Concentración preoperatoria de fibrinógeno plasmático como predictor de sangrado en artroplastía total de cadera / Preoperative concentration of plasma fibrinogen as a predictor of bleeding in total hip arthroplasty

Resumen: Introducción: La artroplastía total de cadera tiene popularidad debido al éxito en el tratamiento de coxartrosis; son procedimientos asociados a la pérdida de sangre. Un sangrado importante provoca complicaciones como aumento en días de estancia intrahospitalaria, mayor costo de la enfermedad, exponiendo al paciente a complicaciones asociadas a transfusión sanguínea. El objetivo del estudio es investigar asociación entre concentración de fibrinógeno plasmático preoperatorio con sagrado transquirúrgico y determinar el nivel de corte de fibrinógeno para presentar mayor sangrado transquirúrgico. Material y métodos: Estudio retrospectivo, observacional, analítico, de Junio a Diciembre de 2020, incluyendo 227 pacientes con coxartrosis IV de la escala de Kellgren y Lawrence sometidos a artroplastía total primaria de cadera, derechohabientes, mayores de 18 años, en ausencia de enfermedades hepáticas o hematológicas y antecedente de sangrado quirúrgico importante. Resultados: El valor promedio de hemoglobina preoperatoria fue 14.6 ± 1.3 g/dl, posterior a cirugía (48 horas) 10.5 ± 1.4 g/dl; observando descenso de 4.1 ± 1.2 g/dl (p ≤ 0.0001). Valor promedio del hematocrito prequirúrgico 43% [41-45], posterior al procedimiento 32% [29-35]; se observó descenso de 11% [8-14] (p ≤ 0.0001); 98 pacientes presentaron sangrado transquirúrgico ≥ 300 ml; 129 tuvieron sangrado ≤ 300 ml; 61.2% de pacientes con sangrado mayor de 300 ml mostraron valores de fibrinógeno debajo del punto de corte (388 mg/dl). Conclusión: En pacientes postoperados los niveles preoperatorios de fibrinógeno ≤ 388 mg/dl y edad ≥ 58 años se asociaron al aumento en el riesgo del OR = 0.18 (IC 95% 0.10-0.32) de presentar sangrado transquirúrgico ≥ 300 ml, con descenso de la Hb de 4.1 ± 1.2 g/dl (p = 0.0001) y Hto de 11% [8-14] (p = 0.0001) entre el preoperatorio y el postoperatorio en 48 horas.

Abstract: Introduction: Total hip arthroplasty is popular for its success in treating coxarthrosis, its associated with substantial blood loss. Significant bleeding causes complications such as increase in hospitalization days, higher costs, exposing the patient to complications associated with blood transfusion. The aim of the study is to investigate the association between preoperative plasma fibrinogen concentration and trans-surgical bleeding and determine fibrinogen level cut-off to present greater trans-surgical bleeding. Material and methods: Retrospective, observational, analytical study, from June to December 2020, including 227 patients with Kellgren and Lawrence scale IV coxarthrosis undergoing primary total hip arthroplasty, beneficiaries, older than 18 years, without liver or hematological diseases, and history of significant surgical bleeding. Results: Mean preoperative hemoglobin value was 14.6 ± 1.3 g/dl, after surgery (48 hours) 10.5 ± 1.4 g/dl; decrease of 4.1 ± 1.2 g/dl (p ≤ 0.0001). Mean preoperative hematocrit value 43% [41-45], after the procedure; 32% [29-35]; decrease of 11% [8-14] (p ≤ 0.0001). 98 patients had intraoperative bleeding ≥ 300 ml, 129 had ≤ 300 ml; 61.2% of patients with bleeding greater than 300 ml had fibrinogen values below the cut-off point (388 mg/dl). Conclusion: In postoperative patients, preoperative fibrinogen levels ≤ 388 mg/dl and age ≥ 58 years were associated with an increased risk of OR = 0.18 (95% CI 0.10-0.32) of presenting trans-surgical bleeding ≥ 300 ml, with a decrease in Hb of 4.1 ± 1.2 g/dl (p = 0.0001) and Hto of 11% [8-14] (p = 0.0001) between the pre and postoperative period in 48 hours.

