Inflammation as common link to progressive neurological diseases.

Life expectancy has increased immensely over the past decades, bringing new challenges to the health systems as advanced age increases the predisposition for many diseases. One of those is the burden of neurologic disorders. While many hypotheses have been placed to explain aging mechanisms, it has been widely accepted that the increasing pro-inflammatory status with advanced age or "inflammaging" is a main determinant of biological aging. Furthermore, inflammaging is at the cornerstone of many age-related diseases and its involvement in neurologic disorders is an exciting hypothesis. Indeed, aging and neurologic disorders development in the elderly seem to share some basic pathways that fundamentally converge on inflammation. Peripheral inflammation significantly influences brain function and contributes to the development of neurological disorders, including Alzheimer's disease, Parkinson's disease, and multiple sclerosis. Understanding the role of inflammation in the pathogenesis of progressive neurological diseases is of crucial importance for developing effective treatments and interventions that can slow down or prevent disease progression, therefore, decreasing its social and economic burden.

A Clinically Relevant Dosage of Mitoxantrone Disrupts the Glutathione and Lipid Metabolic Pathways of the CD-1 Mice Brain: A Metabolomics Study.

Long-term cognitive dysfunction, or "chemobrain", has been observed in cancer patients treated with chemotherapy. Mitoxantrone (MTX) is a topoisomerase II inhibitor that binds and intercalates with DNA, being used in the treatment of several cancers and multiple sclerosis. Although MTX can induce chemobrain, its neurotoxic mechanisms are poorly studied. This work aimed to identify the adverse outcome pathways (AOPs) activated in the brain upon the use of a clinically relevant cumulative dose of MTX. Three-month-old male CD-1 mice were given a biweekly intraperitoneal administration of MTX over the course of three weeks until reaching a total cumulative dose of 6 mg/kg. Controls were given sterile saline in the same schedule. Two weeks after the last administration, the mice were euthanized and their brains removed. The left brain hemisphere was used for targeted profiling of the metabolism of glutathione and the right hemisphere for an untargeted metabolomics approach. The obtained results revealed that MTX treatment reduced the availability of cysteine (Cys), cysteinylglycine (CysGly), and reduced glutathione (GSH) suggesting that MTX disrupts glutathione metabolism. The untargeted approach revealed metabolic circuits of phosphatidylethanolamine, catecholamines, unsaturated fatty acids biosynthesis, and glycerolipids as relevant players in AOPs of MTX in our in vivo model. As far as we know, our study was the first to perform such a broad profiling study on pathways that could put patients given MTX at risk of cognitive deficits.

A Semi-Automatic Method for the Quantification of Astrocyte Number and Branching in Bulk Immunohistochemistry Images.

Immunohistochemical staining of cell and molecular targets in brain samples is a powerful tool that can provide valuable information on neurological mechanisms. However, post-processing of photomicrographs acquired after 3,3'-Diaminobenzidine (DAB) staining is particularly challenging due to the complexity associated with the size, samples number, analyzed targets, image quality, and even the subjectivity inherent to the analysis by different users. Conventionally, this analysis relies on the manual quantification of distinct parameters (e.g., the number and size of cells and the number and length of cell branching) in a large set of images. These represent extremely time-consuming and complex tasks, defaulting the processing of high amounts of information. Here we describe an improved semi-automatic method to quantify glial fibrillary acidic protein (GFAP)-labelled astrocytes in immunohistochemistry images of rat brains, at magnifications as low as 20×. This method is a straightforward adaptation of the Young & Morrison method, using ImageJ's plugin Skeletonize, coupled with intuitive data processing in datasheet-based software. It allows swifter and more efficient post-processing of brain tissue samples, regarding astrocyte size and number quantification, the total area occupied, as well as astrocyte branching and branch length (indicators of astrocyte activation), thus contributing to better understand the possible inflammatory response developed by astrocytes.

Long-Term Tamoxifen Effects in the Cyclic Interaction of the Endocannabinoid and Endocrine System in the Rat Central Nervous System.

