Sensory and memory processing in old female and male Wistar rat brain, and its relationship with the cortical and hippocampal redox state

Abstract

The brain is one of the most sensitive organs damaged during aging due to its susceptibility to the aging-related oxidative stress. Hence, in this study, the sensory nerve pathway integrity and the memory were evaluated and related to the redox state, the antioxidant enzymes function, and the protein oxidative damage in the brain cortex (Cx) and the hippocampus (Hc) of young (4-month-old) and old (24-month-old) male and female Wistar rats. Evoked potentials (EP) were performed for the auditory, visual, and somatosensory pathways. In both males and females, the old rat groups' latencies were larger in almost all waves when compared to the young same-sex animals. The novel object test was performed to evaluate memory. The superoxide dismutase and catalase antioxidant activity, as well as the protein oxidative damage, and the redox state were evaluated. Magnetic resonance (MR) imaging was used to obtain the diffusion tensor imaging, and the brain volume, while MR spectroscopy was used to obtain the brain metabolite concentrations (glutamine, glutamate, Myo-inositol, N-acetyl-aspartate, creatine) in the Cx and the Hc of young and old females. Our data suggest that, although there are limited variations regarding memory and nerve conduction velocity by sex, the differences concerning the redox status might be important to explain the dissimilar reactions during brain aging between males and females. Moreover, the increment in Myo-inositol levels in the Hc of old rats

Combination of memantine and alpha7 nicotinic acetylcholine receptor ligands exerts superior efficacy over monotreatments to improve cognitive performance of aged rats

“…The present study provides evidence for the beneficial procognitive effects of combination treatments by co-targeting glutamatergic and cholinergic neurotransmission in the brain using memantine and two α7 nAChR-selective agents in naturally aged rats. We confirmed that aged rats display substantial cognitive impairment compared to young rats which is in line with several earlier preclinical studies (Burger et al 2007; Long et al 2009; Santín-Márquez et al 2021). Monotreatments with memantine or two α7 nAChR ligands could alleviate the age-related cognitive impairment of rats at certain doses.…”

Chronic consumption of a hypercaloric diet increases neuroinflammation and brain senescence, promoting cognitive decline in middle-aged female Wistar rats

“…As reported previously, the NOR test was used to evaluate short-term and working memory in SD and HD groups at 6 and 13 months of age ( Antunes and Biala, 2012 ; Santín-Márquez et al, 2021 ). The NOR test was performed using a 45 × 45 × 45 cm acrylic box.…”

“…Notably, sexual differences have been reported concerning neurodegeneration and cognitive decline during aging ( Santín-Márquez et al, 2021 ). Moreover, several neurological conditions are associated with sex differences in prevalence or outcome.…”

Application of proteomics in brain's aging research

“…However, the redox processes during aging have a gender bias. By assessing the redox state in the cerebral cortex and hippocampus, the authors found a higher superoxide dismutase (SOD) activity of older females in both regions than older males, though still lower than both of the young groups, as well as more stable redox homeostasis because of better mitochondrial functionality in older female (Santín-Márquez et al, 2021).…”

“…Thus, proteomics contributes to our understanding of the sophisticated biological process regulation that occurs in the brain in an unbiased manner. In addition, thousands of identified proteins from brain tissues constitute the foundation for further excavation of molecular mechanisms including metabolism (Kashem et al, 2016;Wesseling et al, 2013;Johnson et al, 2022;Yang et al, 2022), PTM (Ratovitski et al, 2017;Bai et al, 2021) and signaling pathway networks (Saia-Cereda et al, 2015;Bai et al, 2020), which would be of great significance to uncover deeper or new mechanisms of the aging process.…”