Mixed Ability Teaching and Learning:A didactic unit to narrow the gap between students with different levels of proficiency in the classroom

Este trabajo de fin de máster y la unidad que se propone son el resultado de la observación de un grupo de estudiantes en el colegio Escuelas Pías de Zaragoza, en el que había diferencias notables entre los estudiantes en relación a sus habilidades lingüísticas. Este trabajo plantea una unidad didáctica que toma como base diferentes teorías y estrategias planteadas para este tipo de clases con una variedad de niveles, y tiene como objetivo reducir las diferencias entre aquellos estudiantes con un nivel más alto, normal y más bajo, así como cubrir las necesidades individuales de los alumnos. Además, esta unidad también intenta integrar metodologías y enfoques actuales en relación a la materia de Inglés como lengua extranjera, como es el caso del método comunicativo.<br /

Oligodendrocyte origin and development in the zebrafish visual system

Oligodendrocytes are the myelinating cells in the central nervous system. In birds and mammals, the oligodendrocyte progenitor cells (OPCs) originate in the preoptic area (POA) of the hypothalamus. However, it remains unclear in other vertebrates such as fish. Thus, we have studied the early progression of OPCs during zebrafish visual morphogenesis from 2 days post fertilization (dpf) until 11 dpf using the olig2:EGFP transgenic line; and we have analyzed the differential expression of transcription factors involved in oligodendrocyte differentiation: Sox2 (using immunohistochemistry) and Sox10 (using the transgenic line sox10:tagRFP). The first OPCs (olig2:EGFP/Sox2) were found at 2 dpf in the POA. From 3 dpf onwards, these olig2:EGFP/Sox2 cells migrate to the optic chiasm, where they invade the optic nerve (ON), extending toward the retina. At 5 dpf, olig2:EGFP/Sox2 cells in the ON also colocalize with sox10:tagRFP. When olig2:EGFP cells differentiate and present more projections, they become positive only for sox10:tagRFP. olig2:EGFP/sox10: tagRFP cells ensheath the ON by 5 dpf when they also become positive for a myelin marker, based on the mbpa:tagRFPt transgenic line. We also found olig2:EGFP cells in other regions of the visual system. In the central retina at 2 dpf, they are positive for Sox2 but later become restricted to the proliferative germinal zone without this marker. In the ventricular areas of the optic tectum, olig2:EGFP cells present Sox2 but arborized ones sox10:tagRFP instead. Our data matches with other models, where OPCs are specified in the POA and migrate to the ON through the optic chiasm.Consejería de EducaciónJCyL. GIR-SA136G18, Consejeria de Sanidad de la JCyL GRS2167/1/2020 y GRS2334/A/21, GIR-USAL: “Plasticidad, degeneración y regeneración del sistema visual,” and Centro en Red de Medicina Regenerativa y Terapia Celular de la JCyL

Effect of Risperidone and Fluoxetine on the Movement and Neurochemical Changes of Zebrafish

Brain developmental disorders in humans, including Autism Spectrum Disorders (ASD) and Down’s syndrome, have been linked to increased serotonin levels. This work was designed to study changes in serotonin levels in the early stages of development with two classes of antipsychotic drugs: Risperidone, a drug that blocks serotonin and dopamine receptors, and fluoxetine, a serotonin reuptake inhibitor. The use of antipsychotic drugs is a solid choice to study the decrease and increase of these neurotransmitters and their influence on development. The study of these parameters will give an idea of the effects of serotonin in early developmental stages. To this end, we examined the effects of risperidone and fluoxetine on the locomotor activity, heart rate and brain development of zebrafish larvae. Our results showed that in larvae exposed to fluoxetine alone, swimming was significantly increased at 9 dpf (days post-fertilization). Erratic and abnormal movements were observed suggesting a toxic effect of fluoxetine. No erratic swimming was observed in larvae treated with fluoxetine plus risperidone. Both drugs presented morphological changes in dopaminergic neurons and mononeurons. Exposure to fluoxetine plus risperidone indicated possible reversal effects. Studies in zebrafish allow obtaining new insights into the side effects of these drugs as well as into the brain control of locomotor activity. Testing several drug-induced changes in behavior and serotonin levels is one of the experimental approaches for screening a new therapeutically relevant compound, and thus, merits further research.Instituto Multidisciplinario de Biología Celula

