticotropin cells showed activation only after nursing. However, the central amygdala was also activated before nursing. We conclude that the medial and the cortical amygdala form part of the afferent olfactory pathway for entrainment, and the central amygdala participates in the anticipatory motivational circuit of the control of periodic nursing. The lack of activation of corticotropin cells before nursing is consistent with the possible harmful effects of the doe's high glucocorticoid levels on the developing pups.

Oxytocinergic cells of the posterior hypothalamic paraventricular nucleus participate in the food entrained clock.

The mechanisms underlying food anticipatory activity are still poorly understood. Here we explored the role of oxytocin (OT) and the protein c-Fos in the supraoptic nucleus (SON), medial (PVNm) and posterior (PVNp) regions of the paraventricular hypothalamic nucleus. Adult rats were assigned to one of four groups: scheduled restricted feeding (RF), ad libitum (AL), fasting after restricted feeding (RF-F), to explore the possible persistence of oscillations, or ad libitum fasted (AL-F). In the SON and in the PVNm, OT cells were c-Fos positive after food intake; in contrast, OT cells in the PVNp showed c-Fos activation in anticipation to food access, which persisted in RF-F subjects. We conclude that OT and non-OT cells of the SON and PVNm may play a role as recipients of the entraining signal provided by food intake, whereas those of the PVNp which contain motor preautonomic cells that project to peripheral organs, may be involved in the hormonal and metabolic anticipatory changes in preparation for food presentation and thus, may be part of a link between central and peripheral oscillators. In addition, due to their persistent activation they may participate in the neuronal network for the clock mechanism that leads to food entrainment.

Oxytocinergic Cells of the Hypothalamic Paraventricular Nucleus Are Involved in Food Entrainment.

When food is presented at a specific time of day subjects develop intense locomotor behavior before food presentation, termed food anticipatory activity (FAA). Metabolic and hormonal parameters, as well as neural structures also shift their rhythm according to mealtime. Food-entrained activity rhythms are thought to be driven by a distributed system of central and peripheral oscillators sensitive to food cues, but it is not well understood how they are organized for the expression of FAA. The hormone Oxytocin plays an important role in food intake, satiety and homeostatic glucose metabolism and although it is recognized that food is the main cue for food entrainment this hormone has not been implicated in FAA. Here we investigated the activity of oxytocinergic (OTergic) cells of the hypothalamus in relation to the timing of feeding in rabbit pups, a natural model of food entrainment. We found that OTergic cells of the supraoptic nucleus and the main body of the paraventricular nucleus (PVN) are activated after feeding which suggests that OT may be an entraining signal for food synchronization. Moreover, a detailed analysis of the PVN revealed that OTergic cells of the caudal PVN and a subpopulation in the dorsal part of the main body of this nucleus shows activation before the time of food but not 12 h later. Moreover this pattern persists in fasted subjects at the time of the previous scheduled time of nursing. The fact that those OTergic cells of the dorsal and caudal part of the PVN contain preautonomic cells that project to the adrenal, pancreas and liver perhaps may be related to the physiological changes in preparation for food ingestion, and synchronization of peripheral oscillators, which remains to be determined; perhaps they play a main role in the central oscillatory mechanism of FAA as their activity persists in fasted subjects at the time of the next feeding time.

Long-term ovariectomy increases anxiety- and despair-like behaviors associated with lower Fos immunoreactivity in the lateral septal nucleus in rats.

In woman, surgical menopause is associated with anxiety and depression symptoms. Ovariectomy in rats has been proposed as an experimental model of surgical menopause, but its long-term effects on anxiety- and depression-like behaviors and relationship with cellular changes in specific brain structures are unknown. The effects of ovariectomy on anxiety- and despair-like behavior 1, 3, 6, 9, 12, and 15-weeks postovariectomy were evaluated. Fos-immunoreactivity was evaluated in the lateral septal nucleus (LSN). The effects were compared with rats in the proestrus-estrus and metestrus-diestrus phases of the ovarian cycle and with ovariectomized rats that received 17ß-estradiol (OVXE). Three weeks postovariectomy, the rats exhibited an increase in anxiety-like behavior compared with PE and OVXE groups. Decreases in the locomotor activity and time spent grooming and rearing were detected in all the ovariectomized rats. In the forced swim test, the rats exhibited an increase in immobility time 6-weeks postovariectomy compared with control groups. The Fos-immunoreactivity in the LSN was significantly lower in all groups of ovariectomized rats compared with control groups. These findings indicate that rats develop anxiety-like behavior 3-weeks postovariectomy. Six weeks postovariectomy, the rats also developed despair-like behavior, which was associated with a reduction of Fos immunoreactivity in the LSN. Long-term ovariectomy may be considered a useful tool for understanding the development of neurobiological changes associated with surgical menopause. This model may also be useful for evaluating potential anxiolytic and antidepressant effects of diverse substances to ameliorate typical emotional and affective disorders during surgical menopause in women.

