Seminario Dra. María Herrero

Seminario ICBM 2025

“Effect of age and sex on cognitive decline and neuroinflammation. Studies on Octodon Degus”

Dra. María-Trinidad Herrero Ezquerro
Catedrática de la Facultad de Medicina, de la Universidad de Murcia.
Directora del Instituto de Investigación en Envejecimiento, de la Universidad de Murcia.
Coordinadora del Programa de Doctorado de Envejecimiento y Fragilidad, de la Universidad de Murcia.
Directora del Máster Internacional de Trastornos del Movimiento, de la Universidad de Murcia.
Directora de la Cátedra ASISA de Comunicación Sanitaria, de la Universidad de Murcia.
 

ABSTRACT
Cognitive impairment is a shared feature for physiological aging and several types of dementia; thus, understanding how natural aging affects cognition and behavior is one of the main areas of interest in the field of neuroscience. The use of experimental models is a gold standard tool to uncover mechanistic and interventional studies of brain aging and neurodegeneration. In this line, several signs of neurodegeneration have been described in the Octodon degus (O. degus). However, no studies have been conducted along aging with a sex perspective. We studied the visuoespatial memory performance in vivo along aging with a sex perspective, and its possible relationship with the neuroinflammatory status (microglia and astrocytes) in the dorsal hippocampus. Considering the effect of age, aged O. degus (>4 years) showed a very significant cognitive impairment when they were compared to young animals. Interestingly, when possible differences associated with the sex were investigated, we found that they were significant in the aged animals: during the training sessions, the aged females showed a better performance than the aged males, which was reversed on the day of the final test. Post mortem studies revealed that, in all dorsal hippocampal subareas analyzed, neuroinflammation was significantly increased in older animals, being the basal immunolabeling levels for microglia and astrocytes higher in males than in females. Correlation analyses indicated that increased neuroinflammation is related to worse cognitive performance, especially in the dentate gyrus and Cornu Ammonis subfield 1. The information derived from these studies, for the first time and including sex as an experimental variable, characterizes age-associated cognitive decline in O. degus and its relationship to neuroinflammation in the dorsal hippocampus.