Pattern of Neurogenesis and Identification of Neuronal Progenitor Subtypes during Pallial Development in Xenopus laevis

The complexity of the pallium during evolution has increased dramatically in many different respects. The highest level of complexity is found in mammals, where most of the pallium (cortex) shows a layered organization and neurons are generated during development following an inside-out order, a sequence not observed in other amniotes (birds and reptiles). Species-differences may be related to major neurogenetic events, from the neural progenitors that divide and produce all pallial cells. In mammals, two main types of precursors have been described, primary precursor cells in the ventricular zone (vz; also called radial glial cells or apical progenitors) and secondary precursor cells (called basal or intermediate progenitors) separated from the ventricle surface. Previous studies suggested that pallial neurogenetic cells, and especially the intermediate progenitors, evolved independently in mammalian and sauropsid lineages. In the present study, we examined pallial neurogenesis in the amphibian Xenopus laevis, a representative species of the only group of tetrapods that are anamniotes. The pattern of pallial proliferation during embryonic and larval development was studied, together with a multiple immunohistochemical analysis of putative progenitor cells. We found that there are two phases of progenitor divisions in the developing pallium that, following the radial unit concept from the ventricle to the mantle, finally result in an outside-in order of mature neurons, what seems to be the primitive condition of vertebrates. Gene expressions of key transcription factors that characterize radial glial cells in the vz were demonstrated in Xenopus. In addition, although mitotic cells were corroborated outside the vz, the expression pattern of markers for intermediate progenitors differed from mammals

Patterns of hypothalamic regionalization in amphibians and reptiles: common traits revealed by a genoarchitectonic approach

Most studies in mammals and birds have demonstrated common patterns of hypothalamic development highlighted by the combination of developmental regulatory genes (genoarchitecture), supporting the notion of the hypothalamus as a component of the secondary prosencephalon, topologically rostral to the diencephalon. In our comparative analysis we have summarized the data on the expression patterns of different transcription factors and neuroactive substances, used as anatomical markers, in the developing hypothalamus of the amphibian Xenopus laevis and the juvenile turtle Pseudemys scripta. This analysis served to highlight the organization of the hypothalamus in the anamniote/amniotic transition. We have identified supraoptoparaventricular and the suprachiasmatic regions (SCs) in the alar part of the hypothalamus, and tuberal and mammillary regions in the basal hypothalamus. Shared features in the two species are: (1) The supraoptoparaventricular region (SPV) is defined by the expression of Otp and the lack of Nkx2.1/Isl1. It is subdivided into rostral, rich in Otp and Nkx2.2, and caudal, only Otp-positive, portions. (2) The suprachiasmatic area contains catecholaminergic cell groups and lacks Otp, and can be further divided into rostral (rich in Nkx2.1 and Nkx2.2) and a caudal (rich in Isl1 and devoid of Nkx2.1) portions. (3) Expression of Nkx2.1 and Isl1 define the tuberal hypothalamus and only the rostral portion expresses Otp. (4) Its caudal boundary is evident by the lack of Isl1 in the adjacent mammillary region, which expresses Nkx2.1 and Otp. Differences in the anamnio-amniote transition were noted since in the turtle, like in other amniotes, the boundary between the alar hypothalamus and the telencephalic preoptic area shows distinct Nkx2.2 and Otp expressions but not in the amphibian (anamniote), and the alar SPV is defined by the expression of Otp/Pax6, whereas in Xenopus only Otp is expressed

