Azucena Begega

Azucena Begega
University of Oviedo | UNIOVI · Department of Psychology

PhD

About

87
Publications
7,734
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1,207
Citations
Citations since 2017
13 Research Items
536 Citations
2017201820192020202120222023020406080100
2017201820192020202120222023020406080100
2017201820192020202120222023020406080100
2017201820192020202120222023020406080100
Introduction
Currently , our group studies the relationship between stress and resilience cerebral mechanisms in adult and aged rats. For this objetive, we used different behavioural tests , for example: sucrose preference test, zero maze and sustained attention. Then, the cerebral networks are analized with the multivariate statistical techniques. These techniques shown us the functional cerebral networks , and the different functional profiles of the resilient vs vulnerable subjects.
Additional affiliations
September 1994 - present
University of Oviedo
Position
  • Professor (Full)

Publications

Publications (87)
Article
Our aim was to assess the cognitive and emotional state, as well as related-changes in the glucocorticoid receptor (GR), the corticotropin-releasing factor (CRF) and the brain-derived neurotrophic factor (BDNF) expression of adolescent C57BL/6J male mice after a five-week two-bottle choice protocol (postnatal day (pd) 21 to pd52). Additionally, we...
Article
Feeding behavior is a complex experience that involves not only sensory (i.e., visual, odor, taste, or texture) but also affective or emotional aspects (i.e., pleasure, palatability, or hedonic value) of foods. As such, behavioral tests that assess the hedonic impact of foods are necessary to fully understand the factors involved in ingestive behav...
Chapter
Throughout our lifes we are exposed to different stressors that can make us more vulnerable to suffer from mental disorders, such as depression or anxiety. However, resilient individuals are characterized by their ability to achieve a positive outcome when they are in the face of adversity. Interestingly, both clinical and pre-clinical studies have...
Article
Full-text available
Exposure to environmental enrichment (EE) has been a useful model for studying the effects of experience on brain plasticity, but to date, few is known about the impact of this condition on the brain functional networks that probably underlies the multiple behavioural improvements. Hence, we assessed the effect of an EE protocol in adult Wistar rat...
Article
Full-text available
Our brain has this extraordinary ability to experience functional and structural changes before environmental stimuli, cognitive demand, or our experience itself. Exercise, diet, an appropriate sleep pattern, and reading habits are among those activities proposed to induce effects on cerebral architecture - an active lifestyle seems to induce chang...
Article
Background: Resilience is the ability to achieve a positive outcome when we are in the face of adversity. It supposes an active resistance to adversity by coping mechanisms in which genetic, molecular, neural and environmental factors are involved. Resilience has been usually studied in early ages and few is known about it during aging. Methods:...
Article
Full-text available
Environmental enrichment (EE) is an experimental setting broadly used for investigating the effects of complex social, cognitive, and sensorimotor stimulations on brain structure and function. Recent studies point out that parental EE experience, even occurring in the pre-reproductive phase, affects neural development and behavioral trajectories of...
Article
Environmental enrichment (EE) is an experimental setting broadly used for investigating the effects of complex social, cognitive, and sensorimotor stimulations on brain structure and function. Recent studies point out that parental EE experience, even occurring in the pre-reproductive phase, affects neural development and behavioral trajectories of...
Article
The present study examined c-Fos expression in selected brain areas consequent to intraperitoneal (IP) administration of saccharin and lithium chloride. Rats were tested for aversion to the saccharin as measured by flavor consumption and orofacial reactions in the taste reactivity (TR) test. It was found that intraperitoneal conditioning resulted i...
Chapter
It is well documented that ageing is accompanied by a decline in cognitive functions such as, memory, attention, and speed of information processing. Different nonpharmacological approaches have been proposed for the purpose of promoting health, such as, mental training, mediterranean diet, and physical exercise. This is because their benefits on b...
Article
The present experiment examined the neuronal networks involved in the latent inhibition of conditioned disgust by measuring brain oxidative metabolism. Rats were given nonreinforced intraoral (IO) exposure to saccharin (exposed groups) or water (non-exposed groups) followed by a conditioning trial in which the animals received an infusion of saccha...