Steroid hormones can modulate the endocannabinoid system (ECS). Within the female reproductive tract, estrogen increases the expression of the cannabinoid receptors CB1 and CB2, and modifies the levels of anandamide (AEA), the major endocannabinoid, by altering the expression of both AEA synthesis (NAPE-PLD) and catabolic enzymes (FAAH). Here, we addressed the mechanisms involved in ECS fluctuations within the central nervous system and evaluated the effects of tamoxifen (TAM), a selective estrogen receptor modulator, in central AEA regulation. The current results suggest that the hypothalamic and pituitary AEA levels change differently according to the brain area and phase of the estrous cycle. In TAM-treated rats, there is a disruption of the cyclic fluctuation and reduction of the AEA levels in all brain areas. In the pituitary gland, NAPE-PLD expression increases in the metestrus phase, whereas throughout the rat cycle their expression remained constant, even upon TAM treatment. The fluctuations of pituitary AEA levels result from altered FAAH and NAPE-LPD expression. In contrast, no differences in FAAH or NAPE-PLD hypothalamic expression were observed. Overall, this study presents a broad view of the distribution and expression of ECS elements in the central nervous system and a way to suggest possible brain areas involved in the interaction of the endocannabinoid and neuroendocrine systems to induce several behavioral responses.

Structural, functional and behavioral impact of allergic rhinitis on olfactory pathway and prefrontal cortex.

BACKGROUND: Allergic rhinitis (AR) has been identified as a cause of olfactory dysfunction. Beyond the classic symptoms, AR has been associated with altered sleep patterns, a decline in cognitive performance and higher likelihood of depression and anxiety. The olfactory pathway has been postulated to be a possible link between nasal inflammation and central nervous system (CNS) modifications. Thus, we aimed to investigate the structural, functional and behavioral changes in the olfactory pathway and related areas in an animal model of AR. METHODS: AR was induced in adult Wistar rats by ovalbumin sensitization and challenge. Following olfactory and behavioral tests we investigated the synaptic structure of the olfactory bulb (OB), anterior olfactory nuclei (AON), piriform cortex and prefrontal cortex (PFC), by immunofluorescence detection of synaptophysin (Syn) and glutamatergic, GABAergic and dopaminergic neuronal markers. RESULTS: We detected a significant decrease in Syn in the glomerular layer (GL) of OB and in the PFC of the AR group. Additionally, the optical density of GAD67 and VGLUT2 was reduced in the OB, AON and PFC, compared to controls. The behavioral tests demonstrated olfactory dysfunction and reduced male aggressiveness in AR rats, but we did not find any difference in the cognition and anxiety-like behavior. CONCLUSIONS: We confirmed olfactory dysfunction in a rat model of AR and we identified modifications in synaptic activity by reduction of Syn optical density in the GL of the OB and in the PFC. This was accompanied by structural changes in glutamatergic and GABAergic activity in essential components of the olfactory pathway and PFC.

The effects of delta-9-tetrahydrocannabinol administration in the regulation of female rat sociosexual behaviour.

By targeting the endocannabinoid system, delta-9-tetrahydrocannabinol (THC) modulates female motivated behaviours, influenced by sex hormones. Both medial preoptic nucleus (MPN) and ventromedial nucleus of the hypothalamus (VMN) are involved in the modulation of female sexual responses. The first triggers proceptivity, whereas the ventrolateral division of the latter (VMNvl) triggers receptivity. These nuclei are modulated by glutamate, which inhibits female receptivity, and GABA, which has a dichotomous action in female sexual motivation. Here, we evaluated the action of THC on the modulation of social and sexual behaviours, on signalling pathways of MPN and VMNvl and how sex hormones influence these parameters. Young ovariectomized female rats, given sex hormones (oestradiol benzoate, EB, and progesterone, P) and THC were used for behavioural testing and for immunofluorescence analyses of vesicular glutamate transporter 2 (VGlut2) and GAD (glutamic acid decarboxylase)67 expression. Results showed that females given EB + P exhibited a higher preference for male partner, as well as higher proceptivity and a higher receptivity than control or females given only EB. Females treated with THC presented similar responses in control or EB + P female rats and even more facilitated behavioural responses in EB females than the ones that did not receive THC. Immunofluorescence results in the MPN exhibited a decreased expression of GAD67 and VGlut2 in EB + THC-treated female rats. Within VMNvl of EB-primed rats no changes in the expression of both proteins were observed after THC exposure. This study demonstrates how the possible outcomes of endocannabinoid system instability within hypothalamic neuron connectivity can modify female rat sociosexual behaviour.