Effect of Risperidone and Fluoxetine on the Movement and Neurochemical Changes of Zebrafish

Brain developmental disorders in humans, including Autism Spectrum Disorders (ASD) and Down’s syndrome, have been linked to increased serotonin levels. This work was designed to study changes in serotonin levels in the early stages of development with two classes of antipsychotic drugs: Risperidone, a drug that blocks serotonin and dopamine receptors, and fluoxetine, a serotonin reuptake inhibitor. The use of antipsychotic drugs is a solid choice to study the decrease and increase of these neurotransmitters and their influence on development. The study of these parameters will give an idea of the effects of serotonin in early developmental stages. To this end, we examined the effects of risperidone and fluoxetine on the locomotor activity, heart rate and brain development of zebrafish larvae. Our results showed that in larvae exposed to fluoxetine alone, swimming was significantly increased at 9 dpf (days post-fertilization). Erratic and abnormal movements were observed suggesting a toxic effect of fluoxetine. No erratic swimming was observed in larvae treated with fluoxetine plus risperidone. Both drugs presented morphological changes in dopaminergic neurons and mononeurons. Exposure to fluoxetine plus risperidone indicated possible reversal effects. Studies in zebrafish allow obtaining new insights into the side effects of these drugs as well as into the brain control of locomotor activity. Testing several drug-induced changes in behavior and serotonin levels is one of the experimental approaches for screening a new therapeutically relevant compound, and thus, merits further research.Instituto Multidisciplinario de Biología Celula

REDOX Balance in Oligodendrocytes Is Important for Zebrafish Visual System Regeneration

[EN]Zebrafish (Danio rerio) present continuous growth and regenerate many parts of their body after an injury. Fish oligodendrocytes, microglia and astrocytes support the formation of new connections producing effective regeneration of the central nervous system after a lesion. To understand the role of oligodendrocytes and the signals that mediate regeneration, we use the well-established optic nerve (ON) crush model. We also used sox10 fluorescent transgenic lines to label fully differentiated oligodendrocytes. To quench the effect of reactive oxygen species (ROS), we used the endogenous antioxidant melatonin. Using these tools, we measured ROS production by flow cytometry and explored the regeneration of the optic tectum (OT), the response of oligodendrocytes and their mitochondria by confocal microscopy and Western blot. ROS are produced by oligodendrocytes 3 h after injury and JNK activity is triggered. Concomitantly, there is a decrease in the number of fully differentiated oligodendrocytes in the OT and in their mitochondrial population. By 24 h, oligodendrocytes partially recover. Exposure to melatonin blocks the changes observed in these oligodendrocytes at 3 h and increases their number and their mitochondrial populations after 24 h. Melatonin also blocks JNK upregulation and induces aberrant neuronal differentiation in the OT. In conclusion, a proper balance of ROS is necessary during visual system regeneration and exposure to melatonin has a detrimental impact.his project was funded by: Lanzadera TCUE21-21_003, C2 program for Universidad de Salamanca; Convocatoria de ayudas de investigación Biomédica 2021, FERP21/003, Fundación Eugenio Rodríguez Pascual; ESCI 2022 Exploratory Research Grants; ESCI22/001, European Society for Clinical Investigation ESCI; Internationalization Project “CL-EI-2021-08-IBFG Unit of Excellence” from Spanish National Research Council (CSIC), funded by the Regional Government of Castile and Leon and co-financed by the European Regional Development Fund (ERDF “Europe drives our growth”). CPM is a USAL fellow Plan Especial Grado Medicina. MGM is a Ramón y Cajal Researcher RYC2021-033684-I, MICIN. We are members of Women in Autophagy (WIA), la Sociedad Española de Bioquímica y Biología Molecular (SEBBM) and la Sociedad Española de Autofagia (SEFAGIA)

