Sergio Mora

University of Chile · Instituto de Ciencias Biomédicas (ICBM)

Introducción: El año 2007, se inició en la Facultad de Medicina un proceso de innovación curricular que implicó cambiar el enfoque educativo desde un paradigma centrado en la enseñanza a otro centrado en el proceso formativo y el aprendizaje del estudiante. Al desarrollar una educación centrada en los estudiantes resulta necesario saber cómo aprend...

Introduction: In recent years, an important number of studies have emphasized the psychopharmacological actions of cycloleucine (1-aminocyclopentanecarboxylic acid) acting on the NR1 subunit (glycine allosteric site) of NMDA (N-methyl-D-aspartic acid) receptor. We studied the effects of its injection in an anxiety test. Methods: The elevated plu...

Introducción. La Escuela de Enfermería de la Universidad de Chile implantó en 2013 un nuevo currículo basado en compe-tencias profesionales. El objetivo de este estudio fue evaluar el impacto de esta innovación curricular a través de la per-cepción del ambiente educacional de los estudiantes que, durante 2014, cursaban diferentes tipos de currículo...

Dopamine oxidation in the pathway leading to neuromelanin formation generates the ortho-quinone aminochrome, which is potentially neurotoxic but normally rapidly converted by DT-diaphorase to nontoxic leukoaminochrome. However, when administered exogenously into rat striatum, aminochrome is able to produce damage to dopaminergic neurons. Because of...

Introducción: La Escuela de Enfermería de la Universidad de Chile implantó en 2013 un nuevo currículo basado en competencias profesionales. El objetivo de este estudio fue evaluar el impacto de esta innovación curricular a través de la percepción del ambiente educacional de los estudiantes que, durante 2014, cursaban diferentes tipos de currículos,...

Background: Dendritic arbor simplification and dendritic spine loss in the hippocampus -a limbic structure implicated in mood disorders- are assumed to contribute to symptoms of depression. These morphological changes imply changes in dendritic cytoskeleton. Rho GTPases are regulators of actin dynamics through their effector Rho kinase (ROCK). We...

Background: To establish an educational environment that ensures the quality of the teaching-learning process is a challenge for any educational institution. The questionnaire DREEM (Dundee Ready Educational Environment Measure) is used to identify strengths and weaknesses of an educational environment and to compare different medical schools. Ai...

L-Dopa continues to be the gold drug in Parkinson's disease (PD) treatment from 1967. The failure to translate successful results from preclinical to clinical studies can be explained by the use of preclinical models which do not reflect what happens in the disease since these induce a rapid and extensive degeneration; for example, MPTP induces a s...

Chronic stress promotes cognitive impairment and dendritic spine loss in hippocampal neurons. In this animal model of depression, spine loss probably involves a weakening of the interaction between pre- and postsynaptic cell adhesion molecules, such as N-cadherin, followed by disruption of the cytoskeleton. N-cadherin, in concert with catenin, stab...

Objetivo. Actualmente se acepta que el ambiente educacional influye en forma importante sobre las aptitudes, conocimientos, conducta, logros académicos y grado de satisfacción de los estudiantes. En este trabajo se analizan los cambios en la percepción del ambiente educacional por parte de los estudiantes de la Facultad de Medicina de la Universida...

Aim: To assess and compare the perception about the educational environment of medical students from two Latin-American universities, University of Chile (UCH) and National University of Cuyo (UNC), which develop a traditional curriculum and a problem based curriculum, respectively. Subjects and methods: A transversal study was performed in 465 stu...

To assess and compare the perception about the educational environment of medical students from two Latin-American universities, University of Chile (UCH) and National University of Cuyo (UNC), which develop a traditional curriculum and a problem based curriculum, respectively. Subjects and methods. A transversal study was performed in 465 students...

Depressive disorder involves emotional, cognitive, autonomic and endocrine alterations and also evidences support the role of stress in the development of this disorder. Because the hypothalamic-pituitary-adrenal axis is involved in the stress response with a concomitant rise in plasma corticoids, the present study compares the antidepressant effec...

3,4-methylenedioxymethamphetamine (MDMA; "ecstasy") is a psychoactive drug structurally related to other phenylisopropylamines acting as stimulants or hallucinogens in humans. Although MDMA has a pharmacological identity of its own, the distinction of its acute effects from those of stimulants or even hallucinogens is controversial. In this work, d...