Unhealthy Diets Induce Distinct and Regional Effects on Intestinal Inflammatory Signalling Pathways and Long-Lasting Metabolic Dysfunction in Rats.

The intestinal epithelium is a principal site for environmental agents' detection. Several inflammation- and stress-related signalling pathways have been identified as key players in these processes. However, it is still unclear how the chronic intake of inadequate nutrients triggers inflammatory signalling pathways in different intestinal regions. We aimed to evaluate the impact of unhealthy dietary patterns, starting at a younger age, and the association with metabolic dysfunction, intestinal inflammatory response, and obesity in adulthood. A rat model was used to evaluate the effects of the consumption of sugary beverages (HSD) and a Western diet (WD), composed of ultra-processed foods. Both diets showed a positive correlation with adiposity index, but a positive correlation was found between the HSD diet and the levels of blood glucose and triglycerides, whereas the WD diet correlated positively with triglyceride levels. Moreover, a distinct inflammatory response was associated with either the WD or HSD diets. The WD induced an increase in TLR2, TLR4, and nuclear factor-kappa B (NF-κB) intestinal gene expression, with higher levels in the colon and overexpression of the inducible nitric oxide synthase. In turn, the HSD diet induced activation of the TLR2-mediated NF-κB signalling pathway in the small intestine. Altogether, these findings support the concept that early intake of unhealthy foods and nutrients are a main exogenous signal for disturbances of intestinal immune mechanisms and in a region-specific manner, ultimately leading to obesity-related disorders in later life.

Early unhealthy eating habits underlie morpho-functional changes in the liver and adipose tissue in male rats.

Early-life consumption of high-fat and sugar-rich foods is recognized as a major contributor for the onset of metabolic dysfunction and its related disorders, including diabetes and nonalcoholic fatty liver disease. The lifelong impact of early unhealthy eating habits that start at younger ages remains unclear. Therefore, to better understand the effects of diet, it is essential to evaluate the structural and functional changes induced in metabolic organs and potential mechanisms underlying those changes. To investigate the long-term effects of eating habits, young male rats were exposed to high-sugar and high-energy diets. After 14 weeks, body composition was assessed, and histopathological changes were analyzed in the liver and adipose tissue. Serum biochemical parameters were also determined. Expression of inflammatory markers in the liver was evaluated by immunohistochemistry. Our results revealed that serum levels of glucose, creatinine, aspartate transaminase (AST), alanine transaminase (ALT), and lipid profile were increased in rats red high-sugar and high-energy diets. Histopathological alterations were observed, including abnormal hepatocyte organization and lipid droplet accumulation in the liver, and abnormal structure of adipocytes. In both unhealthy diet groups, hepatic expression of Toll-like receptor 4 (TLR4), cyclooxygenase 2 (COX-2), and E-selectin were increased, as well as a biomarker of oxidative stress. Together, our data demonstrated that unhealthy diets induced functional and structural changes in the metabolic organs, suggesting that proinflammatory and oxidative stress mechanisms trigger the hepatic alterations and metabolic dysfunction.

Chemobrain: mitoxantrone-induced oxidative stress, apoptotic and autophagic neuronal death in adult CD-1 mice.

Mitoxantrone (MTX) is a topoisomerase II inhibitor used to treat a wide range of tumors and multiple sclerosis but associated with potential neurotoxic effects mediated by hitherto poorly understood mechanisms. In adult male CD-1 mice, the underlying neurotoxic pathways of a clinically relevant cumulative dose of 6 mg/kg MTX was evaluated after biweekly administration for 3 weeks and sacrifice 1 week after the last administration was undertaken. Oxidative stress, neuronal damage, apoptosis, and autophagy were analyzed in whole brain, while coronal brain sections were used for a closer look in the hippocampal formation (HF) and the prefrontal cortex (PFC), as these areas have been signaled out as the most affected in 'chemobrain'. In the whole brain, MTX-induced redox imbalance shown as increased endothelial nitric oxide synthase and reduced manganese superoxide dismutase expression, as well as a tendency to a decrease in glutathione levels. MTX also caused diminished ATP synthase ß expression, increased autophagic protein LC3 II and tended to decrease p62 expression. Postsynaptic density protein 95 expression decreased in the whole brain, while hyperphosphorylation of Tau was seen in PFC. A reduction in volume was observed in the dentate gyrus (DG) and CA1 region of the HF, while GFAP-ir astrocytes increased in all regions of the HF except in the DG. Apoptotic marker Bax increased in the PFC and in the CA3 region, whereas p53 decreased in all brain areas evaluated. MTX causes damage in the brain of adult CD-1 mice in a clinically relevant cumulative dose in areas involved in memory and cognition.