Article
The use of more ethological animal models to study the neurobiology of anxiety has increased in recent years. We assessed the effect of an Environmental enrichment (EE) protocol (24h/day over a period of two months) on anxiety-related behaviors when aged Wistar rats (21 months old) were confronted with cat odor stimuli. Owing to the relationship be...
Article
Background: In recent decades, the interest in behavioral interventions has been growing due to the higher prevalence of age-related cognitive impairments. Hence, behavioral interventions, such as cognitive stimulation and physical activity, and along with these, our lifestyle (education level, work position, frequency of cognitive and social acti...
Article
Our study examined how different housing conditions modulated the acquisition of a spatial reference memory task and also, a reversal task in the 4-radial arm water maze (4-RAWM). The animals were randomly assigned to standard or enriched cages, and, as a type of complementary stimulation along with the environmental enrichment (EE), a group of rat...
Article
Spatial orientation is an essential ability, which has shown to decline with aging. Although several researches have focused on the different orientation behaviors and perspectives, few of them have examined the acquisition of multiple paths at the same time. The current study was designed with the intention of investigating age differences in mult...
Article
We have studied the performance of a spatial reference memory task, the navigation strategy and the changes in the cytochrome c oxidase activity (COx) in different brain regions in exercised (forced exercise, 10 consecutive days, 15 min/day) and non-exercised adult Wistar rats. The spatial learning task was carried out in the radial-arm water maze...
Article
Our aim was to assess the changes in the Synapsin I and glucocorticoid receptor (GR) expression induced by behavioral testing in the dorsal and ventral hippocampi of standard and enriched aged Wistar rats. The environmental enrichment (EE) was carried out 3h/day over a period of two months and then, the rats were tested in the elevated zero-maze (E...
Article
Currently, little is known about the effect of environmental enrichment (EE) on astrocytic plasticity, especially during aging. Given the newly discovered role of the astrocytes in regulating the synaptic transmission and thereby, the cognitive functions, we aimed to study the impact of EE on the performance in a spatial memory task and on the numb...
Article
Environmental enrichment (EE) produces a remarkable degree of structural and functional plasticity in the hippocampus and possible mediators of these changes, such as glucocorticoid receptors (GRs), are of considerable interest. GRs are richly expressed in the hippocampus and they are involved in the adaptation to stressors and facilitate active co...
Article
Full-text available
En las últimas décadas se han desarrollado varias estrategias farmacológicas para prevenir el declive cognitivo en el envejecimiento, sin embargo la inefectividad de la mayoría de ellas ha hecho que las intervenciones conductuales estén recibiendo cada vez más atención. La estimulación cognitiva y la actividad física han mostrado importantes benefi...
Article
Mild cognitive impairment is understood as a cognitive deficit of insufficient severity to fulfil the criteria for Alzheimer's disease. Many studies have attempted to identify which cognitive functions are most affected by this type of impairment and which is the most sensitive neuropsychological test for early detection. This study investigated su...
Article
Full-text available
Mild cognitive impairment is understood as a cognitive deficit of insufficient severity to fulfil the criteria for Alzheimer’s disease. Many studies have attempted to identify which cognitive functions are most affected by this type of impairment and which is the most sensitive neuropsychological test for early detection. This study investigated su...
Article
Full-text available
In recent decades, several pharmacological strategies have been developed to prevent age-related cognitive impairment. However, the ineffectiveness of the majority of these strategies has led to growing interest in behavioural intervention. Cognitive stimulation and physical activity have been shown to provide significant benefits by counteracting...
Article
We have studied the effect of an environmental enrichment (EE) protocol in adult Wistar rats on the activity in the elevated zero-maze (EZM), performance in the radial-arm water maze (RAWM) and we have also examined the changes in the neuronal metabolic activity of several brain regions related to anxiety response and spatial memory through cytochr...
