Unlocking the role of dorsal hippocampal α4ß2 nicotinic acetylcholine receptors in Ethanol-Induced conditioned place preference in mice.

Alcohol Use Disorder (AUD) presents a significant and challenging public health concern, marked by a dearth of effective pharmacological treatments. Understanding the neurobiological underpinnings of AUD is of paramount importance for the development of efficacious interventions. The process of addiction entails the acquisition of associative behaviors, prominently engaging the dorsal region of the hippocampus for encoding these associative memories. Nicotinic receptor systems have been implicated in mediating the rewarding effects of ethanol, as well as memory and learning processes. In our current investigation, we delved into the role of α4ß2 nicotinic acetylcholine receptors (nAChRs) within the dorsal hippocampus in the context of ethanol-induced conditioned place preference (CPP), a robust model for scrutinizing the rewarding properties and drug-associated behaviors. To establish CPP, ethanol (2 g/kg) was administered intraperitoneally during a 8-day conditioning phase. Fos immunohistochemistry was employed to assess the involvement of discrete subregions within the dorsal hippocampus in ethanol-induced CPP. Additionally, we probed the influence of α4ß2 nAChRs on CPP via microinjections of a selective nAChR antagonist, dihydro-ß-erythroidine (DHBE, at dosages of 6, 12, and 18 µg/0.5 µL per hemisphere) within the hippocampus. Our results unveiled that ethanol-induced CPP was associated with an increase Fos -positive cells in various subregions of the dorsal hippocampus, including CA1, CA2, CA3, and the dentate gyrus. Intrahippocampal administration of DHBE (at doses of 6 and 18 µg/0.50 µL per hemisphere) effectively blocked ethanol-induced CPP, while leaving locomotor activity unaffected. These findings underscore the critical involvement of the dorsal hippocampus and α4ß2 nAChRs in the acquisition of ethanol-associated learning and reward.

Whole bone subcutaneous transplantation as a strategy to study precisely the bone marrow niche.

Hematopoietic stem cells are maintained in a specialized microenvironment, known as the 'niche', within the bone marrow. Understanding the contribution of cellular and molecular components within the bone marrow niche for the maintenance of hematopoietic stem cells is crucial for the success of therapeutic applications. So far, the roles of crucial mechanisms within the bone marrow niche have been explored in transgenic animals in which genetic modifications are ubiquitously introduced in the whole body. The lack of precise tools to explore genetic alterations exclusively within the bone marrow prevents our determination of whether the observed outcomes result from confounding effects from other organs. Here, we developed a new method - 'whole bone subcutaneous transplantation'- to study the bone marrow niche in transgenic animals precisely. Using immunolabeling of CD45.1 (donor) vs. CD45.2 (recipient) hematopoeitic stem cells, we demonstrated that hematopoeitic stem cells from the host animals colonize the subcutaneously transplanted femurs after transplantation, while the hematopoietic stem cells from the donor disappear. Strikinlgy, the bone marrow niche of these subcutaneously transplanted femurs remain from the donor mice, enabling us to study specifically cells of the bone marrow niche using this model. We also showed that genetic ablation of peri-arteriolar cells specifically in donor femurs reduced the numbers of hematopoietic stem cells in these bones. This supports the use of this strategy as a model, in combination with genetic tools, to evaluate how bone marrow niche specific modifications may impact non-modified hematopoietic stem cells. Thus, this approach can be utilized for genetic manipulation in vivo of specific cell types only within the bone marrow. The combination of whole bone subcutaneous transplantation with rodent transgenic models will facilitate a more precise, complex and comprehensive understanding of existing problems in the study of the hematopoietic stem cell bone marrow niche.

Maternal Separation Stress Affects Voluntary Ethanol Intake in a Sex Dependent Manner.

Maternal separation (MS) stress is a predictive animal model for evaluating the effects of early stress exposure on alcohol use disorders (AUD). The extended amygdala (AMY) is a complex circuit involved in both stress- and ethanol-related responses. We hypothesized that MS stress may increase ethanol consumption in adulthood, as well as augment neuronal activity in extended AMY, in a sex-dependent manner. We aimed to investigate the influence of MS stress on the ethanol consumption of male and female mice, and the involvement of extended amygdala sub-nuclei in this process. The C57BL/6J pups were subjected to 180min of MS, from postnatal day (PND) 1 to 14. The control group was left undisturbed. On PND 45, mice (n=28) in cages were exposed to a bottle containing 20% ethanol (w/v) for 4h during the dark period of the light-dark cycle, for 3weeks. Afterward, mice underwent ethanol self-administration training in operant chambers under fixed ratio (FR) schedule. Then, subjects were tested under 2h sessions of a progressive-ratio (PR) schedule of reinforcement (the last ratio achieved was considered the breaking point), and at the end, a 4h session of FR schedule (binge-intake). An immunohistochemistry assay for Fos protein was performed in Nucleus Accumbens (NAcc), Bed Nucleus of Stria Terminalis (BNST), and AMY. Our results showed that in the third week of training, the female MS group consumed more ethanol than the respective control group. The MS group presented increased breakpoint parameters. Female control group and male MS group were more resistant to bitter quinine taste. Increased Fos-immunoreactive neurons (Fos-IR) were observed in the central nucleus of AMY, but not in NAcc nor BNST in male maternal-separated mice. Maternal separation stress may influence ethanol intake in adulthood, and it is dependent on the sex and reinforcement protocol.