[Preoperative concentration of plasma fibrinogen as a predictor of bleeding in total hip arthroplasty]. / Concentración preoperatoria de fibrinógeno plasmático como predictor de sangrado en artroplastía total de cadera.

INTRODUCTION: Total hip arthroplasty is popular for its success in treating coxarthrosis, its associated with substantial blood loss. Significant bleeding causes complications such as increase in hospitalization days, higher costs, exposing the patient to complications associated with blood transfusion. The aim of the study is to investigate the association between preoperative plasma fibrinogen concentration and trans-surgical bleeding and determine fibrinogen level cut-off to present greater trans-surgical bleeding. MATERIAL AND METHODS: Retrospective, observational, analytical study, from June to December 2020, including 227 patients with Kellgren and Lawrence scale IV coxarthrosis undergoing primary total hip arthroplasty, beneficiaries, older than 18 years, without liver or hematological diseases, and history of significant surgical bleeding. RESULTS: Mean preoperative hemoglobin value was 14.6 ± 1.3 g/dl, after surgery (48 hours) 10.5 ± 1.4 g/dl; decrease of 4.1 ± 1.2 g/dl (p 0.0001). Mean preoperative hematocrit value 43% [41-45], after the procedure; 32% [29-35]; decrease of 11% [8-14] (p 0.0001). 98 patients had intraoperative bleeding 300 ml, 129 had 300 ml; 61.2% of patients with bleeding greater than 300 ml had fibrinogen values below the cut-off point (388 mg/dl). CONCLUSION: In postoperative patients, preoperative fibrinogen levels 388 mg/dl and age 58 years were associated with an increased risk of OR = 0.18 (95% CI 0.10-0.32) of presenting trans-surgical bleeding 300 ml, with a decrease in Hb of 4.1 ± 1.2 g/dl (p = 0.0001) and Hto of 11% [8-14] (p = 0.0001) between the pre and postoperative period in 48 hours.

INTRODUCCIÓN: La artroplastía total de cadera tiene popularidad debido al éxito en el tratamiento de coxartrosis; son procedimientos asociados a la pérdida de sangre. Un sangrado importante provoca complicaciones como aumento en días de estancia intrahospitalaria, mayor costo de la enfermedad, exponiendo al paciente a complicaciones asociadas a transfusión sanguínea. El objetivo del estudio es investigar asociación entre concentración de fibrinógeno plasmático preoperatorio con sagrado transquirúrgico y determinar el nivel de corte de fibrinógeno para presentar mayor sangrado transquirúrgico. MATERIAL Y MÉTODOS: Estudio retrospectivo, observacional, analítico, de Junio a Diciembre de 2020, incluyendo 227 pacientes con coxartrosis IV de la escala de Kellgren y Lawrence sometidos a artroplastía total primaria de cadera, derechohabientes, mayores de 18 años, en ausencia de enfermedades hepáticas o hematológicas y antecedente de sangrado quirúrgico importante. RESULTADOS: El valor promedio de hemoglobina preoperatoria fue 14.6 ± 1.3 g/dl, posterior a cirugía (48 horas) 10.5 ± 1.4 g/dl; observando descenso de 4.1 ± 1.2 g/dl (p 0.0001). Valor promedio del hematocrito prequirúrgico 43% [41-45], posterior al procedimiento 32% [29-35]; se observó descenso de 11% [8-14] (p 0.0001); 98 pacientes presentaron sangrado transquirúrgico 300 ml; 129 tuvieron sangrado 300 ml; 61.2% de pacientes con sangrado mayor de 300 ml mostraron valores de fibrinógeno debajo del punto de corte (388 mg/dl). CONCLUSIÓN: En pacientes postoperados los niveles preoperatorios de fibrinógeno 388 mg/dl y edad 58 años se asociaron al aumento en el riesgo del OR = 0.18 (IC 95% 0.10-0.32) de presentar sangrado transquirúrgico 300 ml, con descenso de la Hb de 4.1 ± 1.2 g/dl (p = 0.0001) y Hto de 11% [8-14] (p = 0.0001) entre el preoperatorio y el postoperatorio en 48 horas.