Article
We assessed the effect of 3 hours of EE exposure per day started at different ages (3 and 18 months old) on the performance in a spatial memory task and on brain regions involved in the spatial learning process using the Principal Component Analysis (PCA). The animals were tested in the four-arm radial water maze (4-RAWM) for 4 days, with 6 daily t...
Article
Currently, little is known about the effect of environmental enrichment (EE) on astrocytic plasticity, especially during aging. Given the newly discovered role of the astrocytes in regulating the synaptic transmission and thereby, the cognitive functions, we aimed to study the impact of EE on the performance in a spatial memory task and on the numb...
Article
We have studied the effects of exercise in aged rats (18 months-old) on spatial learning and changes in neuronal metabolic activity associated with exercise program and the spatial learning process. The changes on neuronal oxidative metabolic activity was studied through cytochrome c oxidase histochemistry (COx) in brain regions related to spatial...
Article
The involvement of different brain regions in place- and response-learning was examined using a water cross-maze. Rats were trained to find the goal from the initial arm by turning left at the choice point (egocentric strategy) or by using environmental cues (allocentric strategy). Although different strategies were required, the same maze and lear...
Article
Our aim was to assess the way that middle-aged rats solve spatial learning tasks that can be performed using different strategies. We assessed the brain networks involved in these spatial learning processes using Principal Component Analysis. Two tasks were performed in a complex context, a four-arm radial maze, in which each group must use either...
Article
Full-text available
The aim of this study was to assess various cognitive abilities such as attention, IQ, reasoning, and memory related to academic achievement in 8- and 9-year-old preterm children. A total of 141 children were assessed. The preterm group (=37 weeks) comprised 63 children and was compared to 78 full-term children. Attention was evaluated using the d2...
Article
The oxidative metabolism was assessed in the hippocampus and related regions in rats that were trained in a spatial short-term memory task in the water maze following distinct training schedules. The cytochrome oxidase (COx) histochemistry was evaluated in groups of rats that received a daily session made up of either two or three learning trials....
Article
Full-text available
Patients with liver dysfunction often suffer from hepatic encephalopathy (HE), a neurological complication that affects attention and memory. Various experimental animal models have been used to study HE, the most frequently used being the portocaval shunt (PCS). In order to determine brain substrates of cognitive impairment in this model, we asses...
Article
Portal hypertension is a major complication of cirrhosis that frequently leads to a neuropsychiatric disorder that affects cognition. We compared the performance of 18-month-old prehepatic portal hypertensive rats (PH) and 18-month-old normal rats (CO) in spatial short-term and reference memory tasks in the Morris water maze and in active avoidance...
Article
The medial prefrontal cortex has been associated with fear, anxiety and stress regulation, and has recently been suggested to play a crucial role in the development of behavioural changes in response to stress. In this study, we evaluated medial prefrontal cortex (mPFC) involvement in both anxiety-like behaviour and increased anxiety-like responses...
Article
The aim of our study was to examine the supramammillary (SuM) area involvement in spatial memory. Sprague-Dawley rats with chronically implanted cannula in the supramammillary area were trained in two spatial memory tasks with different memory demands: reference and working memory. In the spatial reference memory task, the rats received microinject...
Article
Full-text available
The psychometric properties of the d2 Selective Attention Test are analyzed in two samples of premature ( n = 63) and born-at-term ( n = 78) children. The reliability coefficients (internal consistency) reached values of around .90. Principal components analysis revealed a three-factor structure, which accounts for 58% of the variance, and thus coi...
Article
Hippocampal and striatal systems are widely related to spatial tasks. Depending on the strategies used, different memory systems can be activated. In this study, the authors used the cytochrome c-oxidase technique as a functional marker of the hippocampal and dorsal striatum activity related to training in several water maze tasks. Current results...
Article
Long-term memories seem to require protein synthesis to be established. This process can be related with synaptogenesis resulting in changes in the form or even in the number or proportion of synaptic contacts. Results from behavioral studies assessing quantitative changes associated with different learning tasks are controversial. The aim of our w...
Article
The sexual differences in cerebral nuclei are produced by the organizational and the activational function of gonadal hormones. The different performances by male and female rats in memory tasks requiring use of the mammillary bodies (MBs), could be due to structural and functional sexual dimorphic differences. Our work quantifies the number of gli...