CONSUMO DE ÁLCOOL E A INFLUÊNCIA DO EXERCÍCIO FÍSICO NA ATIVIDADE ENZIMÁTICA DE RATOS WISTAR / ALCOHOL CONSUMPTION AND THE INFLUENCE OF PHYSICAL EXERCISE ON ENZYME ACTIVITY OF WISTAR RATS / CONSUMO DE ALCOHOL Y LA INFLUENCIA DEL EJERCICIO FÍSICO EN LA ACTIVIDAD DE LA ENZIMA DE RATAS WISTAR

RESUMO Introdução: Biomarcadores vem sendo utilizados para monitorar o uso do álcool e, atualmente, os mais sensíveis e específicos são enzimas hepáticas, por exemplo, gama glutamiltransferase (GGT), alanina aminotransferase (ALT), aspartato aminotransferase (AST) e fosfatase alcalina (ALP). Objetivo: Verificar, a partir da experimentação animal, as alterações provocadas pelo uso de álcool e pela prática de atividade física nas enzimas hepáticas e pancreáticas. Métodos: Vinte e quatro ratos da linhagem Wistar foram distribuídos aleatoriamente em grupos experimentais, alojados em gaiolas com ambiente controlado, divididos de acordo com os tratamentos recebidos. No tratamento inicial, foi administrado álcool aos grupos álcool sedentário (AS) e álcool exercitado (AE) e, ao final da quarta semana, iniciou-se o programa de treinamento físico em esteira com os grupos AE e controle exercitado (CE). A coleta de sangue foi realizada por punção cardíaca ao final de cada experimento. Na análise estatística, utilizou-se teste de análise de variância (ANOVA) seguido de teste de Tukey e teste de Kruskal-Wallis. Resultados: O grupo AS apresentou valores significativamente mais elevados de ALT e ALP quando comparado aos grupos CE e AE, respectivamente. Não foram observadas diferenças significativas entre os quatro grupos estudados para os parâmetros AST, GGT e amilase. Conclusão: A associação entre consumo de álcool e sedentarismo aumentou a liberação das enzimas ALT e ALP em ratos Wistar; a prática de exercício físico aeróbico após abstinência alcoólica evitou o aumento da liberação de ALP no plasma desses animais.

ABSTRACT Introduction: Biomarkers have been used to monitor the use of alcohol and currently the most sensitive and specific are the liver enzymes, for example, gamma-glutamyl transferase (GGT), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP). Objective: To determine through animal experiments the changes caused by alcohol and the physical activity in liver and pancreatic enzymes. Methods: Twenty-four Wistar rats were randomly assigned into experimental groups, housed in cages with controlled environment, divided according to the treatment received. In the initial treatment, alcohol was administered to sedentary alcohol (SA) and exercised alcohol (EA) groups and at the end of the fourth week the program of physical training on a treadmill began with the AE and control exercised (CE) groups. Blood collection was performed by cardiac puncture at the end of each experiment. For the statistical analysis we used analysis of variance (ANOVA) followed by Tukey test and Kruskal-Wallis test. Results: The AS group had significantly higher values of ALT and ALP when compared to CE and EA groups, respectively. No significant differences were observed between the four groups for the parameters AST, GGT and amylase. Conclusion: The association between alcohol consumption and physical inactivity increased the release of the enzymes ALT and ALP in Wistar rats; the practice of aerobic exercise after alcohol withdrawal prevented the increased release of ALP in the plasma of these animals.

RESUMEN Introducción: Los biomarcadores se han utilizado para controlar el consumo de alcohol y en la actualidad las enzimas hepáticas son las más sensibles y específicas, por ejemplo, gamma glutamil transferasa (GGT), alanina aminotransferasa (ALT), aspartato aminotransferasa (AST) y fosfatasa alcalina (ALP). Objetivo: Determinar, a partir de experimentos con animales, los cambios provocados por el alcohol y la actividad física en las enzimas hepáticas y pancreáticas. Métodos: Veinticuatro ratones Wistar fueron asignados al azar a los grupos experimentales, fueron alojados en jaulas con ambiente controlado, divididos de acuerdo a los tratamientos recibidos. En el tratamiento inicial, el alcohol se administró a los grupos alcohol sedentario (AS) y alcohol ejercicio (AE) y el final de la cuarta semana, se inició el programa de entrenamiento físico en una caminadora con los grupos AE y el control ejercitado (CE). La recogida de sangre se realizó mediante punción cardiaca al final de cada experimento. En el análisis estadístico se utilizó el análisis de varianza (ANOVA), seguido por la prueba de Tukey y la prueba de Kruskal-Wallis. Resultados: El grupo AS tuvo valores significativamente más elevados de ALT y ALP en comparación con los grupos CE y AE, respectivamente. No se observaron diferencias significativas entre los cuatro grupos para los parámetros de AST, GGT y amilasa. Conclusión: La asociación entre el consumo de alcohol y la falta de actividad física aumenta la liberación de las enzimas ALT y ALP en ratones Wistar; la práctica de ejercicio aeróbico después de la retirada del alcohol impidió el aumento de la liberación de ALP en el plasma de estos animales.