| Cognitive dysfunction is a state of losing or having difficulties in remembering,
learning, focusing, or making decisions that impact individual healthy life. Small
single‐stranded and nonprotein coding RNAs, microRNAs (miRNAs) participate actively in regulatory processes, incorporate cognitive signaling pathways, and intensely affect cognitive evolution. miRNAs exert their modification activities
through translational or transcriptional processes. Reportedly, cognitive impairment
and dementia are rising, especially in developing countries. Herein we provided a
brief review of original studies addressing miRNA changes in the most common
neurological diseases with a focus on dementia and Alzheimer's disease. It must be
noted that an increase in the level of certain miRNAs but a decrease in other ones
deteriorate cognitive performance. The current review revealed that induction of
miR‐214‐3p, miR‐302, miR‐21, miR‐ 200b/c, miR‐207, miR‐132, miR‐188‐3p and 5p,
and miR‐873 improved cognitive impairment in various cognitive tasks. On the other
hand, intentionally lowering the level of miR‐34a, miR‐124, miR‐574, and miR‐191a
enhanced cognitive function and memory. Synaptic dysfunction is a core cause of
cognitive dysfunction; miRNA‐34, miRNA‐34‐c, miRNA‐124, miRNA‐188‐5p,
miRNA‐210‐5p, miRNA‐335‐3p, and miRNA‐134 strongly influence synaptic‐
related mechanisms. The downregulation of miRNA‐132 aggregates both amyloid
and tau in tauopathy. Concerning the massive burden of neurological diseases
worldwide, the future challenge is the translation of animal model knowledge into
the detection of pathophysiological stages of neurocognitive disorders and designing
efficient therapeutic strategies. While the delivery procedure of agomir or antagomir miRNAs into the brain is invasive and only applied in animal studies, finding a
safe and specific delivery route is a priority |