Article
The present study assesses the involvement of the supramammillary and adjacent nuclei in spatial memory and anxiety-like behaviors. Rats with electrolytic lesions in the supramammillary nucleus were pre- and post-operatively trained in two spatial memory tasks and two anxiety tasks. Spatial memory tasks were performed in an open field with seven di...
Article
Full-text available
Metabolismo cerebral tras el entrenamiento prolongado en una tarea de condicionamiento del miedo. El condicionamiento Pavloviano del miedo (CPM) es uno de los paradigmas conductuales más usados para estudiar la neurobiología del aprendizaje y la memoria. Se entrenaron ratas en una tarea de supresión condicionada, que recibieron tres (entrenamiento...
Article
The effects of classical fear conditioning in different regions of the limbic system were analysed using cytochrome oxidase (CO) histochemistry. Wistar rats were submitted to different conditions. Rats in the group Paired received tone-shock pairing, to elicit conditioned suppression of lever pressing (i.e., tone will evoke conditioned fear respons...
Article
In the present study, we have calculated the total neuronal number and volume of the tuberomammillary nucleus and of each of its subgroups E1, E2 and E3 in the Wistar rat. This estimation was done using stereological methods that can produce accurate quantifications. Neuronal number was estimated by applying the optical fractionator and the total v...
Article
To investigate brain substrates of spatial memory, neuronal expression of c-Fos protein was studied. Two groups of rats were trained in two spatial memory tasks in the Morris water maze, where the rats have to apply a reference memory rule or a working memory rule. In addition to the experimental groups, two control groups were used to study c-fos...
Article
This work aims to clarify the role of histamine in learning and memory. This is done by studying the effect of administration of the histamine precursor, L-histidine (His), and the agonist of the H(3) receptor (R)-alpha-methylhistamine (RAMH), on acquisition and retention of spatial reference memory in rats. Treatment with RAMH (10 mg/kg i.p.) faci...
Article
This work aims to clarify the role of histamine in learning and memory. This is done by studying the effect of administration of the histamine precursor, l-histidine (His), and the agonist of the H3 receptor (R)-α-methylhistamine (RAMH), on acquisition and retention of spatial reference memory in rats. Treatment with RAMH (10 mg/kg i.p.) facilitate...
Article
The aim of this work is to clarify the role of histamine in learning and memory processes. In order to do this, the effect of administration of the histamine precursor, L-histidine (HIS) and of the agonist of the H(3) receptor, (R)-alpha-methylhistamine (RAMH), on active avoidance response in rats is studied. Treatment with RAMH (10 mg/kg i.p.) inc...
Article
Full-text available
To investigate brain substrates of spatial memory, the cellular expression of c-Fos protein in rats was studied after training the animals to perform a spatial reference memory task and a working reference memory task in a Morris water maze. The number of c-Fos positive neuronal nuclei was quantified in several brain regions: entorhinal cortex, ant...
Article
This study was designed to assess the effect of ageing on spatial (allocentric and egocentric) strategies in rats. Two different tasks were designed for this purpose: one involving Morris' circular pool (distal extramaze cues) and another using the T water maze (egocentric cues). In the first task, the aged rats showed some difficulty in acquiring...
Article
The aim of this study is to determine whether sex-related differences exist in the biosynthetic activity of the mitral cells within the mitral layer of the AOB. Possible functional changes over the estrus cycle and the potential effects of castration and androgenization are assessed. Biosynthetic activity was measured using silver staining of the a...
Article
Since publication of the book The hippocampus as a cognitive map by O'Keefe and Nadel in 1978, several theoretical and experimental works have supported the participation of the hippocampus in rodents in spatial processing. Since then, great advances have been made into understanding the potential role of the hippocampus in learning and memory proc...
Article
The aim of this work was to determine the spatial memory impairments induced by chronic alcohol consumption in rats. The alcoholization process began on the 21st postnatal day and alcohol concentrations were gradually increased to reach a concentration of 20% that was maintained for 4 mon. Behavioral tests were performed in the Morris Water Maze (M...