Circadian Rhythms and Clock Genes in Reproduction: Insights From Behavior and the Female Rabbit's Brain.

Clock gene oscillations are necessary for a successful pregnancy and parturition, but little is known about their function during lactation, a period demanding from the mother multiple physiological and behavioral adaptations to fulfill the requirements of the offspring. First, we will focus on circadian rhythms and clock genes in reproductive tissues mainly in rodents. Disruption of circadian rhythms or proper rhythmic oscillations of clock genes provoke reproductive problems, as found in clock gene knockout mice. Then, we will focus mainly on the rabbit doe as this mammal nurses the young just once a day with circadian periodicity. This daily event synchronizes the behavior and the activity of specific brain regions critical for reproductive neuroendocrinology and maternal behavior, like the preoptic area. This region shows strong rhythms of the PER1 protein (product of the Per1 clock gene) associated with circadian nursing. Additionally, neuroendocrine cells related to milk production and ejections are also synchronized to daily nursing. A threshold of suckling is necessary to entrain once a day nursing; this process is independent of milk output as even virgin does (behaving maternally following anosmia) can display circadian nursing behavior. A timing motivational mechanism may regulate such behavior as mesolimbic dopaminergic cells are entrained by daily nursing. Finally, we will explore about the clinical importance of circadian rhythms. Indeed, women in chronic shift-work schedules show problems in their menstrual cycles and pregnancies and also have a high risk of preterm delivery, making this an important field of translational research.

Induced cytotoxic damage by exposure to gasoline vapors: a study in Sinaloa, Mexico.

Gasoline is a blend of organic compounds used in internal combustion engines. Gasoline-station attendants are exposed to gasoline vapors, which pose a potentially mutagenic risk. According to the International Agency for Research on Cancer, exposure to gasoline and engine exhaust is possibly carcinogenic to humans. We determined the frequency of micronucleus and other nuclear abnormalities, such as pyknotic nuclei, chromatin condensation, cells with nuclear buds, karyolytic cells, karyorrhexis, and binucleated cells in buccal mucosal smears of 60 gasoline-station attendants and 60 unexposed controls. In addition, we explored if factors such as smoking habits, alcohol consumption, and worked years exert an additional synergistic cytotoxic effect. There were statistically significant higher frequencies (p < 0.05) of nuclear abnormalities among exposed attendants compared to the controls. No statistical significant (p > 0.05) additional effect of lifestyle habits such as smoking and alcohol consumption or worked years on the cytotoxicity was observed. The results showed that from the beginning exposure to gasoline vapors increased the frequency of nuclear abnormalities in buccal epithelial cells. Our results provide valuable information on cytotoxic damage for an early pre-symptomatic diagnosis.

Cytogenetic biomonitoring of occupationally exposed workers to ashes from burning of sugar cane in Ahome, Sinaloa, México.

Burning the sugar cane field before harvesting has a negative impact on both air and human health, however this issue had not been explored in Mexico. The objective of this work was to determine the chromosomal damage in workers from sugar cane burning fields in Sinaloa, México. To this purpose, we analyzed 1000 cells of buccal exfoliated epithelia from 60 exposed workers and 60 non-exposed controls to determine micronucleus frequencies and other nuclear abnormalities. The results indicated significant higher values of micronucleus and nuclear abnormalities such as binucleate cells, pyknosis, karyolysis, chromatin condensation and nuclear buds frequencies in the exposed subjects compared to those that were not exposed. Our data indicates that sugar cane burning, that generates polycyclic aromatic hydrocarbons, represents a genotoxic risk for workers in this important sugar cane producing area in Mexico.