Four decades of chemotherapy-induced cognitive dysfunction: comprehensive review of clinical, animal and in vitro studies, and insights of key initiating events.

Cognitive dysfunction has been one of the most reported and studied adverse effects of cancer treatment, but, for many years, it was overlooked by the medical community. Nevertheless, the medical and scientific communities have now recognized that the cognitive deficits caused by chemotherapy have a strong impact on the morbidity of cancer treated patients. In fact, chemotherapy-induced cognitive dysfunction or 'chemobrain'  (also named also chemofog) is at present a well-recognized effect of chemotherapy that could affect up to 78% of treated patients. Nonetheless, its underlying neurotoxic mechanism is still not fully elucidated. Therefore, this work aimed to provide a comprehensive review using PubMed as a database to assess the studies published on the field and, therefore, highlight the clinical manifestations of chemobrain and the putative neurotoxicity mechanisms.In the last two decades, a great number of papers was published on the topic, mainly with clinical observations. Chemotherapy-treated patients showed that the cognitive domains most often impaired were verbal memory, psychomotor function, visual memory, visuospatial and verbal learning, memory function and attention. Chemotherapy alters the brain's metabolism, white and grey matter and functional connectivity of brain areas. Several mechanisms have been proposed to cause chemobrain but increase of proinflammatory cytokines with oxidative stress seem more relevant, not excluding the action on neurotransmission and cellular death or impaired hippocampal neurogenesis. The interplay between these mechanisms and susceptible factors makes the clinical management of chemobrain even more difficult. New studies, mainly referring to the underlying mechanisms of chemobrain and protective measures, are important in the future, as it is expected that chemobrain will have more clinical impact in the coming years, since the number of cancer survivors is steadily increasing.

Panic-like responses of female Wistar rats confronted by Bothrops alternatus pit vipers, or exposure to acute hypoxia: Effect of oestrous cycle.

Anxiety-related diseases are more than twice as common in women than in men, and in women, symptoms may be exacerbated during the late luteal phase of the menstrual cycle. Despite this, most research into the underlying mechanisms, which drives drug development, have been carried out using male animals. In an effort to redress this imbalance, we compared responses of male and female Wistar rats during exposure to two unconditioned threatening stimuli that evoke panic-related defensive behaviours: confrontation with a predator (Bothrops alternatus) and acute exposure to hypoxia (7% O2 ). Threatened by venomous snake, male and female rats initially displayed defensive attention, risk assessment, and cautious interaction with the snake, progressing to defensive immobility to overt escape. Both males and females displayed higher levels of risk assessment but less interaction with the predator. They also spent more time in the burrow, displaying inhibitory avoidance, and more time engaged in defensive attention, and non-oriented escape behaviour. In females, anxiety-like behaviour was most pronounced in the oestrous and proestrus phases whereas panic-like behaviour was more pronounced during the dioestrus phase, particularly during late dioestrus. Acute hypoxia evoked panic-like behaviour (undirected jumping) in both sexes, but in females, responsiveness in late dioestrus was significantly greater than at other stages of the cycle. The results reveal that females respond in a qualitatively similar manner to males during exposure to naturally occurring threatening stimuli, but the responses of females is oestrous cycle dependent with a significant exacerbation of panic-like behaviour in the late dioestrus phase.

Effects of chronic tamoxifen treatment in female rat sexual behaviour.

The medial preoptic (MPN) and the ventromedial hypothalamic nuclei (VMN) modulate the estrogen receptor (ER)-dependent female sexual behavior, a response that is inhibited by tamoxifen (TAM), a modulator of the steroid receptor activation. With the objective to assess TAM action in the brain areas involved in the modulation sexual cues, an animal model on long-term TAM therapy to intact female rats, was used to mimic the 5-year prophylactic TAM therapy offered to women at higher risk of breast cancer. After three months treatment, female sexual behavior with a stud male rat was evaluated. Upon sacrifice, the brains were removed and the MPN and the ventrolateral division of the VMN were screened for the effects of TAM in the expression of ERα, ERß and progesterone receptor. Results show that TAM inhibited the receptive component of the female sexual behavior. Even though TAM decreased estrogen and progesterone levels to values similar to the ones of estrous and diestrus rats, the biochemical data failed to demonstrate such possible causation for the behavioral response. In fact, TAM administration induced a constant low level of ovarian hormones that changed the pattern of ER and PR expression as well as receptor co-expression in the brain areas regulating the behavioral response, dissimilar to the ones seen in the cycle phases with the same low hormone levels. Nevertheless, present data suggests that by affecting ER- and/or PR-dependent mechanisms, TAM may modulate the hypothalamus, a region known to participate in several social behaviors.