Uso de perifiton en un sistema de policultivo en agro acuicultura integrada en la comunidad indígena de Jimaín, Sierra Nevada de Santa Marta (Colombia) / Periphyton-based polyculture in an integrated agri-aquaculture system at the indigenous community of Jimaín, Sierra Nevada de Santa Marta (Colombia)

RESUMEN Los Sistemas de Agro Acuicultura Integrada (SAAI) han sido estudiados como opción para la producción de pescado en comunidades con recursos limitados. Así mismo, el uso de perifiton se ha convertido recientemente en una alternativa viable por el aporte de alimento natural de bajo costo. El objetivo de este estudio fue evaluar el efecto del perifiton sobre el desempeño productivo del policultivo Piaractus sp. (cachama híbrida) y Prochilodus magdalenae (bocachico) en SAAI en la comunidad Indígena de Jimaín, Colombia. Se sembraron 1,5 alevinos de cachama híbrida y 1,5 bocachicos/m2, con peso promedio de 0,49 ± 0,14 g y 1,83 ±1,61 g respectivamente, en seis estaques en tierra de 90 m2 tres de los cuales contaron con varas de madera (3 varas/m2) para la fijación de perifiton. La duración del cultivo fue de 135 días. Los tratamientos (CS: con sustrato y SS: sin sustratos) recibieron una dieta suplementaria dos veces al día, calculada como porcentaje de la biomasa con ajuste quincenal. Se realizaron biometrías quincenales. Los datos productivos por especie y para el policultivo se evaluaron mediante ANOVA con un modelo lineal general (p < 0,05). Los datos de peso (g) y longitud estándar (cm) por especie se evaluaron mediante un modelo mixto de medidas repetidas. No se encontraron efectos del sustrato sobre los parámetros productivos analizados tanto para cada especie, como para el policultivo. Se presentó interacción significativa para el peso del bocachico el día 90 (CS: 74,7 y SS: 47,1). Según los resultados obtenidos, la utilización de perifiton y el manejo en policultivo de especies nativas requiere más estudios.

ABSTRACT Integrated agri-aquaculture systems (IAAS) have been studied as an option for fish production in communities with limited resources. Likewise, the use of periphyton has recently become a viable alternative for its contribution of low-cost natural food. The effect of periphyton use on the productive yield of a hybrid cachama and bocachico polyculture in IAAS, was studied in the Jimaín Indigenous community, Colombia. For this experiment, 1.5 hybrid cachama and 1.5 bocachico fingerlings/m2 were stocked with average weights of 0.49 ± 0.14 g and 1.83 ± 1.61 g, respectively, in six 90 m2 land ponds; three of these ponds had wooden dowels (three dowels/m2) for periphyton fixation. The growth evaluation lasted 135 days. The treatments (WS: with substrate and WOS: without substrates) received a supplementary diet, adjusted as a percentage of the biomass with biweekly adjustment, twice a day. Biometrics were performed every two weeks. The productive data by species and for the polyculture were evaluated using an ANOVA with a general linear model (p <0.05). Weight (g) and standard length (cm) data by species were evaluated using a mixed model of repeated measures. No substrate effects were found on the productive parameters analyzed for each species as well as for the polyculture. A significant interaction was observed for bocachico weight on day 90 (WS: 74.7 and WOS: 47.1). According to the obtained results, optimizing the use of periphyton and the management of native species polyculture requires further studies.