Inverse correlation among organochlorine pesticide levels to total lipid serum contents: a preliminary study in Veracruz, México.

Organochlorine pesticides, due to their hydrophobic nature and persistence, accumulate in tissues rich in lipids, which had been used as a biomarker for environmental pollution. In humans, organochlorine pesticides are continuously circulating and equilibrating among body compartments. The objective of the study was to evaluate the concentrations of organochlorine pesticides in blood serum and compare their levels to the total lipid contents in Veracruz, México inhabitants. Our hypothesis is that concentrations of organochlorine pesticides will increase just as lipid concentrations. Levels of organochlorine pesticides were divided in ascending tertils according to their total lipid content. The linear trend model applied surprisingly reveals that the average level of all organochlorine pesticides decreases as the lipid concentration increases. From one tertil to the next ß-HCH, it shows a decrease of -3.19 mg kg(-1) on lipid basis, pp.'DDE levels decrease by -3.70 mg kg(-1) on lipid basis and pp.'DDT levels decrease -1.13 mg kg(-1) on lipid basis. We conclude that the levels and the orderly sequence of organochlorine pesticide distributions in the blood serum maintain an inverse relationship to total lipid blood serum concentrations.

The median preoptic nucleus exhibits circadian regulation and is involved in food anticipatory activity in rabbit pups.

Rabbit pups are a natural model to study food anticipatory activity (FAA). Recently, we reported that three areas in the forebrain - the organum vasculosum of lamina terminalis, median preoptic nucleus (MnPO) and medial preoptic area - exhibit activation during FAA. Here, we examined the PER1 protein profile of these three forebrain regions in both nursed and fasted subjects. We found robust PER1 oscillations in the MnPO in nursed subjects, with high PER1 levels during FAA that persisted in fasted subjects. In conclusion, our data indicate that periodic nursing is a strong signal for PER1 oscillations in MnPO and future experiments are warranted to explore the specific role of this area in FAA.

Actitudes hacia la conservación del Medio Ambiente de parte de padres de familia, docentes y estudiantes de la zona urbana y rural de Belén 2008 / Rural and urban parents, teachers and student's attitudes towards environment conservation in Belen 2008

El estudio descriptivo comparativo transeccional buscó determinar si existen diferencias significativas en las actitudes hacia la conservación ambiental en docentes, padres de familia y alumnos de educación secundaria del distrito de Belén zona urbana con respecto a los de la rural. Trabajó en una muestra de 773 sujetos, 115 del área rural y 658 del área urbana; tres instituciones educativas del área rural y tres del área urbana. Utilizando la observación indirecta y reactiva como técnica, aplicando una escala tipo Likert de 50 ítems, que luego de ser adpatada a las características y naturaleza de los sujetos se valoraron los componentes cognitivo, reactivo o conductual y afectivo de sus actitudes. Según los resultados los sujetos muestran valores por encima de la media escalar en los tres componentes de las actitudes hacia la conservación ambiental ubicándose mayoritariamente en el nivel de aceptación; los padres de familia y estudiantes rurales alcanzaron puntajes ligeramente más altos que los urbanos; los docentes urbanos obtuvieron la media más alta en comparación con los rurales. Conclusión: existen diferencias estadísticamente significativas entre las actitudes generales y en los componentes reactivo y afectivo hacia la conservación ambiental de docentes urbanos con respecto a los rurales; y en el componente reactivo de los padres de familia rurales con respecto a los urbanos.

The objective of this descriptive transectional research was to find out whether the attitudes towards environment conservation in Belen District's urban area in parents, teachers and students of secondary school was significantly of those in rural area. The reaearch had 773 samples 115 in the rural area and 658 in the urban area, as well as 3 school in rural area and three in the urban area. direct and reactive observation was used as a technique: the contextualized Likert scale of 50 item was adapted to the characteristics and nature of the subjects. The cognitive, reactive and affective attitudes of the samples were valued.According the results, the subjects show values on top of the media in the three components of the attitudes towards environment conservation, which mean a level of acceptation. tehe rural area parents ans students scored slightly higher than those in rural ones. Conclusion: statistical sgnificant differences exist between general attitudes and the reactive and effective components towards environment conservation of urban teachers in comparison to rural ones, and in the reactive component of rural parents in comparison to urban ones.