Tracing Poly(Vinyl Acetate) Emulsions by Infrared and Raman Spectroscopies: Identification of Spectral Markers.

Vinyl emulsions started to be used by artists in paintings at least since the early 1960s, being now present in several artworks worldwide. However, different vinyl formulations can result in distinct behaviours over time, and if some artworks are currently showing a good condition, others already show damages due to the use of compositions more susceptible to degradation. For this reason, it is fundamental to identify the main components in the vinyl acetate-based (VAc-based) emulsion. This work focuses on the molecular study of VAc-based emulsions by infrared and Raman spectroscopies. It aims at deepening the knowledge on the variability of the composite formulation and on the identification of characteristic bands and spectral profiles (identified as spectral markers) for both polymer and additives. To this end, a broad set of vinyl emulsions was gathered, including reference materials, historical commercial brands in use by Portuguese artists, and commercial brands collected from industrial companies. The entire set includes vinyl homopolymers produced for the purpose of the study and known formulations of vinyl homopolymers and copolymers, with and without plasticisers, according to technical data sheets and previous studies. Furthermore, unknown formulations have been included to validate the usefulness of the identified spectral markers. This set has been studied in the form of solid films deposited in glass slides by infrared spectroscopy in attenuated total reflection mode (ATR-FTIR) and micro-Raman spectroscopy (µ-Raman), both conducted in situ. As conclusions, the combined use of ATR-FTIR and µ-Raman proved to be very useful as different spectral markers were detected by each technique, confirming their complementarity. Besides the clear identification of vinyl acetate-based emulsions by both techniques, it was also possible to suggest spectral markers for the copolymerisation of vinyl acetate with vinyl versatate by µ-Raman, the stabilisation of the emulsion with poly(vinyl alcohol) by ATR-FTIR, and the addition of phthalates or benzoates plasticisers by both ATR-FTIR and µ-Raman.

Behavioral and brain morphological analysis of non-inflammatory and inflammatory rat models of preterm brain injury.

Investigations using preclinical models of preterm birth have much contributed, together with human neuropathological studies, for advances in our understanding of preterm brain injury. Here, we evaluated whether the neurodevelopmental and behavioral consequences of preterm birth induced by a non-inflammatory model of preterm birth using mifepristone would differ from those after inflammatory prenatal transient hypoxia-ischemia (TSHI) model. Pregnant Wistar rats were either injected with mifepristone, and pups were delivered on embryonic day 21 (ED21 group), or laparotomized on the 18th day of gestation for 60 min of uterine arteries occlusion. Rat pups were tested postnatally for characterization of developmental milestones and, after weaning, they were behaviorally tested for anxiety and for spatial learning and memory. One month later, brains were processed for quantification of doublecortin (DCX)- and neuropeptide Y (NPY)-immunoreactive cells, and cholinergic varicosities in the hippocampus. ED21 rats did not differ from controls with respect to neonatal developmental milestones, anxiety, learning and memory functions, and neurochemical parameters. Conversely, in TSHI rats the development of neonatal reflexes was delayed, the levels of anxiety were reduced, and spatial learning and memory was impaired; in the hippocampus, the total number of DCX and NPY cells was increased, and the density of cholinergic varicosities was reduced. With these results we suggest that a preterm birth, in a non-inflammatory prenatal environment, does not significantly change neonatal development and adult neurologic outcome. On other hand, prenatal hypoxia and ischemia (inflammation) modifies developmental trajectory, learning and memory, neurogenesis, and NPY GABAergic and cholinergic brain systems.

Gut Microbiome Composition and Metabolic Status Are Differently Affected by Early Exposure to Unhealthy Diets in a Rat Model.