Aim. To establish a correlation between medical student learning styles (LS) and the geographical context, the curricular context and different academic levels. Subjects and methods. The study was performed in 490 undergraduate students from Medical Schools of the Universities of Chile (Santiago, Chile), Nacional de Cuyo (Mendoza, Argentina), San F...

Aim. To establish a correlation between medical student learning styles (LS) and the geographical context, the curricular context and different academic levels. Subjects and methods. The study was performed in 490 undergraduate students from Medical Schools of the Universities of Chile (Santiago, Chile), Nacional de Cuyo (Mendoza, Argentina), San F...

The aim of the present work is to evaluate the putative antidepressant-like effects of a hydro-ethanolic extract (CEAp) and their fractions from the aerial parts of Aloysia polystachya (Griseb.) Moldenke (Verbenaceae) on the performance of male mice in the forced swimming test (FST). A single dose (100.0mg/kgp.o.) of CEAp, in male mice provoked a s...

The dependence of copper neurotoxicity on DT-diaphorase inhibition was suggested from results obtained from a cell line derived from substantia nigra. Therefore, the aim of this study was to evaluate whether CuSO4 neurotoxicity in vivo, which was evaluated by determining the contralateral rotation and loss of tyrosine hydroxylase immunostaining, wa...

The University is undergoing a process of refoundation with far-reaching epistemological changes. The EU's decision of developing a "knowledge based economy" need to establish common educational objectives, which are implemented by the Bologna process, a key tool in the construction of the European Space of High Education. In this context, the Univ...

The University is undergoing a process of refoundation with far-reaching epistemological changes. The EU's decision of developing a "knowledge based economy" need to establish common educational objectives, which are implemented by the Bologna process, a key tool in the construction of the European Space of High Education. In this context, the Univ...

Salvia elegans Vahl (Lamiaceae), popularly known as "mirto", is a shrub that has been widely used in Mexican traditional medicine for the treatment of different central nervous system (CNS) diseases, principally, anxiety. Nevertheless, the available scientific information about this species is scarce and there are no reports related to its possible...

Behavioral effects of a hydroalcoholic (60% ethanol) extract from the leaves of Salvia elegans Vahl (Lamiaceae) were studied in male Sprague-Dawley rats. The extract was administered intraperitoneally and its effects on spontaneous motor activity (total motility, locomotion, rearing and grooming behavior) were monitored. Putative anxiolytic and ant...

Chronic stress affects brain areas involved in learning and emotional responses. These alterations have been related with the development of cognitive deficits in major depression. Moreover, stress induces deleterious actions on the epithalamic pineal organ, a gland involved in a wide range of physiological functions. The aim of this study was to i...

The aim of the present work is to demonstrate the putative sedative and anxiolytic-like effects of a hydro-ethanolic extract obtained from the aerial parts of Aloysia polystachya (Verbenaceae) in male mice using several behavioural assays. Groups of male mice orally treated with doses of 1.0, 10.0 and 100.0 mg/kg of the extract did not show any sig...

Behavioral effects of a hydroalcoholic extract from leaves of Aloysia polystachya (Griseb.) Moldenke (Verbenaceae) were studied in female Sprague-Dawley rats. The extract was administered intraperitoneally and its effects on spontaneous motor activity (total motility, locomotion, rearing and grooming behavior) were monitored. Anxiolytic-like proper...

In order to evaluate the effects produced by the hydroalcoholic extract of leaves from Casimiroa edulis on the central nervous system, different behavioral tests and animal models of depression and anxiety were performed. The extract was administered intraperitoneally in male and female rats and tested on spontaneous motor activity, locomotor activ...

Chronic stress affects brain areas involved in learning and emotional responses. These alterations have been related with the development of cognitive deficits in major depression. The aim of this study was to determine the effect of chronic immobilization stress on the auditory and visual mesencephalic regions in the rat brain. We analyzed in Golg...

The purpose of this study was to evaluate the contribution of DT-diaphorase inhibition to in vivo neurodegenerative effects of dopamine (DA) oxidation to the corresponding o-quinones. The neurotoxicity to nigrostriatal DA neurons was induced by injection of manganese pyrophosphate (Mn(3+)) complex as a prooxidizing agent alone or together with the...

The present study shows that intranigral injection of dicoumarol, a DT-diaphorase inhibitor, potentiates the neurotoxic effect of salsolinol (salsolinol 1.25 nmoles plus dicoumarol 2 nmoles; in 2 microl). Rats treated with dicoumarol plus salsolinol presented a characteristic contralateral rotational behaviour when they were stimulated with apomorp...

