Neonatal inhibition of androgen activity alters the programming of body weight and orexinergic peptides differentially in male and female rats.

The involvement of androgens in the regulation of energy metabolism has been demonstrated. The main objective of the present research was to study the involvement of androgens in both the programming of energy metabolism and the regulatory peptides associated with feeding. For this purpose, androgen receptors and the main metabolic pathways of testosterone were inhibited during the first five days of postnatal life in male and female Wistar rats. Pups received a daily s.c. injection from the day of birth, postnatal day (P) 1, to P5 of Flutamide (a competitive inhibitor of androgen receptors), Letrozole (an aromatase inhibitor), Finasteride (a 5-alpha-reductase inhibitor) or vehicle. Body weight, food intake and fat pads were measured. Moreover, hypothalamic Agouti-related peptide (AgRP), neuropeptide Y (NPY), orexin, and proopiomelanocortin (POMC) were analyzed by quantitative real-time polymerase chain reaction assay. The inhibition of androgenic activity during the first five days of life produced a significant decrease in body weight in females at P90 but did not affect this parameter in males. Moreover, the inhibition of aromatase decreased hypothalamic AgRP mRNA levels in males while the inhibition of 5α-reductase decreased hypothalamic AgRP and orexin mRNA levels in female rats. Finally, food intake and visceral fat, but not subcutaneous fat, were affected in both males and females depending on which testosterone metabolic pathway was inhibited. Our results highlight the differential involvement of androgens in the programming of energy metabolism as well as the AgRP and orexin systems during development in male and female rats.

Genistein early in life modifies the arcuate nucleus of the hypothalamus morphology differentially in male and female rats.

In the present work we analyzed the effects of postnatal exposure to two doses of genistein (10 µg/g or 50 µg/g) from postnatal (P) day 6 to P13, on the morphology of the arcuate nucleus (Arc). The analyses of Arc coronal brain sections at 90 days showed that the ArcMP had higher values in volume, Nissl-stained neurons and GPER-ir neurons in males than in females and the treatment with genistein abolished these sex differences in most of the parameters studied. Moreover, in males, but not in females, the GPER-ir neurons decreased in the ArcMP but increased in the ArcL with both doses of genistein. In the ArcLP, GPER-ir population increased with the lowest doses and decreased with the highest one in males. Our results confirm that the Arc subdivisions have differential vulnerability to the effects of genistein during development, depending on which neuromorphological parameters, dose and sex are analyzed.

Activity-based anorexia alters hypothalamic POMC and orexin populations in male rats.

The objective of this study was to investigate the orexin and POMC populations in the hypothalamic nuclei of male Wistar rats after the activity-based anorexia (ABA) procedure. Four groups were established based on food restriction and activity: activity (A), ABA, diet (D) and control (C). The ABA protocol consisted of free access to a running wheel for a period of 22 h and access to food for 1 h. When the animals in the ABA group reached the ABA criterion, were sacrificed, and their brains were collected and serially sectioned. The free-floating sections were processed for orexin and POMC immunostaining. The number of orexin A-ir cells in the perifornical-dorsomedial-hypothalamus continuum (PFD) and lateral hypothalamus (LH) and the number of POMC-ir cells in the arcuate nucleus (Arc) were estimated. Data on food intake, body weight and wheel turns were also analyzed. The ABA procedure caused a significant decrease in body weight along with a significant increase in activity. Moreover, at the end of the ABA procedure, the number of POMC-ir cells decreased in the Arc in the A group, and significantly more in the ABA group, and the number of orexin A-ir positive cells decreased in the LH in D and ABA groups. The differential decrease in POMC in the ABA group emphasizes the importance of the melanocortin system in the maintenance of ABA, but more research is needed to elucidate the involvement of this peptide in the mechanism that promotes and maintains anorexia nervosa and how increased activity may interact with all these processes.

G Protein-Coupled Estrogen Receptor Immunoreactivity in the Rat Hypothalamus Is Widely Distributed in Neurons, Astrocytes, and Oligodendrocytes, Fluctuates during the Estrous Cycle, and Is Sexually Dimorphic.