Síndrome de hipermovilidad articular / Joint hypermobility syndrome

Resumen: El síndrome de hipermovilidad articular es un desorden hereditario con patrón autosómico dominante; se caracteriza por hiperlaxitud articular y dolores musculoesqueléticos. El término hipermovilidad se refiere al incremento en los movimientos activos o pasivos de las articulaciones con base en sus rangos normales. El síndrome de hipermovilidad articular presenta además síntomas gastrointestinales, trastornos de sueño, fibromialgia, trastornos sicológicos, cefalea migrañosa, oftálmicos, autonómicos, entre otros. Para diagnosticar el síndrome de hipermovilidad, en general son aceptados los criterios de Brighton, los cuales fueron publicados en 1998. También se le conoce como síndrome de hipermovilidad articular benigno. El término benigno se utiliza para distinguirlo de otras condiciones más severas como Ehler-Danlos (tipo clásico o vascular), síndrome de Marfan y osteogénesis imperfecta. El tratamiento con fisioterapia y medidas farmacológicas ayudan a mejorar la calidad de vida de los pacientes.

Abstract: Joint hypermobility syndrome is an inherited disorder with autosomal dominant pattern; is characterized by joint hyperlaxity and musculoskeletal pains. Thermal hypermobility refers to the increase in active or passive movements of joints based on their normal ranges. Joint hypermobility syndrome also has gastrointestinal symptoms, sleep disorders, fibromyalgia, psychological disorders, migraine headache, ophthalmic, autonomic, among others. To diagnose hypermobility syndrome, Brighton's criteria are generally accepted and published in 1998. This criteria also known as benign joint hypermobility syndrome. The term benign is used to distinguish it from other more severe conditions such as Ehler-Danlos (classic or vascular type), Marfan syndrome, and imperfect osteogenesis. Treatment with physiotherapy and pharmacological means help improve patients' quality of life.

[Joint hypermobility syndrome]. / Síndrome de hipermovilidad articular.

Joint hypermobility syndrome is an inherited disorder with autosomal dominant pattern; is characterized by joint hyperlaxity and musculoskeletal pains. Thermal hypermobility refers to the increase in active or passive movements of joints based on their normal ranges. Joint hypermobility syndrome also has gastrointestinal symptoms, sleep disorders, fibromyalgia, psychological disorders, migraine headache, ophthalmic, autonomic, among others. To diagnose hypermobility syndrome, Brighton's criteria are generally accepted and published in 1998. This criteria also known as benign joint hypermobility syndrome. The term benign is used to distinguish it from other more severe conditions such as Ehler-Danlos (classic or vascular type), Marfan syndrome, and imperfect osteogenesis. Treatment with physiotherapy and pharmacological means help improve patients' quality of life.

El síndrome de hipermovilidad articular es un desorden hereditario con patrón autosómico dominante; se caracteriza por hiperlaxitud articular y dolores musculoesqueléticos. El término hipermovilidad se refiere al incremento en los movimientos activos o pasivos de las articulaciones con base en sus rangos normales. El síndrome de hipermovilidad articular presenta además síntomas gastrointestinales, trastornos de sueño, fibromialgia, trastornos sicológicos, cefalea migrañosa, oftálmicos, autonómicos, entre otros. Para diagnosticar el síndrome de hipermovilidad, en general son aceptados los criterios de Brighton, los cuales fueron publicados en 1998. También se le conoce como síndrome de hipermovilidad articular benigno. El término benigno se utiliza para distinguirlo de otras condiciones más severas como Ehler-Danlos (tipo clásico o vascular), síndrome de Marfan y osteogénesis imperfecta. El tratamiento con fisioterapia y medidas farmacológicas ayudan a mejorar la calidad de vida de los pacientes.

El trabajo multidisciplinar en el abordaje del dolor crónico. La hipnosis como coadyuvante / Multidisciplinary work in addressing chronic pain assisted by hypnosis

No disponible

Seroprevalence of Trypanosoma cruzi in kidney transplant donors and recipients in Mexico City.