Article
The aim of this work was to attempt to determine whether nucleolar synthetic activity is modified in the tuberomammillary nucleus (TMN), a nucleus connected to the supraoptic nucleus (SON), following a classical dehydration model and subsequent rehydration process in the rat. Argyrophilic staining was used to label the nucleolar organizer regions (...
Article
In this study, we demonstrate that aging does not provoke any changes in neuronal number or in the glial cells of the medial mammillary nucleus (MMN) in humans. Three age groups were used: young (age 17-35), adult (age 50-57), and aged (age 70-88). Furthermore, no age-dependent volumetric changes were observed in the MMN. All the estimations were p...
Article
This work examines the effects of electrolytic mammillary body (MB) lesions on the performance of rats in different spatial memory tasks in the Morris water maze. The first experiment assessed the effect of MB lesion on performance in a spatial reference memory task (place learning with multiple trials). The second experiment examined the effect of...
Article
Full-text available
Condicionamiento de evitación activa en ratas: ausencia de efecto del sexo y ciclo estral. En este artículo se estudian las posibles diferencias entre las ratas macho y hembra (Rattus norvegicus) en la adquisición y consolidación del aprendizaje de evitación de 2 vías. Además de monitorizar los parámetros conductuales (escapes y evitaciones), se de...
Article
Age-related morphological and functional changes were studied in the medial mamillary nuclei of the hypothalamus (MMN). The number of nerve cells and the volume of MMN were estimated in both groups of Wistar rats, adult and old (3 and 22 months, respectively) using stereologic methods such as the optical fractionator and Cavalieri's method respecti...
Article
portocaval shunt and extrahepatic cholestasis are experimental models of chronic hepatic insufficiency of different etiology and histological characteristics, and which probably also differ in the mechanism of impairment of oxidative metabolism. To test this hypothesis we measured hepatic cytochrome oxidase. cytochrome oxidase was assayed with a hi...
Article
This study was designed to investigate the potential effects of medial mammillary nucleus (MMn) lesions on spontaneous alternation behavior in rats. Behavioral measurements were made in a water T maze in which the side arms were not differentially reinforced. Spontaneous alternation was tested before and after surgery alone. In both experiments, vo...
Article
Full-text available
The recent applications of the stereology in the neurocience has permitted to accomplish unbiased estimates of numerous morphologic parameters of the Nervous System. This work intends to analyze the precision of the stereological estimations in two psicobiological studies: numerical and volumetric quantifications of nervous cells applying two stere...
Article
The existence of efferent connections between tuberomammillary (TM) and the supraoptic (SON) nuclei led us to study the morphological changes at these levels during dehydration induced in rats by repeated administration of hypertonic saline. The dehydration effects are evaluated by three parameters: nucleus area, argyrophilic nucleolar organizer re...
Article
Full-text available
The portacaval shunt in the rat is a frequently used experimental model of portosystemic encephalopathy. Among other consequences of this surgical preparation is an important decrease in hepatic and testicular volume. Different sham-operation methods including a laparotomy were used as controls in each case. Given that the liver volume varies great...
Article
Full-text available
En esta revisión se analiza críticamente la implicación de los cuerpos mamilares (CCMM) en procesos de aprendizaje y memoria espacial, poniendo de manifiesto las controversias actuales existentes y sus implicaciones clínicas. La literatura existente sobre el tema parece indicar que los CCMM forman parte de las estructuras diencefáli­cas relacionada...
Article
This study shows the consequences of the administration of diazepam and ethanol on two types of learning: spatial discrimination learning (water T maze) and an active avoidance task (shuttle box). The anxiolytic agents diazepam and ethanol, at the doses administered, favoured performance to a greater or lesser extent in stress behavioural tests, de...
Article
This study aims to analyze the effect of the administration of diazepam and alcohol on cytochrome c oxidase activity (COX) in the mammillary bodies (MB) with a quantitative densitometry method. The histochemical reaction of the COX is used as a reflection of energy consumption. Our results show an increase in the COX activity after treatment with d...
