Relació entre patrons d’activitat autònoma i el record d’estímuls emocionals en joves sans

Antecedents: estudis previs han destacat que la naturalesa emocional dels estímuls i el nivell d’activitat de determinades estructures cerebrals responsables de la regulació de l’activitat autònoma condicionen la codificació i record posterior. Així doncs, aquest estudi pilot té com a principal objectiu explorar la relació entre patrons d’activitat autònoma i el record de material emocional. Mètode: es va registrar la freqüència cardíaca de forma continua en un total de 27 homes i dones d’entre 18 i 29 anys d’edat mentre eren exposats a estímuls emocionals. Immediatament després, havien de recordar les imatges que havien vist. Es van identificar dos grups diferenciats en quant al patró d’activitat cardiovascular: un grup que va mostrar un canvi en la seua activitat autònoma en ser exposat a estímuls emocionals –grup Canvi–, i un grup que no va canviar durant l’exposició –grup No-Canvi–. Resultats: els nostres resultats van mostrar que el grup de Canvi van recordar un major nombre d’imatges emocionals –negatives i positives– que d’imatges neutres. A més, el grup Canvi va mostrar un pitjor record d’imatges negatives, comparat amb el seu propi rendiment en el record d’imatges positives i amb el record d’imatges negatives pel grup No-Canvi. Conclusions principals: els resultats d’aquest estudi recolzen les dades prèvies que han destacat la importància de l’activació autònoma en el procés d’aprenentatge i record de material emocional

A low cortisol response to acute stress is related to worse basal memory performance in older people

Age-related memory decline has been associated with a faulty regulation of the hypothalamus-pituitary-adrenal axis (HPA-axis). The aim of this study was to investigate whether the magnitude of the stress-induced cortisol increase is related to memory performance when memory is measured in non-stressful conditions. To do so, declarative and working memory performance were measured in 31 men and 35 women between 55 and 77 years of age. On a different day, the magnitude of their cortisol response to acute psychosocial stress was measured. The relationship between the cortisol response and memory performance was U shaped: a low cortisol response to stress was related to poorer declarative and working memory performance, whereas those who did not increase their cortisol levels and those who had the largest cortisol increase had better declarative and working memory capabilities. Sex did not moderate these relationships. These results suggest that a low cortisol response to stress could reflect a defective HPA-axis response to stressors that is accompanied by poorer memory performance. Conversely, a high cortisol response seems to reflect a correct functioning of the HPA-axis and may protect against memory deficits in the later stages of human life

Cortisol and the aging brain: Hypothalamic-pituitary-adrenal axis and cognitive performance in older people.

One of the greatest achievements in modern society is the increase in life expectancy. This increment is so great that children born after 2011 have a one in three chance of reaching their 100th birthday, and specifically in Europe, a quarter of the population will be over 60 years of age by 2020 (European Commission, 2014). This is an important change in society that is occurring for the first time in human history and producing new challenges that need to be addressed, especially those concerning age-related health problems. In this regard, one of the main aims of new research programs, such as Horizon 2020 in Europe, is to increase the possibilities of keeping older people healthy and independent as long as possible. To do so, it is critical to understand what processes can provoke, or at least contribute to, an increase in the vulnerability of older people because this will help to develop new strategies of prevention and intervention. Conserving good cognitive functioning is especially important for the maintenance of independent life. Therefore, it is essential to identify those mechanisms that can affect cognitive performance in older people and their adaptation to the environment. Along these lines, changes in the activity of the hypothalamus-pituitary-adrenal axis (HPA-axis) have been related to changes in the cognitive performance of both young and older people, and it has become a research target that can shed light on the changes that can be observed in aging. This dissertation presents the results of a research study focused on investigating the relationship between cognitive performance and the activity of the HPA-axis in older people. The first chapter of this dissertation provides a description of the HPA-axis, its main functions and the biological samples commonly used in research to measure the hormone cortisol, the end product of this neuroendocrine axis. Additionally, this chapter explains the age-related changes that can be observed in the circadian activity of the HPA-axis and in the stress-induced cortisol response. The last part of this chapter presents a short overview of the studies that have investigated the effects of acute stress and cortisol on memory performance in young and older people, and the relationship between the basal activity of the HPA-axis and cognitive performance in older people. The second and third chapters present two studies designed to investigate the effect of acute stress on memory in older men and women. The first empirical study of this dissertation investigated the effects of the cortisol response to stress on long-term memory retrieval. In the second study, two experiments were performed to investigate the effects of acute stress on the memory span and the executive component of the working memory. The fourth chapter describes the third study, designed to investigate whether differences in the long-term endogenous cortisol exposure and in the diurnal regulation of the HPA-axis are related to inter-individual differences in the cognitive performance of older people. In this study, a new technique was used to assess cortisol levels in hair samples, making it possible to measure cortisol exposure during the three months prior to the cognitive performance assessment. The fifth chapter includes a study designed to investigate whether the cortisol awakening response, a discrete component of the diurnal HPA-axis, was related to walking speed, a commonly used measure of physical activity that has been closely related to cognitive performance in older people. Also focused on the CAR, the sixth chapter describes the fifth study. It investigated whether the CAR is different in normotensive and hypertensive older people. Additionally, the relationship between the cortisol awakening response and cognitive performance was studied in these two groups. The seventh chapter contains a general discussion, the clinical implications of the findings, study limitations, and future considerations drawn from the results of the previous empirical studies. Finally, the eighth chapter includes a summary of the main conclusions of this doctoral dissertation