Infectious diseases are common causes of morbidity and mortality among kidney transplant recipients. Chagas disease (CD) has been recognized as an emerging infectious complication of transplantation caused by the parasite Trypanosoma cruzi. CD is prevalent in Mexico, particularly in the southern coastal region. The impact on Mexican kidney transplant programs has not been previously studied prospectively. From 2009 through 2010, serum samples from 59 kidney transplant donors and 405 renal transplant recipients were screened for antibodies against T. cruzi. Serum was initially screened using a locally developed ELISA test; positive results were confirmed by an indirect immunofluorescense test, in accordance with Panamerican Health Organization/World Health Organization guidelines. None of the donors were seropositive for T. cruzi, while 8 (1.97%) kidney transplant recipients were confirmed to be seropositive for T. cruzi. None of them have developed clinical manifestations of CD, although specific screening of recipients was not performed. A prospective study is planned to define the epidemiology and outcome of CD among kidney transplant donors and recipients in Mexico more thoroughly.

Dopaminergic activity coincides with stimulus detection by the frontal lobe.

For midbrain dopamine (DA) neurons to respond to sensory events, the presence of a stimulus must first be detected. Where is the signal that activates DA neurons coming from? Here we show that DA responses to a vibrotactile stimulus lag significantly behind those of the primary somatosensory cortex, but they arise with a latency that closely matches the onset of premotor neurons known to encode perceptual decisions. In agreement with previous findings, these data suggest that sensory evoked DA activity does not signal a stimulus physical presence but arises from the output of a perceptual decision.

Immune response after rabies vaccine in a kidney transplant recipient.

A 48-year-old male kidney-transplant recipient was bitten by a rabid dog. His immunosuppressive treatment consisted of cyclosporine 60 mg b.i.d., mycophenolate mofetil (MMF) 250 mg t.i.d., and prednisone 5 mg. After wound care, he received 5 doses of purified vero cell rabies vaccine on days 0, 3, 7, 14, and 28, and human rabies immunoglobulin, according to international guidelines. Adequate levels of rabies virus neutralizing antibodies were observed after the administration of the third vaccine dose. However, a decrease of antibody titer was detected by day 28. Immunosuppressive medication was minimized, withdrawing MMF and reducing the dose of cyclosporine. Booster doses of the same vaccine were administered on days 38, 41, 45, 52, and 66. Adequate neutralizing antibody response was recovered during the ensuing 12 months, under reduced immunosuppression. Nineteen months after the incident, the patient remains with good graft function and is asymptomatic for rabies. It remains to be determined whether the attained immune response was either the result of the booster vaccinations or the reduction of immunosuppression alone. Nevertheless, such an outcome would have been possible only with the combined management strategy implemented.

El papel de la atención a la urgencia en el seno del Sistema Sanitario Español. Una perspectiva histórica y global / No disponible

Se presenta una breve historia de la evolución de la atenciónal enfermo crítico en el ámbito occidental, con especialreferencia a nuestro país, diferenciando el desarrollo de lasactividades propias de los cuidados intensivos hospitalariosde los prehospitalarios y de la atención primaria, finalizandocon unas breves reflexiones sobre la visión del problemapresente y futura.La asistencia intensiva comenzó en España en 1968, en laClínica de la Concepción, bajo la dirección de anestesiólogos,desarrollándose posteriormente durante los añossetenta la especialidad de Medicina Intensiva.Con respecto a la atención urgente, suministrada inicialmentepor dispensarios, casas de socorro y equipos quirúrgicosmunicipales, servicios normales y especiales deurgencias les fueron sustituyendo modernos dispositivosmóviles, incluidos en sistemas integrales al estilo francoalemán,británico y norteamericano. Se está a la espera deuna normativa unificadora de ámbito nacional, encontrándonosen un proceso tácito de reflexión crítica(AU)