Expression and localization of the polarity protein CRB2 in adult mouse brain: a comparison with the CRB1rd8 mutant mouse model

Acquisition of cell polarization is essential for the performance of crucial functions, like a successful secretion and appropriate cell signaling in many tissues, and it depends on the correct functioning of polarity proteins, including the Crumbs complex. The CRB proteins, CRB1, CRB2 and CRB3, identified in mammals, are expressed in epithelial-derived tissues like brain, kidney and retina. CRB2 has a ubiquitous expression and has been detected in embryonic brain tissue; but currently there is no data regarding its localization in the adult brain. In our study, we characterized the presence of CRB2 in adult mice brain, where it is particularly enriched in cortex, hippocampus, hypothalamus and cerebellum. Double immunofluorescence analysis confirmed that CRB2 is a neuron-specific protein, present in both soma and projections where colocalizes with certain populations of exocytic and endocytic vesicles and with other members of the Crumbs complex. Finally, in the cortex of CRB1rd8 mutant mice that contain a mutation in the Crb1 gene generating a truncated CRB1 protein, there is an abnormal increase in the expression levels of the CRB2 protein which suggests a possible compensatory mechanism for the malfunction of CRB1 in this mutant background.This study was supported by Fondo de Investigaciones Sanitarias Instituto Carlos III (PI15/01240), co-funded by European Union (ERDF/ESF, “Investing in your future”) to C.L. A. Velasco, R. Arévalo and C. Lillo are members of the UIC.077 from Junta de Castilla y León

Sox10 Expression in Goldfish Retina and Optic Nerve Head in Controls and after the Application of Two Different Lesion Paradigms

[EN]The mammalian central nervous system (CNS) is unable to regenerate. In contrast, the CNS of fish, including the visual system, is able to regenerate after damage. Moreover, the fish visual system grows continuously throughout the life of the animal, and it is therefore an excellent model to analyze processes of myelination and re-myelination after an injury. Here we analyze Sox10+ oligodendrocytes in the goldfish retina and optic nerve in controls and after two kinds of injuries: cryolesion of the peripheral growing zone and crushing of the optic nerve. We also analyze changes in a major component of myelin, myelin basic protein (MBP), as a marker for myelinated axons. Our results show that Sox10+ oligodendrocytes are located in the retinal nerve fiber layer and along the whole length of the optic nerve. MBP was found to occupy a similar location, although its loose appearance in the retina differed from the highly organized MBP+ axon bundles in the optic nerve. After optic nerve crushing, the number of Sox10+ cells decreased in the crushed area and in the optic nerve head. Consistent with this, myelination was highly reduced in both areas. In contrast, after cryolesion we did not find changes in the Sox10+ population, although we did detect some MBP- degenerating areas. We show that these modifications in Sox10+ oligodendrocytes are consistent with their role in oligodendrocyte identity, maintenance and survival, and we propose the optic nerve head as an excellent area for research aimed at better understanding of de- and remyelination processes

Doublecortin in the fish visual system, a specific protein of maturing neurons Biology-basel

Doublecortin (DCX) is an essential protein in the development of the central nervous system and in lamination of the mammalian cortex. It is known that the expression of DCX is restricted to newborn neurons. The visual system of teleost fish has been postulated as an ideal model since it continuously grows throughout the animal’s life. Here, we report a comparative expression analysis of DCX between two teleost fish species as well as a bioinformatic analysis with other animal groups. Our results demonstrate that DCX is very useful for identifying new neurons in the visual systems of Astatotilapia burtoni, but is absent in Danio rerio.This research was funded by Junta de Castilla y León, Consejería de Sanidad. Centro en Red de Terapia Celular de la Junta de Castilla y León, grant number GRS2167/1/2020. L. DeOliveira-Mello was supported by a grant from The University of Salamanca and Santander Bank during her predoctoral period

Proyecto BRIDGE de formación para la inserción laboral de alumnos de la Facultad de Biología

Memoria ID-130. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2018-2019

Diseño de una revista on line sobre noticias de investigaciones relevantes en Biotecnología en el campo de la Biología Celular y Tisular

Memoria ID-0010. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2017-2018