The exact mechanism of cell death in neurodegenerative diseases remains obscure, although there is evidence that their pathogenesis may involve the formation of free radicals originating from the oxidative metabolism of catecholamines. The purpose of this study was to evaluate the degree of neurodegenerative changes and behavioral impairments induc...

Intracerebral manganese administration together with the DT-diaphorase inhibitor dicoumarol [Mn(III) 40 nmol + -dicoumarol 2 nmol; in 4 micro l] into the left medial forebrain bundle (MFB) produced a behavioural pattern characterized by contralateral behaviour when the rats were stimulated with apomorphine (0.5 mg/kg s.c.), in a manner similar to t...

This study examines whether the hormonal condition of the rat modifies the effects of diazepam (0.25 and 1.0 mg/kg) on avoidance conditioning and other behavioral responses. Acquisition of a conditioning avoidance response (CAR) and spontaneous motor behaviors were assessed in intact male, in intact diestrous and estrous females, and in ovariectomi...

RESUMEN Las algas constituyen una fuente importante de compuestos de interés biomédico. En este estudio se presentan los resultados del pesquisaje realizado a extractos de 7 especies de algas en modelos de conducta exploratoria y convulsiones inducidas por choque eléctrico en ratones machos Balb-c y OF1 respectivamente, de 18-22 g de peso corporal;...

The influence of the hormonal condition on the reactivity of central dopamine (DA) receptors was studied in male and in intact and ovariectomized (OVX) female rats. They were injected with selective DA agonists, acting either on D1 (SKF 38393, 2.5 or 10 mg/kg) or D2 receptors (PPHT, 31.3 or 125 microg/kg), or with selective DA antagonists, acting e...

DÍAZ-VÉLIZ, G., M. S. BENAVIDES, S. BUTRÓN, N. DUSSAUBAT AND S. MORA, S. Behavioral effects of dopamine agonists and antagonists: Influence of estrous cycle, ovariectomy, and estrogen replacement in rats. PHARMACOL BIOCHEM BEHAV 62(1) 21–29, 1999.—The influence of the hormonal condition on the reactivity of central dopamine (DA) receptors was studi...

Several studies have demonstrated that the peptide LHRH can modify behavior in the male rat. Peripheral and intracerebral infusions of LHRH impair the acquisition of conditioned avoidance responses (CARs) and increase some spontaneous motor behaviors, such as head shaking and grooming. The present study was undertaken to detect the effects of LHRH...

The influence of gender, estrous cycle, ovariectomy and ovarian hormones on the behavioral effects of the 5-HT2 receptor antagonist, ketanserin (KET), was studied. Intact males, female rats in the four stages of the estrous cycle and ovariectomized (OVX) female rats 14 days after surgery were used. The OVX rats received progesterone [PROG, 25 mg/kg...

DÍAZ-VÉLIZ, G., DUSSAUBAT, N. AND MORA, S. Ketanserin effects on rat behavioral responses: modifications by the estrous cycle, ovariectomy and estradiol replacement. PHARMACOL BIOCHEM BEHAV 57[4]687–692, 1997.—The present investigation was designed to explore the influence of estrous cycle phase, ovariectomy, and estradiol replacement on the behavi...

The influence of the estrous cycle and the effects of exogenous administration of estradiol and progesterone on level of anxiety were studied in intact and ovariectomized rats. Intact Sprague-Dawley female rats were classified according to the stages of estrous cycle. Another group of rats was ovariectomized bilaterally and, 14 days after surgery,...

This study was designed to evaluate the influence of the hormonal status of the rat on the effects of a potent reversible muscarinic agonist, oxotremorine, on the acquisition of conditioning avoidance responses (CARs) and the performance of some spontaneous motor behaviors. Oxotremorine (OXO 50 and 100 μg/kg, intraperitoneally) given 5 min before t...

This experiment was designed to investigate the influence of hormonal status of the rat on the effects of two doses of an indirect-acting dopamine agonist (amphetamine 0.25 and 1.0 mg/kg, IP) and a direct-acting dopamine agonist (apomorphine 62.5 and 250 μg/kg, SC) on the acquisition of conditioning avoidance responses (CARs) and the performance of...