We introduce a brief history of the evolution of criticalcare patients inWestern, with special reference to our country,distinguishing the development of the activities of thehospital intensive care and the prehospital care, endingwith brief reflections on the vision of present and futureproblems.The intensive care in Spain began in 1968 in the Clínicade la Concepción, under the guidance of anesthesiologists,developed during the subsequent 70 years the specialty ofIntensive Care Medicine.With regard to the urgent attention, initially provided byclinics, houses of local relief and surgical equipment, servicesand special emergency were replacing modern mobiledevices, including systems in the style Franco-German,British and American.We wait for a unifying national legislation,finding ourselves in a process of critical tacit reflection(AU)

Severe alterations in expression and localisation of {alpha}6{beta}4 integrin in salivary gland acini from patients with Sjogren syndrome.

OBJECTIVES: In salivary glands from patients with Sjögren syndrome, overexpression of laminins 1 and 5 and disorganisation of the acinar basal lamina have been reported. Laminin 5 mediates association of the basal lamina with epithelial cells by forming adhesion complexes upon interaction with alpha6beta4 integrin. In the present work, mRNA and protein levels of alpha6beta4 integrin were determined and its localisation in salivary glands evaluated in patients with Sjögren syndrome. METHODS: Salivary glands of 12 patients with Sjögren syndrome and 8 controls were studied. The mRNA and protein levels of alpha6beta4 were determined by semiquantitative reverse transcriptase (RT)-PCR and western blot analysis, respectively. The subcellular localisation of alpha6beta4 and laminin were evaluated by confocal microscopy. RESULTS: In patients, no significant differences in alpha6 and beta4 mRNA levels were detected. However, beta4 integrin protein levels were significantly lower, whereas, changes in alpha6, were highly variable. In controls, alpha6beta4 was detected in the basolateral and basal surface of serous and mucous acini, respectively. In patients, alterations in alpha6beta4 distribution were particularly dramatic for acini with strong basal lamina disorganisation. alpha6beta4 was also detected in the cytoplasm and lateral plasma membrane in serous and mucous acini. CONCLUSION: Mild alterations in the basal lamina correlated with lateral redistribution of alpha6beta4 integrin and the formation of new cell-cell adhesions that help maintain acinar organisation and promote cell survival. Conversely, in cases with severe basal lamina alterations, lateral alpha6beta4 redistribution was no longer sufficient to maintain acinar cell survival. Thus, maintenance of equilibrium between cell-cell and cell-basal lamina attachment is required to sustain gland cell survival.

Reduced sulfation of muc5b is linked to xerostomia in patients with Sjögren syndrome.

OBJECTIVES: MUC5B contains sulfated and sialylated oligosaccharides that sequester water required for moisturising the oral mucosa. Xerostomia, in patients with Sjögren syndrome, is generally associated with reduced quantities, rather than altered properties, of saliva. Here, we determined the amount of MUC5B (mRNA and protein) as well as sulfation levels in salivary glands of patients with normal or altered unstimulated salivary flow. Localisation of MUC5B and sulfated MUC5B, as well as total levels sulfated groups were determined and compared with acini basal lamina disorganisation. PATIENTS AND METHODS: In all, 18 patients with normal or altered unstimulated salivary flow and 16 controls were studied. MUC5B mRNA and protein were evaluated in salivary glands by semiquantitative RT-PCR and Western blot analysis. MUC5B sulfation was determined by Western blotting. MUC5B and sulfo-Lewis(a) antigen localisation were assessed by immunohistochemistry. The total amount of sulfated oligosaccharides was determined microdensitometrically. RESULTS: No significant differences were detected in MUC5B mRNA and protein levels between controls and patients, while sulfo-Lewis(a) antigen levels were lower in patients. The number of sulfo-Lewis(a) positive mucous acini was reduced in patients but no correlation was observed between lower levels of sulfation and unstimulated salivary flow. Microdensitometric data confirmed the presence of reduced sulfated oligosaccharides levels in mucous acini from patients with highly disorganised basal lamina. CONCLUSION: Disorganisation of the basal lamina observed in patients with Sjögren syndrome may lead to dedifferentiation of acinar mucous cells and, as a consequence, alter sulfation of MUC5B. These changes are suggested to represent a novel mechanism that may explain xerostomia in these patients.