Agustín González, an inspirational leader in spanish comparative neuroanatomy

It is our pleasure to open this Festschrift dedicated to our mentor Prof. Agustín González (Fig. 1) on his retirement after more than 40 years of academic work at the Universidad Complutense de Madrid. Agustín is a key figure in the field of comparative neuroanatomy, essential to understanding the evolution of this field in Spain and beyond over the last decades. This special issue collects a rich number of contributions by collaborators, pupils, and colleagues from all over the world, reflecting the impact of their achievements and the respect and admiration of the entire international community. The volume also serves as a homage to Prof. Luis Puelles, an occasional collaborator of Agustín and another giant of Spanish neuroscience. In this commentary, we summarize Agustín’s work as a researcher, teacher, mentor, and member of the scientific community. We also consider the broader impact of Agustín’s activity, primarily when it comes to its ability to influence others. As alumni from his laboratory, we do this from a very personal point of view, reflecting on our imperfect memories of the time we spent together. We wish that this imperfect historical glimpse on Agustín’s professional career will bring a smile to the face of the many colleagues who have worked with Agustín over the past few decades and inspire those who have not personally known him

Equine infection with Leishmania spp. in Costa Rica: Study of five cases

Background: Cutaneous forms of leishmaniosis due to Leishmania braziliensis have been reported in horses in the New World. Domestic animals play a role in the transmission of the disease. In Costa Rica, human cases of L. braziliensis, L. panamensis and L. infantum have been reported. Objectives: The present report describes five cases of equine cutaneous leishmaniosis in Costa Rica. The aetiological diagnosis was based on the presence of the parasite within the lesions. Methods: Skin biopsies were used to perform histopathological analyses of the lesions. Immunohistochemistry was used to detect the presence of the Leishmania spp. antigens in tissue sections. Laser-capture micro-dissection and quantitative real-time PCR techniques were carried out to detect the pathogen nucleic acid within the microscopic lesions. Results: Histopathological analyses showed a granulomatous inflammation within the dermis, with multi-nucleated giant cells, macrophages, lymphocytes and few neutrophils and eosinophils. We detected the parasite by immunohistochemistry, using a rabbit polyclonal antibody raised against Leishmania spp. However, we could not identify Leishmania spp. by quantitative real-time PCR in formalin-fixed paraffin-embedded tissues, using specific primers for the conserved region in the minicircle of the Leishmania DNA kinetoplast. Conclusions: Our results emphasise the importance of Leishmania spp. not only as a causative agent of equine cutaneous disease in the New World, but also as a possible emerging pathogen. Leishmaniosis is one of the most prevalent parasitic public health problems worldwide, and equines may have a role in the epidemiology of the disease.This study was supported by the Ayuntamiento de Madrid of the Comunidad de Madrid S2013/ABI-2747 (TAVS-CM) and by the Structural Funds of the European Union.S

Digitalización de la histoteca de las prácticas de Biología Celular e Histología

Depto. de Biología CelularFac. de Ciencias BiológicasFALSEsubmitte

Modelling and simulation of pathogen inactivation with sanitizers in a food washing tank operated continuously and with turbulent flow

[Resumen] Las autoridades de seguridad alimentaria en los últimos años están demandando avances en el modelado y simulación de la lavado de frutas y verduras que permitan diseñar modos de operación sostenible (mínimo consumo de agua) garantizando la seguridad final del alimento Se requiere, además, evitar que los residuos y patógenos se trasladen del agua de lavado al alimento (contaminación cruzada). En este estudio, se simula el proceso de lavado y desinfección en un tanque industrial en régimen turbulento. Para modelar el transporte de especies (desinfectante, patógenos y materia orgánica), se considera la ecuación de advección-difusión. Para describir la inactivación de los patógenos en el agua, se incluye el modelo de reacción describiendo las interacciones entre las distintas especies. Los resultados revelan que, aunque un incremento en las velocidades del flujo (aumento de la turbulencia) genera mayor homogeneidad en la distribución de desinfectante, el tiempo característico del proceso resulta insuficiente para inactivar eficazmente los patógenos en el agua.[Abstract] Food safety authorities in recent years are demanding advances in modeling and simulating the washing of fruits and vegetables to support the development of sustainable operation designs (minimum water use) and guaranteeing final product safety. It is required, moreover, to avoid the transference of residues and pathogens from the wash water to the food (cross-contamination). In this study, we simulate an industrial washing and disinfection process in a tank in a turbulent regime. We consider the advectiondiffusion equation to model the species (disinfectant, pathogens, and organic matter) transport, and we include the reaction model between the different species to describe pathogen inactivation in the wash water. The results reveal that, although increasing flow velocities (increased turbulence) generates greater homogeneity in the disinfectant distribution, the characteristic time of the process becomes insufficient to inactivate pathogens in the water.Consejo Superior de Investigaciones Científicas; 20213AT001Consejo Superior de Investigaciones Científicas; 202270I19

