Researchers at the Salk Institute report that dysplasia in tiny brain structures can lead to memory challenges for older adults, while healthy aging does not bring these issues. Findings appear in Frontiers in Aging Neuroscience.
The brain comprises distinct regions, each housing millions of neurons linked by thousands of synapses. These synapses enable dialogue between neurons and connect to even smaller elements such as presynaptic buds and dendrites. In a healthy brain, the size and arrangement of all these parts align to support steady function.
A new investigation using electron microscopy shows that memory disorders can emerge when the size relationship between synaptic buds and the mitochondria they contain becomes mismatched.
With normal aging, this dimensional mismatch does not develop, making cognitive impairment less likely.
“A ripple effect occurs when extremely small synaptic structures alter the wiring of neuronal networks, brain function, and behavior. Studying these microscopic dysfunctions opens a new chapter in understanding aging and its effects on cognition,” state the researchers in the publication.