Immunohistochemical characterization of human fulminant amoebic colitis.

In cases of fulminant amoebic colitis we have determined the interactions between Entamoeba histolytica trophozoites and immune cells in order to better understand the pathophysiology of amoebic colitis. Eleven specimens of amoebic colitis and five specimens of colon without amoebic lesions were studied. Trophozoites and immune cells were located by topographic stains, histochemistry and immunohistochemistry. Trophozoites were seen in both damaged and undamaged areas of the colonic mucosa. Specimens of fulminant amoebic colitis showed: (a) an increase in IgA+, IgG+ B cells and neutrophils; (b) a reduction in IgM+ B cells, CD8+ T cells, macrophages, eosinophils and mast cells; and (c) no change in the number of NK and CD4+ T cells. The cellular infiltrate in amoebic colitis may represent the combined effects of amoebic monocyte locomotion inhibitory factor and switching of IgM+ B cells to IgG+ and IgA+ plasma cells, induced by amoebic antigens. Tissue damage in the absence of trophozoites may result from ischaemia or host immune responses.

Probing the cortical neuronal correlates of a sensory discrimination process.

Key to understanding perception is the form of how sensory stimuli are represented in the evoked activity of the brain. Here, we addressed the question of which components of the evoked neuronal activity in the somatosensory cortex represent the stimulus features while trained monkeys discriminated the difference in frequency between two vibrotactile stimuli. We probed whether these cortical neuronal representations are essential to perception. The results show a strong link between the cortical representation of the stimulus and perception.

[Neural codes for perception]. / Códigos neurales para la percepción.

OBJECTIVE: This article describes experiments designed to show the neural codes associated with the perception and processing of tactile information. DEVELOPMENT: The results of these experiments have shown the neural activity correlated with tactile perception. The neurones of the primary somatosensory cortex (S1) represent the physical attributes of tactile perception. We found that these representations correlated with tactile perception. By means of intracortical microstimulation we demonstrated the causal relationship between S1 activity and tactile perception. In the motor areas of the frontal lobe is to be found the connection between sensorial and motor representation whilst decisions are being taken. CONCLUSIONS: S1 generates neural representations of the somatosensory stimuli which seen to be sufficient for tactile perception. These neural representations are subsequently processed by central areas to S1 and seem useful in perception, memory and decision making.

Códigos neurales para la percepción / Neural codes for perception

Objetivo. Este artículo describe experimentos diseñados para poner en evidencia los códigos neurales asociados a la percepción y el procesamiento de información táctil. Desarrollo. Los resultados obtenidos en estos experimentos han revelado la actividad neural correlacionada con la percepción táctil. Las neuronas de la corteza somatosensorial primaria (S1) representan los atributos físicos de los estímulos táctiles. Se encontró que estas representaciones se correlacionan con la percepción táctil. Se comprobó por medio de la microestimulación intracortical la relación causal entre la actividad de S1 y la percepción táctil. En las áreas motoras del lóbulo frontal se encontró el enlace entre las representaciones sensoriales y motoras durante la toma de decisiones. Conclusiones. S1 genera representaciones neurales de los estímulos somatosensoriales que parecen ser suficientes para la percepción táctil. Estas representaciones neurales son posteriormente procesadas por áreas centrales a S1 y parecen ser útiles para la percepción, memoria y la toma de decisiones (AU)

Tactile shape processing.

Neuroimaging techniques may aid in the identification of areas of the human brain that are involved in tactile shape perception. Bodegård et al. (2001) relate differences in the properties of tactile stimuli to differences in areas of cortical activation to infer tactile processing in the somatosensory network.