Distribution of the transcription factor islet-1 in the central nervous system of nonteleost actinopterygian fish: Relationshipwith cholinergic and catecholaminergic systems

Islet-1 (Isl1) is one of the most conserved transcription factors in the evolution of vertebrates, due to its continuing involvement in such important functions as the differentiation of motoneurons, among other essential roles in cell fate in the forebrain. Although its functions are thought to be similar in all vertebrates, the knowledge about the conservation of its expression pattern in the central nervous system goes as far as teleosts, leaving the basal groups of actinopterygian fishes overlooked, despite their important phylogenetic position. In order to assess the extent of its conservation among vertebrates, we studied its expression pattern in the central nervous system of selected nonteleost actinopterygian fishes. By means of immunohistochemical techniques, we analyzed the Isl1 expression in the brain, spinal cord, and sensory ganglia of the cranial nerves of young adult specimens of the cladistian species Polypterus senegalus and Erpetoichthys calabaricus, the chondrostean Acipenser ruthenus, and the holostean Lepisosteus oculatus. We also detected the presence of the transcription factor Orthopedia and the enzymes tyrosine hydroxylase (TH) and choline acetyltransferase (ChAT) to better locate all the immunoreactive structures in the different brain areas and to reveal the possible coexpression with Isl1. Numerous conserved features in the expression pattern of Isl1 were observed in these groups of fishes, such as populations of cells in the subpallial nuclei, preoptic area, subparaventricular and tuberal hypothalamic regions, prethalamus, epiphysis, cranial motor nuclei and sensory ganglia of the cranial nerves, and the ventral horn of the spinal cord. Double labeling of TH and Isl1 was observed in cells of the preoptic area, the subparaventricular and tuberal hypothalamic regions, and the prethalamus, while virtually all motoneurons in the hindbrain and the spinal cord coexpressed ChAT and Isl1. Altogether, these results show the high degree of conservation of the expression pattern of the transcription factor Isl1, not only among fish, but in the subsequent evolution of vertebrates.Depto. de Biología CelularFac. de Ciencias BiológicasTRUEMinisterio de Ciencia e Innovación (MICINN)Universidad Complutense de Madrid (UCM)pu

Calidad y sostenibilidad : una propuesta metodológica interdisciplinar para la innovación competitiva de los municipios turísticos maduros

En el contexto de las primeras manifestaciones de una fase recesiva relacionada con la falta de competitividad de los destinos de sol y playa convencionales en países desarrollados en comparación con los análogos de países emergentes, se esgrimen como alternativa la evolución hacia un modelo de excelencia, identificado con calidad ambiental y calidad en el servicio. En el artículo se presenta una propuesta metodológica que tiene como objetivo fundamental reorientar la actitud de los agentes sociales de los municipios correspondientes a estos destinos hacia aquella que facilite la asunción por éstos de los criterios de calidad y sostenibilidad en sus prácticas económicas y territoriales. Esta metodología tiene un carácter interdisciplinar desde dos dimensiones. Una definida por la combinación de metodologías procedentes de dos áreas temáticas: los estudios turísticos y los estudios sobre procesos de innovación en el marco del desarrollo local. Otra, aportada por la composición del equipo, integrado por geógrafos, antropólogos y economistas.Environmental quality (sustainability) and service quality are being argued as a way to do more competitive the mature sun and beach destination, that are living the competition of young destinations. This paper presents a methodologic proposal whose main aim is helping to the local stakeholders in these destination to modify their behaviour in order to take on their economic and environmental skills these issues of sustainability and quality. This methodology is interdisciplinary in two ways: On the one hand, it arranges the methodologies belonging to tourist studies with that of the local development studies. On the other hand, it arranges the methodologies belonging to the study workteam: geographers, anthropologists and economists