This study demonstrates a significant impairment in the acquisition of conditioned avoidance responses in female rats during their estrus phase. Progesterone (PROG 5 mg) injected 6 h prior to the test, signficantly enhanced the performance exhibited by rats at estrus, but not at diestrus. In ovariectomized rats, the acquisition of conditioned avoid...

The effects of the LHRH antagonism on the acquisition of conditioned responses (CARs) and spontaneous motility were studied in intact and ovariectomized rats. A synthetic antagonist of LHRH, , was injected in a single dose (10 μg/rat, SC) at noon on the day of proestrus in the normally cycling rat, and behavioral experiments were carried out on the...

The acquisition of conditioned avoidance responses along with spontaneous behaviors were studied in ovariectomized rats. Fourteen days after ovariectomy, they were injected subcutaneously with one of the following doses of estradiol benzoate: 0.2, 2 or 20 microgram/rat. Behavioral tests were applied 3, 24, 48 or 72 hours after estradiol treatment....

The effects of LHRH intracerebrally infused on acquisition of conditioned avoidance responses (CARs) and spontaneous motility were studied in adult male rats. The results were the following: 1) LHRH (1 and 2.5 micrograms/rat) administered through a cannula stereotaxically implanted into the lateral ventricle induced an impairment in the acquisition...

The changes in the acquisition of conditioned avoidance responses (CARs) and the performance of some spontaneous behaviors were examined across the estrous cycle of female rats. CARs were facilitated during diestrus, impaired at proestrus and practically abolished at estrus and metestrus. Motor activity and head shaking were minimally affected with...

The effects of the pretreatment with LHRH on the behavioral effects induced by low doses of apomorphine were studied in male rats. Three doses of apomorphine (31.25, 62.50 and 125 micrograms/kg) were subcutaneously administered two hours after LHRH 100 micrograms/kg or solvent SC treatment. Apomorphine induced repeated episodes of yawning and genit...

The influence of LHRH on the behavioral effects induced by apomorphine (APO) was studied in male rats. Several doses of apomorphine (31.25, 62.5, 125, 250 and 500 micrograms/kg) were administered subcutaneously (SC) after LHRH 100 micrograms/kg or solvent. Low doses of apomorphine induced hypomotility and impaired acquisition of a conditioned avoid...

The influence of L-DOPA on the behavioral effects of LHRH was studied in male rats. Subcutaneous administration of LHRH (100 micrograms/kg) caused a significant disruption in the acquisition of a conditioned avoidance response (CAR) and a significant increase in head shaking behavior (HSB). Pretreatment with this hormone antagonized the stimulatory...

The influence of posttraining subcutaneous administration of luteinizing-hormone-releasing hormone (LHRH) was tested on the retention of either active or passive avoidance conditioning in male rats. Injection of LHRH (200/kg) immediately after the acquisition of an active avoidance response (two-way shuttle behavior) enhanced retention of the respo...

The influence of luteinizing hormone releasing hormone (LHRH) on the behavioral effects induced by several doses of D-amphetamine (0.25, 0.5, 1.0 and 2.0 mg/kg IP) was studied. A dose response relation was previously established for the effects of LHRH (50, 100 and 200 μg/kg SC) on acquisition and retention of conditioned avoidance responses (CARs)...

Pretraining subcutaneous administration of a high dose of LHRH (100 micrograms/kg) to intact rats impaired acquisition of a conditioned avoidance response (CAR) in a two way shuttle box. Acquisition of a CAR was also decreased when LHRH was administered to castrated rats. LHRH antagonized the dose related impairment in acquisition and retention per...

TRH (10 micrograms) intracerebroventricularly injected improves the acquisition of a two-day avoidance conditioning. This effect is partially antagonized by pretreatment IP with alpha-methyltyrosine (60 mg/kg) or disulfiram (300 mg/kg). L-DOPA (100 mg/kg) administered IP 2 hr after alpha-MT partially restores the facilitatory effect of the hormone....

The effects of LHRH on acquisition and retention of a two-way avoidance conditioned were studied. Normal and castrated adult Wistar male rats were used. LHRH (100 μg/kg) and the solvent were injected subcutaneously two hours before the acquisition session. Retention tests were carried out a week later. The peptide reduced significantly both acquisi...

The behavioral effects (tremors, tail erection, increased motility) of intracerebrally injected TRF are enhanced by pretreatment with chlorpromazine, reserpine and sulpiride; haloperidol does not exert appreciable effects. L-Dopa attenuates or abolishes the potentiation.