Childhood is a critical stage of development during which diet can have profound influence on the microbiota-host interactions, leading to potentially lifelong impacts. This study aimed to investigate whether the consumption of cafeteria diet (CAFD) and sugary drinks during early rat life alters the structure of the gut microbial community and the metabolic activity. Four-week-old male Wistar rats (n = 27) were fed a standard chow diet with ad libitum access to water (CD) or to sucrose solution (HSD), and a third group was fed with CAFD and a sucrose solution for 14 weeks. HSD and CAFD consumption induced alterations in Firmicutes to Bacteroidetes ratio, Proteobacteria, and Verrucomicrobia. HSD increased the abundance of Barnesiella, whereas CAFD induced a depletion of Saccharibacteria. CAFD increased total white adipose tissue (WAT) weight (p < 0.0005) compared to CD. When CAFD was compared to HSD, a significant difference was found only for retroperitoneal WAT (p < 0.0005). Unhealthy diet-fed groups presented higher glucose (p < 0.0005), total cholesterol and creatinine serum levels (p < 0.005) compared to the CD rats. Early-life consumption of HSD, and of CAFD even more so, can have long-lasting negative effects on metabolic function. The gut microbiota communities were distinctively perturbed by diet composition.

Application of Infrared Reflectance Spectroscopy on Plastics in Cultural Heritage Collections: A Comparative Assessment of Two Portable Mid-Fourier Transform Infrared Reflection Devices.

Plastics have been increasingly used to create modern and contemporary art and design, and nowadays, museum collections hold numerous objects completely or partially made of plastics. However, the preservation of these materials is still a challenging task in heritage conservation, especially because some plastics show signs of degradation shortly after their production. In addition, different degradation mechanisms can often take place depending on the plastic composition and appropriate environmental and packaging conditions should be adopted. Therefore, methods for in situ and rapid characterization of plastic artifacts' composition are greatly needed to outline proper conservation strategies. Infrared (IR) spectroscopy, such as attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR), is a well-established method for polymeric material analysis. However, ATR FT-IR requires an intimate contact with the object, which makes its application less appropriate for the in situ investigation of fragile or brittle degraded plastic objects. Mid-FT-IR reflectance spectroscopy may represent a valid alternative as it allows in situ measurements with minimum or even no contact, and IR data can be acquired rapidly. On the other hand, spectral interpretation of reflectance spectra is usually difficult as IR bands may appear distorted with significant changes in band maximum, shape, and relative intensity, depending on the optical properties and surface texture of the material analyzed. Presently, mid-FT-IR reflection devices working in external reflection (ER FT-IR) and diffuse reflection infrared Fourier transform spectroscopy (DRIFTS) modes have been used in cultural heritage research studies. As the collected vibrational information depends on the optical layout of the measuring system, differences between ER FT-IR and DRIFT spectra are thus expected when the same polymer is analyzed. So far, ER FT-IR and DRIFT spectroscopy have been individually explored for the identification of plastic objects, but comparative studies between the application of two reflectance FT-IR modes have not been presented yet. In this work, the use of two portable FT-IR spectrometers equipped with ER FT-IR and DRIFTS modes were compared for plastics identification purposes for the first time. Both references of polymeric materials and historical plastic objects (from a Portuguese private collection) were studied and the differences between ER FT-IR and DRIFT spectra were discussed. The spectra features were examined considering the two different optical geometries and analytes' properties. This new insight can support a better understanding of both vibrational information acquired and practical aspects in the application of the ER FT-IR and DRIFTS in plastic analysis.

Effects of ovariectomy on the inputs from the medial nucleus of the amygdala to the ventromedial nucleus of the hypothalamus in young adult rats.

