Brain aging, memory impairment and oxidative stress: A study in Drosophila melanogaster

Drosophila nervous system as a target of aging and anti-aging interventions

“…Enrichment in mutants with neurodegeneration among flies with shortened lifespan has been reported (Buchanan and Benzer, 1993; Kretzschmar et al, 1997). The brain from old flies demonstrates the ultrastructural neurodegenerative changes such as reduction in the number of synapses, defects in mitochondria, and increase in neuronal apoptosis (Haddadi et al, 2014). However, anti-aging interventions may postpone the neurodegeneration (Bgatova et al, 2015).…”

Conserved regulators of cognitive aging: From worms to humans

“…A recent study by Haddadi et al (2014) more closely examined the neurons of the MBs in young and aged flies. More vacuolated areas were observed in the MBs of 50-day-old flies when compared to 5-day-old animals, indicating neurodegeneration in the area, although it remains to be determined whether there is any significant loss of neuronal number in the region [76]. Electron microscopy of MBs revealed a reduction in the number of synapses and decreased numbers of mitochondria [76], which also tended to be irregular in size and shape in aged flies [76].…”

“…More vacuolated areas were observed in the MBs of 50-day-old flies when compared to 5-day-old animals, indicating neurodegeneration in the area, although it remains to be determined whether there is any significant loss of neuronal number in the region [76]. Electron microscopy of MBs revealed a reduction in the number of synapses and decreased numbers of mitochondria [76], which also tended to be irregular in size and shape in aged flies [76]. These mitochondrial abnormalities were also accompanied by a significant reduction in the activity of catalase and superoxide dismutase, two antioxidant enzymes [76].…”

Longevity pathways and memory aging

“…Transgenic C. elegans expressing the human G93A SOD1 variant, associated with familial amyotrophic lateral sclerosis (ALS), in motor neurons show motor defects and increased autophagy in an age-dependent manner (Aksenov et al, 2013; Li et al, 2013). SOD-1 overexpression has also been associated with mitochondrial swelling, and learning and memory impairment in flies, mice, and humans (Shin et al, 2004; Perluigi and Butterfield, 2012; Haddadi et al, 2014). For example, transgenic flies expressing a zinc-deficient SOD1 mutant display behavioral defects, including impairment of locomotion, associated with mitochondrial respiratory chain deficiency and matrix vacuolization, that is not accompanied by shortening of lifespan (Bahadorani et al, 2013).…”

“…At the same time, knock-down of sod-1 in the mushroom bodies deteriorates mid-term memory and LTM. These memory defects associate with reduced synapse formation and mitochondrial damage during Drosophila aging (Haddadi et al, 2014). …”