Expression of SATB1 and SATB2 in the brain of bony fishes: what fish reveal about evolution

Satb1 and Satb2 belong to a family of homeodomain proteins with highly conserved functional and regulatory mechanisms and posttranslational modifications in evolution. However, although their distribution in the mouse brain has been analyzed, few data exist in other non-mammalian vertebrates. In the present study, we have analyzed in detail the sequence of SATB1 and SATB2 proteins and the immunolocalization of both, in combination with additional neuronal markers of highly conserved populations, in the brain of adult specimens of different bony fish models at key evolutionary points of vertebrate diversification, in particular including representative species of sarcopterygian and actinopterygian fishes. We observed a striking absence of both proteins in the pallial region of actinopterygians, only detected in lungfish, the only sarcopterygian fish. In the subpallium, including the amygdaloid complex, or comparable structures, we identified that the detected expressions of SATB1 and SATB2 have similar topologies in the studied models. In the caudal telencephalon, all models showed significant expression of SATB1 and SATB2 in the preoptic area, including the acroterminal domain of this region, where the cells were also dopaminergic. In the alar hypothalamus, all models showed SATB2 but not SATB1 in the subparaventricular area, whereas in the basal hypothalamus the cladistian species and the lungfish presented a SATB1 immunoreactive population in the tuberal hypothalamus, also labeled with SATB2 in the latter and colocalizing with the gen Orthopedia. In the diencephalon, all models, except the teleost fish, showed SATB1 in the prethalamus, thalamus and pretectum, whereas only lungfish showed also SATB2 in prethalamus and thalamus. At the midbrain level of actinopterygian fish, the optic tectum, the torus semicircularis and the tegmentum harbored populations of SATB1 cells, whereas lungfish housed SATB2 only in the torus and tegmentum. Similarly, the SATB1 expression in the rhombencephalic central gray and reticular formation was a common feature. The presence of SATB1 in the solitary tract nucleus is a peculiar feature only observed in non-teleost actinopterygian fishes. At these levels, none of the detected populations were catecholaminergic or serotonergic. In conclusion, the protein sequence analysis revealed a high degree of conservation of both proteins, especially in the functional domains, whereas the neuroanatomical pattern of SATB1 and SATB2 revealed significant differences between sarcopterygians and actinopterygians, and these divergences may be related to the different functional involvement of both in the acquisition of various neural phenotypes.Depto. de Biología CelularFac. de Ciencias BiológicasTRUEMinisterio de Ciencia e Innovación (grant no. PID2020- 112681GB100), and the Santander/Complutense University of Madrid, Grant/Award Number: PR108/20-17Universidad Complutense de Madrid (UCM) /Banco de Santanderpu

¿Por qué la representatividad de la muestra no siempre es importante?

Recientemente hemos constatado que se ha generalizado la idea errónea de que, a fin de que los resultados de un estudio epidemiológico sean generalizables, la muestra a estudio debe ser representativa de la población general. Se trata, desgraciadamente de un error persistente en investigación biomédica que radica en la tergiversación de las definiciones de la estadística descriptiva y la estadística inferencial1 . Dado que no se puede estudiar la población completa, toda investigación debe apoyarse en muestras, más o menos grandes, de esa población. Decimos que una muestra es representativa cuando su estructura en relación a las variables de interés (proporción de varones y mujeres, de expuestos y no expuestos o de sanos y enfermos..., por ejemplo) es la misma que la de la población de la que procede