A Simple and Low-Cost, but Naturalistic Method for Introducing Students to Action Potentials

Abstract Current trends in science education recommend the complementary use of virtual and hands-on methods of teaching. In neurobiology, for instance, there is a plethora of virtual laboratories and simulators that can be readily combined with traditional physical labs. Unfortunately, physical laboratories are almost unaffordable for many institutions due to the high cost of equipment. In this paper, we present a simple and low-cost in vivo method for demonstrating some of the basic biophysical properties of neural action potentials. The method involves the following steps: a) dissection of the ventral nerve cord of earthworm; b) electrical stimulation; c) amplification and visualization of the medial and lateral giant fibers' action potentials; and d) recording. The system showed stability, expected amplification, high signal-to-noise ratio, and an estimated total cost of US$ 5.662. We provide guidelines for assembling the system and discus its utility as a teaching alternative for low budget institutions.

Revisión sistemática de modelos neurobiológicos y ejecutivos en alcoholismo / Systematic review on neurobiological and executive models in alcoholism

Resumen Alteraciones estructurales y funcionales en alcoholismo son identificadas de manera usual, pero sin claridad respecto a la diferenciación de si estas son secuelas o son previas al mismo. El objetivo de la investigación fue realizar una revisión de las publicaciones de los años 2010 a 2015 respecto a la neurobiología y el funcionamiento ejecutivo desde los enfoques de secuelas y de vulnerabilidad, en PubMed, Dialnet, Elsevier y Google Scholar, con los descriptores en inglés y español secuelas o vulnerabilidad neurobiológica al alcoholismo y secuelas o vulnerabilidad en funciones ejecutivas en el alcoholismo. Se encontraron 59 artículos de los cuales 37 corresponden al modelo de secuelas y 22 al modelo de vulnerabilidad. Se evidencia incremento en los estudios que resaltan los factores de predisposición neurobiológica y neuropsicológica para el inicio de consumo de alcohol.

Abstract Structural and functional alterations are usually identified, but without clarity regarding the definition of whether they are prior to it. The objective was to review the publications of 2010 to 2015 regarding neurobiology and executive functioning from the sequel and vulnerability models, publishing in PubMed, Dialnet, Elsevier and Google Scholar, with Spanish and English descriptor: sequel or neurobiological vulnerability to alcoholism and sequelae or vulnerability in executive functions on alcoholism. We found 59 articles of which 37 correspond to sequel model and 22 to vulnerability model. It evidenced an increase in studies about neurobiological and neuropsychological predisposition for onset of alcohol consumption.

Neurotransmitters in alcoholism: A review of neurobiological and genetic studies.

Recent advances in the study of alcoholism have thrown light on the involvement of various neurotransmitters in the phenomenon of alcohol addiction. Various neurotransmitters have been implicated in alcohol addiction due to their imbalance in the brain, which could be either due to their excess activity or inhibition. This review paper aims to consolidate and to summarize some of the recent papers which have been published in this regard. The review paper will give an overview of the neurobiology of alcohol addiction, followed by detailed reviews of some of the recent papers published in the context of the genetics of alcohol addiction. Furthermore, the author hopes that the present text will be found useful to novices and experts alike in the field of neurotransmitters in alcoholism.

Imagens do corpo e imagens do eu: Ramachandran, Sacks e Damásio / Body images and self images: Ramachandran, Sacks e Damásio

Abordar o tema da imagem corporal na contemporaneidade é acima de tudo ressaltar a sua importância a partir dos transtornos da percepção da imagem do corpo. No entanto, a tecnologia médica forneceu à neurologia e às neurociências novos subsídios para a compreensão dos distúrbios da imagem corporal verificando in loco todos os distúrbios cerebrais correlacionados às disfunções de imagem corporal. Sem a representação mental ou física do nosso próprio corpo, não conseguiríamos ter a noção de ipseidade no mundo. Quando o esquema corporal entra em conflito com a imagem corporal, podemos encontrar aquilo que denominamos de distorções da imagem do corpo. Esse campo tem sido colocado em relevo por novas disciplinas, transformando o cérebro como o agente principal da nossa identidade pessoal, tal como formulado pelo conceito de sujeito cerebral. A partir dessa perspectiva, objetivamos analisar as origens da imagem corporal a partir de três autores nitidamente distintos: Ramachandran e os membros fantasmas, que procura compreender a formação da imagem corporal a partir de um mapa cerebral; Oliver Sacks a partir de uma neuro-fenomenologia do eu e António Damásio a partir da neuro-anatomia das emoções e dos sentimentos e sua correlação com a corporeidade. Mostrar essas abordagens torna-se necessário primeiramente para que possamos sair de uma abordagem reducionista, materialista e localizacionista, fomentado pelas disciplinas médicas que tem ganho notoriedade nos últimos anos; segundo, para construção de novas metáforas ou narrativas da mente no campo dos distúrbios de imagens corporais, e por fim, para mostrar o ônus teórico que se encontra em cada uma dessas disciplinas.