Identificación y formas de uso de plantas medicinales por los pobladores de las comunidades aledañas a la Facultad de Farmacia y Bioquímica de la UNAP, Nina Rumi, San Juan Bautista / Identification and uses of medicinal plants by the neigbouring

En el departamento de Loreto el uso de especies vegetales en la medicina tradicional es elevado , pero el estudio científico es escaso. Nuestro principal problema es pretender ignorar el uso de plantas medicinales para la recuperación de la salud, ya que no existe un conocimiento de cuáles serían las plantas con poder curativo que vienen siendo utilizadas por las diferentes comunidades principalmente de aquellas que se encuentran cercanas a la Facultad de Farmacia y Bioquímica, por lo que nuestro objetivo es identificar las plantas medicinales y conocer las formas de uso de éstas por los pobladores de las comunidades aledañas al caserío de Nina Rumi. Para ello se realizó un estudio de levantamiento de la información sobre la base de encuestas y luego se procedió a su clasificación botánico-taxonómica, así como a la identificación de sus actividades fármaco-terapéuticas. se aplicaron encuestas a 127 pobladores de las comunidades de Corrientillo (28), Llanchama(25), Nina Rumi(22), Puerto Almendra (22) y Tarapoto (30), quines, en promedio, reportan usar tres plantas medicinales. Las plantas más usadas son la malva, lancetilla, orégano y mucura. Las principales formas de uso son: como extractos y como agua de tiempo. Según los 328 reportes, existen 79 plantas con diferentes usos medicinales, estas pertenecen a 44 familias; asimismo, 55 de ellas son usadas por sus propiedades antipiréticas, 29 por sus propiedades antimuscarínicas, 24 por sus propiedades analgésicas y 24 por sus propiedades antiinflamatorias.

In the Loreto regio the uses of plant species in traditional medicine is very important, at the same time research on the subject is scared. The main problem is ignoring the use of medicinal plants for improving health. there is no knowledge about the plants with curative power being used by communities, in particular those communities which are neighbours of the Faculty of Pharmacy and Biochemistry of the Peruvian Amazon National University. the objective of the research was to identify medicinal plants and learn how the Nina Rumi community uses these plants. Data was gathered using pools and then plants were classified on botanical and taxonomical basis, as well as on the identification of its pharmacy and therapeutically activities. Pools were used on 127 inhabitants of the communities of Corrientillo (28), Llanchama (25), Nina Rumi (22), Puerto Almendra (22) and Tarapoto(30). These communities report the use of three medicinal plants. The plants most used were: malva, lantecilla, oregano and mucura. The most common uses are: extracts and as drinking water. According to the 328 reports, there are 79 plants with different medicinal uses belonging to 44 families. From these, 55 are used for its antiphiretical properties.

Hormonal and metabolic rhythms associated with the daily scheduled nursing in rabbit pups.

Young rabbits are nursed every 24 h for a period of 3-5 min. As a consequence, pups are synchronized to this nursing event; this synchronization is characterized by increased locomotor activity and a peaking of core temperature and plasma corticosterone in anticipation of the daily meal. Ghrelin is a hormone suggested to play a role in meal initiation and to promote food intake. The present study explored the role of ghrelin in food-entrained conditions. Newborn rabbits were maintained in constant darkness and nursed once daily at 1000 by the lactating dam. On postnatal day 7, rabbits were killed at six different time points to complete a 24-h cycle. All pups developed locomotor rhythms entrained by mealtime and exhibited anticipatory activity. Food-entrained rhythms in plasma corticosterone and free fatty acids were observed even if two meals were omitted. In contrast, daily food-driven rhythms in stomach weight, plasma glucose, liver glycogen, and ghrelin did not persist when two meals were omitted. Peak ghrelin levels were observed at the moment in the cycle when the stomach weight was lowest, i.e., before initiation of anticipation. The present data are in agreement with previous data from rabbit pups maintained in light-dark conditions and provide evidence that 7- to 9-day-old rabbits in constant darkness can exhibit metabolic and hormonal rhythms mainly driven by the restricted daily nursing.