INTRODUCTION: The membrane-associated G protein-coupled estrogen receptor 1 (GPER) mediates the regulation by estradiol of arginine-vasopressin immunoreactivity in the supraoptic and paraventricular hypothalamic nuclei of female rats and is involved in the estrogenic control of hypothalamic regulated functions, such as food intake, sexual receptivity, and lordosis behavior. OBJECTIVE: To assess GPER distribution in the rat hypothalamus. METHODS: GPER immunoreactivity was assessed in different anatomical subdivisions of five selected hypothalamic regions of young adult male and cycling female rats: the arcuate nucleus, the lateral hypothalamus, the paraventricular nucleus, the supraoptic nucleus, and the ventromedial hypothalamic nucleus. GPER immunoreactivity was colocalized with NeuN as a marker of mature neurons, GFAP as a marker of astrocytes, and CC1 as a marker of mature oligodendrocytes. RESULTS: GPER immunoreactivity was detected in hypothalamic neurons, astrocytes, and oligodendrocytes. Sex and regional differences and changes during the estrous cycle were detected in the total number of GPER-immunoreactive cells and in the proportion of neurons, astrocytes, and oligodendrocytes that were GPER-immunoreactive. CONCLUSIONS: These findings suggest that estrogenic regulation of hypothalamic function through GPER may be different in males and females and may fluctuate during the estrous cycle in females.

Blocking of Estradiol Receptors ERα, ERß and GPER During Development, Differentially Alters Energy Metabolism in Male and Female Rats.

Estradiol not only participates in the regulation of energy metabolism in adulthood, but also during the first stages of life as it modulates the alterations induced by under- and over-nutrition. The objectives of the present study were to determine: 1) If estradiol is involved in the normal programming of energy metabolism in rats; 2) If there is a specific window of time for this programming and 3) If males and females are differentially vulnerable to the action of this hormone. Estrogen receptors (ER) α, ERß and GPER were blocked by their specific antagonists MPP, PHTPP and G15, respectively, from postnatal day (P) 1 (the day of birth) to P5 or from P5 to P13. Physiological parameters such as body weight, fat depots and caloric intake were then analysed at P90. Hypothalamic AgRP, POMC, MC4R, ERα, ERß and GPER mRNA levels and plasma levels of estradiol, were also studied. We found that blocking ER receptors from P5 to P13 significantly decreases long-term body weight in males and hypothalamic POMC mRNA levels in females. The blocking of ERs from P1 to P5 only affected plasma estradiol levels in females. The present results indicate programming actions of estradiol from P5 to P13 on body weight in male and POMC expression in female rats and emphasize the importance of including both sexes in metabolic studies. It is necessary to unravel the mechanisms that underlie the actions of estradiol on food intake, both during development and in adulthood, and to determine how this programming differentially takes place in males and females.

Estrogen receptor beta and G protein-coupled estrogen receptor 1 are involved in the acute estrogenic regulation of arginine-vasopressin immunoreactive levels in the supraoptic and paraventricular hypothalamic nuclei of female rats.

The ovarian hormone 17ß-estradiol is known to regulate the release, expression and immunoreactivity of arginine-vasopressin (AVP) in the supraoptic and paraventricular hypothalamic nuclei of rodents. Previous studies have shown that estrogen receptor α is involved in the effects of chronic estradiol administration on arginine-vasopressin immunoreactivity in the female rat hypothalamus. In this study we have examined the effect of an acute administration of estradiol or specific agonists for estrogen receptors α, ß and G protein-coupled estrogen receptor 1 on the immunoreactivity of arginine-vasopressin in the hypothalamus of adult ovariectomized female rats. Acute estradiol administration resulted in a significant decrease in the number of arginine-vasopressin immunoreactive neurons in the supraoptic and paraventricular nuclei after 24 h. The effects of the specific estrogen receptors agonists suggest that the action of estradiol on arginine-vasopressin immunoreactivity is mediated in the supraoptic nucleus by G protein-coupled estrogen receptor 1 and in the paraventricular nucleus by both estrogen receptor ß and G protein-coupled estrogen receptor 1. Thus, in contrast to previous studies on the effect of chronic estrogenic treatments, the present findings suggest that estrogen receptor ß and G protein-coupled estrogen receptor 1 mediate the acute effects of estradiol on arginine-vasopressin immunoreactivity in the hypothalamus of ovariectomized rats.

Physiological and brain alterations produced by high-fat diet in male and female rats can be modulated by increased levels of estradiol during critical periods of development.