To study body-image today is to standing out its importance from the perception of body image disfunctions. However, the medical technology supplied to neurology and to neuroscience gave new approaches to the understanding the body-image disfunctions verifying all the correlated cerebral roots to the disfuctions of body-image. Without the mental or physical representation of our body, we would not obtain our sense we are one in the world. When the body-schema enters in conflict with the "body-image ", wecan find what we call distortions of body-image". This approach has been placed inrelief for new disciplines wich the brain become a new agent of our personal identity as brainhood (cerebral subject). To this point of view, we aims to analyze the origins of the body-image, identity, subjectivity and self image from three distinct approaches: Ramachandran and the their "phantom limbs", wich body image is understood as a brain map; Oliver Sacks from a neuro- phenomenology of the self and António Damásio from the neuro-anatomy ou neuro-biology of emotions and feelings and its correlation with the corporeality or embodiment. First of all, to analize these differents approaches is important because we can leave a reducionist, materialistic and localizacionist toughts,to the new disciplines whom profit has notoriety in the last years; second, forconstruction of new metaphors or narratives of the mind and self in the field of bodyimage, and finally, to show the theoretical responsibility that found out in each one of these respective discipline..

Un modelo anfibio para el estudio evolutivo del control respiratorio / Anphibian model study for evolutionary respiratory control

Los enormes progresos de la medicina perinatal han permitido la sobrevivencia de recién nacidos prematuros en estadios de desarrollo cada vez más precoces. Estos pequeños pacientes requieren de medios muy sofisticados y costosos para paliar su inmadurez respiratoria. Además de las complicaciones asociadas al desarrollo pulmonar, la inestabilidad respiratoria y las apneas asociadas a la inmadurez de los circuitos nerviosos productores del control respiratorio, contribuyendo éstos últimas, como factor principal de morbilidad, a las prolongadas hospitalizaciones que presenta esta tan vulnerable población. Éstos imperativos médicos combinados a la curiosidad fisiológica han contribuido al desenvolvimiento de novedosas investigaciones en neurobiología respiratoria. Si bien la mayoría de los trabajos realizados en éste campo utilizan a los múridos como modelos experimentales, las investigaciones recientes efectuadas a partir del tronco cerebral aislado de anfibios (Rana catesbeiana) han revelado las ventajas técnicas de este modelo animal, para mostrar los principales fenómenos que rigen el funcionamiento y el desarrollo del sistema de control respiratorio entre los vertebrados. El presente artículo se propone repasar los avances más recientes realizados en la investigación de la neurobiología evolutiva del control respiratorio, prestando una atención particular a la respiración episódica, así como al rol que desempeñan la modulación serotoninérgica y Gabaérgica de la actividad respiratoria en el curso del desarrollo.

Recent perinal advances have made possible that premature newborns survive increasingtly in earlier developmental stages. This babies requires sophisticated and costly critical intensive care to address the problems associated with inmadurity of the respiratory system. In addition respiratory instability and apnea reflecting inmaturity of the respiratory control system are major causes of morbidity and prolonged hospitalization in this highly vulnerable group of patients. These concerns have contributed to the development of research in respiratoy evolutionary neurobiology. While the majority of researchers working in this field use rodents as an animal model, recent research using in vitro brainstem preparations from bullfrog (Rana catesbeiana) have reveled the technical advantages of this model to study the basic principles underlying respiratory control and its ontogeny between vertebrates. The present article review the recent advances in the area of research with special interest on episodic breathing and the role of serotoninergic and GABAergic modulation of respiratory control during development.