During puberty, sexual hormones induce crucial changes in neural circuit organization, leading to significant sexual dimorphism in adult behaviours. The ventrolateral division of the ventromedial nucleus of the hypothalamus (VMHvl) is the major neural site controlling the receptive component of female sexual behaviour, which is dependent on ovarian hormones. The inputs to the VMHvl, originating from the medial nucleus of the amygdala (MeA), transmit essential information to trigger such behaviour. In this study, we investigated the projection pattern of the MeA to the VMHvl in ovariectomized rats at early puberty. Six-week-old Sprague-Dawley rats were ovariectomized (OVX) and, upon reaching 90 days of age, were subjected to iontophoretic injections of the neuronal anterograde tracer Phaseolus vulgaris leucoagglutinin into the MeA. Projections from the MeA to the VMHvl and to other structures included in the neural circuit responsible for female sexual behaviour were analysed in the Control and OVX groups. The results of the semi-quantitative analysis showed that peripubertal ovariectomy reduced the density of intra-amygdalar fibres. The stereological estimates, however, failed to find changes in the organization of the terminal fields of nerve fibres from the MeA to the VMHvl in the adult. The present data show that ovariectomized rats during the peripubertal phase did not undergo significant changes in MeA fibres reaching the VMHvl; however, they suggest a possible effect of ovariectomy on MeA connectivity under amygdalar subnuclei.

Effects of ovariectomy on inputs from the medial preoptic area to the ventromedial nucleus of the hypothalamus of young adult rats.

Puberty is an important phase of development when the neural circuit organization is transformed by sexual hormones, inducing sexual dimorphism in adult behavioural responses. The principal brain area responsible for the control of the receptive component of female sexual behaviour is the ventrolateral division of the ventromedial nucleus of the hypothalamus (VMHvl), which is known for its dependency on ovarian hormones. Inputs to the VMHvl originating from the medial preoptic nucleus (MPN) are responsible for conveying essential information that will trigger such behaviour. Here, we investigated the pattern of the projection of the MPN to the VMHvl in rats ovariectomized at the onset of puberty. Sprague Dawley rats were ovariectomized (OVX) at puberty and then subjected to iontophoretic injections of the neuronal anterograde tracer Phaseolus vulgaris leucoagglutinin into the MPN once they reached 90 days of age. This study analysed the connectivity pattern established between the MPN and the VMH that is involved in the neuronal circuit responsible for female sexual behaviour in control and OVX rats. The data show the changes in the organization of the connections observed in the OVX adult rats that displayed a reduced axonal length for the MPN fibres reaching the VMHvl, suggesting that peripubertal ovarian hormones are relevant to the organization of MPN connections with structures involved in the promotion of female sexual behaviour.

A first approach into the characterisation of historical plastic objects by in situ diffuse reflection infrared Fourier transform (DRIFT) spectroscopy.

This research explores the potential of a portable instrumentation of diffuse reflection infrared Fourier transform (DRIFT) spectroscopy for the in situ characterisation of plastics cultural objects. As sampling has been increasingly questioned in the conservation field, the development of portable devices has been sought. Among them, infrared (IR) spectroscopy in reflection mode has been gaining a powerful position in conservation research. Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) has been widely used for plastics, yet the strong contact required by the technique can make it inappropriate for flexible and/or fragile historic objects. Therefore, in this study, the potential of in situ DRIFT spectroscopy is assessed on both references and historical objects made of the same polymers - polyethylene (PE), polypropylene (PP) and polystyrene (PS). Plastic samples showing different characteristics such as refractive and absorption indexes and topography are also included. These different polymers and surface qualities are discussed as factors influencing the final spectra. In situ DRIFT proved to be very versatile as it could be applied in a variety of plastics and objects' shapes, does not require sampling nor an intimate contact as ATR. Moreover, specific bands and spectral profiles were identified as DRIFT markers of the polymers under study. The acquisition conditions for the in situ analysis were optimized and a pilot spectral database using different IR modes (transmission, ATR and DR) was created. Important information was collected, which allowed the polymer identification of the majority of the historical objects produced between the 1940s and 1980s, from a Portuguese private collection.

Hepatic effects of long-term tamoxifen administration to cycling female rats.

The metabolic implications of tamoxifen (TAM) used as preventive therapy of young premenopausal women with high risk of breast cancer is unknown. To unravel this problem, an animal model of long-term TAM administration to cycling young adult female rats was used to evaluate its effects in the liver. Body weight and food consumption were monitored, and at the end of the study, both parameters were lower in TAM-treated rats. Biochemical measurements showed that the TAM administration induced alterations in serum levels of liver enzymes when compared with control rats at different stages of the estrous cycle. In TAM-treated rats, lower glycogen storage was observed in hepatocytes close to the portal areas and pericentrolobular cells had a higher concentration of glycogen. Liver sections of TAM-treated rats presented mild steatosis-a high percentage of area occupied by lipid droplets in the hepatocytes. These results point to metabolic changes upon long-term TAM therapy.