What Electrophysiology Tells Us About Alzheimer’s Disease::A Window into the Synchronization and Connectivity of Brain Neurons

Electrophysiology provides a real-time readout of neural functions and network capability in different brain states, on temporal (fractions of milliseconds) and spatial (micro, meso, and macro) scales unmet by other methodologies. However, current international guidelines do not endorse the use of electroencephalographic (EEG)/magnetoencephalographic (MEG) biomarkers in clinical trials performed in patients with Alzheimer’s disease (AD), despite a surge in recent validated evidence. This Position Paper of the ISTAART Electrophysiology Professional Interest Area endorses consolidated and translational electrophysiological techniques applied to both experimental animal models of AD and patients, to probe the effects of AD neuropathology (i.e., brain amyloidosis, tauopathy, and neurodegeneration) on neurophysiological mechanisms underpinning neural excitation/inhibition and neurotransmission as well as brain network dynamics, synchronization, and functional connectivity reflecting thalamocortical and cortico-cortical residual capacity. Converging evidence shows relationships between abnormalities in EEG/MEG markers and cognitive deficits in groups of AD patients at different disease stages. The supporting evidence for the application of electrophysiology in AD clinical research as well as drug discovery pathways warrants an international initiative to include the use of EEG/MEG biomarkers in the main multicentric projects planned in AD patients, to produce conclusive findings challenging the present regulatory requirements and guidelines for AD studies

Impaired glucose metabolism reduces the neuroprotective action of adipocytokines in cognitively normal older adults with insulin resistance.

Evidence suggests that aging-related dysfunctions of adipose tissue and metabolic disturbances increase the risk of diabetes and metabolic syndrome (MtbS), eventually leading to cognitive impairment and dementia. However, the neuroprotective role of adipocytokines in this process has not been specifically investigated. The present study aims to identify metabolic alterations that may prevent adipocytokines from exerting their neuroprotective action in normal ageing. We hypothesize that neuroprotection may occur under insulin resistance (IR) conditions as long as there are no other metabolic alterations that indirectly impair the action of adipocytokines, such as hyperglycemia. This hypothesis was tested in 239 cognitively normal older adults (149 females) aged 52 to 87 years (67.4 ± 5.9 yr). We assessed whether the homeostasis model assessment-estimated insulin resistance (HOMA-IR) and the presence of different components of MtbS moderated the association of plasma adipocytokines (i.e., adiponectin, leptin and the adiponectin to leptin [Ad/L] ratio) with cognitive functioning and cortical thickness. The results showed that HOMA-IR, circulating triglyceride and glucose levels moderated the neuroprotective effect of adipocytokines. In particular, elevated triglyceride levels reduced the beneficial effect of Ad/L ratio on cognitive functioning in insulin-sensitive individuals; whereas under high IR conditions, it was elevated glucose levels that weakened the association of the Ad/L ratio with cognitive functioning and with cortical thickness of prefrontal regions. Taken together, these findings suggest that the neuroprotective action of adipocytokines is conditioned not only by whether cognitively normal older adults are insulin-sensitive or not, but also by the circulating levels of triglycerides and glucose, respectively.This work was supported by the Spanish Ministry of Economy and Competitiveness (PSI2017-85311-P to M.A., PSI2017-89389-C2-2-R to F.D., PID2020-118825GB-I00 to M.A., PID2020-119978RB-I00 to J.L.C.), CIBERNED (CB06/05/1111 to J.L.C.), the International Center on Aging CENIE-POCTEP (0348_CIE_6_E to M.A.), the Research Program for a Long-Life Society (0551_PSL_6_E to J.L.C.), the Junta de Andalucía (PY20_00858 to J.L.C.), the Andalucía-FEDER Program (UPO-1380913 to J.L.C.), and the Galician Government (ED431-2017/27 to F.D.) with ERDF/FEDER funds.S

Valoración de la eficacia de un blog de medicina de urgencias como medio de comunicación

Objetivos: En 2006 SEMES Galicia aprobó la creación de un blog de medicina de urgencias, adaptándose a las nuevas tendencias en comunicación. Después de un año realizó un estudio para determinar el interés que despertaba, cuyos objetivos fueron, entre otros, analizar su frecuentación, el grado de fidelidad, el porcentaje de abandono desde la misma página de acceso y la relación entre el número de artículos publicados y su frecuentación. Material y método: Se realizaron estudios descriptivos, analíticos y de correlación para determinar la frecuentación, la fidelidad, el porcentaje de abandono desde la página de acceso y la distribución geográfica de los lectores, así como la relación entre los artículos publicados y las visitas recibidas. Se utilizaron los programas Google Analytics y el SPSS 12.0 for Windows. Resultados: A lo largo del año creció la frecuentación del blog cada mes y pasó de una única página vista en el mes de enero a 3.800 en diciembre. El 93% de las visitas procedieron de España, sobre todo de Galicia (50%). La fidelidad fue media, alta o muy alta en el 49%. Cuando la página de acceso al blog era la principal, el 52% no lo abandonaba y se visitaban otras secciones. La frecuentación del blog estaba directamente relacionada con el número de artículos publicados (r = 0,9, p < 0,01). Conclusiones: El interés por el blog ha crecido a lo largo del año. La mayoría de nuestros visitantes fueron fieles, pues repitieron sus visitas, y leyeron otras secciones además de la página principal. La frecuentación del blog estuvo directamente relacionada con el número de artículos publicados. El 93% de visitas procedieron de España. El blog SEMES Galicia es un poderoso y barato medio de comunicación

Assessing the effect of sound complexity on the audiotactile cross-modal dynamic capture task.

Neurophysiological and behavioural evidence now show that audiotactile interactions are more pronounced for complex auditory stimuli than for pure tones. In the present study, we examined the effect of varying the complexity of auditory stimuli (i.e., noise vs. pure tone) on participants' performance in the audiotactile cross-modal dynamic capture task. Participants discriminated the direction of a target stream (tactile or auditory) while simultaneously trying to ignore the direction of a distracting auditory or tactile apparent motion stream presented in a different sensory modality (i.e., auditory or tactile). The distractor stream could be either spatiotemporally congruent or incongruent with respect to the target stream on each trial. The results showed that sound complexity modulated performance, decreasing the accuracy of tactile direction judgements when presented simultaneously with noise distractors, while facilitating judgements of the direction of the noise bursts (as compared to pure tones). Although auditory direction judgements were overall more accurate for noise (than for pure tone) targets, the complexity of the sound failed to modulate the tactile capture of auditory targets. These results provide the first demonstration of enhanced audiotactile interactions involving complex (vs. pure tone) auditory stimuli in the peripersonal space around the hands (previously these effects have only been reported in the space around the head)