Article
During recent decades, the existence of cerebral and behavioural asymmetries has been manifested in many different animal species. In this work, the asymmetric spatial preference recorded in the water T-maze has been analysed. Fifty-five male rats were tested in this maze for 8 consecutive days. Spatial preference, the number of times each arm was...
Article
La respuesta psico-neuro-inmune-endocrina en fisiología y patología. Se propone que la respuesta del organismo a la agresión por energía mecánica está constituida por tres fases consecutivas: una fase inmediata o nerviosa, una fase intermedia o inmune y una fase tardía o endocrina. Las funciones que caracterizan cada una de estas tres fases podrían...
Article
The aim of this study was to evaluate the effects of ethanol and diazepam on neuronal protein synthesis activity. We used 32 male Wistar rats, divided into four groups. Group 1 (n = 8) received diazepam i.p. (2 mg kg-1), Group 2 (n = 8) received distilled water i.p. (2 mg kg-1), Group 3 was chronically alcoholised and Group 4 (n = 8) was untreated....
Article
Full-text available
Metabolismo oxidativo cerebral y aprendizaje en el laberinto de agua de Morris. Mediante el uso de una reciente técnica histoquímica cuantitativa para la medida de la actividad citocromo oxidasa (CO) en el SNC, un enzima mitocondrial cuyos niveles están relacionados estrechamente con la incorporación basal de 2-desoxiglucosa y con la actividad func...
Article
Metabolismo oxidativo cerebral y aprendizaje en el laberinto de agua de Morris. Mediante el uso de una reciente técnica histoquímica cuantitativa para la medida de la actividad citocromo oxidasa (CO) en el SNC, un enzima mitocondrial cuyos niveles están relacionados estrechamente con la incorporación basal de 2-desoxiglucosa y con la actividad func...
Article
Mechanical energy is an etiological factor of traumatisms which, in the human being, can produce a local pathology as well as localized systemic acute inflammation as in the case of polytraumatized patients. Acute local inflammation is a process that occurs with vasoconstriction, vasodilatation, exudation, cellular infiltration, coagulation, fibrin...
Article
A review is made of the literature on brain biogenic monoamine metabolic alterations in portosystemic encephalopathy in rats, and the results obtained by our group over the past 14 years are presented. The determination of noradrenaline and dopamine concentrations in different noradrenergic and dopaminergic brain areas shows that the depletion of c...
Article
The mammillary bodies are already shaped in the last stages of the fetal development, and you can differentiate clearly in them the medial mammillary nucleus (MMN) and lateral mammillary nucleus (LMN). All this allow to study the variations in cellular density, the relation between neuronal and glial cells, so as the number of nucleoli present in t...
Article
En este trabajo se realiza una tarea de memoria espacial, laberinto de agua en T y registro de una serie de pautas comportamentales (conducta exploratoria, acicalamiento, pasividad, actividad oral, enriquecimiento) en rata blanca. A continuación se lesiona electrolíticamente el núcleo mamilar lateral, mediante la administración de una corriente con...
Conference Paper
Patients with liver dysfunction often suffer from hepatic encephalopathy (HE) a neurological complication which affects to attention and memory. This disease is one of the main clinical conditions affecting the western world. For this reason, different experimental animal models have been used to study HE, being the most used the portocaval shunt....
Article
Full-text available
The applications of the stereology in Neuroscience have been improved by the recent advances in the precision of stereological estimates. Here we make a comparision between two methods of estimating the coefficients of error. The new formula described by Cruz-Orive (1999) incorporate the local or ¿nugget¿ effect in addition to the error due to the...
Article
En: Psicothema Oviedo 2007, v. 19, n.4 ; p. 706-710 Se analizan las propiedades ricas del test de atención selectiva d2 en dos grupos de niños: prematuros (n= 63) y nacidos a término (n=78). Los coeficientes de fiabilidad, calculados por métodos de consistencia interna, se han situado en valores en torno a 0,90. El análisis de componentes principal...

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