Psicothema

Resumen tomado de la publicaciónRespuesta psicofisiológica a estresores sociales: relevancia del sexo y la edad. Antecedentes: entender los factores involucrados en la respuesta psicofisiológica ante situaciones de estrés agudo es crucial para prevenir y tratar problemas de salud relacionados con el estrés. El objetivo es integrar los resultados de estudios en humanos relacionados con el papel del sexo y la edad en las diferencias individuales en la respuesta de estrés en diferentes biomarcadores. Metodología: se integran los principales resultados de nuestro grupo de investigación y de otros laboratorios centrados en las diferencias debidas al sexo y la edad en la respuesta psicofisiológica a situaciones de estrés psicosocial. Resultados: se observan diferencias en la respuesta de estrés entre hombres y mujeres en presión sanguínea y en niveles de cortisol, pero no en frecuencia cardíaca, variabilidad de la frecuencia cardíaca y alfa-amilasa. Además, la edad influye en los niveles de cortisol y en la actividad basal del sistema nervioso simpático. Conclusiones: los resultados ponen de manifiesto la importancia de tener en cuenta el sexo y la edad de los participantes para poder entender la respuesta de estrés y sus posibles efectos en salud.Universidad de Oviedo. Biblioteca de Psicología; Plaza Feijoo, s/n.; 33003 Oviedo; Tel. +34985104146; Fax +34985104126; [email protected]

Psicothema

Resumen basado en el de la publicaciónDepresión y riesgo de suicidio en el deterioro cognitivo leve: el rol de los biomarcadores de la enfermedad de Alzheimer. Antecedentes: los pacientes con depresión y deterioro cognitivo leve (DCL) tienen un alto riesgo de desarrollar demencia. La depresión implica un alto riesgo de ideación suicida (IS) e intentos de suicidio (AS). Los biomarcadores de la enfermedad de Alzheimer (EA) pueden clarificar el papel de la depresión e IS en la EA. Método: cincuenta y nueve participantes >50 años con criterios de DCL-EA positivo (DCL-EA; 22) y negativo (DCL-NoEA; 24) y 13 controles sanos. La depresión fue evaluada con la Escala Geriátrica de Depresión (GDS-30) y la IS con el factor GDS-IS. Además, se midieron los siguientes biomarcadores en el líquido cefalorraquídeo: ß-amiloide (ß-A), tau hiperfosforilada (H-tau) y total (T-tau). Resultados: no se encontraron diferencias significativas entre los tres grupos de participantes en depresión o en IS. Sin embargo, en el grupo DCL-EA, niveles más bajos de H-tau y T-tau, indicadores de menor patología EA, se relacionaron significativamente con mayor riesgo de suicidio indirecto. Conclusiones: este resultado subraya la importancia de considerar la IS en fases iniciales de EA, y el potencial papel de los biomarcadores de EA para detectar sus síntomas.ES