BACKGROUND: Overnutrition due to a high-fat diet (HFD) can increase the vulnerability of the metabolic system to maladjustments. Estradiol has an inhibitory role on food intake and this hormone has demonstrated to be a crucial organizer during brain development. OBJECTIVE: Our aim was to determine whether increased levels of estradiol in the early postnatal period modulate the alterations in metabolism and brain metabolic circuits produced by overnutrition. METHODS: Twenty-four male and 24 female Wistar rats were submitted to a HFD (34.9% fat) or a control diet (5% fat) from gestational day 6. From postnatal (P) 6 to P13, both control and HFD groups were administered a s.c. injection of vehicle or estradiol benzoate (0.4 mg/kg), resulting in eight experimental groups (n = 6 in each group). Body weight, food intake and subcutaneous, visceral, and brown fat pads were measured. Agouti-related peptide, neuropeptide Y, orexin, and proopiomelanocortin (POMC) were analyzed by quantitative real-time polymerase chain reaction assay and plasma estradiol levels were measured by ELISA. RESULTS: Males fed a HFD showed an increase in body weight and the amount of visceral and subcutaneous fat, which was coincident with an increase in the number of kilocalories ingested. Neonatal estradiol treatment restored the body weight and subcutaneous fat of HFD males to control levels. Hypothalamic POMC mRNA levels in HFD females were increased with respect to control females. This increase was reverted with estradiol treatment during development. DISCUSSION: HFD and estradiol treatment have different effects on males and females. Overnutrition affects physiological parameters, such as body weight, visceral, and subcutaneous fat content, in males, while females present alterations in hypothalamic POMC mRNA levels. Hence, the increase in estradiol levels during a period that is critical for the programing of the feeding system can modulate some of the alterations produced by the continuous intake of high-fat content food.

The Psychoexposome: A holistic perspective beyond health and disease / Psicoexposoma: una perspectiva holística más allá de la salud y la enfermedad

Background: The concept of the exposome has emerged as a new strategy for studying all environmental exposures throughout an individual’s life and their impact on human health. Nowadays, electronic devices are available to collect data about an individual’s geolocation, biological function, or exposure biomarkers. The appearance of "omic" sciences and advances in bioinformatics have allowed massive data-gathering and analysis from various scientific fields. Objective: to propose the term Psychoexposome in line with the concept of the exposome from the field of environmental sciences. Method: a literature review of psychological terms associated with the exposome concept was carried out and the rationale and benefits of a psychoexposme approach for psychological sciences is discussed. Results: the terms psychology, psychiatry and neurological diseases are scarce in the exposome approach. A long tradition in psychology of performing epidemiological studies and in the study of multifactorial influences traits places psychologists at an advantageous starting point for conducting psychoexposome studies. Conclusion: psychology may take advantage from both exposome and omic sciences to create an integrated psychoexposome approach that may help in deciphering the etiology of psychological disorders and improving people's mental health (AU)

Antecedentes: el concepto de exposoma surgió como una estrategia para impulsar el estudio exhaustivo de las exposiciones ambientales a lo largo de la vida del individuo y su impacto en la salud. El desarrollo de dispositivos electrónicos para obtener datos de geolocalización, biológicos o biomarcadores de exposición y los avances en las ciencias "ómicas" y en bioinformática permiten la recopilación y el análisis masivo de datos muy diversos. Objetivo: proponer el término psicoexposoma en línea con el concepto de exposoma generado desde las ciencias ambientales. Método: se llevó a cabo una revisión de la literatura para buscar la inclusión de términos psicológicos asociados al concepto de exposoma. Se discute la justificación de un enfoque de psicoexposición para las ciencias psicológicas. Resultados: los términos psicología, psiquiatría o enfermedades neurológicas son escasos en el enfoque del exposoma. La experiencia en el control de variables ambientales sitúa al psicólogo en un punto de partida ventajoso para realizar estudios de psicoexposoma. Conclusión: la psicología puede aprovechar tanto las ciencias de la exposición como las ciencias "ómicas" para crear un enfoque integrado de psicoexposición que pueda ayudar a descifrar la etiología de los trastornos psicológicos y a promover la salud mental del individuo (AU)

The Psychoexposome: A holistic perspective beyond health and disease.

BACKGROUND: The concept of the exposome has emerged as a new strategy for studying all environmental exposures throughout an individual’s life and their impact on human health. Nowadays, electronic devices are available to collect data about an individual’s geolocation, biological function, or exposure biomarkers. The appearance of “omic” sciences and advances in bioinformatics have allowed massive data-gathering and analysis from various scientific fields. OBJECTIVE: to propose the term Psychoexposome in line with the concept of the exposome from the field of environmental sciences. METHOD: a literature review of psychological terms associated with the exposome concept was carried out and the rationale and benefits of a psychoexposme approach for psychological sciences is discussed. RESULTS: the terms psychology, psychiatry and neurological diseases are scarce in the exposome approach. A long tradition in psychology of performing epidemiological studies and in the study of multifactorial influences traits places psychologists at an advantageous starting point for conducting psychoexposome studies. CONCLUSION: psychology may take advantage from both exposome and omic sciences to create an integrated psychoexposome approach that may help in deciphering the etiology of psychological disorders and improving people’s mental health.